| 1 | 31 | IfcOrganization | <EPM-HTML>
<p>A named and structured grouping with a corporate identity.</p>
<blockquote class="note">
NOTE: The relationships between <I>IfcOrganizations</I>, like a Department within a Company, can be expressed using <I>IfcOrganizationRelationship</I>.
</blockquote>
<blockquote class="note">
NOTE Corresponds to the following entity in ISO-10303-41: organization.
</blockquote>
<blockquote class="history">
HISTORY New entity in IFC Release 1.5.1.<br>
IFC 2x4 change: attribute <I>Id</I> renamed to <i>Identification</i>.
</blockquote>
</EPM-HTML> |
|---|
| 2 | 40 | IfcActorRole | <EPM-HTML>
<p>Definition: A role which is performed by an actor, either a person, an organization or a
person related to an organization.</p>
<blockquote class="note">
NOTE: The list of roles of the enumeration values of the <I>Role</I> attribute can never
be complete. Therefore using enumeration value USERDEFINED, the user can provide his/her own role as a value
of the attribute <I>UserDefinedRole</I>.
</blockquote>
<blockquote class="note">
Corresponds to the following entity in ISO-10303-41: organization_role and person_role.
</blockquote>
<blockquote class="history">
HISTORY New entity in IFC Release 1.5.1
</blockquote>
</EPM-HTML> |
| 3 | 70 | IfcAddress | <EPM-HTML>
<p>Definition: An abstract entity type for various kinds of postal and telecom addresses.</p>
<blockquote class="note">
NOTE Corresponds to the following entity in ISO-10303-41: address.
</blockquote>
<blockquote class="history">
HISTORY New entity in IFC Release 1.5.1.
</blockquote>
</EPM-HTML> |
| 4 | 79 | IfcPostalAddress | <EPM-HTML>
<p>Definition: The address for delivery of paper based mail.</p>
<blockquote class="history">
HISTORY New entity in IFC Release 2x.
</blockquote>
</EPM-HTML> |
| 5 | 88 | IfcTelecomAddress | <EPM-HTML>
<p>Definition: Address to which telephone, electronic mail and other forms of telecommunications should be addressed.</p>
<blockquote>
HISTORY New entity in IFC Release 2x.
<br>
IFC 2x4 change: Added attribute <i>MessagingIDs</i>.
Type of attribute <i>WWWHomePageURL</i> compatibly changed from <i>IfcLabel</i> to <i>IfcURIReference</i>.
</blockquote>
</EPM-HTML> |
| 6 | 102 | IfcPerson | <EPM-HTML>
<p>Definition: an individual human being.</p>
<blockquote class="note">
NOTE Many countries have legislation concerning the identification of individual persons within databases. Although the intent of the IFC Model is to act as a specification for data exchange
and sharing, an IFC file might in some situations be considered to be a database that enables identification of a particular person under the terms of such legislation. Users should be aware of the constraints of legislation that might apply in the places where IFC files are used.
</blockquote>
<blockquote class="note">
NOTE Corresponds to the following entity in ISO-10303-41: person.
</blockquote>
<blockquote class="history">
HISTORY New entity in IFC Release 1.5.1.<br>
IFC 2x4 change: attribute <I>Id</I> renamed to <I>Identification</I>. WHERE rule relaxed to allow omission of names if <i>Identification</i> is provided.
</blockquote>
</EPM-HTML> |
| 7 | 113 | IfcPersonAndOrganization | <EPM-HTML>
<p>Definition: Identification of a person within an organization.</p>
<blockquote class="note">
NOTE Corresponds to the following entity in ISO-10303-41: person_and_organization.
</blockquote>
<blockquote class="history">
HISTORY New entity in IFC Release 1.5.1
</blockquote>
</EPM-HTML> |
| 8 | 117 | IfcOrganizationRelationship | <EPM-HTML>
<p>Definition: establishes an association between one relating organization and one or more related organizations.</p>
<blockquote class="note">
NOTE Corresponds to the following entity in ISO-10303-41: organization_relationship.
</blockquote>
<blockquote class="history">
HISTORY New entity in IFC Release 2x.<BR>
IFC 2x4 change: attribute <I>Name</I> made optional.
</blockquote>
</EPM-HTML> |
| 9 | 123 | IfcApproval | <EPM-HTML>
<p>Definition: An <i>IfcApproval</i> represents information about approval processes such as for a plan, a design, a proposal, or a change order in a construction or facilities management project. <i>IfcApproval</i> is referenced by <i>IfcRelAssociatesApproval</i> in <i>IfcControlExtension</i> schema, and thereby can be related to all subtypes of <i>IfcRoot</i>. An approval may also be given to resource objects using <i>IfcResourceApprovalRelationship</i>
</p>
<blockquote class="history">
HISTORY New Entity in IFC Release 2.0
</blockquote>
<blockquote class="change-ifc2x4">
IFC2x Edition 4 CHANGE Attributes Identifier and Name made optional, where rule added to require at least one of them being asserted. Inverse attributes ApprovedObjects, ApprovedResources and HasExternalReferences added. Inverse attribute Properties deleted (more general relationship via inverse ApprovedResources to be used instead).
</blockquote>
</EPM-HTML> |
| 10 | 139 | IfcApprovalRelationship | <EPM-HTML>
<p>An <i>IfcApprovalRelationship</i> associates approvals (one
relating approval and one or more related approvals), each having different status or level as the approval process or the approved
objects evolve.</p>
<blockquote class="history">
HISTORY: New entity in Release IFC2x2.</span><br>
</blockquote>
<blockquote class="change-ifc2x4">
IFC2x4 CHANGE Subtyped from <em>IfcResourceLevelRelationship</em>, order of attributes changed.
</blockquote>
</EPM-HTML> |
| 11 | 142 | IfcResourceApprovalRelationship | <EPM-HTML>
<p>An <i>IfcResourceApprovalRelationship</i> is used for
associating an approval to resource objects. A single approval
might be given to one or many items via <i>IfcResourceObjectSelect</i>.</p>
<blockquote class="history">
HISTORY New
Entity in IFC Release 2x4
</blockquote>
</EPM-HTML> |
| 12 | 146 | IfcPerformanceHistory | <EPM-HTML>
<p><i>IfcPerformanceHistory</i> is used to document the actual performance of an occurrence instance over time. In practice, performance-related data are generally not easy to obtain as they can originate from different sources (predicted, simulated, or measured) and occur during different stages of the building life-cycle. Such time-related data cover a large spectrum, including meteorological data, schedules, operational status measurements, trend reports, etc.</p>
<p><i>IfcPerformanceHistory</i> is assigned to other objects (represented by subtypes of <i>IfcObjectDefinition</i>, excluding subtypes of <i>IfcControl</i>), by the objectified relationship <i>IfcRelAssignsToControl</i>.
</p>
<blockquote class="history">
HISTORY: New entity in Release IFC2x Edition 2.
</blockquote>
</EPM-HTML> |
| 13 | 152 | IfcRelAssociatesApproval | <EPM-HTML>
<p>The entity <i>IfcRelAssociatesApproval</i> is used to apply approval information defined by <i>IfcApproval</i>, in <i>IfcApprovalResource</i> schema, to subtypes of <i>IfcRoot</i>.
</p>
<blockquote class="history">
HISTORY: New entity in IFC2x2.
</blockquote>
</EPM-HTML> |
| 14 | 154 | IfcRelAssociatesConstraint | <EPM-HTML>
<p>The entity <i>IfcRelAssociatesConstraint</i> is used to apply constraint information defined by <i>IfcConstraint</i>, in the <i>IfcConstraintResource</i> schema, to subtypes of <i>IfcRoot</i>.
</p>
<blockquote class="history">
HISTORY: New entity in IFC2x2.
</blockquote>
</EPM-HTML> |
| 15 | 157 | IfcRelAssociatesTimeSeries | <EPM-HTML>
<p><i>IfcRelAssociatesTimeSeries</i> associates to objects (subtypes of <i>IfcRoot</i>) a time-series that is applicable to one or more calendar dates.</p>
<blockquote class="history">
HISTORY: New entity in Release IFC2x Edition 2.
</blockquote>
<blockquote class="change-ifc2x4">
IFC2x Edition 4 CHANGE entity renamed to <i>IfcRelAssociatesTimeSeries</i> and made an objectified realtionship (subtype of <i>IfcRelAssociates</i>), replacing the old entity <i>IfcTimeSeriesSchedule</i> (was subtype of <i>IfcControl</i>
</blockquote>
</EPM-HTML> |
| 16 | 162 | IfcPileType | <EPM-HTML>
<p><u>Definition from IAI:</u> Provides shared material, decomposition, representation maps, and property sets for instances of <i>IfcPile</i>.</p>
<blockquote><font color="#0000ff" size="-1">HISTORY New entity in IFC Release 2x4</font></blockquote>
<p><u><b>Material Use Definition</b></u>:</p>
<p>Material profile set association analogous to <a href="../../ifcsharedbldgelements/lexical/ifccolumnstandardcase.htm"><i>IfcColumnStandardCase</i></a> should be used when applicable.</p>
</EPM-HTML> |
| 17 | 174 | IfcFootingType | <EPM-HTML>
<p><u>Definition from IAI:</u> Provides shared material, decomposition, representation maps, and property sets for instances of <i>IfcFooting</i>.</p>
<blockquote><font color="#0000ff" size="-1">HISTORY New entity in IFC Release 2x4</font></blockquote>
<p>Note, slab foundation types are not instantiated as <i>IfcFootingType</i> but as <i>IfcSlabType</i> with a predefined type of <i>IfcSlabTypeEnum</i>.BASESLAB.</p>
<p><u><b>Material Use Definition</b></u>:</p>
<p>Material profile set or material layer set association analogous to <a href="../../ifcsharedbldgelements/lexical/ifcbeamstandardcase.htm"><i>IfcBeamStandardCase</i></a> or <a href="../../ifcsharedbldgelements/lexical/ifcslabstandardcase.htm"><i>IfcSlabStandardCase</i></a> should be used when applicable.</p>
</EPM-HTML> |
| 18 | 185 | IfcSurfaceFeature | <EPM-HTML>
<p><u>Definition from IAI:</u> A surface feature is a modification at (onto, or into) of the surface of an element. Parts of the surface of the entire surface may be affected. The volume and mass of the element may be increased, remain unchanged, or be decreased by the surface feature, depending on manufacturing technology.</u></p>
<p>The standard use of instances of <i>IfcSurfaceFeature</i> is as a part of element type objects (instances of subtypes of <i>IfcElementType</i>). The part–whole relationship is established by an aggregation relationship object, expressing the decomposition of an element type into one or more additive elements (element parts) and zero or more feature elements.</p>
<blockquote><font color="#0000ff" size="-1">HISTORY New type in IFC 2x4.</font></blockquote>
<p><b><u>Containment Use Definition</u></b>:</p>
<p>Surface features shall have no spatial containment relationship to the spatial structure since they are dependent on element types without spatial containment relationships or on an element occurrence with own spatial containment relationship.</p>
<ul>
<li>The <i>SELF\IfcElement.ContainedInStructure</i> relationship shall be NIL.</li>
</ul>
<p><b><u>Geometry use definition</u></b>:</p>
<p>The geometric representation of <i>IfcSurfaceFeatureElement</i> is given by the <i>IfcProductDefinitionShape</i>, allowing multiple geometric representation.</p>
<p><b>Local Placement</b></p>
<p>The local placement for <i>IfcSurfaceFeatureElement</i> is defined in its supertype <i>IfcProduct</i>. It is defined by the <i>IfcLocalPlacement</i>, which defines the local coordinate system that is referenced by all geometric representations.</p>
<ul>
<li>In case of features which are part of an element type, absolute placement into the type object's implied coordinate system shall be used.</li>
<li>In case of features which are voiding an element occurrence, the <i>PlacementRelTo</i> relationship of <i>IfcLocalPlacement</i> shall point to the local placement of the respective element.</li>
</ul>
<p><b>Shape representation</b></p>
<p>Different shape representations may be used, depending on the nature of the feature and information requirements:</p>
<ul>
<li>Symbolic representation, such as the two-dimensional bounding box of a tag.</p>
<li>A geometric set representing the geometric items of a mark.</li>
<li>Surface representations of treated parts of the lement surface by means of <i>IfcShellBasedSurfaceModel</i>. The faces within the surface model may be included into a B-Rep model within a representation map of the parent element type.</li>
</ul>
<p>Higher-level parameters (geometric and non-geometric) may be provided by property sets based on local agreements.</p>
</EPM-HTML>
|
| 19 | 194 | IfcVoidingFeature | <EPM-HTML>
<p><u>Definition from IAI:</u> A voiding feature is a modification of an element which reduces its volume. Such a feature may be manufactured in different ways, for example by cutting, drilling, or milling of members made of various materials, or by inlays into the formwork of cast members made of materials such as concrete.</u></p>
<p>The standard use of instances of <i>IfcVoidingFeature</i> is as a part of element type objects (instances of subtypes of <i>IfcElementType</i>). The part–whole relationship is established by an aggregation relationship object, expressing the decomposition of an element type into one or more additive elements (element parts) and zero or more feature elements.</p>
<blockquote><font color="#0000ff" size="-1">HISTORY New type in IFC 2x4.</font></blockquote>
<p><b><u>Containment Use Definition</u></b>:</p>
<p>Voiding features shall have no spatial containment relationship to the spatial structure since they are dependent on element types without spatial containment relationships or on an element occurrence with own spatial containment relationship.</p>
<ul>
<li>The <i>SELF\IfcElement.ContainedInStructure</i> relationship shall be NIL.</li>
</ul>
<p><b><u>Geometry use definition</u></b>:</p>
<p>The geometric representation of <i>IfcVoidingFeatureElement</i> is given by the <i>IfcProductDefinitionShape</i>, allowing multiple geometric representation.</p>
<p><b>Local Placement</b></p>
<p>The local placement for <i>IfcVoidingFeatureElement</i> is defined in its supertype <i>IfcProduct</i>. It is defined by the <i>IfcLocalPlacement</i>, which defines the local coordinate system that is referenced by all geometric representations.</p>
<ul>
<li>In case of features which are part of an element type, absolute placement into the type object's implied coordinate system shall be used.</li>
<li>In case of features which are voiding an element occurrence, the <i>PlacementRelTo</i> relationship of <i>IfcLocalPlacement</i> shall point to the local placement of the respective element.</li>
</ul>
<p><b>Shape representation</b></p>
<p>Different shape representations may be used, depending on the nature of the feature and information requirements:</p>
<ul>
<li>Symbolic representations, such as an axis representation, may be used for simple shapes such as holes or edge features.</p>
<li>Volumetric representations by means of subtypes of <i>IfcSweptSurface</i> or of <i>IfcCsgPrimitive3D</i> may be used to semi-parametrically model the actual volume of the void created by the feature. The objects within the shape model of the feature's shape representation can be included into a CSG model within a representation map of the parent element type.</li>
<li>Surface representations of cutting planes by means of <i>IfcShellBasedSurfaceModel</i>. The faces within the surface model may be included into a B-Rep model within a representation map of the parent element type.</li>
</ul>
<p>Higher-level parameters (geometric and non-geometric) may be provided by property sets based on local agreements.</p>
</EPM-HTML>
|
| 20 | 206 | IfcFooting | <EPM-HTML>
<p>A footing is a part of the foundation of a structure that spreads and transmits the load to the soil, either directly or via piles.</p>
<blockquote class="history">
HISTORY New entity in IFC2x2
</blockquote>
<p>Note, slab foundations are not instantiated as <i>IfcFooting</i> but as <i>IfcSlab</i> or <i>IfcSlabStandardCase</i> with a predefined type of <i>IfcSlabTypeEnum</i>.BASESLAB.</p>
<p class="use-head">Property Set Use Definition</p>
<p>The following property set definitions are part of this IFC release:</p>
<ul>
<li><a href="../../psd/IfcStructuralElementsDomain/Pset_FootingCommon.xml" target="SOURCE">Pset_FootingCommon</a>: common property set for all footing occurrences.</li>
<li><a href="../../psd/IfcStructuralElementsDomain/Pset_ReinforcementBarCountOfIndependentFooting.xml" target="SOURCE">Pset_ReinforcementBarCountOfIndependentFooting</a>: property set for independent <i>IfcFooting</i> occurrences.</li>
<li><a href="../../psd/IfcStructuralElementsDomain/Pset_ReinforcementBarPitchOfContinuousFooting.xml" target="SOURCE">Pset_ReinforcementBarPitchOfContinuousFooting</a>: property set for continuous <i>IfcFooting</i> occurrences.</li>
</ul>
<p class="use-head">Quantity Use Definition</p>
<p> The quantities relating to this entity are defined by <a href="../../ifcproductextension/lexical/ifcelementquantity.htm">IfcElementQuantity</a> and attached by the <a href="../../ifckernel/lexical/ifcreldefinesbyproperties.htm">IfcRelDefinesByProperties</a> relationship. They are accessible by the <i>IsDefinedBy</i> inverse attribute. The following base quantities are defined and should be exchanged with the <i>IfcElementQuantity.Name</i> = 'BaseQuantities'. Other quantities, being subjected to local standard of measurement, can be defined with another string value assigned to <i>Name</i>. In this case a valid value for <i>MethodOfMeasurement</i> has to be provided. </p>
<ul>
<li><a href="../../qto/IfcStructuralElementsDomain/Qto_FootingBaseQuantities.xml" target="SOURCE">Qto_FootingBaseQuantities</a></li>
</ul>
<p class="use-head">Geometry Use Definition</p>
<p>Local placement and product representations are defined by the supertype <a href="../../ifcproductextension/lexical/ifcbuildingelement.htm"><i>IfcBuildingElement</i></a>. Standard representations as defined at <a href="../../ifcsharedbldgelements/lexical/ifcbeamstandardcase.htm"><i>IfcBeamStandardCase</i></a> or <a href="../../ifcsharedbldgelements/lexical/ifcslabstandardcase.htm"><i>IfcSlabStandardCase</i></a> should be used when applicable.</p>
</EPM-HTML> |
| 21 | 210 | IfcPile | <EPM-HTML>
<p>A pile is a slender timber, concrete, or steel structural element, driven, jetted, or otherwise embedded on end in the ground for the purpose of supporting a load.</p>
<blockquote class="history">
HISTORY New entity in IFC2x2
</blockquote>
<p class="use-head">Property Set Use Definition</p>
<p>The following property set definitions are part of this IFC release:</p>
<ul>
<li><a href="../../psd/IfcStructuralElementsDomain/Pset_PileCommon.xml" target="SOURCE">Pset_PileCommon</a>: common property set for all pile occurrences.</li>
</ul>
<p class="use-head">Quantity Use Definition</p>
<p> The quantities relating to this entity are defined by <a href="../../ifcproductextension/lexical/ifcelementquantity.htm">IfcElementQuantity</a> and attached by the <a href="../../ifckernel/lexical/ifcreldefinesbyproperties.htm">IfcRelDefinesByProperties</a> relationship. They are accessible by the <i>IsDefinedBy</i> inverse attribute. The following base quantities are defined and should be exchanged with the <i>IfcElementQuantity.Name</i> = 'BaseQuantities'. Other quantities, being subjected to local standard of measurement, can be defined with another string value assigned to <i>Name</i>. In this case a valid value for <i>MethodOfMeasurement</i> has to be provided. </p>
<ul>
<li><a href="../../qto/IfcStructuralElementsDomain/Qto_PileBaseQuantities.xml" target="SOURCE">Qto_PileBaseQuantities</a></li>
</ul>
<p class="use-head">Geometry Use Definition</p>
<p>Local placement and product representations are defined by the supertype <a href="../../ifcproductextension/lexical/ifcbuildingelement.htm"><i>IfcBuildingElement</i></a>. Standard representations as defined at <a href="../../ifcsharedbldgelements/lexical/ifccolumnstandardcase.htm"><i>IfcColumnStandardCase</i></a> should be used when applicable.</p>
</EPM-HTML> |
| 22 | 222 | IfcReinforcingElementType | <EPM-HTML>
<p><u>Definition from IAI:</u> Types of bars, wires, strands, meshes, tendons, and other components embedded in concrete in such a manner that the reinforcement and the concrete act together in resisting forces.</p>
<blockquote><font color="#0000ff" size="-1">HISTORY New entity in IFC Release 2x4</font></blockquote>
</EPM-HTML>
|
| 23 | 230 | IfcReinforcingElement | <EPM-HTML>
<p><u>Definition from IAI:</u> Bars, wires, strands, meshes, tendons, and other components embedded in concrete in such a manner that the reinforcement and the concrete act together in resisting forces.</p>
<blockquote><font color="#0000ff" size="-1">HISTORY New entity in IFC Release 2x2</font></blockquote>
<blockquote><font color="#ff0000" size="-1">IFC 2x4 CHANGE Entity made non-abstract.<br>
Subtypes <i>IfcTendon</i> and <i>IfcTendonAnchor</i> removed.<br>
Attribute <i>SteelGrade</i> removed.<br>
Attributes <i>PredefinedType</i> and <i>Role</i> added.</font></blockquote>
</EPM-HTML>
|
| 24 | 237 | IfcReinforcingBar | <EPM-HTML>
<p><u>Definition from IAI:</u> A steel bar, usually with manufactured deformations in the surface,
used in concrete and masonry construction to provide additional strength. A single instance
of this class may represent one or many of actual rebars, for example a row of rebars.</p></p>
<blockquote><font color="#0000ff" size="-1">HISTORY New entity in IFC Release 2x2</font></blockquote>
<blockquote><font color="#ff0000" size="-1">IFC 2x4 CHANGE All attributes removed; information now provided by <i>IfcReinforcingBarType</i>.</font></blockquote>
<p><u><b>Geometry Use Definition</b></u></p>
<p> The geometric representation of <i>IfcReinforcingBar</i> is given by the <i>IfcProductDefinitionShape</i>,
allowing multiple geometric representations. Included are:</p>
<p><b>Local Placement</b><br>
The use of local placement is defined at the supertype <i>IfcElementComponent</i>.</p>
<p><b>Multiple Mapped Representation</b><br>
See supertype <i>IfcElementComponent</i>. This method of representation allows for several rebars
represented by a single instance of <i>IfcReinforcingBar</i>. The representation map should contain
one <i>IfcSweptDiskSolidPolygonal</i>.</p>
<p>An <i>IfcElementQuantity</i>,
attached via <i>IfcRelDefinesByProperties</i>, should contain an <i>IfcQuantityCount</i> named 'Count'
with the number rebars and, if this is a regularly spaced arrangement of rebars, an
<i>IfcQuantityLength</i> named 'Spacing' which expresses the center-to-center distances of bars.</p>
<p><b>Simplified Geometric Representation</b><br>
Simplified geometric representations may be used based on local agreements.</p>
</EPM-HTML>
|
| 25 | 249 | IfcReinforcingMesh | <EPM-HTML>
<p><u>Definition from IAI:</u> A series of longitudinal and transverse wires or bars of various gauges, arranged at right angles to each other and welded at all points of intersection; usually used for concrete slab reinforcement. Also known as welded wire fabric.</p>
<blockquote><font color="#0000ff" size="-1">HISTORY New entity in IFC Release 2x2</font></blockquote>
<blockquote><font color="#ff0000" size="-1">IFC 2x4 CHANGE All attributes removed; information now provided by <i>IfcReinforcingMeshType</i>.</font></blockquote>
<p><u><b>Geometry Use Definition</b></u></p>
<p> The geometric representation of <i>IfcReinforcingBar</i> is given by the <i>IfcProductDefinitionShape</i>,
allowing multiple geometric representations. Included are:</p>
<p><b>Local Placement</b><br>
The use of local placement is defined at the supertype <i>IfcElementComponent</i>.</p>
<p><b>Multiple Mapped Representation</b><br>
See supertype <i>IfcElementComponent</i>. This method of representation allows for several meshes
represented by a single instance of <i>IfcReinforcingMesh</i>.</p>
<p>An <i>IfcElementQuantity</i>,
attached via <i>IfcRelDefinesByProperties</i>, should contain an <i>IfcQuantityCount</i> named 'Count'
with the number of meshes represented by this instance.</p>
<p><b>Simplified Geometric Representation</b><br>
Simplified geometric representations may be used based on local agreements.</p>
</EPM-HTML>
|
| 26 | 252 | IfcReinforcingBarType | <EPM-HTML>
<p><u>Definition from IAI:</u> A steel bar, usually with manufactured deformations in the surface,
used in concrete and masonry construction to provide additional strength.</p></p>
<blockquote><font color="#0000ff" size="-1">HISTORY New entity in IFC Release 2x4</font></blockquote>
<p><u><b>Material Use Definition</b></u>:</p>
<p>An associated material denotes the steel grade, preferrably by material classification.</p>
<p><u><b>Geometry Use Definition</b></u>:</p>
<p>The <i>IfcReinforcingBarType</i> may define the shared geometric representation for all rebar occurrences. The <i>RepresentationMaps</i> attribute refers to a list of <i>IfcRepresentationMap</i>'s, that allow for multiple geometric representations (e.g. with <i>IfcShapeRepresentation</i>'s having an <i>RepresentationIdentifier</i> 'Box', 'Axis', or 'Body').</p>
<p>A 'Body' representation map should contain one <i>IfcSweptDiskSolidPolygonal</i>.</p>
<p>Simplified geometric representations may be used based on local agreements.</p>
</EPM-HTML>
|
| 27 | 258 | IfcReinforcingMeshType | <EPM-HTML>
<p><u>Definition from IAI:</u> A series of longitudinal and transverse wires or bars of various gauges, arranged at right angles to each other and welded at all points of intersection; usually used for concrete slab reinforcement. Also known as welded wire fabric.</p>
<blockquote><font color="#0000ff" size="-1">HISTORY New entity in IFC Release 2x4</font></blockquote>
<p><u><b>Material Use Definition</b></u>:</p>
<p>An associated material denotes the steel grade, preferrably via material classification.</p>
<p><u><b>Geometry Use Definition</b></u>:</p>
<p>The <i>IfcReinforcingMeshType</i> may define the shared geometric representation for all mesh occurrences. The <i>RepresentationMaps</i> attribute refers to a list of <i>IfcRepresentationMap</i>'s, that allow for multiple geometric representations.</p>
</EPM-HTML>
|
| 28 | 271 | IfcReinforcementDefinitionProperties | <EPM-HTML>
<P> <U>Definition from IAI:</U> An
<I>IfcReinforcementDefinitionProperties</I> defines the cross section
properties of reinforcement included in reinforced concrete building elements.
The property set definition may be used both in conjunction with insitu and
precast structures. </P>
<blockquote><font color="#0000ff" size="-1">HISTORY New entity in IFC Release 2x2<br>
IFC 2x4 change: Supertype changed from <i>IfcPropertySetDefinition</i> to <i>IfcPreDefinedPropertySet</i></font></blockquote>
<P><B>General usage:</B></P>
<P> This subtype of <I>IfcPropertySetDefinition</I> is used to define the
reinforcement properties in early design stages, such as in requirement
definition or scheme design. In later design stages explicit instances of
subtypes of <I>IfcReinforcingElement</I> are used. The intended usage may be
indicated using the <I>DefinitionType</I> attribute value as a designator:
recommended values are 'Reinforcement area requirement' or 'Reinforcement
configuration requirement'. Other values may be used according to local
standards. </P>
<P> Only one property set definition of this kind is used for each concrete
building element in each intended usage indicated by the <I>DefinitionType</I>
attribute value. This set then defines a list of cross section properties in a
discrete number of longitudinal sections as instances of
<I>IfcSectionReinforcementProperties</I> (one for each structural reinforcement
bar role), which in turn have a section cross section property defined as a
profile and a number of reinforcement properties, one for each steel grade /
bar type. </P>
</EPM-HTML> |
| 29 | 279 | IfcPreDefinedTextFont | <EPM-HTML>
<p>The pre defined text font determines those qualified names which can be used for fonts that are in scope of the current data exchange specification (in contrary to externally defined text fonts). There are two choices:</p>
<ul>
<li><i>IfcDraughtingPreDefinedTextFont</i> for definitions from ISO/IS 10303-46:1994 for (old) vector based and monospace text.<br>
</li>
<li><i>IfcTextStyleFontModel</i> for definitions from <a target="_blank" href="http://www.w3.org/TR/REC-CSS1">Cascading Style Sheets, level 1</a>, W3C Recommendation 17 Dec 1996, revised 11 Jan 1999, CSS1, for all true type text. The use of the CSS1 definitions is the preferred way to represent text fonts.</li>
</ul>
<blockquote class="note">
NOTE Corresponding ISO 10303 name: pre_defined_text_font. Please refer to ISO/IS 10303-46:1994, p. 138 for the final definition of the formal standard.
</blockquote>
<blockquote class="history">
HISTORY New entity in IFC2x2.
</blockquote>
<blockquote class="change-ifc2x3">
IFC2x3 CHANGE The <i>IfcTextStyleFontModel</i> has been added as new subtype.
</blockquote>
</EPM-HTML> |
| 30 | 282 | IfcPreDefinedItem | <EPM-HTML>
<p>A pre defined item is a qualified name given to a style or font which is determined within the data exchange specification by convention on using the <i>Name</i> attribute value (in contrary to externally defined items, which are agreed by an external source).</p>
<blockquote class="note">
NOTE The convention on using the <i>Name</i> value is defined at the subtypes of <i>IfcPreDefinedItem</i> and is part of the specification.
</blockquote>
<blockquote class="note">
NOTE Corresponding ISO 10303 name: pre_defined_item. Please refer to ISO/IS 10303-41:1994, page 137 for the final definition of the formal standard.
</blockquote>
<blockquote class="history">
HISTORY New entity in IFC2x2.
</blockquote>
</EPM-HTML> |
| 31 | 286 | IfcPreDefinedColour | <EPM-HTML>
<p>The pre defined colour determines those qualified names which can be used to identify a colour that is in scope of the current data exchange specification (in contrary to colour specification which defines the colour directly by its colour components).</p>
<blockquote class="note">
NOTE Corresponding ISO 10303 name: pre_defined_colour. It has been made into an abstract entity in IFC. Please refer to ISO/IS 10303-46:1994, p. 141 for the final definition of the formal standard.
</blockquote>
<blockquote class="history">
HISTORY New entity in IFC2x2.
</blockquote>
</EPM-HTML> |
| 32 | 288 | IfcDraughtingPreDefinedColour | <EPM-HTML>
<p>The draughting pre defined colour is a pre defined colour for the purpose to identify a colour by name. Allowable names are:</p>
<ul>
<li>'black',</li>
<li>'red',</li>
<li>'green',</li>
<li>'blue',</li>
<li>'yellow',</li>
<li>'magenta',</li>
<li>'cyan',</li>
<li>'white',</li>
<li>'by layer'</li>
</ul>
<blockquote class="note">
NOTE The <i>IfcDraughtingPreDefinedColour</i> is an entity that had been adopted from ISO 10303-202, Industrial automation systems and integration—Product data representation and exchange, Part 202: Application protocol: Associative draughting.
</blockquote>
<p>The following table states the RGB values associated with the names given by the <i>IfcDraughtingPreDefinedColour.</i></p>
<blockquote>
<table>
<tbody>
<tr>
<td><b>Colour name</b></td>
<td align="center"><b>Red</b></td>
<td align="center"><b>Green</b></td>
<td align="center"><b>Blue</b></td>
</tr>
<tr>
<td>black</td>
<td align="center">0</td>
<td align="center">0</td>
<td align="center">0</td>
</tr>
<tr>
<td>red</td>
<td align="center">1.0</td>
<td align="center">0</td>
<td align="center">0</td>
</tr>
<tr>
<td>green</td>
<td align="center">0</td>
<td align="center">1.0</td>
<td align="center">0</td>
</tr>
<tr>
<td>blue</td>
<td align="center">0</td>
<td align="center">0</td>
<td align="center">1.0</td>
</tr>
<tr>
<td>yellow</td>
<td align="center">1.0</td>
<td align="center">1.0</td>
<td align="center">0</td>
</tr>
<tr>
<td>magenta</td>
<td align="center">1.0</td>
<td align="center">0</td>
<td align="center">1.0</td>
</tr>
<tr>
<td>cyan</td>
<td align="center">0</td>
<td align="center">1.0</td>
<td align="center">1.0</td>
</tr>
<tr>
<td>white</td>
<td align="center">1.0</td>
<td align="center">1.0</td>
<td align="center">1.0</td>
</tr>
<tr valign="top">
<td>by layer</td>
<td align="left" colspan="3">colour values obtained from<br>
<i>IfcPresentationLayerWithStyle</i>.</td>
<td></td>
<td></td>
</tr>
</tbody>
</table>
</blockquote>
<blockquote class="note">
NOTE Corresponding ISO 10303 name: draughting_pre_defined_colour. Please refer to ISO/IS 10303-202:1994 page 194 for the final definition of the formal standard.
</blockquote>
<blockquote class="history">
HISTORY New entity in IFC2x2.
</blockquote>
<p><u>Informal proposition</u></p>
<ol>
<li>The value 'by layer' shall only be inserted, if the geometric representation item using the colour definition has an association to <i>IfcPresentationLayerWithStyle</i>, and if that instance of <i>IfcPresentationLayerWithStyle</i> has a valid colour definition for <i>IfcCurveStyle</i>, <i>IfcSymbolStyle</i>, or <i>IfcSurfaceStyle</i> (depending on what is applicable).</li>
</ol>
</EPM-HTML> |
| 33 | 290 | IfcDraughtingPreDefinedTextFont | <EPM-HTML>
<p>The draughting pre defined text font is a pre defined text font for the purpose to identify a font by name. Allowable names are:</p>
<ul>
<li>'ISO 3098-1 font A',</li>
<li>'ISO 3098-1 font B',</li>
</ul>
<p>The ISO 3098-1 font A is the text font as denoted as Letterng A in clause 3 of ISO 3098-1, the ISO 3098-1 font B is the text font as denoted as Letterng B in clause 3 of ISO 3098-1.</p>
<blockquote class="note">
NOTE The <i>IfcDraughtingPreDefinedTextFont</i> is an entity that had been adopted from ISO 10303, Industrial automation systems and integration—Product data representation and exchange, Part 202: Application protocol: Associative draughting. Corresponding ISO 10303 name: draughting_pre_defined_text_font. Please refer to ISO/IS 10303-202:1994 page 196 for the final definition of the formal standard.
</blockquote>
<blockquote class="history">
HISTORY New entity in IFC2x2.
</blockquote>
</EPM-HTML> |
| 34 | 292 | IfcTextStyleFontModel | <EPM-HTML>
<p><u>Definition from CSS1 (W3C Recommendation)</u>: Setting font properties will be among the most common uses of style sheets. Unfortunately, there exists no well-defined and universally accepted taxonomy for classifying fonts, and terms that apply to one font family may not be appropriate for others. For example, 'italic' is commonly used to label slanted text, but slanted text may also be labeled as being <i>Oblique</i>, <i>Slanted</i>, <i>Incline</i>, <i>Cursive</i> or <i>Kursiv</i>. Therefore it is not a simple problem to map typical font selection properties to a specific font.</p>
<p><b>Font matching</b></p>
<p>Because there is no accepted, universal taxonomy of font properties, matching of properties to font faces must be done carefully. The properties are matched in a well-defined order to ensure that the results of this matching process are as consistent as possible across user agents (assuming that the same library of font faces is presented to each of them).
</p>
<ol>
<li>The user agent makes (or
accesses) a database of relevant CSS1
properties of all the fonts of which the UA is aware. The UA may be
aware of a font because it has been installed locally or it has been
previously downloaded over the web. If there are two fonts with
exactly the same properties, one of them is ignored. </li>
<li>At a given element and for
each character in that element, the UA
assembles the font-properties applicable to that element. Using the
complete set of properties, the UA uses the 'font-family' property to
choose a tentative font family. The remaining properties are tested
against the family according to the matching criteria described with
each property. If there are matches for all the remaining properties,
then that is the matching font face for the given element. </li>
<li>If there is no matching font
face within the 'font-family' being
processed by step 2, and if there is a next alternative 'font-family'
in the font set, then repeat step 2 with the next alternative
'font-family'. </li>
<li>If there is a matching font
face, but it doesn't contain a glyph
for the current character, and if there is a next alternative
'font-family' in the font sets, then repeat step 2 with the next
alternative 'font-family'. </li>
<li>If there is no font within
the family selected in 2, then use a
UA-dependent default 'font-family' and repeat step 2, using the best
match that can be obtained within the default font. </li>
</ol>
<p>(The above algorithm can be
optimized to avoid having to revisit
the CSS1 properties for each character.)
</p>
<p>The per-property matching rules
from (2) above are as follows:
</p>
<ol>
<li>'font-style' is tried first.
'italic'
will be satisfied if there is either a face in the UA's font database
labeled with the CSS keyword 'italic' (preferred) or 'oblique'.
Otherwise the values must be matched exactly or font-style will fail. </li>
<li>'font-variant' is tried
next. 'normal'
matches a font not labeled as 'small-caps'; 'small-caps' matches (1) a
font labeled as 'small-caps', (2) a font in which the small caps are
synthesized, or (3) a font where all lowercase letters are replaced by
upper case letters. A small-caps font may be synthesized by
electronically scaling uppercase letters from a normal font. </li>
<li>'font-weight' is matched next, it will never fail. (See 'font-weight' below.) </li>
<li>'font-size' must be matched within a
UA-dependent margin of tolerance. (Typically, sizes for scalable fonts
are rounded to the nearest whole pixel, while the tolerance for
bitmapped fonts could be as large as 20%.) Further computations, are
based on the 'font-size' value that is used, not the one that is specified.</li>
</ol>
<p>The inherited <i>Name</i> attribute is used to define the font name, particularly in cases, where no (list of) font families are provided. </p>
<blockquote class="note">
NOTE Corresponding CSS1 definitions are Font properties ('font-family', 'font-style', 'font-variant', 'font-weight').</font>
</blockquote>
<blockquote class="history">
HISTORY New entity in IFC2x3.
</blockquote>
</EPM-HTML> |
| 35 | 306 | IfcExternallyDefinedTextFont | <EPM-HTML>
<p><u>Definition from ISO/CD 10303-46:1992</u>: The externally defined text font is an external reference to a text font</p>
<blockquote class="note">
NOTE Restrictions of the font source and font names to be used may be exposed by implementation guidelines.
</blockquote>
<blockquote class="note">
NOTE Corresponding ISO 10303 name: externally_defined_text_font. Please refer to ISO/IS 10303-46:1994, p. 137 for the final definition of the formal standard.
</blockquote>
<BLOCKQUOTE class="history">
HISTORY New entity in IFC2x2.
</blockquote>
</EPM-HTML> |
| 36 | 307 | IfcColourSpecification | <EPM-HTML>
<p><u>Definition from ISO/CD 10303-46:1992</u>: The colour specification entity contains a direct colour definition. Colour component values refer directly to a specific colour space.</p>
<blockquote class="note">
NOTE Corresponding ISO 10303 name: colour_specification. It has been made into an abstract entity in IFC. Please refer to ISO/IS 10303-46:1994, p. 138 for the final definition of the formal standard.
</blockquote>
<blockquote class="history">
HISTORY New entity in IFC2x2.
</blockquote>
</EPM-HTML> |
| 37 | 310 | IfcColourRgb | <EPM-HTML>
<p><u>Definition from ISO/CD 10303-46:1992</u>: A colour rgb as a subtype of colour specifications is defined by three colour component values for red, green, and blue in the RGB colour model.</p>
<blockquote class="note">
NOTE In contrary to the usual value range of colour components being integer from 0...255, the definition from ISO10303-46 defines the colour components as real from 0.0 ... 1.0. Applications need to execute this conversion before populating the colour RGB values.
</blockquote>
<blockquote class="note">
NOTE Corresponding STEP name: colour_rgb. The name attribute has been omitted, the data type for the reg, green and blue parts is <i>IfcNormalizedRatioMeasure</i>, that already includes the range restrictions for the values. Please
refer to ISO/IS 10303-46:1994, p. 138 for the final definition of the formal standard.
</blockquote>
<blockquote class="history">
HISTORY New entity in IFC2x2.
</blockquote>
</EPM-HTML> |
| 38 | 314 | IfcPlanarExtent | <EPM-HTML>
<p>The planar extent defines the extent along the two axes of the two-dimensional coordinate system, independently of its position.</p>
<blockquote class="note">
NOTE Corresponding ISO 10303 name: planar_extent. Please refer to ISO/IS 10303-46:1994, p. 141 for the final definition of the formal standard.
</blockquote>
<blockquote class="history">
HISTORY New entity in IFC2x2.
</blockquote>
</EPM-HTML> |
| 39 | 318 | IfcPlanarBox | <EPM-HTML>
<p><u>Definition from ISO/CD 10303-46:1992</u>: A planar box specifies an arbitrary rectangular box and its location in a two dimensional Cartesian coordinate system.</p>
<blockquote class="note">
NOTE Corresponding ISO 10303 name: planar_box. Please refer to
ISO/IS 10303-46:1994, p. 141 for the final definition of the formal standard.
</blockquote>
<blockquote class="history">
HISTORY New entity in IFC2x2.
</blockquote>
</EPM-HTML> |
| 40 | 324 | IfcPropertyDependencyRelationship | <EPM-HTML>
<p>An <i>IfcPropertyDependencyRelationship</i> describes an identified dependency between the value of one property and that of another.</p>
<blockquote class="history">
HISTORY New entity in IFC2x2
</blockquote>
<blockquote class="change-ifc2x4">
IFC2x4 CHANGE Made subtype of <i>IfcResourceLevelRelationship</i> (attribute order changed).
</blockquote>
<p class="use-head">Use Definition</p>
<p>Whilst the <i>IfcPropertyDependencyRelationship</i> may be used to describe the dependency, and it may do so in terms of the expression of how the dependency operates, it is not possible through the current IFC model for the value of the related property to be actually derived from the value of the relating property. The determination of value according to the dependency is required to be performed by an application that can then use the Expression attribute to flag the form of the dependency.</p>
</EPM-HTML> |
| 41 | 329 | IfcProperty | <EPM-HTML>
<p><i>IfcProperty</i> is an abstract generalization for all types of properties that can be associated with IFC objects through the property set mechanism.</p>
<blockquote class="history">
HISTORY New entity in IFC Release 1.0.
</blockquote>
</EPM-HTML> |
| 42 | 339 | IfcComplexProperty | <EPM-HTML>
<p><i>IfcComplexProperty</i> is used to define complex properties to be handled completely within a property set. The included set of properties may be a mixed or consistent collection of <i>IfcProperty</i> subtypes. This enables the definition of a set of properties to be included as a single 'property' entry in an <i>IfcPropertySet</i>. The definition of such an <i>IfcComplexProperty</i> can be reused in many different <i>IfcPropertySet</i>'s.</p>
<blockquote class="note">
NOTE Since an <i>IfcComplexProperty</i> may contain other complex properties, sets of properties can be nested. This nesting may be restricted by view definitions and implementer agreements.
</blockquote>
<blockquote class="history">
HISTORY New Entity in IFC Release 2.0, capabilities enhanced in IFC Release 2x.
</blockquote>
</EPM-HTML> |
| 43 | 344 | IfcSimpleProperty | <EPM-HTML>
<p><i>IfcSimpleProperty</i> is a generalization of a single property object. The various subtypes of <i>IfcSimpleProperty</i> establish different ways in which a property value can be set.</p>
<blockquote class="history">
HISTORY New Entity in IFC Release 1.0, definition changed in IFC Release 2x.
</blockquote>
</EPM-HTML> |
| 44 | 351 | IfcPropertySingleValue | <EPM-HTML>
<p>The property with a single value
<i>IfcPropertySingleValue</i> defines a property object which has
a single (numeric or descriptive) value assigned. It defines a
property - single value combination for which the property
<i>Name</i>, an optional <i>Description</i>,and an optional
<i>NominalValue</i> with measure type is provided. In addition,
the default unit as specified within the project unit context can
be overriden by assigning an <i>Unit</i>.</p>
<p>The unit is handled by the <i>Unit</i> attribute:</p>
<ul>
<li>If the <i>Unit</i> attribute is not given, then the unit is
already implied by the type of <i>IfcMeasureValue</i> or
<i>IfcDerivedMeasureValue</i>. The associated unit can be found
at the <i>IfcUnitAssignment</i> globally defined at the project
level (<i>IfcProject.UnitsInContext</i>).</li>
<li>If the <i>Unit</i> attribute is given, then the unit assigned
by the <i>Unit</i> attribute overrides the globally assigned
unit.</li>
</ul>
<p>Examples of a property with single value are:</p>
<table border="1" cellpadding="2" cellspacing="2">
<tbody>
<tr valign="top">
<td valign="top" width="15%"><b>Name</b></td>
<td valign="top" width="30%"><b>NominalValue</b></td>
<td valign="top" width="25%"><b>Type<br></b> <font size=
"-1">(through <i>IfcValue</i>)</font></td>
<td valign="top" width="30%"><b>Unit<br></b></td>
</tr>
<tr>
<td width="15%">Description</td>
<td width="30%">Manufacturer "A" door</td>
<td width="25%"><i>IfcLabel</i></td>
<td width="30%">-</td>
</tr>
<tr>
<td width="15%">PanelThickness</td>
<td width="30%">0.12</td>
<td width="25%"><i>IfcPositiveLengthMeasure</i></td>
<td width="30%">-</td>
</tr>
<tr>
<td width="15%">ThermalTransmittance</td>
<td width="30%">2.6</td>
<td width="25%"><i>IfcThermalTransmittanceMeasure</i></td>
<td width="30%">W/(m<sup>2</sup>K)</td>
</tr>
</tbody>
</table>
<blockquote class="history">
HISTORY New entity in IFC Release 1.0. The entity has been renamed from IfcSimpleProperty in IFC Release 2x.
</blockquote>
<blockquote class="change-ifc2x3">
IFC2x3 CHANGE Attribute <i>NominalValue</i> has been made OPTIONAL with upward compatibility for file based exchange.
</blockquote>
</EPM-HTML> |
| 45 | 354 | IfcPropertyEnumeratedValue | <EPM-HTML>
<p>A property with an enumerated
value, <i>IfcPropertyEnumeratedValue</i>, defines a property
object which has a value assigned that is chosen from an
enumeration. It defines a property - value combination for which
theproperty <i>Name</i>, an optional <i>Description</i>,the
<font color="#FF0000">optional</font> <i>EnumerationValues</i>
with measure type and optionally an <i>Unit</i> is given.</p>
<blockquote>
NOTE Multiple choices from the property enumeration are supported.
</blockquote>
<p>The unit is handled by the <i>Unit</i> attribute of the
<i>IfcPropertyEnumeration</i>:</p>
<ul>
<li>If the <i>Unit</i> attribute is not given, then the unit is
already implied by the type of <i>IfcMeasureValue</i> or
<i>IfcDerivedMeasureValue</i>. The associated unit can be found
at the <i>IfcUnitAssignment</i> globally defined at the project
level (<i>IfcProject.UnitsInContext</i>).</li>
<li>If the <i>Unit</i> attribute is given, then the unit assigned
by the unit attribute overrides the globally assigned unit.</li>
</ul>
<p>More precisely: The <i>IfcPropertyEnumeratedValue</i> defines
a property, which value is selected from a defined list of
enumerators. The enumerators are stored in a dynamic enumeration
of values including the type information from <i>IfcValue</i>
(see <i>IfcPropertyEnumeration</i>). This enables applications to
use an enumeration value as a property within a property set
(<i>IfcPropertySet</i>) including the allowed list of
values.</p>
<blockquote class="note">
NOTE An <i>IfcPropertyEnumeratedValue</i> may be exchanged with no values assigned yet. In this case the <i>EnumerationValues</i> are set to NIL.
</blockquote>
<blockquote>
<p>Examples of a property with enumerated value are:</p>
</blockquote>
<blockquote>
<table border="1" cellpadding="2" cellspacing="2" width="600">
<tbody>
<tr valign="top">
<td valign="top" width="15%"><b>Name</b></td>
<td valign="top" width="30%"><b>Value<br></b> <font size=
"-1">(EnumerationValue)</font></td>
<td valign="top"><b>Type<br></b> <font size="-1">(through
IfcValue)</font></td>
<td valign="top">ref.<b>IfcPropertyEnumeration<br></b>
<font size="-1">(Name)</font></td>
</tr>
<tr>
<td>BladeAction</td>
<td>Opposed</td>
<td width="25%"><i>IfcString</i></td>
<td width="30%">DamperBladeActionEnum</td>
</tr>
<tr>
<td>BladeAction</td>
<td>Parallel</td>
<td width="25%"><i>IfcString</i></td>
<td width="30%">DamperBladeActionEnum</td>
</tr>
</tbody>
</table>
<p>The <i>IfcPropertyEnumeratedValue</i> refers to an
<i>IfcPropertyEnumeration</i>, e.g. for the above:</p>
</blockquote>
<blockquote>
<table border="1" cellpadding="2" cellspacing="2" width="600">
<tbody>
<tr>
<td width="30%"><b>Name</b></td>
<td width="30%"><b>EnumerationValues</b></td>
<td width="25%"><b>Type<br></b> <font size="-1">(through
IfcValue)</font></td>
<td width="15%"><b>Unit</b></td>
</tr>
<tr>
<td>DamperBladeActionEnum</td>
<td>(Parallel, Opposed, Other, Unset)</td>
<td><i>IfcString</i></td>
<td>-</td>
</tr>
</tbody>
</table>
</blockquote>
<p>It is not mandatory to use an instance of
<i>IfcPropertyEnumeration</i> to hold the applicable values for
<i>IfcPropertyEnumeratedValue</i>, however this is the preferred
way. A single instance of <i>IfcPropertyEnumeration</i> can be
referenced by multiple instances of
<i>IfcPropertyEnumeratedValue</i>.</p>
<blockquote class="history">
HISTORY New Entity in IFC Release 2.0, capabilities enhanced in IFC2x. The entity has
been renamed from <i>IfcEnumeratedProperty</i> in IFC2x.
</blockquote>
<blockquote class="change-ifc2x4">
IFC2x4 CHANGE Attribute <i>EnumerationValues</i> has been made OPTIONAL with upward
compatibility for file based exchange.
</blockquote>
</EPM-HTML> |
| 46 | 358 | IfcPropertyEnumeration | <EPM-HTML>
<p><i>IfcPropertyEnumeration</i> is a collection of simple
or measure values that define a prescribed set of alternatives from
which 'enumeration values' are selected. This enables inclusion of
enumeration values in property sets. <i>IfcPropertyEnumeration</i>
provides a name for the enumeration as well as a list of unique
(numeric or descriptive) values (that may have a measure type
assigned). The entity defines the list of potential enumerators to be
exchanged together (or separately) with properties of type <i>IfcPropertyEnumeratedValue</i>
that selects their actual property values from this enumeration. </p>
<p>The unit is handled by the <i>Unit</i> attribute:</p>
<ul>
<li>If the <i>Unit</i> attribute is not given,
than the unit is already implied by the type of <i>IfcMeasureValue</i>
or <i>IfcDerivedMeasureValue</i>. The associated unit can
be found at the <i>IfcUnitAssignment</i> globally defined
at the project level (<i>IfcProject.UnitsInContext</i>).</li>
<li> If the <i>Unit</i> attribute is given, the
unit assigned by the unit attribute overrides the globally assigned
unit.</li>
</ul>
<table border="1" cellpadding="2" cellspacing="2"
width="80%">
<tbody>
<tr>
<td width="30%"><b>Name</b></td>
<td width="30%"><b>EnumerationValues</b></td>
<td width="25%"><b>Type </b><font
size="-1">(through <i>IfcValue</i>)</font></td>
<td width="15%"><b>Unit</b></td>
</tr>
<tr>
<td>PEnum_DamperBladeAction</td>
<td>Parallel</td>
<td><i>IfcString</i></td>
<td>-</td>
</tr>
<tr>
<td> </td>
<td>Opposed</td>
<td><i>IfcString</i></td>
<td> </td>
</tr>
<tr>
<td> </td>
<td>Other</td>
<td><i>IfcString</i></td>
<td> </td>
</tr>
<tr>
<td> </td>
<td>Unset</td>
<td><i>IfcString</i></td>
<td> </td>
</tr>
</tbody>
</table>
<blockquote class="history">
HISTORY New Entity in IFC Release 2.0, capabilities enhanced in IFC Release 2x. Entity has been renamed from IfcEnumeration in IFC Release 2x.
</blockquote>
</EPM-HTML> |
| 47 | 365 | IfcPropertyBoundedValue | <EPM-HTML>
<p>
A property with a bounded
value, <i>IfcPropertyBoundedValue</i>, defines a property
object which has a maximum of two (numeric or descriptive)
values assigned, the first value specifying the upper bound
and the second value specifying the lower bound. It defines
a property - value bound (min-max) combination for which
the property <i>Name</i>, an optional
<i>Description</i>,the optional <i>UpperBoundValue</i>
with measure type, the optional <i>LowerBoundValue</i> with
measure type, and the optional <i>Unit</i> is given.
</p>
<p>A set point value can be provided in addition to the upper and lower bound values for operational value setting.
</p>
<p>
The unit is handled by the <i>Unit</i> attribute:
</p>
<ul>
<li>If the <i>Unit</i> attribute is not given, then the
unit is already implied by the type of
<i>IfcMeasureValue</i> or <i>IfcDerivedMeasureValue</i>.
The associated unit can be found at the
<i>IfcUnitAssignment</i> globally defined at the project
level (<i>IfcProject.UnitsInContext</i>).
</li>
<li>If the <i>Unit</i> attribute is given, then the unit
assigned by the <i>Unit</i> attribute overrides the
globally assigned unit.
</li>
</ul>
<p>
The <i>IfcPropertyBoundedValue</i> allows for the
specification of an interval for the value component of the
property description. If either the
<i>LowerBoundValue</i> or the <i>UpperBoundValue</i> is not
given, then it indicates an open bound (either a minimum
value or a maximum value). The interval is by definition
inclusive, that is, the value given for the
<i>LowerBoundValue</i> or the <i>UpperBoundValue</i> is
included in the interval.
</p>
<blockquote class="note">
NOTE An <i>IfcPropertyBoundedValue</i> may be
exchanged with no values assigned yet. In this case the
<i>LowerBoundValue</i> and the <i>UpperBoundValue</i> are
set to NIL.
</blockquote>
<blockquote>
<p>
Examples of a property with bounded value are:
</p>
<table border="1">
<tbody>
<tr valign="top">
<td valign="top" width="15%">
<b>Name</b>
</td>
<td valign="top" width="15%">
<b>UpperBoundValue</b>
</td>
<td valign="top" width="15%">
<b>LowerBoundValue</b>
</td>
<td valign="top" width="15%">
<b>SetPointValue</b>
</td>
<td valign="top" width="45%">
<b>Type<br></b> <font size="-1">(through
<i>IfcValue</i>, WR1 ensures same type for both
values)</font>
</td>
<td valign="top" width="10%">
<b>Unit<br></b>
</td>
</tr>
<tr valign="top">
<td align="left" valign="top" width="15%">
OverallHeight
</td>
<td align="left" valign="top" width="15%">
1930
</td>
<td align="left" valign="top" width="15%">
2300
</td>
<td align="left" valign="top" width="15%">
<nil>
</td>
<td align="left" valign="top" width="45%">
<i>IfcPositiveLengthMeasure</i>
</td>
<td align="left" valign="top" width="10%">
-
</td>
</tr>
<tr valign="top">
<td align="left" valign="top" width="15%">
OverallWidth
</td>
<td align="left" valign="top" width="15%">
0.9
</td>
<td align="left" valign="top" width="15%">
1.25
</td>
<td align="left" valign="top" width="15%">
<nil>
</td>
<td align="left" valign="top" width="45%">
<i>IfcPositiveLengthMeasure</i>
</td>
<td align="left" valign="top" width="10%">
m
</td>
</tr>
<tr valign="top">
<td align="left" valign="top" width="15%">
MaxHeight
</td>
<td align="left" valign="top" width="15%">
20.0
</td>
<td align="left" valign="top" width="15%">
<nil>
</td>
<td align="left" valign="top" width="15%">
<nil>
</td>
<td align="left" valign="top" width="45%">
<i>IfcPositiveLengthMeasure</i>
</td>
<td align="left" valign="top" width="10%">
-
</td>
</tr>
<tr valign="top">
<td align="left" valign="top" width="15%">
MinWeight
</td>
<td align="left" valign="top" width="15%">
<nil>
</td>
<td align="left" valign="top" width="15%">
20
</td>
<td align="left" valign="top" width="15%">
<nil>
</td>
<td align="left" valign="top" width="45%">
<i>IfcMassMeasure</i>
</td>
<td align="left" valign="top" width="10%">
kg
</td>
</tr>
</tbody>
</table>
</blockquote>
<blockquote class="history">
HISTORY New entity in IFC Release 2x.
</blockquote>
<blockquote class="change-ifc2x2">
IFC2x2 CHANGE The attribute type of the attribute <i>UpperBoundValue</i> and <i>LowerBoundValue</i> has been changed from mandatory to optional with upward compatibility for file based exchange.
</blockquote>
<blockquote class="change-ifc2x4">
IFC2x4 CHANGE The attribute <i>SetPointValue</i> has been added.
</blockquote>
<p>
Informal proposition:
</p>
<ol>
<li>If the measure type for the upper and lover bound value
is a numeric measure, then the following shall be true: <i>
UpperBoundValue</i> > <i>LowerBoundValue</i>.
</li>
</ol>
</EPM-HTML> |
| 48 | 373 | IfcPropertyTableValue | <EPM-HTML>
<p>
A property with a range value
(<i>IfcPropertyTableValue</i>) defines a property object
which has two lists of (numeric or descriptive) values
assigned, the values specifying a table with two columns.
The defining values provide the first column and establish
the scope for the defined values (the second column).
Interpolations are out of scope of the
<i>IfcPropertyTableValue</i>. An optional <i>Expression</i>
attribute may give the equation used for deriving the range
value, which is for information purposes only.
</p>
<p>
The <i>IfcPropertyTableValue</i> defines a defining/defined
property value combination for which the property name, the
table with defining and defined values with measure type
(and optional the units for defining and defined values)
are given.
</p>
<p>
The units are handled by the <i>DefiningUnit</i> and
<i>DefinedUnit</i> attributes:
</p>
<ul>
<li>If the <i>DefiningUnit</i> or <i>DefinedUnit</i>
attribute is not given, then the unit is already implied by
the type of <i>IfcMeasureValue</i> or
<i>IfcDerivedMeasureValue</i>. The associated unit can be
found at the <i>IfcUnitAssignment</i> globally defined at
the project level (<i>IfcProject.UnitsInContext</i>).
</li>
<li>If the <i>DefiningUnit</i> or <i>DefinedUnit</i>
attribute is given, then the unit assigned by the unit
attribute overrides the globally assigned unit.
</li>
</ul>
<p>
The <i>IfcPropertyTableValue</i> allows for the
specification of a table of defining/defined value pairs of
the property description. <font color="#0000ff">The optional
attribute <i>CurveInterpolation</i> allows to determine the
interval between two given values.</font>
</p>
<p>
Examples of a property with range value are:
</p>
<table border="1" cellpadding="2" cellspacing="2">
<tbody>
<tr valign="top">
<td align="left" valign="top" width="20%">
<b>Name</b>
</td>
<td align="left" valign="top" width="10%">
<b>DefiningValues</b>
</td>
<td align="left" valign="top" width="20%">
<b>DefiningValue Type<br></b> (through IfcValue)
</td>
<td align="left" valign="top" width="10%">
<b>DefinedValues</b>
</td>
<td align="left" valign="top" width="20%">
<b>DefinedValue Type<br></b> (through
<i>IfcValue</i>)
</td>
<td align="left" valign="top" width="10%">
<b>DefingUnit</b>
</td>
<td align="left" valign="top" width="10%">
<b>DefinedUnit</b>
</td>
</tr>
<tr>
<td align="left" valign="top" width="20%">
SoundTransmissionLoss
</td>
<td width="10%">
100
</td>
<td width="20%">
<i>IfcFrequencyMeasure</i>
</td>
<td width="10%">
20
</td>
<td width="20%">
<i>IfcNumericMeasure</i>
</td>
<td width="10%">
-
</td>
<td width="10%">
dB
</td>
</tr>
<tr valign="top">
<td align="left" bgcolor="#C8C8C8" valign="top" width=
"20%">
</td>
<td width="10%">
200
</td>
<td width="20%">
<i>IfcFrequencyMeasure</i>
</td>
<td width="10%">
42
</td>
<td width="20%">
<i>IfcNumericMeasure</i>
</td>
<td bgcolor="#C8C8C8" width="10%">
</td>
<td bgcolor="#C8C8C8" width="10%">
</td>
</tr>
<tr valign="top">
<td align="left" bgcolor="#C8C8C8" valign="top" width=
"20%">
</td>
<td width="10%">
400
</td>
<td width="20%">
<i>IfcFrequencyMeasure</i>
</td>
<td width="10%">
46
</td>
<td width="20%">
<i>IfcNumericMeasure</i>
</td>
<td bgcolor="#C8C8C8" width="10%">
</td>
<td bgcolor="#C8C8C8" width="10%">
</td>
</tr>
<tr valign="top">
<td align="left" bgcolor="#C8C8C8" valign="top" width=
"20%">
</td>
<td width="10%">
800
</td>
<td width="20%">
<i>IfcFrequencyMeasure</i>
</td>
<td width="10%">
56
</td>
<td width="20%">
<i>IfcNumericMeasure</i>
</td>
<td bgcolor="#C8C8C8" width="10%">
</td>
<td bgcolor="#C8C8C8" width="10%">
</td>
</tr>
<tr valign="top">
<td align="left" bgcolor="#C8C8C8" valign="top" width=
"20%">
</td>
<td width="10%">
1600
</td>
<td width="20%">
<i>IfcFrequencyMeasure</i>
</td>
<td width="10%">
60
</td>
<td width="20%">
<i>IfcNumericMeasure</i>
</td>
<td bgcolor="#C8C8C8" width="10%">
</td>
<td bgcolor="#C8C8C8" width="10%">
</td>
</tr>
<tr valign="top">
<td align="left" bgcolor="#C8C8C8" valign="top" width=
"20%">
</td>
<td width="10%">
3200
</td>
<td width="20%">
<i>IfcFrequencyMeasure</i>
</td>
<td width="10%">
65
</td>
<td width="20%">
<i>IfcNumericMeasure</i>
</td>
<td bgcolor="#C8C8C8" width="10%">
</td>
<td bgcolor="#C8C8C8" width="10%">
</td>
</tr>
</tbody>
</table>
<blockquote class="history">
HISTORY: New entity in IFC2x.
</blockquote>
<blockquote class="change-ifc2x4">
IFC2x4 CHANGE Attributes <i>DefiningValues</i> and <i>DefinedValues</i> have been made OPTIONAL with upward compatibility for file based exchange. The attribute <i>CurveInterpolation</i> has been added.</font>.</small>
</blockquote>
<p>
Informal propositions:
</p>
<ol>
<li>The list of <i>DefinedValues</i> and the list of
<i>DefiningValues</i> are corresponding lists.
</li>
</ol>
</EPM-HTML> |
| 49 | 388 | IfcPropertyReferenceValue | <EPM-HTML>
<p><i>IfcPropertyReferenceValue</i> allows a property value to
be given by referencing other entities within the resource
definitions of IFC. Those other entities are regarded as
predefined complex properties and can be aggregated within
a property set (<i>IfcPropertySet</i>). The allowable
entities to be used as value references are given by the
<i>IfcObjectReferenceSelect</i>.</p>
<blockquote class="history">
HISTORY New entity in IFC
Release 1.5. Entity has been renamed from
IfcObjectReference in IFC Release 2x.
</blockquote>
<blockquote class="change-ifc2x4">
IFC2x4 CHANGE Attribute
<i>PropertyReference</i> has been made OPTIONAL with upward
compatibility for file based exchange.
</blockquote>
</EPM-HTML> |
| 50 | 400 | IfcPropertyListValue | <EPM-HTML>
<p>
An <i>IfcPropertyListValue</i>
defines a property that has several (numeric or
descriptive) values assigned, these values are given by an
ordered list.It defines a property - list value
combination for which the property <i>Name</i>, an optional
<i>Description</i>,the optional <i>ListValues</i> with measure
type and optionally an <i>Unit</i> is given.
</p>
<p>
An <i>IfcPropertyListValue</i> is a list of values. The
order in which values appear is significant. <s>Each value in
the list is unique i.e. no duplicate values are allowed.</s>
All list members shall be of the same type.
</p>
<p>
The unit applicable to all values is handled by the
<i>Unit</i> attribute:
</p>
<ul>
<li>If the <i>Unit</i> attribute is not given, then the
unit is already implied by the type of
<i>IfcMeasureValue</i> or <i>IfcDerivedMeasureValue</i>.
The associated unit can be found at the
<i>IfcUnitAssignment</i> globally defined at the project
level (<i>IfcProject.UnitsInContext</i>).
</li>
<li>If the <i>Unit</i> attribute is given, then the unit
assigned by the <i>Unit</i> attribute overrides the
globally assigned unit.
</li>
</ul>
<blockquote><p>
Example of a property with list value is:
</p>
<table border="1" cellpadding="2" cellspacing="2" width=
"600">
<tbody>
<tr valign="top">
<td valign="top" width="15%">
<b>Name</b>
</td>
<td valign="top" width="30%">
<b>ListValues</b>
</td>
<td valign="top" width="25%">
<b>Type<br></b> <font size="-1">(through
IfcValue)</font>
</td>
<td valign="top" width="30%">
<b>Unit<br></b>
</td>
</tr>
<tr>
<td width="15%">
ApplicableSizes
</td>
<td width="30%">
1200
</td>
<td width="25%">
<i>IfcPositiveLengthMeasure</i>
</td>
<td width="30%">
-
</td>
</tr>
<tr>
<td width="15%">
-
</td>
<td width="30%">
1600
</td>
<td width="25%">
<i>IfcPositiveLengthMeasure</i>
</td>
<td width="30%">
-
</td>
</tr>
<tr>
<td width="15%">
-
</td>
<td width="30%">
2400
</td>
<td width="25%">
<i>IfcPositiveLengthMeasure</i>
</td>
<td width="30%">
-
</td>
</tr>
</tbody>
</table></blockquote>
<blockquote class="history">
HISTORY New Entity in Release IFC 2x Edition 2.
</blockquote>
<blockquote class="change-ifc2x4">
IFC2x4 CHANGE Attribute <i>ListValues</i> has been made OPTIONAL with upward compatibility for file based exchange.
</blockquote>
</EPM-HTML> |
| 51 | 406 | IfcPhysicalQuantity | <EPM-HTML>
<p>The physical quantity, <i>IfcPhysicalQuantity</i>, is an abstract entity that holds a complex or simple quantity measure together with a semantic definition of the usage for the single or several measure value.</p>
<p>The <i>Name</i> attribute defines the actual usage or kind of measure. The interpretation of the name label has to be established within the actual exchange context. In addition an informative text may be associated to each quantity by the <i>Description</i> attribute.</p>
<blockquote class="history">
HISTORY New entity in IFC2x. It replaces the calcXxx attributes used in previous IFC Releases.
</blockquote>
</EPM-HTML> |
| 52 | 413 | IfcPhysicalSimpleQuantity | <EPM-HTML>
<p>The physical quantity, <i>IfcPhysicalSimpleQuantity</i>, is an entity that holds a single quantity measure value (as defined at the subtypes of <i>IfcPhysicalSimpleQuantity</i>) together with a semantic definition of the usage for the measure value.</p>
<blockquote class="example">
EXAMPLE An element, like a wall, may have several area measures, like footprint area, left wall face area, right wall face area. These areas would be given by three instances of the area quantity subtype, with different <I>Name</I> string values.
</blockquote>
<p>A section "Quantity Use Definition" at individual entities as subtypes of <i>IfcBuildingElement</i> gives guidance to the usage of the <i>Name</i> attribute to characterize the individual quantities. If the <i>Unit</i> attribute is given, the value attribute (introduced at the level of subtypes of <i>IfcPhysicalSimpleQuantity</i>) are given as quantities of this unit, otherwise the global unit definitions (given by <i>IfcUnitAssignment</i>) are used.</p>
<blockquote class="history">
HISTORY New entity in IFC2x2 Addendum 1.
</blockquote>
<blockquote class="change-ifc2x2">
IFC2x2 ADDENDUM 1 CHANGE The abstract entity <i>IfcPhysicalSimpleQuantity</i> has been added. Upward compatibility for file based exchange is guaranteed.
</blockquote>
</EPM-HTML> |
| 53 | 421 | IfcQuantityLength | <EPM-HTML>
<p><i>IfcQuantityLength</i> is a physical quantity that defines a derived length measure to provide an element's physical property. It is normally derived from the physical properties of the element under the specific measure rules given by a method of measurement.</p>
<blockquote class="example">
EXAMPLE A rafter within a roof construction may be measured according to its length (taking a common cross section into account). The actual size of the length depends on the method of measurement used.
</blockquote>
<blockquote class="history">
HISTORY New entity in IFC Release 2.x. It replaces the calcXxx attributes used in previous IFC Releases.
</blockquote>
</EPM-HTML> |
| 54 | 426 | IfcQuantityArea | <EPM-HTML>
<p><i>IfcQuantityArea</i> is a physical quantity that defines a derived area measure to provide an element's physical property. It is normally derived from the physical properties of the element under the specific measure rules given by a method of measurement.</p>
<blockquote class="example">
EXAMPLE An opening may have an opening area used to deduct it from the wall surface area. The actual size of the area depends on the method of measurement used.
</blockquote>
<blockquote class="history">
HISTORY New entity in IFC2x. It replaces the calcXxx attributes used in previous IFC Releases.
</blockquote>
</EPM-HTML> |
| 55 | 431 | IfcQuantityVolume | <EPM-HTML>
<p><i>IfcQuantityVolume</i> is a physical quantity that defines a derived volume measure to provide an element's physical property. It is normally derived from the physical properties of the element under the specific measure rules given by a method of measurement.</p>
<blockquote class="example">
EXAMPLE A thick brick wall may be measured according to its volume. The actual size of the volume depends on the method of measurement used.
</blockquote>
<blockquote class="history">
HISTORY New entity in IFC2x. It replaces the calcXxx attributes used in previous IFC Releases.
</blockquote>
</EPM-HTML> |
| 56 | 436 | IfcQuantityCount | <EPM-HTML>
<p><i>IfcQuantityCount</i> is a physical quantity that defines a derived count measure to provide an element's physical property. It is normally derived from the physical properties of the element under the specific measure rules given by a method of measurement.</p>
<blockquote class="example">
EXAMPLE An radiator may be measured according to its number of coils. The actual counting method depends on the method of measurement used.
</blockquote>
<blockquote class="history">
HISTORY New entity in IFC2x. It replaces the calcXxx attributes used in previous IFC Releases.
</blockquote>
</EPM-HTML> |
| 57 | 440 | IfcQuantityWeight | <EPM-HTML>
<p><i>IfcQuantityWeight</i> is a physical element quantity that defines a derived weight measure to provide an element's physical property. It is normally derived from the physical properties of the element under the specific measure rules given by a method of measurement.</p>
<blockquote class="example">
EXAMPLE The amount of reinforcement used within a building element may be measured according to its weight. The actual size of the weight depends on the method of measurement used.
</blockquote>
<blockquote class="history">
HISTORY New entity in IFC2x. It replaces the calcXxx attributes used in previous IFC Releases.
</blockquote>
</EPM-HTML> |
| 58 | 445 | IfcQuantityTime | <EPM-HTML>
<p><i>IfcQuantityTime</i> is an element quantity that defines a time measure to provide an property of time related to an element. It is normally given by the recipe information of the element under the specific measure rules given by a method of measurement.</p>
<blockquote class="example">
EXAMPLE The amount of time needed to pour concrete for a wall is given as a time quantity for the labor part of the recipe information.
</blockquote>
<blockquote class="history">
HISTORY New entity in IFC2x2.
</blockquote>
</EPM-HTML> |
| 59 | 450 | IfcPhysicalComplexQuantity | <EPM-HTML>
<p>The complex physical quantity, <i>IfcPhysicalComplexQuantity</i>, is an entity that holds a set of single quantity measure value (as defined at the subtypes of <i>IfcPhysicalSimpleQuantity</i>), that all apply to a given component or aspect of the element.</p>
<blockquote class="example">
EXAMPLE: A layered element, like a wall, may have several material layers, each having individual quantities, like footprint area, side area and volume. An instance of <i>IfcPhysicalComplexQuantity</i> would group these individual quantities (given by a subtype of <i>IfcPhysicalSimpleQuantity</i>) and name them according to the material layer name by using the <i>Name</i> attribute. The <i>Discrimination</i> attribute would then be 'layer'.
</blockquote>
<p>A section "Quantity Use Definition" at individual entities as subtypes of <i>IfcBuildingElement</i> gives guidance to the usage of the <i>Name</i> and <i>Discrimination</i> attribute to characterize the complex quantities.</p>
<blockquote class="history">
HISTORY New entity in IFC2x2 Addendum 1.
</blockquote>
<blockquote class="change-ifc2x2">
IFC2x2 ADDENDUM 1 CHANGE The entity <i>IfcPhysicalComplexQuantity</i> has been added. Upward compatibility for file based exchange is guaranteed.
</blockquote>
</EPM-HTML> |
| 60 | 459 | IfcSystem | <EPM-HTML>
<p>
<u>Definition from IAI</u>: Organized combination of
related parts within an AEC product, composed for a common
purpose or function or to provide a service. System is
essentially a functionally related aggregation of products.
The grouping relationship to one or several instances of
<i>IfcProduct</i> (the system members) is handled by
<i>IfcRelAssignsToGroup</i>.
</p>
<blockquote>
<font size="-1">NOTE: The use of <i>IfcSystem</i> often
applies to the representation of building services related
systems, such as the piping system, cold water system, etc.
Members within such a system may or may not be connected
using the connectivity related entities (e.g. through
<i>IfcPort</i>).</font>
</blockquote>
<blockquote>
<p>
<font color="#0000FF" size="-1">HISTORY: New entity in
IFC Release 1.0</font>
</p>
</blockquote>
</EPM-HTML> |
| 61 | 464 | IfcZone | <EPM-HTML>
<p><u>Definition from IAI</u>: A zone isa group of spaces,
partial spaces or other zones. Zone structures may not be
hierarchical (in contrary to the spatial structure of a project -
see <i>IfcSpatialStructureElement</i>), i.e. one individual
<i>IfcSpace</i> may be associated with zero, one, or several
<i>IfcZone</i>'s. <i>IfcSpace</i>'s are grouped into an
<i>IfcZone</i> by using the objectified relationship
<i>IfcRelAssignsToGroup</i> as specified at the supertype
<i>IfcGroup</i>.</p>
<blockquote><small>NOTE Certain use cases may restrict the
freedom of non hierarchical relationships. In some building
service use cases the zone denotes aview based delimited volume
for the purpose of analysis and calculation. This type of zone
cannot overlap with respect to that analysis, but may overlap
otherwise.</small></blockquote>
<p>An <i>IfcZone</i> is a spatial system under which individual
<i>IfcSpace</i>'s (and other <i>IfcZone</i>'s) are grouped. In
contrary to the <i>IfcSpatialZone</i> entity, <i>IfcZone</i> is a
mere grouping, it can not define an own geometric representation
and placement. Therefore it cannot be used for spatial zones
having a different shape and size compared to the shape and size
of aggregated spaces.</p>
<blockquote><small>NOTE The <i>IfcZone</i> is regarded as the
spatial system (as compared to the building service, electrical,
or analytical system), the name remains <i>IfcZone</i> for
compatibility reasons, instead of using a proper naming
convention, like IfcSpatialSystem.</small></blockquote>
<blockquote><small>NOTE One of the purposes of a zone is to
define a fire compartmentation. In this case it defines the
geometric information about the fire compartment (through the
contained spaces) and information, whether this compartment is
ventilated or sprinkler protected. In addition the fire risk code
and the hazard type can be added, the coding is normally defined
within a national fire regulation. All that information is
available within the relevant property sets. Again, if an
independent shape has to be provided to the fire compartment,
then the entity <i>IfcSpatialZone</i> shall be
used.</small></blockquote>
<blockquote><small>RECOMMENDATION In case of a zone denoting a
(fire) compartment, the following types should be used, if
applicable, as values of the <i>ObjectType</i> attribute:</small>
<ul>
<li><small>FireCompartment - a zone of spaces, collected to
represent a single fire compartment.</small></li>
<li><small>ElevatorShaft - a collection of spaces within an
elevator, potentially going through many storeys.</small></li>
<li><small>RisingDuct</small></li>
<li><small>RunningDuct</small></li>
</ul>
</blockquote>
<p>Additional classifications of the <i>IfcZone</i>, as provided
by a national classification system, can be assigned by using the
<i>IfcRelAssociatesClassification</i> relationship, accessible
via the inverse attribute <i>HasAssociations</i>. The
<i>IfcZone</i> can be assigned to a spatial structure element, it
refers to, e.g. to a particular <i>IfcBuildingStorey</i> by using
the <i>IfcRelServicesBuildings</i> relationship, accessible via
the inverse attribute <i>ServicesBuilding</i>.</p>
<blockquote><small><font color="#0000FF">HISTORY New entity in
IFC Release 1.0</font></small><br>
<small><font color="#FF0000">IFC2x4 CHANGE The entity is now
subtyped from <i>IfcSystem</i> (not its supertype
<i>IfcGroup</i>) with upward compatibility for file based
exchange.</font></small></blockquote>
<p><u><b>Property Set Use Definition</b></u>:</p>
<p>The property sets relating to the <i>IfcZone</i> are defined
by the <i>IfcPropertySet</i> and attached by the
<i>IfcRelDefinesByProperties</i> relationship. It is accessible
by the inverse <i>IsDefinedBy</i> relationship. The following
property set definitions specific to the <i>IfcZone</i> are part
of this IFC release:</p>
<ul>
<li><a href="../../psd/IfcProductExtension/Pset_ZoneCommon.xml"
target="SOURCE">Pset_ZoneCommon</a>: common property set for all
types of zone</li>
<li><a href=
"../../psd/IfcProductExtension/Pset_SpaceFireSafetyRequirements.xml"
target="SOURCE">Pset_SpaceFireSafetyRequirements</a>: common
property set for all types of zones to capture the fire safety
requirements</li>
<li><a href=
"../../psd/IfcProductExtension/Pset_SpaceLightingRequirements.xml"
target="SOURCE">Pset_SpaceLightingRequirements</a>: common
property set for all types of zones to capture the lighting
requirements</li>
<li><a href=
"../../psd/IfcProductExtension/Pset_SpaceOccupancyRequirements.xml"
target="SOURCE">Pset_SpaceOccupancyRequirements</a>: common
property set for all types of zones to capture the occupancy
requirements</li>
<li><a href=
"../../psd/IfcProductExtension/Pset_SpaceThermalRequirements.xml"
target="SOURCE">Pset_SpaceThermalRequirements</a>: common
property set for all types of zones to capture the thermal
requirements</li>
</ul>
</EPM-HTML> |
| 62 | 467 | IfcRelConnectsElements | <EPM-HTML>
<p>
<u>Definition from IAI</u>: The
<i>IfcRelConnectsElements</i> objectified relationship
provides the generalization of the connectivity between
elements. It is a 1 to 1 relationship. The concept of two
elements being physically or logically connected is
described independently from the connecting elements. The
connectivity may be related to the shape representation of
the connected entities by providing a connection geometry.
</p>
<ul>
<li>In this case the geometrical constraints of the
connection are provided by the optional relationship to the
<i>IfcConnectionGeometry</i>. The connection geometry is
provided as a point, curve or surface within the local
placement coordinate systems of the connecting elements.
</li>
<li>If the connection geometry is omitted then the
connection is provided as a logical connection. Under this
circumstance, the connection point, curve or surface has to
be recalculated by the receiving application.
</li>
</ul>
<blockquote>
<p>
<small><font color="#0000FF">HISTORY New entity in IFC
Release 1.0.</font></small>
</p>
</blockquote>
</EPM-HTML> |
| 63 | 474 | IfcRelSpaceBoundary | <EPM-HTML>
<p>The space boundary defines the
physical or virtual delimiter of a space by the relationship
<i>IfcRelSpaceBoundary</i> to the surrounding elements.</p>
<ul>
<li>In the case of a physical space boundary, the placement and
shape of the boundary may be given, and the building element,
providing the boundary, is referenced,</li>
<li>In the case of a virtual space boundary, the placement and
shape of the boundary may be given, <s>but no building element is
referenced</s> <font color="#0000FF">and a virtual element is
referenced instead</font>.</li>
</ul>
<p>The <i>IfcRelSpaceBoundary</i> is defined as an objectified
relationship that handles the element to space relationship by
objectifying the relationship between an element and the space it
bounds. It is given as a one-to-one relationship, but allows each
element (including virutal elements and openings) to define many
such relationship and each space to be defined by many such
relationships.</p>
<p>Space boundaries are always defined as seen from the space. In
general two basic types of space boundaries are
distinguished:</p>
<ul>
<li>1<sup><small>st</small></sup> level space boundary: defined
as boundaries of the space, not taking into account any change in
building element or spaces on the other side.</li>
<li>2<sup><small>nd</small></sup> level space boundary: defined
as boundary taking any change in building element or spaces on
the other side into account. It can be further distinguished into
<ul>
<li>2<sup><small>nd</small></sup> level type A: There is a space
on the other side.</li>
<li>2<sup><small>nd</small></sup> level type B: There is a
building element on the other side.</li>
</ul>
</li>
</ul>
<blockquote><small>The exact definition of how space boundaries
are broken down depends on the view definition, more detailed
conventions on how space boundaries are decomposed can only be
given at the domain or application type level.</small>
<ul>
<li><small>In an architectural or FM related view, a space
boundary is defined totally from inside the space. This is a
1<sup><small>st</small></sup> level space boundary.</small></li>
<li><small>In a thermal view, the decomposition of the space
boundary depends on the material of the providing building
element and the adjacent spaces behind. This is a
2<sup><small>nd</small></sup> level space boundary.</small></li>
</ul>
</blockquote>
<table summary="space boundary types" border="0">
<tr>
<td><img src="figures/IfcRelSpaceBoundary_1stLevel.png" alt=
"1st level"></td>
<td><img src="figures/IfcRelSpaceBoundary_2ndLevel.png" alt=
"2nd level"></td>
</tr>
<tr>
<td><p class="figure">Figure 42 — Space boundary at first level</p></td>
<td><p class="figure">Figure 43 — Space boundary at second level</p></td>
</tr>
<tr>
<td><img src="figures/IfcRelSpaceBoundary_2ndLevel_TypeA.png"
alt="2nd level type a"></td>
<td><img src="figures/IfcRelSpaceBoundary_2ndLevel_TypeB.png"
alt="2nd level type b"></td>
</tr>
<tr>
<td><p class="figure">Figure 44 — Space boundary at second level type A</p></td>
<td><p class="figure">Figure 45 — Space boundary at second level type B</p></td>
</tr>
</table>
<blockquote class="history">HISTORY New entity in IFC Release 1.5, the entity has been modified in IFC Release
2x.</blockquote>
<blockquote class="change-ifc2x">IFC2x CHANGE The data type of the attribute<i>RelatedBuildingElement</i> has
been changed from <i>IfcBuildingElement</i> to its supertype <i>IfcElement</i>. The data type of the attribute
<i>ConnectionGeometry</i> has been changed from <i>IfcConnectionSurfaceGeometry</i> to its supertype
<i>IfcConnectionGeometry</i>.</blockquote>
<blockquote class="change-ifx2x4">IFC2x4 CHANGE The attribute <i>RelatedBuildingElement</i> has been made mandatory. For virtual boundaries the reference to <i>IfcVirtualElement</i> is now mandatory.</font></small></blockquote>
<p class="use-head">Attribute Use Definitions</p>
<p>The differences between the 1<sup><small>st</small></sup> and
2<sup><small>nd</small></sup> level space boundaries is
identified by:</p>
<ul>
<li><b>1<sup><small>st</small></sup> level:</b><br>
SELF\IfcRoot.Name = "1stLevel"<br>
SELF\IfcRootDescription = NIL</li>
<li><b>2<sup><small>nd</small></sup> level:</b><br>
SELF\IfcRoot.Name = "2ndLevel"<br>
SELF\IfcRootDescription = "2a", or "2b"</li>
</ul>
<p>Differentiation between physical and virtual space boundary is illustrated in Figure 46 and Figure 47.</p>
<p>As shown in Figure 46, if the <i>IfcRelSpaceBoundary</i> is used to express a virtual boundary, the attribute <i>PhysicalOrVirtualBoundary</i> has to be set to VIRTUAL. The attribute <i>RelatedBuildingElement</i> shall point to an instance of <i>IfcVirtualElement</i>. If the correct location is of interest, the attribute <i>ConnectionGeometry</i> is required.</p>
<blockquote class="note">NOTE The connection geometry, either by a 2D curve or a 3D surface, is used to describe the portion of the "virtual wall" that separates the two spaces. All instances of <i>IfcRelSpaceBoundary</i> given at the adjacent spaces share the same instance of <i>IfcVirtualElement</i>. Each instance of <i>IfcRelSpaceBoundary</i> provides in addition the <i>ConnectionGeometry</i> given within the local placement of each space.</blockquote>
<table summary="virtual">
<tr><td><img alt="IfcRelSpaceBoundary_virtual (35K)" src="figures/IfcRelSpaceBoundary_virtual.png" height="500" width="600"></td></tr>
<tr><td><p class="figure">Figure 46 — Space boundary of virtual element</p></td></tr>
</table>
<p>As shown in Figure 47, if the <i>IfcRelSpaceBoundary</i> is used to express a physical boundary between two spaces, the attribute <i>PhysicalOrVirtualBoundary</i> has to be set to PHYSICAL. The attribute <i>RelatedBuildingElement</i> has to be given and points to the element providing the space boundary. The attribute <i>ConnectionGeometry</i> may be inserted, in this case it describes the physical space boundary geometically, or it may be omited, in that case it describes a physical space boundary logically.</p>
<table summary="physical">
<tr><td><img alt="IfcRelSpaceBoundary_physical (35K)" src="figures/IfcRelSpaceBoundary_physical.png" height="500" width="600"></td></tr>
<tr><td><p class="figure">Figure 47 — Space boundary of physical element</p></td></tr>
</table>
<p class="use-head">Geometry Use Definitions</p>
<p>The <i>IfcRelSpaceBoundary</i> may have geometry attached. If
geometry is not attached, the relationship between space and
building element is handled only on a logical level. If geometry
is attached, it is given within the local coordinate systems of
the space.</p>
<blockquote><small>NOTE: The attributes
<i>CurveOnRelatingElement</i> at
<i>IfcConnectionCurveGeometry</i> or
<i>SurfaceOnRelatingElement</i> at
<i>IfcConnectionSurfaceGeometry</i> provide the geometry within
the local coordinate system of the <i>IfcSpace</i>, whereas the
attributes <i>CurveOnRelatedElement</i> at
<i>IfcConnectionCurveGeometry</i> or
<i>SurfaceOnRelatedElement</i> at
<i>IfcConnectionSurfaceGeometry</i> provide the geometry within
the local coordinate system of the subtype of
<i>IfcElement</i></small>.<br>
<small>NOTE In most view definitions the connection geometry for
the related <i>IfcElement</i> is not
provided.</small></blockquote>
<p>The geometric representation (through the
<i>ConnectionGeometry</i> attribute) is defined using either 2D
curve geometry or 3D surface geometry for space boundaries. In
most view definitions the 3D connection surface geometry is
required.</p>
<ul>
<li>1<sup><small>st</small></sup> level space boundary:
<ul>
<li>only connection geometry for related space shall be
provided</li>
<li>only surface connection geometry shall be provided</li>
<li>only the following surface representations are supported:
<ul>
<li><i>IfcSurfaceOfLinearExtrusion</i></li>
<li><i>IfcCurveBoundedPlane</i></li>
<li><i>IfcCurveBoundedSurface</i></li>
<li><i>IfcFaceBasedSurfaceModel</i></li>
</ul>
</li>
</ul>
</li>
<li>2<sup><small>nd</small></sup> level space boundary:
<ul>
<li>only connection geometry for related space shall be
provided</li>
<li>only surface connection geometry shall be provided</li>
<li>only the following surface representations are supported:
<ul>
<li><i>IfcCurveBoundedPlane</i> with restrictions to have
polygonal boundaries only</li>
<li><i>IfcFaceBasedSurfaceModel</i></li>
</ul>
</li>
</ul>
</li>
</ul>
<p><b>Surface connection geometry</b></p>
<p>The following constraints apply to the surface connection
geometry representation:</p>
<ul>
<li>planar boundaries:
<ul>
<li><i>IfcSurfaceOfLinearExtrusion</i> defined by a
<i>SweptCurve</i> being an <i>IfcArbitraryOpenProfileDef</i> with
straight segements, or</li>
<li><i>IfcCurveBoundedPlane</i></li>
</ul>
</li>
<li>curved boundaries
<ul>
<li><i>IfcSurfaceOfLinearExtrusion</i> defined by a
<i>SweptCurve</i> being an <i>IfcArbitraryOpenProfileDef</i> with
curves segements, or</li>
<li><i>IfcCurveBoundedSurface</i> with a <i>BasisSurface</i>
being a non planar surface, such as <i>IfcCylindricalSurface</i>,
or</li>
<li><i>IfcFaceBasedSurfaceModel</i> if already faceted.</li>
</ul>
</li>
</ul>
<p><b>Curve connection geometry</b></p>
<p>The following constraints apply to the 2D curve
representation:</p>
<ul>
<li>Curve: <i>IfcPolyline</i>, <i>IfcTrimmedCurve</i> or
<i>IfcCompositeCurve</i></li>
</ul>
</EPM-HTML> |
| 64 | 483 | IfcRelSpaceBoundary1stLevel | <EPM-HTML>
<p>The 1st level space boundary
defines the physical or virtual delimiter of a space by the
relationship <i>IfcRelSpaceBoundary1stLevel</i> to the
surrounding elements. 1st level space boundaries are
characterizeda by:</p>
<ul>
<li>1st level space boundaries are the boundaries of a space
defined by the surfaces of building elements bounding this space
(physical space boundaries) or by virtual surfaces provided by an
adjacent space with no dividing wall.</li>
<li>1st level space boundaries do not consider any change of
material in the bounding building elements, or different
spaces/zones behind a wall or slab (floor or ceiling).</li>
<li>1st level space boundaries are differentiated in two ways:
virtual or physical and internal,external, or undefined (internal
and external) e.g. for a wall that is partially inside and
outside.</li>
<li>1st level space boundaries form a closed shell around the
space (so long as the space is completely enclosed) and include
overlapping boundaries representing openings (filled or not) in
the building elements (see implementers agreement below).</li>
</ul>
<p>1st level space boundaries define a space by its boundary
surfaces without taking anything on the other side of the
bounding elements into account.</p>
<blockquote><small>NOTE 1st level space boundaries are used e.g.
in quantity take-off and facility management as they describe the
surfaces for finishes. They cannot be directly used for thermal
analysis. However 1st level space boundaries can provide the
input to preprocessors to thermal analysis software that take 1st
level space boundaries and perform the necessary transformation
into 2nd level space boundaries that are required for energy
analysis.</small></blockquote>
<blockquote class="history">HISTORY New entity in IFC2x4.</blockquote>
<p class="use-head">Relationship Use Definitions</p>
<p>As shown in Figure 48, the attribute <i>ParentBoundary</i> with inverse <i>InnerBoundaries</i> is provided to link the space boundaries of doors, windows, and openings to the parent boundary, such as of a wall or slab.</p>
<blockquote class="note">NOTE The space boundary of the parent is not cut by the inner boundary - both overlap.</blockquote>
<table border="0" cellpadding="2" cellspacing="2" summary=
"parent/inner boundaries">
<tr><td><img alt="IfcRelSpaceBoundary1stLevel" src=
"figures/IfcRelSpaceBoundary1stLevel-fig1.png" height="550"
width="600"></td></tr>
<tr><td><p class="figure">Figure 48 — Space boundary first level relationships</p></td></tr>
</table>
<p class="use-head">Geometry Use Definitions</p>
<p>See the definition at the supertype IfcRelSpaceBoundary for
guidance on using the connection geometry for first level space
boundaries.</p>
</EPM-HTML> |
| 65 | 486 | IfcRelSpaceBoundary2ndLevel | <EPM-HTML>
<p>The 2nd level space boundary defines the physical or virtual delimiter of a space by the relationship <i>IfcRelSpaceBoundary2ndLevel</i> to the surrounding elements. 2nd level space boundaries are characterized by:</p>
<ul>
<li>2nd level space boundaries still represent building elements that bound the space, but are more granular in that they are subdivided in any of the following cases:
<ul>
<li>Differences in materials and/or material assemblies (for example, a wainscot or paneling on the lower portion of a wall).</li>
<li>Differences in spaces or zones on the other side of the building element (or virtual boundary) represented by the space boundary (for example, two different spaces on the other side of a wall)</li>
</ul>
</li>
<li>2nd level space boundaries are differentiated in two ways: virtual or physical and internal or external, whereby any space boundary that is both internal and external has to be split into segments being either or.</li>
<li>2nd level space boundaries represent both sides of a heat transfer surface separated by the thickness of the building element. They can be further differentiated in:
<ul>
<li>Type 2a that occurs when there is a space on the opposite side of the building element providing the space boundary</li>
<li>Type 2b occurs if there is a building element on the opposite side of the building element providing the space boundary.</li>
</ul>
</li>
<li>The connection geometry of 2nd level space boundaries is restricted to planar surfaces only. This means that curved surfaces must be segmented.</li>
</ul>
<p>2nd level space boundaries define the heat transfer surfaces on both sides of building elements that separate spaces. The generation of 2nd level space boundaries has to take building elements and spaces on the other side into account.</p>
<blockquote class="note">NOTE 2nd level space boundaries are used by many analysis packages that require a surface view of the building that can be transformed into the various simple topological models. Examples of such analysis packages include: (1) energy analysis, (2) lighting analysis, (3) fluid dynamics</blockquote>
<blockquote class="history">HISTORY New entity in IFC2x4.</font></small></blockquote>
<p class="use-head">Relationship Use Definitions</p>
<p>As shown in Figure 49, the attribute <i>ParentBoundary</i> with inverse <i>InnerBoundaries</i> is provided to link the space boundaries of doors, windows, and openings to the parent boundary, such as of a wall or slab.</p>
<blockquote class="note">NOTE The space boundary of the parent is not cut by the inner boundary - both overlap.</blockquote>
<p>The attribute <i>CorrespondingBoundary</i> with inverse <i>Corresponds</i> is provided to link the pair of space boundaries on the opposite sides of the building element.</p>
<blockquote class="note">NOTE Only 2nd level space boundaries of type A have corresponding boundaries.</blockquote>
<table border="0" cellpadding="2" cellspacing="2" summary="parent/inner boundaries">
<tr><td><img alt="IfcRelSpaceBoundary2ndLevel" src="figures/IfcRelSpaceBoundary2ndLevel-fig1.png" height="650" width="600"></td></tr>
<tr><td><p class="figure">Figure 49 — Space boundary second level relationships</p></td></tr>
</table>
<p class="use-head">Geometry Use Definitions</p>
<p>See the definition at the supertype <i>IfcRelSpaceBoundary</i>
for guidance on using the connection geometry for second level
space boundaries.</p>
</EPM-HTML> |
| 66 | 494 | IfcSpace | <EPM-HTML>
<p>A space represents an area or volume
bounded actually or theoretically. Spaces are areas or volumes that
provide for certain functions within a building.</p>
<p>A space is associated to a building storey (or in case of
exterior spaces to a site). A space may span over several connected
spaces. Therefore a space group provides for a collection of spaces
included in a storey. A space can also be decomposed in parts,
where each part defines a partial space. This is defined by the
<i>CompositionType</i> attribute of the supertype
<i>IfcSpatialStructureElement</i> which is interpreted as
follow:</p>
<ul>
<li>COMPLEX = space group</li>
<li>ELEMENT = space</li>
<li>PARTIAL = partial space</li>
</ul>
<blockquote><small>NOTE View definitions and implementation
agreements may restrict spaces with <i>CompositionType</i>=ELEMENT
to be non-overlapping.</small></blockquote>
<p>The following guidelines should apply for using the <i>Name</i>,
<i>Description</i>, <i>LongName</i> and <i>ObjectType</i>
attributes.</p>
<ul>
<li><i>Name</i> holds the unique name (or space number) from the
plan.</li>
<li><i>Description</i> holds any additional information field the
user may have specified, there are no further recommendations.</li>
<li><i>LongName</i> holds the full name of the space, it is often
used in addition to the <i>Name</i>, if a number is assigned to the
room, then the descriptive name is exchanged as
<i>LongName</i>.</li>
<li><i>ObjectType</i> holds the space type, i.e. usually the
functional category of the space .</li>
</ul>
<blockquote class="history">HISTORY New Entity in IFC Release 1.0</blockquote>
<p class="use-head">Property Set Use Definition</p>
<p>The property sets relating to the <i>IfcSpace</i> are defined by
the <i>IfcPropertySet</i> and attached by the
<i>IfcRelDefinesByProperties</i> relationship. It is accessible by
the inverse <i>IsDefinedBy</i> relationship. The following property
set definitions specific to the <i>IfcSpace</i> are part of this
IFC release:</p>
<ul>
<li><a href="../../psd/IfcProductExtension/Pset_SpaceCommon.xml"
target="SOURCE">Pset_SpaceCommon</a>: common property set for all
types of spaces
<ul>
<li><a href="../../psd/IfcProductExtension/Pset_SpaceParking.xml"
target="SOURCE">Pset_SpaceParking</a>: specific property set for
only those spaces that are used to define parking spaces by
<i>PredefinedType</i>: PARKING</li>
</ul>
</li>
<li><a href=
"../../psd/IfcProductExtension/Pset_SpaceFireSafetyRequirements.xml"
target="SOURCE">Pset_SpaceFireSafetyRequirements</a>: common
property set for all types of spaces to capture the fire safety
requirements</li>
<li><a href=
"../../psd/IfcProductExtension/Pset_SpaceLightingRequirements.xml"
target="SOURCE">Pset_SpaceLightingRequirements</a>: common property
set for all types of spaces to capture the lighting
requirements</li>
<li><a href=
"../../psd/IfcProductExtension/Pset_SpaceOccupancyRequirements.xml"
target="SOURCE">Pset_SpaceOccupancyRequirements</a>: common
property set for all types of spaces to capture the occupancy
requirements</li>
<li><a href=
"../../psd/IfcProductExtension/Pset_SpaceThermalRequirements.xml"
target="SOURCE">Pset_SpaceThermalRequirements</a>: common property
set for all types of spaces to capture the thermal
requirements</li>
<li><a href=
"../../psd/IfcSharedBldgServiceElements/Pset_SpaceThermalDesign.xml"
target="SOURCE">Pset_SpaceThermalDesign</a>: common property set
for all all types of spaces to capture building service design
values</li>
</ul>
<p class="use-head">Quantity Use Definition</p>
<p>The quantities relating to the <i>IfcSpace</i> are defined by
the <i>IfcElementQuantity</i> and attached by the
<i>IfcRelDefinesByProperties</i> relationship. It is accessible by
the inverse <i>IsDefinedBy</i> relationship. The following base
quantities are defined and should be exchanged with the
<i>IfcElementQuantity.Name</i> = 'BaseQuantities'. Other
quantities, being subjected to local standard of measurement, can
be defined with another string value assigned to <i>Name</i>. In
this case a valid value for <i>MethodOfMeasurement</i> has to be
provided.</p>
<ul>
<li><a href=
"../../qto/IfcProductExtension/Qto_SpaceBaseQuantities.xml" target=
"SOURCE">Qto_SpaceBaseQuantities</a>: base quantities for all space
occurrences.</li>
</ul>
<p class="use-head">Spatial Structure Use Definition</p>
<p>The <i>IfcSpace</i> is used to build the spatial structure of a
building (that serves as the primary project breakdown and is
required to be hierarchical). The spatial structure elements are
linked together by using the objectified relationship
<i>IfcRelAggregates</i>. The <i>IfcSpace</i> references them by its
inverse relationships:</p>
<ul>
<li><i>IfcSpace.Decomposes</i> -- referencing (<i>IfcSite</i> ||
<i>IfcBuildingStorey</i> || <i>IfcSpace</i>) by
<i>IfcRelAggregates.RelatingObject</i>, If it refers to another
instance of <i>IfcSpace</i>, the referenced <i>IfcSpace</i>
needs to have a different and higher <i>CompositionType</i>, i.e.
COMPLEX (if the other <i>IfcSpace</i> has ELEMENT), or ELEMENT (if
the other <i>IfcSpace</i> has PARTIAL).</li>
<li><i>IfcSpace.IsDecomposedBy</i> -- referencing (<i>IfcSpace</i>)
by <i>IfcRelAggregates.RelatedObjects</i>. If it refers to another
instance of <i>IfcSpace</i>, the referenced <i>IfcSpace</i> needs
to have a different and lower <i>CompositionType</i>, i.e. ELEMENT
(if the other <i>IfcSpace</i> has COMPLEX), or PARTIAL (if the
other <i>IfcSpace</i> has ELEMENT).</li>
</ul>
<p>If there are building elements and/or other elements directly
related to the <i>IfcSpace</i> (like most furniture and
distribution elements), they are associated with the
<i>IfcSpace</i> by using the objectified relationship
<i>IfcRelContainedInSpatialStructure</i>. The <i>IfcSpace</i>
references them by its inverse relationship:</p>
<ul>
<li><i>IfcSpace.ContainsElements</i> -- referencing any subtype of
<i>IfcProduct</i> (with the exception of other spatial structure
element) by
<i>IfcRelContainedInSpatialStructure.RelatedElements</i>.</li>
</ul>
<p>Figure 57 shows the <i>IfcSpace</i> as part of the spatial structure. It also serves as the spatial container for space related elements.</p>
<blockquote class="note">NOTE Detailed requirements on mandatory element containment and placement structure relationships are given in view definitions and implementer agreements.</blockquote>
<table summary="spatial structure" cellpadding="2" cellspacing="2">
<tr><td align="left" valign="top"><img src="figures/IfcSpace-SpatialStructure.png" alt="spatial structure" border="0" height="350" width="800"></td></tr>
<tr><td><p class="figure">Figure 57 — Space composition</p></td></tr>
</table>
<p class="use-head">Attribute Use Definition</p>
<p>Figure 58 describes the heights and elevations of the <i>IfcSpace</i>.</p>
<ul>
<li>elevation of the space (top of construction slab) equals elevation of storey: provided by <i>IfcBuildingStorey.Elevation</i> relative to <i>IfcBuilding.ElevationOfRefHeight</i></li>
<li>elevation of the space flooring (top of flooring on top of slab): provided by <i>IfcSpace.ElevationWithFlooring</i> relative to <i>IfcBuilding.ElevationOfRefHeight</i></li>
<li>height of space (top of slab below to bottom of slab above): provided by BaseQuantity with Name="Height"</li>
<li>floor height of space (top of slab below to top of flooring): provided by BaseQuantity with Name="FinishFloorHeight"</li>
<li>net height of space (top of flooring to bottom of suspended ceiling): provided by BaseQuantity with Name="FinishCeilingHeight"</li>
</ul>
<table summary="attributes" cellpadding="2" cellspacing="2">
<tr><td align="left" valign="top"><img src=
"figures/IfcSpace_Heights.png" alt="space heights" border="0"
height="400" width="450"></td></tr>
<tr><td><p class="figure">Figure 58 — Space elevations</p></td></tr>
</table>
<p class="use-head">Geometry Use Definition</p>
<p>The geometric representation of <i>IfcSpace</i> is given by the
<i>IfcProductDefinitionShape</i> and <i>IfcLocalPlacement</i>
allowing multiple geometric representations.</p>
<blockquote class="note">NOTE In cases of inconsistency between the
geometric representation of the <i>IfcSpace</i> and the combined
geometric representations of the surrounding
<i>IfcRelSpaceBoundary</i>, the geometric representation of the
space should take priority over the geometric representation of the
surrounding space boundaries.</blockquote>
<p><b>Local Placement</b></p>
<p>The local placement for <i>IfcSpace</i> is defined in its
supertype <i>IfcProduct</i>. It is defined by the
<i>IfcLocalPlacement</i>, which defines the local coordinate system
that is referenced by all geometric representations.</p>
<ul>
<li>The <i>PlacementRelTo</i> relationship of
<i>IfcLocalPlacement</i> shall point to the local placement of the
<i>IfcSpatialStructureElement</i> of type "IfcBuildingStorey", if
relative placement is used, or of type "IfcSpace" (e.g. to position
a space relative to a space group, or a partial space to a
space).</li>
<li>If the relative placement is not used, the absolute placement
is defined within the world coordinate system.</li>
</ul>
<p><b><i>Geometric Representations</i></b></p>
<p>Currently, the use of a 2D 'FootPrint' representation of type
'Curve2D' or 'GeometricCurveSet' and a 3D 'Body' representation of
type 'SweptSolid, 'Clipping' and 'Brep' is supported.</p>
<p><b>'Foot Print' Representation</b></p>
<p>The 2D geometric representation of <i>IfcSpace</i> is defined
using the 'Curve2D' or 'GeometricCurveSet' geometry. The following
attribute values should be inserted</p>
<ul>
<li><i>IfcShapeRepresentation.RepresentationIdentifier</i> =
'FootPrint'.</li>
<li><i>IfcShapeRepresentation.RepresentationType</i> = 'Curve2D' or
'GeometricCurveSet' .</li>
</ul>
<p>The following constraints apply to the 2D representation:</p>
<ul>
<li><u>Profile</u>: <i>IfcBoundedCurve</i> is required, using
<i>IfcPolyline</i> for faceted space contours or
<i>IfcCompositeCurve</i> for space contours with arc segments. For
spaces with inner boundaries, a set of <i>IfcBoundedCurve</i>'s is
used, that should be grouped into an
<i>IfcGeometricCurveSet</i>.</li>
</ul>
<p>Figure 59 shows a two-dimensional bounded curve representing the
foot print of <i>IfcSpace</i>.</p>
<table cellpadding="2" cellspacing="2">
<tr valign="top"><td align="left" valign="top"><img src="figures/IfcSpace_2D-Layout1.gif" alt="2d representation" border="0" height="300" width="400"></td></tr>
<tr><td><p class="figure">Figure 59 — Space footprint</p></td></tr>
</table>
<p><b>'Swept Solid' Representation</b></p>
<p>The standard geometric representation of <i>IfcSpace</i> is
defined using the swept area solid geometry. The following
attribute values should be inserted</p>
<ul>
<li><i>IfcShapeRepresentation.RepresentationIdentifier</i> =
'Body'.</li>
<li><i>IfcShapeRepresentation.RepresentationType</i> =
'SweptSolid'.</li>
</ul>
<p>The following constraints apply to the standard
representation:</p>
<ul>
<li><u>Solid</u>: <i>IfcExtrudedAreaSolid</i> is required,</li>
<li><u>Profile</u>: <i>IfcArbitraryClosedProfileDef</i> is
required, <i>IfcArbitraryProfileDefWithVoids</i> shall be
supported.</li>
<li><u>Extrusion</u>: The extrusion direction shall be vertically,
i.e., along the positive Z Axis of the co-ordinate system of the
containing spatial structure element.</li>
</ul>
<p>Figure 60 shows an extrusion of an arbitrary profile definition with voids into the swept area solid of <i>IfcSpace</i>.</p>
<table cellpadding="2" cellspacing="2">
<tr valign="top"><td align="left" valign="top"><img src=
"figures/IfcSpace_Standard-Layout1.gif" alt="fig1" border="0"
height="300" width="400"></td></tr>
<tr><td><p class="figure">Figure 60 — Space body swept solid</p></td></tr>
</table>
<p><b>'Clipping' representation</b></p>
<p>The advanced geometric representation of <i>IfcSpace</i> is
defined using the swept area solid geometry that can be subjected
to a Boolean expression. The following attribute values should be
inserted.</p>
<ul>
<li><i>IfcShapeRepresentation.RepresentationIdentifier</i> =
'Body'.</li>
<li><i>IfcShapeRepresentation.RepresentationType</i> =
'Clipping'.</li>
</ul>
<p>The following additional constraints apply to the advanced
representation:</p>
<ul>
<li><u>Solid</u>: see standard geometric representation,</li>
<li><u>Profile</u>: see standard geometric representation,</li>
<li><u>Extrusion</u>: see standard geometric representation,</li>
<li><u>Boolean result</u>: The difference operation with the second
operand being of type <i>IfcHalfSpaceSolid</i> (or one of its
subtypes) shall be supported.</li>
</ul>
<p>Figure 61 shows an extrusion of an arbitrary profile definition into the swept area solid. The solid and an half space solid are operands of the Boolean result of <i>IfcSpace</i>.</font></td>
<table cellpadding="2" cellspacing="2">
<tr valign="top"><td align="left" valign="top"><img src="figures/IfcSpace_Advanced-Layout1.gif" alt="fig2" border="0" height="300" width="400"></td></tr>
<tr><td><p class="figure">Figure 61 — Space body clipping</p></td></tr>
</table>
<p><b>'Brep' representation</b></p>
<p>The fallback advanced geometric representation of
<i>IfcSpace</i> is defined using the Brep solid geometry. may
be represented as a single or multiple instances of
<i>IfcFacetedBrep</i> or <i>IfcFacetedBrepWithVoids</i>. The Brep
representation allows for the representation of complex element
shape. The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric representation
shall be used:</p>
<ul>
<li><i>IfcShapeRepresentation.</i><i>RepresentationIdentifier</i> :
'Body'</li>
<li><i>IfcShapeRepresentation.</i><i>RepresentationType</i> :
'Brep'</li>
</ul>
</EPM-HTML> |
| 67 | 501 | IfcSpatialStructureElement | <EPM-HTML>
<p>A spatial structure element
(<i>IfcSpatialStructureElement</i>) is the generalization of all
spatial elements that might be used to define a spatial
structure. That spatial structure is often used to provide a
project structure to organize a building project.</p>
<p>A spatial project structure might define as many levels of
decomposition as necessary for the building project. Elements
within the spatial project structure are:</p>
<ul>
<li>site as <i>IfcSite</i></li>
<li>building as <i>IfcBuilding</i></li>
<li>storey as <i>IfcBuildingStorey</i></li>
<li>space as <i>IfcSpace</i></li>
</ul>
<p>or aggregations or parts thereof. The composition type
declares an element to be either an element itself, or an
aggregation (complex) or a decomposition (part). The
interpretation of these types is given at each subtype of
<i>IfcSpatialStructureElement</i>.</p>
<p>The <i>IfcRelAggregates</i> is defined as an 1-to-many
relationship and used to establish the relationship between
exactly two levels within the spatial project structure. Finally
the highest level of the spatial structure is assigned to
<i>IfcProject</i> using the <i>IfcRelAggregates</i>.</p>
<p><u>Informal proposition</u>:</p>
<ol>
<li>The spatial project structure, established by the
<i>IfcRelAggregates</i>, shall be acyclic.</li>
<li>A site should not be (directly or indirectly) associated to a
building, storey or space.</li>
<li>A building should not be (directly or indirectly) associated
to a storey or space.</li>
<li>A storey should not be (directly or indirectly) associated to
a space.</li>
</ol>
<blockquote class="history">HISTORY New entity in IFC Release 2x.</blockquote>
<p class="use-head">Relationship Use Definition</p>
<p>The subtypes of <i>IfcSpatialStructureElement</i> relate to
other elements and systems by establishing the following
relationships:</p>
<ul>
<li><b>Containment of elements</b> :
<i>IfcRelContainedInSpatialStructure</i> by inverse attribute
<i>ContainsElements</i>, used to assign any element, like
building elements, MEP elements, etc. to the spatial structure
element in which they are primarily contained.
<ul>
<li style="list-style-type=none"><small>NOTE This relationship is
mandatory for elements in several view definitions and
implementer agreements.</small></li>
</ul>
</li>
<li><b>Reference of elements</b> :
<i>IfcRelReferencedInSpatialStructure</i> by inverse attribute
<i>ReferencesElements</i>, used to reference any element, like
building elements, MEP elements, etc. in spatial structure
elements, other then the one, where it is contained.</li>
<li><b>Reference of systems</b> : <i>IfcRelServicesBuildings</i>
by inverse attribute <i>ServicedBySystems</i>, used to reference
a sytem, like a building service or electrical distribution
system, a zonal system, or a structural analysis system, that is
assigned to this spatial structure element.
<ul>
<li style="list-style-type=none"><small>NOTE Elements within the
referenced system may be directly contained (or referenced) by
other spatial structure elements.</small></li>
</ul>
</li>
</ul>
<p>The subtypes of <i>IfcSpatialStructureElement</i> relate to
each other by using the <i>IfcRelAggregates</i> relationship to
build the project spatial structure.</p>
<p>Figure 62 shows the use of <i>IfcRelAggregates</i> to establish a spatial structure including site, building, building section and storey. More information is provided at the level of the subtypes.</p>
<table cellpadding="2" cellspacing="2" summary="spatial structure">
<tr valign="top"><td align="left" valign="top"><img src=
"figures/IfcSpatialStructureElement-SpatialStructure.png" alt="fig1" border="0" height="701" width="551"></td></tr>
<tr><td><p class="figure">Figure 62 — Spatial structure element composition</p></td></tr>
</table>
</EPM-HTML> |
| 68 | 509 | IfcSpatialElement | <EPM-HTML>
<p>
<u>Definition from IAI</u>: A spatial element is the
generalization of all spatial elements that might be used
to define a spatial structure or to define spatial zones.
</p>
<ul>
<li>a hierarchical spatial structure element as
<i>IfcSpatialStructureElement</i>
<ul>
<li>a spatial structure is a hiearchical decomposition
of the project. That spatial structure is often used to
provide a project structure to organize a building
project.
</li>
<li>A spatial project structure might define as many
levels of decomposition as necessary for the building
project. Elements within the spatial project structure
are site, building, storey, and space
</li>
</ul>
</li>
<li>a spatial zone as <i>IfcSpatialZone</i>
<ul>
<li>a spatial zone is a non-hierarchical and
potentially overlapping decomposition of the project
under some functional consideration.
</li>
<li>a spatial zone might be used to represent a thermal
zone, a lighting zone, a usable area zone.
</li>
<li>a spatial zone might have its independent placement
and shape representation.
</li>
</ul>
</li>
</ul>
<blockquote>
<small><font color="#0000FF">HISTORY New entity in IFC
Release 2x Edition 4.</font></small>
</blockquote>
</EPM-HTML> |
| 69 | 516 | IfcElement | <EPM-HTML>
<p><u>Definition from IAI</u>: Generalization of all components
that make up an AEC product. Those elements can be logically
contained by a spatial structure element that constitutes a
certain level within a project structure hierarchy (e.g., site,
building, storey or space). This is done by using the
<i>IfcRelContainedInSpatialStructure</i> relationship.</p>
<p>Elements are physically existent objects, although they might
be void elements, such as holes. Elements either remain
permanently in the AEC product, or only temporarily, as formwork
does. Elements can be either assembled on site or
pre-manufactured and built in on site.</p>
<blockquote><small>EXAMPLEs of elements in a building
construction context are walls, floors, windows and
recesses.</small></blockquote>
<p>An element can have material and quantity information assigned
through the <i>IfcRelAssociatesMaterial</i> and
<i>IfcRelDefinesByProperties</i> relationship.</p>
<p>In addition an element can be declared to be a specific
occurrence of an element type (and thereby be defined by the
element type properties) using the <i>IfcRelDefinesByType</i>
relationship.</p>
<p>An element can also be defined as an element assembly that is
a group of semantically and topologically related elements that
form a higher level part of the AEC product. Those element
assemblies are defined by virtue of the <i>IfcRelAggregates</i>
relationship.</p>
<blockquote><font size="-1">EXAMPLEs for element assembly are
complete Roof Structures, made by several Roof Areas, or a Stair,
composed by Flights and Landings.</font></blockquote>
<p>Elements that performs the same function may be grouped by an
"Element Group By Function". It is realized by an instance of
<i>IfcGroup</i> with the <i>ObjectType</i> =
'ElementGroupByFunction".</p>
<blockquote><small><font color="#0000FF">HISTORY New entity in
IFC Release 1.0</font></small></blockquote>
<p><u><b>Property Set Use Definition</b></u>:</p>
<p>The property sets relating to the <i>IfcElement</i> are
defined by the <i>IfcPropertySet</i> and attached by the
<i>IfcRelDefinesByProperties</i> relationship. It is accessible
by the inverse <i>IsDefinedBy</i> relationship.</p>
<p><u><b>Quantity Use Definition</b></u>:</p>
<p>The quantities relating to the <i>IfcElement</i> are defined
by the <i>IfcElementQuantity</i> and attached by the
<i>IfcRelDefinesByProperties</i>. A detailed specification for
individual quantities is introduced at the level of subtypes of
<i>IfcElement</i>.</p>
<p><u><b>Geometry Use Definitions</b></u></p>
<p>The geometric representation of any <i>IfcElement</i> is given
by the <i>IfcProductDefinitionShape</i> and
<i>IfcLocalPlacement</i> allowing multiple geometric
representations. A detailed specification for the local placement
and shape representaion is introduced at the level of subtypes of
<i>IfcElement</i>.</p>
</EPM-HTML> |
| 70 | 537 | IfcBuildingElement | <EPM-HTML>
<p><u>Definition from ISO 6707-1:1989</u>: Major functional part
of a building, examples are foundation, floor, roof, wall.</p>
<p>The building element comprises all
elements that are primarily part of the construction of a
building, i.e., its structural and space separating system.</p>
<blockquote><small>EXAMPLEs of building elements are walls,
beams, or doors, they are all physically existent and tangible
things.</small></blockquote>
<p>The <i>IfcBuildingElement</i> utilizes the following
capabilities mainly through inverse attributes referencing
objectified relationships:</p>
<blockquote><small>NOTE View definitions and implementer
agreements will determine those relationships that have to be
supported in actual exchange.</small></blockquote>
<ol>
<li>Grouping - being part of a logical group of objects
<ul>
<li>objectified relationship: <i>IfcRelAssignsToGroup</i></li>
<li>object referenced by relationship: <i>IfcGroup</i> (and
subtypes)</li>
<li>inverse attribute: <i>HasAssignment</i></li>
</ul>
</li>
<li>Work processes - reference to work tasks, in which this
building element is used
<ul>
<li>objectified relationship: <i>IfcRelAssignsToProcess</i></li>
<li>object referenced by relationship: <i>IfcProcess</i> (and
subtypes)</li>
<li>inverse attribute: <i>HasAssignments</i></li>
</ul>
</li>
<li>Structural member reference - information whether the
building element is represented in a structural analysis model by
a structural member
<ul>
<li>objectified relationship: <i>IfcRelAssignsToProduct</i></li>
<li>object referenced by relationship: <i>IfcStructuralMember</i>
(and by default <i>IfcStructuralCurveMember</i>)</li>
<li>inverse attribute: <i>HasAssignments</i></li>
</ul>
</li>
<li>Aggregation - aggregated together with other elements to form
an aggregate
<ul>
<li>objectified relationship: <i>IfcRelAggregates</i></li>
<li>object referenced by relationship: <i>IfcElement</i> (and
subtypes)</li>
<li>inverse attribute (for container): <i>IsDecomposedBy</i></li>
<li>inverse attribute (for contained parts):
<i>Decomposes</i></li>
</ul>
</li>
<li>Material - assignment of material used by this building
element
<ul>
<li>objectified relationship:
<i>IfcRelAssociatesMaterial</i></li>
<li>object referenced by relationship: <i>IfcMaterialSelect</i>
(and selected items)</li>
<li>inverse attribute: <i>HasAssociations</i></li>
</ul>
</li>
<li>Classification - assigned reference to an external
classification
<ul>
<li>objectified relationship:
<i>IfcRelAssociatesClassification</i></li>
<li>object referenced by relationship:
<i>IfcClassificationNotationSelect</i> (and selected items,
default <i>IfcClassificationReference</i>)</li>
<li>inverse attribute: <i>HasAssociations</i></li>
</ul>
</li>
<li>Library - assigned reference to an external library item
reference
<ul>
<li>objectified relationship:
<i>IfcRelAssociatesClassification</i></li>
<li>object referenced by relationship: <i>IfcLibrarySelect</i>
(and selected items, default <i>IfcLibraryReference</i>)</li>
<li>inverse attribute: <i>HasAssociations</i></li>
</ul>
</li>
<li>Documentation - assigned reference to an external
documentation
<ul>
<li>objectified relationship:
<i>IfcRelAssociatesDocumentation</i></li>
<li>object referenced by relationship: <i>IfcDocumentSelect</i>
(and selected items, default <i>IfcDocumentReference</i>)</li>
<li>inverse attribute: <i>HasAssociations</i></li>
</ul>
</li>
<li>Type - reference to the common product type information for
the element occurrence
<ul>
<li>objectified relationship: <i>IfcRelDefinesByType</i></li>
<li>object referenced by relationship:
<i>IfcBuildingElementType</i> (and subtypes)</li>
<li>inverse attribute: <font color=
"#0000FF"><i>IsTypedBy</i></font></li>
</ul>
</li>
<li>Properties - reference to all attached properties, including
quantities
<ul>
<li>objectified relationship:
<i>IfcRelDefinesByProperties</i></li>
<li>object referenced by relationship:
<i>IfcPropertySetDefinition</i> (default
<i>IfcPropertySet</i>)</li>
<li>inverse attribute: <i>IsDefinedBy</i></li>
</ul>
</li>
<li>Connection - connectivity to other elements, including the
definition of the joint
<ul>
<li>objectified relationship: <i>IfcRelConnectsElements</i></li>
<li>object referenced by relationship: <i>IfcElement</i></li>
<li>inverse attribute: <i>ConnectedTo</i></li>
<li>inverse attribute: <i>ConnectedFrom</i></li>
</ul>
</li>
<li>Realization - information, whether the building element is
used to realize a connection (e.g. as a weld in a connection
between two members)
<ul>
<li>objectified relationship:
<i>IfcRelConnectsWithRealizingElements</i></li>
<li>object referenced by relationship: <i>IfcElement</i></li>
<li>inverse attribute: <i>IsConnectionRealization</i></li>
</ul>
</li>
<li>Assignment to spatial structure - hierarchical assignment to
the right level within the spatial structure
<ul>
<li>objectified relationship:
<i>IfcRelContainedInSpatialStructure</i></li>
<li>object referenced by relationship:
<i>IfcSpatialStructureElement</i></li>
<li>inverse attribute: <i>ContainedInStructure</i></li>
</ul>
</li>
<li>Reference to spatial structure(s) - non hierarchical
reference to one or more elements within the spatial structure
(e.g. a curtain wall, being contained in the building, references
several stories)
<ul>
<li>objectified relationship:
<i>IfcRelContainedInSpatialStructure</i></li>
<li>object referenced by relationship:
<i>IfcSpatialElement</i></li>
<li>inverse attribute: <i>ContainedInStructure</i></li>
</ul>
</li>
<li>Boundary - provision of space boundaries by this building
element
<ul>
<li>objectified relationship: <i>IfcRelSpaceBoundary</i></li>
<li>object referenced by relationship: <i>IfcSpace</i></li>
<li>inverse attribute: <i>ProvidesBoundaries</i></li>
</ul>
</li>
<li>Coverings - assignment of covering elements to this building
element (note: normally covering elements are assigned to the
space, only used for special cases)
<ul>
<li>objectified relationship:
<i>IfcRelCoversBldgElements</i></li>
<li>object referenced by relationship: <i>IfcCovering</i></li>
<li>inverse attribute: <i>HasCoverings</i></li>
</ul>
</li>
<li>Voids - information, whether the building element includes
openings, recesses or other voids
<ul>
<li>objectified relationship: <i>IfcRelVoidsElement</i></li>
<li>object referenced by relationship:
<i>IfcFeatureElementSubtraction</i> (default
<i>IfcOpeningElement</i>)</li>
<li>inverse attribute: <i>HasOpenings</i></li>
</ul>
</li>
<li>Projection - information, whether the building element has
projections (such as a fascia)
<ul>
<li>objectified relationship: <i>IfcRelProjectsElement</i></li>
<li>object referenced by relationship:
<i>IfcFeatureElementAddition</i> (default
<i>IfcProjectionElement</i>)</li>
<li>inverse attribute: <i>HasProjections</i></li>
</ul>
</li>
<li>Filling - information whether the building element is used to
fill openings
<ul>
<li>objectified relationship: <i>IfcRelFillsElement</i></li>
<li>object referenced by relationship:
<i>IfcOpeningElement</i></li>
<li>inverse attribute: <i>FillsVoids</i></li>
</ul>
</li>
</ol>
<blockquote class="history">HISTORY New entity in IFC Release 1.0</blockquote>
<p class="use-head">Property Set Use Definition</p>
<p>The properties relating to the <i>IfcBuildingElement</i> are
defined by the <i>IfcPropertySet</i> and attached by the
<i>IfcRelDefinesByProperties</i>. A detailed specification for
individual property sets applicable is introduced at the level of
subtypes of <i>IfcBuildingElement</i>.</p>
<blockquote><small>NOTE The applicable property sets are provided
by an xml property set definition that includes multilingual
translations for each property. The xml definition file format,
psdXML, can be used to automatically configure the properties for
each building element.</small></blockquote>
<p><u><b>Quantity Use Definition</b></u>:</p>
<p>The quantities relating to the <i>IfcBuildingElement</i> are
defined by the <i>IfcElementQuantity</i> and attached by the
<i>IfcRelDefinesByProperties</i>. A detailed specification for
individual quantities is introduced at the level of subtypes of
<i>IfcBuildingElement</i>.</p>
<blockquote><small>NOTE The applicable element quantities are
provided by an xml quantity definition that includes multilingual
translations for each quantity. The xml definition file format,
qdXML, can be used to automatically configure the quantities for
each building element.</small></blockquote>
<p class="use-head">Geometry Use Definitions</p>
<p>The geometric representation of any <i>IfcBuildingElement</i>
is given by the <i>IfcProductDefinitionShape</i> and
<i>IfcLocalPlacement</i> allowing multiple geometric
representations.</p>
<p><b>Local Placement</b></p>
<p>The local placement for any <i>IfcBuildingElement</i> is
defined in its supertype <i>IfcProduct</i>. It is defined by the
<i>IfcLocalPlacement</i>, which defines the local coordinate
system that is referenced by all geometric representations.
Further constraints are defined at the level of its subtypes.</p>
<p><b><i>Geometric Representations</i></b></p>
<p>An <i>IfcBuildingElement</i> can be represented by one or
several geometric representations. The following representation
identifiers are used for building elements 'Box', 'Axis',
'FootPrint', 'Surface', and 'Body'. A detailed specification is
introduced at the level of subtypes.</p>
<blockquote><small>NOTE Some subtypes of
<i>IfcBuildingElement</i> may exclude one or several geometric
representation types, e.g. standard case elements, such as
<i>IfcWallStandardCase</i>, do not allow the use of
'SurfaceModel', 'Brep', 'AdvancedBrep', and
'MappedRepresentation'. In addition view definitions and
implementer agreements may restrict the use of geometric
representation types, e.g. the use of
'AdvancedBrep'.</small></blockquote>
<p><b>Box Representation</b></p>
<p>Any <i>IfcBuildingElement</i> may be represented as a bounding
box, which shows the maximum extend of the body within the
coordinated system established by the <i>IfcLocalPlacement</i>.
The bounding box representation is the simplest geometric
representation available. The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Box'</li>
<li><i>RepresentationType</i> : 'BoundingBox'</li>
</ul>
<p>As shown in Figure 22, the bounding box representation is given by an
<i>IfcShapeRepresentation</i> that includes a single item, an
<i>IfcBoundingBox</i>.</p>
<table>
<tbody>
<tr valign="top">
<td align="left" valign="top"><img src=
"figures/IfcBuildingElement-BoundingBox-Layout1.gif" alt=
"bounding box" border="0" height="275" width="400"></td>
<td align="left" valign="top">
</td></tr>
<tr><td><p class="figure">Figure 22 — Building element box representation</p></td></tr>
</tbody>
</table>
<p><b>Axis Representation</b></p>
<p>Some <i>IfcBuildingElement</i> may be represented by an axis
as an abstract geometric representation. See each subtype for
specific guidance. The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric
representation are used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Axis'</li>
<li><i>RepresentationType</i> : 'Curve2D', 'Curve3D'</li>
</ul>
<p><b>Surface Representation</b></p>
<p>Some <i>IfcBuildingElement</i> may be represented by an
surface as an abstract geometric representation. See each subtype
for specific guidance. The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric
representation are used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Surface'</li>
<li><i>RepresentationType</i> : 'Surface2D', 'Surface3D'</li>
</ul>
<p><b>FootPrint Representation</b></p>
<p>Any <i>IfcBuildingElement</i> may be represented by a
footprint as a specific floor plan geometric representation. See
each subtype for specific guidance. The following attribute
values for the <i>IfcShapeRepresentation</i> holding this
geometric representation are used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'FootPrint'</li>
<li><i>RepresentationType</i> : 'GeometricCurveSet',
'Annotation2D'</li>
</ul>
<p><b>Body Representation</b></p>
<p>The body representation of any <i>IfcBuildingElement</i> can
have the following representation types: 'SurfaceModel', 'Brep',
'AdvancedBrep', and 'MappedRepresentation'. Other representation
types might be specified at the level of subtypes.</p>
<p><i>SurfaceModel Representation Type</i></p>
<p>Any <i>IfcBuildingElement</i> (so far no further constraints
are defined at the level of its subtypes) may be represented as a
single or multiple surface models, based on either shell or face
based models. The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'SurfaceModel'</li>
</ul>
<p>In some cases it may be useful to also expose a simple
representation as a bounding box representation of the same
complex shape.</p>
<p>As shown in Figure 23, the surface model representation is given by an <i>IfcShapeRepresentation</i>, which includes a single item which is either:</p>
<ul>
<li><i>IfcShellBasedSurfaceModel</i>, or</li>
<li><i>IfcFaceBasedSurfaceModel</i>.</li>
</ul>
<table>
<tbody>
<tr valign="top"><td align="left" valign="top"><img src="figures/IfcBuildingElement-SurfaceModel-Layout1.gif" alt="bounding box" border="0" height="275" width="400"></td></tr>
<tr><td><p class="figure">Figure 23 — Building element surface model representation</p></td></tr>
</tbody>
</table>
<p><i>Brep Representation Type</i></p>
<p>Any <i>IfcBuildingElement</i> (so far no further constraints
are defined at the level of its subtypes) may be represented as a
single or multiple Boundary Representation elements (which are
restricted to faceted Brep with or without voids). The Brep
representation allows for the representation of complex element
shape. The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'Brep'</li>
</ul>
<p>In some cases it may be useful to also expose a simple
representation as a bounding box representation of the same
complex shape.</p>
<p>As shown in Figure 24, the Brep representation is given by an <small>IfcShapeRepresentation</small>, which includes one or more items, all of type <i>IfcFacetedBrep</i>.</p>
<table cellpadding="2" cellspacing="2">
<tbody>
<tr valign="top"><td align="left" valign="top"><img src="figures/IfcBuildingElement-BRep-Layout1.gif" alt="Brep representation" border="0" height="275" width="400"></td></tr>
<tr><td><p class="figure">Figure 24 — Building element body boundary representation</p></td></tr>
</tbody>
</table>
<p><i>AdvancedBrep Representation Type</i></p>
<p>An <i>IfcBuildingElement</i> (so far no further constraints
are defined at the level of its subtypes or by view definitions)
may be represented as a single or multiple Boundary
Representation elements (which are based on advanced surfaces,
usually refered to as NURBS surfaces). The AdvancedBrep
representation allows for the representation of complex free-form
element shape. The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'AdvancedBrep'</li>
</ul>
<p>In some cases it may be useful to also expose a simple
representation as a bounding box representation of the same
complex shape.</p>
<p><i>MappedRepresentation Representation Type</i></p>
<p>Any <i>IfcBuildingElement</i> (so far no further constraints
are defined at the level of its subtypes) may be represented
using the MappedRepresentation. This shall be supported as it
allows for reusing the geometry definition of a type at all
occurrences of the same type. The following attribute values for
the <i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'MappedRepresentation'</li>
</ul>
<p>The same constraints, as given for 'SurfaceModel', 'Brep', and
'AdvancedBrep' geometric representation, shall apply to the
<i>MappedRepresentation</i> of the
<i>IfcRepresentationMap</i>.</p>
</EPM-HTML> |
| 71 | 540 | IfcFurnishingElement | <EPM-HTML>
<p><u>Definition from IAI</u>: Generalization of all furniture
related objects. Furnishing objects are characterized as
being</p>
<ul>
<li>pre-manufactured and assembled on-site, or</li>
<li>manufactured on-site (built-in)</li>
</ul>
<p>Thus furnishing elements can either be movable, or not (as the
built-ins).</p>
<blockquote><small><font color="#0000FF">HISTORY New entity in
IFC Release 2x.</font></small><br>
<small><font color="#FF0000">IFC2x4 CHANGE The entity is marked
as deprecated for instantiation - will be made ABSTRACT after
IFC2x4.</font></small></blockquote>
<p><u><b>Geometry Use Definitions</b></u>:</p>
<p>The geometric representation of <i>IfcFurnishingElement</i> is
given by the <i>IfcProductDefinitionShape</i> and
<i>IfcLocalPlacement</i> allowing multiple geometric
representation.</p>
<p><b>Local Placement</b></p>
<p>The local placement for <i>IfcFurnishingElement</i> is defined
in its supertype <i>IfcProduct</i>. It is defined by the
<i>IfcLocalPlacement</i>, which defines the local coordinate
system that is referenced by all geometric representations.</p>
<ul>
<li>The <i>PlacementRelTo</i> relationship of
<i>IfcLocalPlacement</i> shall point (if given) to the local
placement of the same <i>IfcSpatialStructureElement</i> , which
is used in the <i>ContainedInStructure</i> inverse attribute, or
to a spatial structure element at a higher level, referenced by
that.</li>
<li>If the relative placement is not used, the absolute placement
is defined within the world coordinate system.</li>
</ul>
<p><b><i>Geometric Representations</i></b></p>
<p>Any <i>IfcFurnishingElement</i> can be represented by one or
several geometric representations. This includes the general
representation types 'BoundingBox', 'GeometricCurveSet',
'SurfaceModel', 'Brep', and 'MappedRepresentation' being defined
here.</p>
<p><b>Bounding Box Representation</b></p>
<p>Any <i>IfcFurnishingElement</i> may be represented as a
bounding box, which shows the maximum extend of the body within
the coordinated system established by the
<i>IfcLocalPlacement</i>. The bounding box representation is the
simplest geometric representation available. The following
attribute values for the <i>IfcShapeRepresentation</i> holding
this geometric representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Box'</li>
<li><i>RepresentationType</i> : 'BoundingBox'</li>
</ul>
<p><b>Foot Print Representation</b></p>
<p>The foot print representation of <i>IfcFurnishingElement</i>
is given by either a single or multiple 2D points and curves. The
representation identifier and type of this geometric
representation are:</p>
<ul>
<li><i>IfcShapeRepresentation.RepresentationIdentifier</i> =
'FootPrint'</li>
<li><i>IfcShapeRepresentation.RepresentationType</i> =
'GeometricCurveSet'</li>
</ul>
<p><b>SurfaceModel Representation</b></p>
<p>Any <i>IfcFurnishingElement</i> (so far no further constraints
are defined at the level of its subtypes) may be represented as a
single or multiple surface models, based on either shell or face
based models. In some cases it may be useful to also expose a
simple representation as a bounding box representation of the
same complex shape. The representation identifier and type of
this geometric representation are:</p>
<ul>
<li><i>IfcShapeRepresentation.RepresentationIdentifier</i> =
'Body'</li>
<li><i>IfcShapeRepresentation.RepresentationType</i> =
'SurfaceModel'</li>
</ul>
<p><b>Brep Representation</b></p>
<p>Any <i>IfcFurnishingElement</i> (so far no further constraints
are defined at the level of its subtypes) may be represented as a
single or multiple Boundary Representation elements (which are
restricted to faceted Brep with or without voids). The Brep
representation allows for the representation of complex element
shape. In some cases it may be useful to also expose a simple
representation as a bounding box representation of the same
complex shape. The representation identifier and type of this
geometric representation are:</p>
<ul>
<li><i>IfcShapeRepresentation.RepresentationIdentifier</i> =
'Body'</li>
<li><i>IfcShapeRepresentation.RepresentationType</i> =
'Brep'</li>
</ul>
<p><b>MappedRepresentation</b></p>
<p>The <i>IfcMappedItem</i> should always be used in appropriate
cases as it allows for reusing the geometry definition of the
furnishing type for all occurrences of the same type. The
representation identifier and type of this geometric
representation are:</p>
<ul>
<li><i>IfcShapeRepresentation.RepresentationIdentifier</i> =
'FootPrint', or 'Body' (depending of the representation map)</li>
<li><i>IfcShapeRepresentation.RepresentationType</i> =
'MappedRepresentation'</li>
</ul>
</EPM-HTML> |
| 72 | 541 | IfcDistributionElement | <EPM-HTML>
<p><u>Definition from IAI</u>: Generalization of all elements
that participate in a distribution system. Typical examples of
<i>IfcDistributionElement</i> are (among others):</p>
<ul>
<li>building service elements within a heating systems</li>
<li>building service elements within a cooling system</li>
<li>building service elements within a ventilation system</li>
<li>building service elements within a plumbing system
<ul>
<li>e.g. sanitary elements, fire suppression elements</li>
</ul>
</li>
<li>electrical elements</li>
<li>elements within a communication network</li>
</ul>
<p>The <i>IfcDistributionElement</i> is further specialized in
the IFC model. Direct instantiation of
<i>IfcDistributionElement</i> without an assigned subtype of
<i>IfcDistributionElementType</i> provides the meaning of an
distribution element proxy.</p>
<blockquote><small><font color="#0000FF">HISTORY New entity in
IFC Release 1.5.</font></small><br>
<small><font color="#FF0000">IFC2x4 CHANGE The entity is marked
as deprecated for instantiation - will be made ABSTRACT after
IFC2x4.</font></small></blockquote>
<p><b><u>Relationship Use Definition</u></b></p>
<ol>
<li>Ports - information, whether the distribution element has
ports for system connections
<ul>
<li>objectified relationship:
<i>IfcRelConnectsPortToElement</i></li>
<li>object referenced by relationship: <i>IfcPort</i></li>
<li>inverse attribute: <i>HasPorts</i></li>
</ul>
</li>
</ol>
<p><b><u>Type Use Definition</u></b></p>
<p>The <i>IfcDistributionElement</i> defines the occurrence of
any HVAC, electrical, sanitary or other element within a
distribution system. Common information about distribution
element types (or styles) is handled by subtypes of
<i>IfcDistributionElementType</i>. The
<i>IfcDistributionElementType</i> (if present) may establish the
common type name, usage (or predefined) type, common material,
common set of properties and common shape representations (using
<i>IfcRepresentationMap</i>). The
<i>IfcDistributionElementType</i> is attached using the
<i>IfcRelDefinedByType.RelatingType</i> objectified relationship
and is accessible by the inverse <i>IsDefinedBy</i>
attribute.</p>
<p>The assignment of types to distribution element occurrences is
vital for providing the additional meaning, or ontology, of the
distribution element. Many specialized type are defined in other
schemas of the IFC specification.</p>
<p><b><u>Quantity Use Definition</u></b></p>
<p>The quantities relating to the <i>IfcDistributionElement</i>
are defined by the <i>IfcElementQuantity</i> and attached by the
<i>IfcRelDefinesByProperties</i>. A detailed specification for
individual quantities is introduced at the level of subtypes of
<i>IfcDistributionElement</i>.</p>
<p><u><b>Containment Use Definition</b></u></p>
<p>The <i>IfcDistributionElement</i> may participate in two
different containment relationships. The first (and in most
implementation scenarios mandatory) relationship is the
hierachical spatial containment, the second (optional)
relationship is the aggregation within anelement assembly.</p>
<ul>
<li>The <i>IfcDistributionElement</i> is places within the
project spatial hierarchy using the objectified relationship
<i>IfcRelContainedInSpatialStructure</i>, referring to it by its
inverse attribute <i>SELF\IfcElement.ContainedInStructure</i>.
Subtypes of<i>IfcSpatialStructureElement</i> are valid spatial
containers, with <i>IfcSpace</i> being the default
container.</li>
<li>The <i>IfcDistributionElement</i> may be aggregated into an
element assembly using the objectified relationship
<i>IfcRelAggregates</i>, referring to it by its inverse attribute
<i>SELF\IfcObjectDefinition.Decomposes</i>. Any subtype of
<i>IfcElement</i> can be an element assembly, with
<i>IfcElementAssembly</i> as a special focus subtype. In this
case it should not be additionally contained in the project
spatial hierarchy,
i.e.<i>SELF\IfcElement.ContainedInStructure</i> should be
<i>NIL.</i></li>
</ul>
<p><b><u>Geometry Use Definitions</u></b></p>
<p>The geometric representation of <i>IfcDistributionElement</i>
is given by the <i>IfcProductDefinitionShape</i>, allowing
multiple geometric representation.</p>
<p><b>Local Placement</b></p>
<p>The local placement for <i>IfcDistributionElement</i> is
defined in its supertype <i>IfcProduct</i>. It is defined by the
<i>IfcLocalPlacement</i>, which defines the local coordinate
system that is referenced by all geometric representations.</p>
<ul>
<li>The <i>PlacementRelTo</i> relationship of
<i>IfcLocalPlacement</i> shall point (if given) to the local
placement of the same <i>IfcSpatialStructureElement</i> , which
is used in the <i>ContainedInStructure</i> inverse attribute, or
to a spatial structure element at a higher level, referenced by
that.</li>
<li>If the relative placement is not used, the absolute placement
is defined within the world coordinate system.</li>
</ul>
<p><b>Geometric Representations</b></p>
<p>The geometric representation of <i>IfcDistributionElement</i>
is defined using different geometric representation types for the
various subtypes. Only general recommendations are given at the
level of the supertype, further constraints are defined at the
level of its subtypes.</p>
<ul>
<li>all occurrences of <i>IfcDistributionElement</i> (and its
subtypes) should (whenever possible) share a representation map
established by the assigned type. The geometric representation of
the occurrence is then an <i>IfcMappedItem</i>. The
<i>IfcShapeRepresentation</i> has:
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'MappedRepresentation'</li>
</ul>
</li>
</ul>
<p>The shared geometric representation of the distribution
element type (or in some cases of the distribution element)
should follow (if applicable) the the following guidelines:</p>
<ul>
<li>all fixtures (all non distribution flow elements, i.e.
everything which is not a duct, a pipe, a cable, or a cable
carrier) should be defined by an b-rep geometry. This includes
also the complex flow fitting elements (e.g. Y branch or T
branch) or distribution flow elements with size changes (e.g.
reducer). The <i>IfcShapeRepresentation</i> has:
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'Brep'<br>
<br></li>
</ul>
</li>
<li>if the geometric model consistency of a b-rep shape
representation can not be guaranteed (arcwise connected volume
bounded by faces, each being connected, oriented, finite, closed
2-manifold), a surface representation based on open shells should
be used. The <i>IfcShapeRepresentation</i> then has:
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'SurfaceModel'<br>
<br></li>
</ul>
</li>
<li>all "simple" distribution flow elements (general ducts and
pipes) are defined by sweep geometry. The
<i>IfcShapeRepresentation</i> has:
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'SweptSolid'<br>
<br></li>
</ul>
</li>
<li>an additional representation type for all "simple"
distribution flow elements (general ducts and pipes) is the
ability to have a simple line based representation. The
<i>IfcShapeRepresentation</i> has:
<ul>
<li><i>RepresentationIdentifier</i> : 'FootPrint'</li>
<li><i>RepresentationType</i> : 'GeometricCurveSet'<br>
<br></li>
</ul>
</li>
<li>if only the analytical shape is required for which the exact
interpolation between the cross sections is not required, a
sectioned spine can be used.
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'SectionedSpine'<br></li>
</ul>
</li>
</ul>
</EPM-HTML> |
| 73 | 545 | IfcDistributionElementType | <EPM-HTML>
<p><u>Definition from IAI</u>: The
<i>IfcDistributionElementType</i> defines a list of commonly
shared property set definitions of an element and an optional set
of product representations. It is used to define an element
specification (i.e. the specific product information, that is
common to all occurrences of that product type).</p>
<blockquote><small>NOTE The product representations are defined
as representation maps (at the level of the supertype
<i>IfcTypeProduct</i>, which gets assigned by an element
occurrence instance through the
<i>IfcShapeRepresentation.Item[1]</i> being an
<i>IfcMappedItem</i>.</small></blockquote>
<p>A distribution element type is used to define the common
properties of a certain type of a distribution element that may
be applied to many instances of that feature type to assign a
specific style. Distribution element types (or the instantiable
subtypes) may be exchanged without being already assigned to
occurrences.</p>
<p>The occurrences of the <i>IfcDistributionElementType</i> are
represented by instances of <i>IfcDistributionElement</i> (or its
subtypes).</p>
<blockquote><small><font color="#0000FF">HISTORY New entity in
Release IFC2x Edition 2.</font><br>
<font color="#FF0000">IFC2x3 CHANGE The entity has been made
non-abstract</font></small><br>
<small><font color="#FF0000">IFC2x4 CHANGE The entity is marked
as deprecated for instantiation - will be made ABSTRACT after
IFC2x4.</font></small></blockquote>
</EPM-HTML> |
| 74 | 549 | IfcElementType | <EPM-HTML>
<p>
<u>Definition from IAI</u>: The <i>IfcElementType</i>
defines a list of commonly shared property set definitions
of an element and an optional set of product
representations. It is used to define an element
specification (i.e. the specific product information, that
is common to all occurrences of that product type).
</p>
<blockquote>
<p>
<small>NOTE The product representations are defined as
representation maps (at the level of the supertype
<i>IfcTypeProduct</i>, which gets assigned by an element
instance through the
<i>IfcShapeRepresentation.Item[1]</i> being an
<i>IfcMappedItem</i>.</small>
</p>
</blockquote>
<p>
An element type is used to define the common properties of
a certain type or style of an element that may be applied
to instances of that element type to assign a specific
style. Element types (the instantiable subtypes) may be
exchanged without being already assigned to occurrences.
</p>
<blockquote>
<p>
<small><font color="#0000FF">HISTORY New entity in
Release IFC2x Edition 2</font></small>
</p>
</blockquote>
</EPM-HTML> |
| 75 | 557 | IfcSpatialElementType | <EPM-HTML>
<p><u>Definition from IAI</u>: The <i>IfcSpatialElementType</i>
defines a list of commonly shared property set definitions of a
spatial structure element and an optional set of product
representations. It is used to define a spatial element
specification (i.e. the specific element information, that is
common to all occurrences of that element type).</p>
<blockquote>
<p><small>NOTE The product representations are defined as
representation maps (at the level of the supertype
<i>IfcTypeProduct</i>, which gets assigned by an element
occurrence instance through the
<i>IfcShapeRepresentation.Item[1]</i> being an
<i>IfcMappedItem</i>.</small></p>
</blockquote>
<p>A spatial element type is used to define the common properties
of a certain type of a spatial structure element that may be
applied to many instances of thattype to assign a specific
style. Spatial element types (i.e. the instantiable subtypes) may
be exchanged without being already assigned to occurrences.</p>
<blockquote>
<p><small>NOTE The spatial element types are often used to
represent catalogues of predefined spatial types for shared
attributes, less so for sharing a common representation
map.</small></p>
</blockquote>
<p>The occurrences of subtypes of the abstract
<i>IfcSpatialElementType</i> are represented by instances of
subtypes of the abstract <i>IfcSpatialElement</i>.</p>
<blockquote>
<p><small><font color="#0000FF">HISTORY New entity in Release
IFC2x Edition 4.</font></small></p>
</blockquote>
</EPM-HTML> |
| 76 | 561 | IfcSpatialStructureElementType | <EPM-HTML>
<p>
<u>Definition from IAI</u>: The element type
(<i>IfcSpatialStructureElementType</i>) defines a list of
commonly shared property set definitions of a spatial
structure element and an optional set of product
representations. It is used to define an element
specification (i.e. the specific element information, that
is common to all occurrences of that element type).
</p>
<blockquote>
<p>
<small>NOTE The product representations are defined as
representation maps (at the level of the supertype
<i>IfcTypeProduct</i>, which gets assigned by an element
occurrence instance through the
<i>IfcShapeRepresentation.Item[1]</i> being an
<i>IfcMappedItem</i>.</small>
</p>
</blockquote>
<p>
A spatial structure element type is used to define the
common properties of a certain type of a spatial structure
element that may be applied to many instances of thattype
to assign a specific style. Spatial structure element types
(i.e. the instantiable subtypes) may be exchanged without
being already assigned to occurrences.
</p>
<blockquote>
<p>
<small>NOTE The spatial structure element types are
often used to represent catalogues of predefined spatial
types for shared attributes, less so for sharing a common
representation map.</small>
</p>
</blockquote>
<p>
The occurrences of subtypes of the
abstract<i>IfcSpatialStructureElementType</i> are
represented by instances of subtypes of
<i>IfcSpatialStructureElement</i>.
</p>
<blockquote>
<p>
<small><font color="#0000FF">HISTORY New entity in
Release IFC2x Edition 3.</font></small>
</p>
</blockquote>
</EPM-HTML> |
| 77 | 563 | IfcSpaceType | <EPM-HTML>
<p><u>Definition from IAI</u>: A space represents an area or
volume bounded actually or theoretically. Spaces are areas or
volumes that provide for certain functions within a building.</p>
<p>The <i>IfcSpaceType</i> defines a list of commonly shared
defines commonly shared information for occurrences of spaces.
The set of shared information may include:</p>
<ul>
<li>common properties within shared property sets</li>
<li>common shape representations</li>
</ul>
<p>It is used to define an space specification (i.e. the specific
space information, that is common to all occurrences of that
space type. Space types may be exchanged without being already
assigned to occurrences.</p>
<blockquote><small>NOTE The space types are often used to
represent space catalogues, less so for sharing a common
representation map. Space types in a space catalogue share same
space classification and a common set of space requirement
properties.</small></blockquote>
<p>The occurrences of <i>IfcSpaceType</i> are represented by
instances of <i>IfcSpace</i>.</p>
<blockquote>
<p><small><font color="#0000FF">HISTORY New entity in
IFC2x3.</font></small></p>
</blockquote>
<p><u><b>Property Set Use Definition</b></u>:</p>
<p>The shared property sets relating to the <i>IfcSpaceType</i>
are defined by the <i>IfcPropertySet</i> and are attached by the
<i>HasPropertySets</i> attribute. The following property set
definitions specific to the <i>IfcSpaceType</i> are part of this
IFC release:</p>
<blockquote><small>NOTE There is no differentiation between
properties within the property set that are only assignable to
<i>IfcSpaceType</i> and those that are only assignable to
<i>IfcSpace</i>. If the same property is assigned to the
<i>IfcSpaceType</i> and the <i>IfcSpace</i> being an occurrence
of the <i>IfcSpaceType</i>, then the occurrence property
overrides the type property.</small></blockquote>
<ul>
<li><a href="../../psd/IfcProductExtension/Pset_SpaceCommon.xml"
target="SOURCE">Pset_SpaceCommon</a>: common property set for all
types of spaces
<ul>
<li><a href="../../psd/IfcProductExtension/Pset_SpaceParking.xml"
target="SOURCE">Pset_SpaceParking</a>: specific property set for
only those spaces that are used to define parking spaces by
<i>PredefinedType</i>: PARKING</li>
</ul>
</li>
<li><a href=
"../../psd/IfcProductExtension/Pset_SpaceFireSafetyRequirements.xml"
target="SOURCE">Pset_SpaceFireSafetyRequirements</a>: common
property set for all types of spaces to capture the fire safety
requirements</li>
<li><a href=
"../../psd/IfcProductExtension/Pset_SpaceLightingRequirements.xml"
target="SOURCE">Pset_SpaceLightingRequirements</a>: common
property set for all types of spaces to capture the lighting
requirements</li>
<li><a href=
"../../psd/IfcProductExtension/Pset_SpaceOccupancyRequirements.xml"
target="SOURCE">Pset_SpaceOccupancyRequirements</a>: common
property set for all types of spaces to capture the occupancy
requirements</li>
<li><a href=
"../../psd/IfcProductExtension/Pset_SpaceThermalRequirements.xml"
target="SOURCE">Pset_SpaceThermalRequirements</a>: common
property set for all types of spaces to capture the thermal
requirements</li>
<li><a href=
"../../psd/IfcSharedBldgServiceElements/Pset_SpaceThermalDesign.xml"
target="SOURCE">Pset_SpaceThermalDesign</a>: common property set
for allall types of spaces to capture building service design
values</li>
</ul>
<p><u><b>Geometry Use Definition</b></u>:</p>
<p>The <i>IfcSpaceType</i> may define the shared geometric
representation for all space occurrences. The
<i>RepresentationMaps</i> attribute refers to a list of
<i>IfcRepresentationMap</i>'s, that allow for multiple geometric
representations (e.g. with <i>IfcShaperepresentation</i>'s having
an RepresentationIdentifier 'Box', 'FootPrint', or 'Body').</p>
<blockquote>
<p><small>NOTE The product representations are defined as
representation maps (at the level of the supertype
<i>IfcTypeProduct</i>, which gets assigned by an element
occurrence instance through the
<i>IfcShapeRepresentation.Item[1]</i> being an
<i>IfcMappedItem</i>.</small></p>
</blockquote>
<blockquote><small>However view definitions and implementer
agreements may prevent the usage of shared geometry for
spaces.</small></blockquote>
.
</EPM-HTML> |
| 78 | 574 | IfcSpatialZoneType | <EPM-HTML>
<p><u>Definition from IAI</u>: The <i>IfcSpatialZoneType</i>
defines a list of commonly shared property set definitions of a
space and an optional set of product representations. It is used
to define a space specification (i.e. the specific space
information, that is common to all occurrences of that space
type).</p>
<blockquote>
<p><small>NOTE The product representations are defined as
representation maps (at the level of the supertype
<i>IfcTypeProduct</i>, which gets assigned by an element
occurrence instance through the
<i>IfcShapeRepresentation.Item[1]</i> being an
<i>IfcMappedItem</i>.</small></p>
</blockquote>
<p>A spatial zone type is used to define the common properties of
a certain type of space that may be applied to many instances of
that type to assign a specific style. Space types may be
exchanged without being already assigned to occurrences.</p>
<blockquote>
<p><small>NOTE The spatial zone types are often used to
represent space catalogues, less so for sharing a common
representation map. Spatial zone types in a space catalogue share
same space classification and a common set of space requirement
properties.</small></p>
</blockquote>
<p>The occurrences of <i>IfcSpatialZoneType</i> are represented
by instances of <i>IfcSpatialZone</i>.</p>
<blockquote>
<p><small><font color="#0000ff">HISTORY New entity in Release
IFC2x Edition 4.</font></small></p>
</blockquote>
</EPM-HTML> |
| 79 | 586 | IfcBuildingElementType | <EPM-HTML>
<p>
<u>Definition from IAI</u>: The element type
(<i>IfcBuildingElementType</i>) defines a list of commonly
shared property set definitions of a building element and
an optional set of product representations. It is used to
define an element specification (i.e. the specific product
information, that is common to all occurrences of that
product type).
</p>
<blockquote>
<p>
<font size="-1">NOTE: The product representations are
defined as representation maps (at the level of the
supertype <i>IfcTypeProduct</i>, which gets assigned by
an element occurrence instance through the
<i>IfcShapeRepresentation.Item[1]</i> being an
<i>IfcMappedItem</i>.</font>
</p>
</blockquote>
<p>
A building element type is used to define the common
properties of a certain type of a building element that may
be applied to many instances of that feature type to assign
a specific style. Building element types (or the
instantiable subtypes) may be exchanged without being
already assigned to occurrences.
</p>
<p>
The <i>IfcBuildingElementType</i> is an abstract type.
Occurrences of subtypes of the
<i>IfcBuildingElementType</i> are represented by instances
of the appropriate subtypes of <i>IfcBuildingElement</i>.
</p>
<blockquote>
<p>
<small><font color="#0000FF">HISTORY New entity in
Release IFC2x Edition 2.</font></small>
</p>
</blockquote>
</EPM-HTML> |
| 80 | 587 | IfcFurnishingElementType | <EPM-HTML>
<p><u>Definition from IAI</u>: The
<i>IfcFurnishingElementType</i> defines a list of commonly shared
property set definitions of an element and an optional set of
product representations. It is used to define an element
specification (i.e. the specific product information, that is
common to all occurrences of that product type).</p>
<blockquote><small>NOTE The product representations are defined
as representation maps (at the level of the supertype
<i>IfcTypeProduct</i>, which gets assigned by an element
occurrence instance through the
<i>IfcShapeRepresentation.Item[1]</i> being an
<i>IfcMappedItem</i>.</small></blockquote>
<p>A furnishing element type is used to define the common
properties of a certain type of a furnishing element that may be
applied to many instances of that feature type to assign a
specific style. Furnishing element types (or the instantiable
subtypes) may be exchanged without being already assigned to
occurrences.</p>
<p>The occurrences of the <i>IfcFurnishingElementType</i> are
represented by instances of <i>IfcFurnishingElement</i> (or its
subtypes).</p>
<blockquote><small><font color="#0000FF">HISTORYNew entity in
Release IFC2x Edition 2.</font></small><br>
<small><font color="#FF0000">IFC2x3 CHANGE The entity has been
made non-abstract</font></small><br>
<small><font color="#FF0000">IFC2x4 CHANGE The entity is marked
as deprecated for instantiation - will be made ABSTRACT after
IFC2x4.</font></small></blockquote>
</EPM-HTML> |
| 81 | 590 | IfcTransportElementType | <EPM-HTML>
<p><u>Definition from IAI</u>: The element type
<i>IfcTransportElementType</i> defines commonly shared
information for occurrences of transport elements. The set of
shared information may include:</p>
<ul>
<li>common properties within shared property sets</li>
<li>common material information</li>
<li>common shape representations</li>
</ul>
<p>It is used to define a transport element specification (i.e.
the specific product information that is common to all
occurrences of that beam type). Transport element types (or the
instantiable subtypes) may be exchanged without being already
assigned to occurrences.</p>
<p>The occurrences of the <i>IfcTransportElementType</i> are
represented by instances of <i>IfcTransportElement</i> (or its
subtypes).</p>
<blockquote>
<p><font color="#0000FF" size="-1">HISTORY: New entity in Release
IFC2x Edition 2.</font></p>
</blockquote>
<p><u><b>Property Set Use Definition</b></u>:</p>
<p>The shared property sets relating to the
<i>IfcTransportElementType</i> are defined by the
<i>IfcPropertySet</i> and are attached by the
<i>HasPropertySets</i> attribute. The following property set
definitions specific to the <i>IfcTransportElementType</i> are
part of this IFC release:</p>
<blockquote><small>NOTE There is no differentiation between
properties within the property set that are only assignable to
<i>IfcTransportElementType</i> and those that are only assignable
to <i>IfcTransportElement</i>. If the same property is assigned
to the <i>IfcTransportElementType</i> and the
<i>IfcTransportElement</i> being an occurrence of the
<i>IfcTransportElementType</i>, then the occurrence property
overrides the type property.</small></blockquote>
<ul>
<li><a href=
"../../psd/IfcProductExtension/Pset_TransportElementCommon.xml"
target="SOURCE">Pset_TransportElementCommon</a>: common property
set for all transport element types
<ul>
<li><a href=
"../../psd/IfcProductExtension/Pset_TransportElementElevator.xml"
target="SOURCE">Pset_TransportElementElevator</a>: specific
property set for all types of transport elements with the
<i>PredefinedType</i>: ELEVATOR</li>
</ul>
</li>
</ul>
<p><u><b>Geometry Use Definition</b></u>:</p>
<p>The <i>IfcTransportElementType</i> may define the shared
geometric representation for all transport element occurrences.
The <i>RepresentationMaps</i> attribute refers to a list of
<i>IfcRepresentationMap</i>'s, that allow for multiple geometric
representations (e.g. with <i>IfcShaperepresentation</i>'s having
an <i>RepresentationIdentifier</i> 'Box', 'FootPrint', or
'Body').</p>
<blockquote><small>NOTE The product shape representations are
defined as <i>RepresentationMaps</i> (attribute of the supertype
<i>IfcTypeProduct</i>), which get assigned by an element
occurrence instance through the
<i>IfcShapeRepresentation.Item[n]</i> being an
<i>IfcMappedItem</i>. See <i>IfcTypeProduct</i> for further
information.</small></blockquote>
<blockquote><small>NOTE The values of attributes
<i>RepresentationIdentifier</i> and <i>RepresentationType</i> of
<i>IfcShapeRepresentation</i> are restricted in the same way as
those for <i>IfcTransportElementType</i>.</small></blockquote>
</EPM-HTML> |
| 82 | 601 | IfcGeographicElementType | <EPM-HTML>
<p>
<u>Definition from IAI</u>: An
<i>IfcGeographicElementType</i> is used to define an
element specification of a geographic element (i.e. the
specific product information, that is common to all
occurrences of that product type).Geographic element types
include for different types of element that may be used to
represent information within a geographical landscape
external to a building. Within the world of geographic
information they are referred to generally as 'features'.
</p>Geographic element types includes for many possibilities:
<ul>
<li>linear elements such as sections of a roadway
(including carriageway/pavement, verge, median, marker
line, kerb etc.), path, river, stream
</li>
<li>connections and junctions including traffic
roundabouts, T junctions, 4 way junctions
</li>
<li>point features such as street lighting, seating, bus
shelters, signage, trees
</li>
<li>linear features such as layby's
</li>
<li>area features such as ponds, lakes, woods and forests
</li>
</ul>
<p>
The specification of the specific types are given by the
inherited attribute <i>IfcElementType.ElementType</i> given
as an <i>IfcLabel</i>.
</p>
<blockquote>
<p>
<small>NOTE This is due to the range of choices of
element type thyat are available and their expression in
different languages. It is not considered possible to
create a reasonably full list of types within an
enumeration. It is suggested that selection of the
relevant type be drawn from an available 'feature
catalog'.</small>
</p>
<p>
<small><font color="#0000FF">HISTORY New entity in
Release IFC2x Edition 4.</font></small>
</p>
</blockquote>
<p>
<b><u>Feature Catalog Use Definition</u></b>
</p>
<p>
Geographic element types are frequently identified in
feature catalogs that are produced for particular
purposes.The <i>IfcGeographicElementType</i> entity
enables the continued use of existing feature catalogs
through capture of their identity and attributes.
</p>
<p>
Information from feature catalogs might be captured in
various ways:
</p>
<ol>
<li>via property sets, some of which will be specifically
defined within the IFC property set catalog whilst others
will be created for local use; this is the form of capture
that is expected to be most widely used
</li>
<li>through use of the IFC classification model whereby
features might be identified through a classification
notation and additional description; in which case, any
further attributes required would still need to be captured
in property sets.
</li>
</ol>
</EPM-HTML> |
| 83 | 607 | IfcElementAssemblyType | <EPM-HTML>
<p><u>Definition from IAI</u>: The <i>IfcElementAssemblyType</i>
defines a list of commonly shared property set definitions of an
element and an optional set of product representations. It is
used to define an element specification (i.e. the specific
product information, that is common to all occurrences of that
product type).</p>
<blockquote><small>NOTE The product representations are defined
as representation maps (at the level of the supertype
<i>IfcTypeProduct</i>, which gets assigned by an element
occurrence instance through the
<i>IfcShapeRepresentation.Item[1]</i> being an
<i>IfcMappedItem</i>.</small></blockquote>
<p>An element assembly type is used to define the common
properties of a certain type of an element assembly that may be
applied to many instances of that type to assign a specific
style. An element assembly types (or the instantiable subtypes)
may be exchanged without being already assigned to
occurrences.</p>
<p>The occurrences of the <i>IfcElementAssemblyType</i> are
represented by instances of <i>IfcElementAssembly</i>.</p>
<blockquote><small><font color="#0000FF">HISTORY New entity in
Release IFC2x Edition 4.</font></small></blockquote>
</EPM-HTML> |
| 84 | 622 | IfcRelConnectsPortToElement | <EPM-HTML>
<p>The objectified relationship
<em>IfcRelConnectsPortToElement</em> defines the relationship that
is made between a port and the <em>IfcElement</em>, or
<em>IfcElementType</em> in which it is contained. It is a 1 to 1
relationship.</p>
<blockquote>
<p><span style="font-size:smaller">The
<em>IfcRelConnectsPortToElement</em> established a whole part
relationship between the element and its port. The port is used as
the means to connect to other ports in other elements. Since both,
the element-to-port, and the port-to-port relationships are 1:1
relationships, a topological system (or system path or ciruit) can
be defined.</span></p>
</blockquote>
<p>Ports contained in different elements are connected to each
other using the <em>IfcRelConnectsPorts</em> relationship.</p>
<blockquote>
<p><span style="font-size:smaller">See relevant subtypes of
<em>IfcDistributionElement</em> for examples and port use
definition sections.</span></p>
</blockquote>
<blockquote>
<p><span style="font-size:smaller;color:blue">HISTORY New
entity in Release IFC2x Edition 2.</span><br>
<span style="font-size:smaller;color:red">IFC2x4 CHANGE The
definition has been extended to include element types.</span></p>
</blockquote>
</EPM-HTML> |
| 85 | 626 | IfcPort | <EPM-HTML>
<p>
<u>Definition from IAI</u>: An <i>IfcPort</i> provides the
means for an element to connect to other elements.
</p>
<p>
An <i>IfcPort</i> is associated with an <i>IfcElement</i>,
it belongs to, through the objectified relationship
<i>IfcRelConnectsPortToElement</i>. Exactly two ports,
belonging to two different elements, are connected with
each other through the objectified relationship
<i>IfcRelConnectsPorts</i>.
</p>
<p>
An instance of <i>IfcElement</i> may have one or more
points at which it connects to other instances of
<i>IfcElement</i>. An instance of <i>IfcPort</i> is located
at a point where a connection can occur. The location of
the port is determined in the context of the local
coordinate system of the element to which it belongs.
</p>
<blockquote>
<p>
<small><font color="#0000FF">HISTORY New entity in
Release IFC2x Edition 2.</font></small>
</p>
</blockquote>
<p>
<b><u>Containment Use Definitions</u></b>
</p>
<p>
As a subordinate part being fully dependent on the master
element the <i>IfcPort</i> shall have no
independent containment relationship to the spatial
structure.
</p>
<p>
<b><u>Geometry Use Definition</u></b>
</p>
<p>
The geometric representation of <i>IfcPort</i> is
given by the <i>IfcProductDefinitionShape</i>, allowing
multiple geometric representation.
</p>
<p>
<b>Local Placement</b>
</p>
<p>
The local placement for <i>IfcPort</i> is defined
in its supertype <i>IfcProduct</i>. It is defined by the
<i>IfcLocalPlacement</i>, which defines the local
coordinate system that is referenced by all geometric
representations.
</p>
<ul>
<li>The <i>PlacementRelTo</i> relationship of
<i>IfcLocalPlacement</i> shall point to the
local placement of the master <i>IfcElement</i> (its
relevant subtypes), which is associated to the
<i>IfcPort</i> by the relationship object
<i>IfcRelConnectsPortToElement</i>.
</li>
</ul>
<p>
<b>Shape Representation</b>
</p>
<p>
The geometry use definitions for the shape representation
of the <i>IfcPort</i> is given at the level of
its subtypes.
</p>
</EPM-HTML> |
| 86 | 630 | IfcRelConnectsPorts | <EPM-HTML>
<p>
<u>Definition from IAI</u>: An <i>IfcRelConnectsPorts</i>
defines the relationship that is made between two ports at
their point of connection. It may include the connection
geometry between two ports.
</p>
<p>
<i>IfcRelConnectsPorts</i> is required for defining how
instances of <i>IfcPort</i> connect together. Each of the
port is being logically attached to the <i>IfcElement</i>
by using the <i>IfcRelConnectsPortToElement</i>
relationship.
</p>
<blockquote>
<p>
<small><font color="#0000FF">HISTORY New entity in IFC
2.0, modified in IFC2x.</font></small>
</p>
</blockquote>
</EPM-HTML> |
| 87 | 638 | IfcTransportElement | <EPM-HTML>
<p><u>Definition from IAI</u>: Generalization of all transport
related objects that move people, animals or goods within a
building or building complex. The <i>IfcTransportElement</i>
defines the occurrence of a transport element, that (if given),
is expressed by the <i>IfcTransportElementType</i>.</p>
<blockquote><small>EXAMPLE Transportation elements include
elevator (lift), escalator, moving walkway, etc.</small><br>
<small>NOTE More detailed equipment that may be a part of a
transportation device, like a lifting hook, is defined as
<i>IfcDiscreteAccessory</i></small></blockquote>
<p>Depending on local classification systems transport elements
and transportation systems in buildings are either considered as
part of a building system, or as part of a building service
system. Within IFC they are considered as part of a building
system and may have to be mapped appropriately.</p>
<blockquote><small><font color="#0000FF">HISTORY New entity in
IFC Release 2x.</font></small><br>
<font color="#FF0000"><small>IFC2x PLATFORM CHANGE The attribute
<i>PredefinedType</i> (previously OperationType) is made
optional.</small></font></blockquote>
<p><u><b>Type Use Definition</b></u></p>
<p><i>IfcTransportElement</i> defines the occuurence of any
transportation device, common information about transportation
device types (or styles) is handled by
<i>IfcTransportElementType</i>. The
<i>IfcTransportElementType</i> (if present) may establish the
commontype name, usage (or predefined) type, common material
layer set, common set of properties and common shape
representations (using <i>IfcRepresentationMap</i>). The
<i>IfcTransportElementType</i> is attached using the
<i>IfcRelDefinedByType.RelatingType</i> objectified relationship
and is accessible by the inverse <i><font color=
"#0000FF">IsTypedBy</font></i> attribute.</p>
<p>If no <i>IfcTransportElementType</i> is attached(i.e. if only
occurrence information is given) the <i>PredefinedType</i> should
be provided. If set to .USERDEFINED. a user defined value can be
provided by the <i>ObjectType</i> attribute.</p>
<p><u><b>Property Set Use Definition</b></u>:</p>
<p>The property sets relating to the <i>IfcTransportElement</i>
are defined by the <i>IfcPropertySet</i> and attached by the
<i>IfcRelDefinesByProperties</i> relationship. It is accessible
by the inverse <i>IsDefinedBy</i> relationship. The following
property set definitions specific to the
<i>IfcTransportElement</i> are part of this IFC release:</p>
<ul>
<li><a href=
"../../psd/IfcProductExtension/Pset_TransportElementCommon.xml"
target="SOURCE">Pset_TransportElementCommon</a>: common property
set for all transport element occurrences
<ul>
<li><a href=
"../../psd/IfcProductExtension/Pset_TransportElementElevator.xml"
target="SOURCE">Pset_TransportElementElevator</a>: specific
property set for all occurrences of transport elements with the
<i>PredefinedType</i>: ELEVATOR</li>
</ul>
</li>
</ul>
<p><u><b>Containment Use Definition</b></u></p>
<p>The <i>IfcTransportElement</i>, as any subtype of
<i>IfcElement</i>, may have a hierarchical spatial containment
relationships that is mandatory in most implementation
scenarios.</p>
<ul>
<li>The <i>IfcTransportElement</i> is placed within the project
spatial hierarchy using the objectified relationship
<i>IfcRelContainedInSpatialStructure</i>, refering to it by its
inverse attribute <i>SELF\IfcElement.ContainedInStructure</i>.
Subtypes of<i>IfcSpatialStructureElement</i> are valid spatial
containers, with <i>IfcBuilding</i> being the default
container.</li>
</ul>
<p><u><b>Geometry Use Definitions</b></u>:</p>
<p>The geometric representation of <i>IfcTransportElement</i> is
given by the <i>IfcProductDefinitionShape</i>, allowing multiple
geometric representation.</p>
<p><b>Local Placement</b></p>
<p>The local placement for <i>IfcTransportElement</i> is defined
in its supertype <i>IfcProduct</i>. It is defined by the
<i>IfcLocalPlacement</i>, which defines the local coordinate
system that is referenced by all geometric representations.</p>
<ul>
<li>The <i>PlacementRelTo</i> relationship of
<i>IfcLocalPlacement</i> shall point (if given) to the local
placement of the same <i>IfcSpatialStructureElement</i> , which
is used in the <i>ContainedInStructure</i> inverse attribute, or
to a spatial structure element at a higher level, referenced by
that.</li>
<li>If the relative placement is not used, the absolute placement
is defined within the world coordinate system.</li>
</ul>
<p><b>SurfaceModel Representation</b></p>
<p>Any <i>IfcTransportElement</i> (so far no further constraints
are defined at the level of its subtypes) may be represented as a
single or multiple surface models, based on either shell or face
based models. Then the following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'SurfaceModel'</li>
</ul>
<p><b>Brep Representation</b></p>
<p>Any <i>IfcTransportElement</i> (so far no further constraints
are defined at the level of its subtypes) may be represented as a
single or multiple Boundary Representation elements (which are
restricted to faceted Brep with or without voids). Then the
following attribute values for the <i>IfcShapeRepresentation</i>
holding this geometric representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'Brep'</li>
</ul>
<p><b>MappedRepresentation</b></p>
<p>The mapped item, <i>IfcMappedItem</i>, should be used if
appropriate as it allows for reusing the geometry definition of
the property element type at occurrences of the same equipement
type. Then the following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'MappedRepresentation'</li>
</ul>
</EPM-HTML> |
| 88 | 644 | IfcFeatureElement | <EPM-HTML>
<p><u>Definition from IAI</u>: Generalization of all existence
dependent elements which modify the shape and appearance of the
associated master element. The <i>IfcFeatureElement</i> offers
the ability to handle shape modifiers as semantic objects within
the IFC object model.</p>
<blockquote>
<p><small>NOTE The term "feature" has a predefined meaning in a
context of "feature-based modeling" and within steel construction
work. It is introduced here in a broader sense to cover all
existence dependent, but semantically described, modifiers of an
element's shape and appearance. It is envisioned that future
releases enhance the feature-based capabilities of the IFC
model.</small></p>
</blockquote>
<p>In contrary to the aggregation, as used in
<i>IfcElementAssembly</i>, that defines the aggregate as a
container element, that has equally treated parts, the feature
concept introduced by <i>IfcFeatureElement</i> defines the master
element with subordinate parts as additions, or with voids or
cut-outs as subtractions.</p>
<blockquote>
<p><small><font color="#0000FF">HISTORY New entity in Release
IFC2x Edition 2.</font></small><br>
<small><font color="#FF0000">NOTE The entity is introduced as an
upward compatible extension of the IFC2x platform. It is an
intermediate abstract supertype without defining its own explicit
attributes.</font></small></p>
</blockquote>
<p><b><u>Containment Use Definition</u></b></p>
<p>As a subordinate part being fully dependent on the master
element the <i>IfcFeatureElement</i> shall have no independent
containment relationship to the spatial structure.</p>
<ul>
<li>The <i>SELF\IfcElement.ContainedInStructure</i> relationship
shall be NIL.</li>
</ul>
<p><b><u>Geometry Use Definition</u></b></p>
<p>The geometric representation of <i>IfcFeatureElement</i> is
given by the <i>IfcProductDefinitionShape</i>, allowing multiple
geometric representation.</p>
<p><b>Local Placement</b></p>
<p>The local placement for <i>IfcFeatureElement</i> is defined in
its supertype <i>IfcProduct</i>. It is defined by the
<i>IfcLocalPlacement</i>, which defines the local coordinate
system that is referenced by all geometric representations.</p>
<ul>
<li>The <i>PlacementRelTo</i> relationship of
<i>IfcLocalPlacement</i> shall point (if given) to the local
placement of the master <i>IfcElement</i> (its relevant
subtypes), which is associated to the <i>IfcFeatureElement</i> by
the appropriate relationship object.</li>
<li>If the relative placement is not used, the absolute placement
is defined within the world coordinate system.</li>
</ul>
<p><b>Geometric Representations</b></p>
<p>Any <i>IfcFeatureElement</i> can be represented by one or
several geometric representations. A detailed specification is
introduced at the level of subtypes. Only the general
representation identifier 'Box' with representation type
'BoundingBox', and representation identifier 'Body' with
representation type 'Brep' are defined here.</p>
<p><b>Box Representation</b></p>
<p>Any <i>IfcFeatureElement</i> may be represented as a bounding
box, which shows the maximum extend of the body within the
coordinated system established by the <i>IfcLocalPlacement</i>.
The bounding box representation is the simplest geometric
representation available. The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Box'</li>
<li><i>RepresentationType</i> : 'BoundingBox'</li>
</ul>
<p><b>Body Representation</b></p>
<p>The body representation of any <i>IfcFeatureElement</i> can
have the following representation types: 'Brep'. Other
representation types might be specified at the level of
subtypes.</p>
<p><i>Brep Representation Type</i></p>
<p>Any <i>IfcFeatureElement</i> (so far no further constraints
are defined at the level of its subtypes) may be represented as a
single or multiple Boundary Representation elements (which are
restricted to faceted Brep with or without voids). The Brep
representation allows for the representation of complex element
shape. The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'Brep'</li>
</ul>
<p>In some cases it may be useful to also expose a simple
representation as a bounding box representation of the same
complex shape.</p>
</EPM-HTML> |
| 89 | 647 | IfcFeatureElementAddition | <EPM-HTML>
<p>
<u>Definition from IAI</u>: A specialization of the general
feature element, that represents an existence dependent
element which modifies the shape and appearance of the
associated master element. The
<i>IfcFeatureElementAddition</i> offers the ability to
handle shape modifiers as semantic objects within the IFC
object model that add to the shape of the master element.
</p>
<blockquote>
<p>
<small><font color="#0000FF">HISTORY New entity in
Release IFC2x Edition 2.</font></small><br>
<small><font color="#FF0000">NOTE The entity is
introduced as an upward compatible extension of the IFC2x
platform. It is an intermediate abstract supertype
without defining its own explicit
attributes.</font></small>
</p>
</blockquote>
<p>
The <i>IfcFeatureElementAddition</i> is associated to its
master element by virtue of the objectified relationship
<i>IfcRelProjectsElement</i>. This relationship implies a
Boolean 'union' operation between the shape of the master
element and the shape of the addition feature.
</p>
<p>
<b><u>Containment use definition</u></b>
</p>
<p>
The containment to the spatial structure is defined at the
level of the supertype <i>IfcFeatureElement</i>
</p>
<p>
<b><u>Geometry Use Definitions</u></b>
</p>
<p>
The geometric representation of
<i>IfcFeatureElementAddition</i> is given by the
<i>IfcProductDefinitionShape</i>, allowing multiple
geometric representations.
</p>
<p>
<b>Local Placement</b>
</p>
<p>
The local placement for <i>IfcFeatureElementAddition</i> is
defined in its supertype <i>IfcProduct</i>. It is defined
by the <i>IfcLocalPlacement</i>, which defines the local
coordinate system that is referenced by all geometric
representations. The local placement is always defined in
relation to the local placement of the element to which the
feature element is added:
</p>
<ul>
<li>The <i>PlacementRelTo</i> relationship of
<i>IfcLocalPlacement</i> shall point to the local placement
of the same <i>IfcElement</i>, which is used in the
<i>HasAdditionFeature.RelatingElement</i> inverse
attribute.
</li>
</ul>
<p>
<b>Shape Representation</b>
</p>
<p>
The geometry use definitions for the shape representation
of the <i>IfcFeatureElementAddition</i> is given at the
level of its subtypes.
</p>
</EPM-HTML> |
| 90 | 650 | IfcProjectionElement | <EPM-HTML>
<p>The projection element is a
specialization of the general feature element to represent
projections applied to building elements. It represents a solid
attached to any element that has physical manifestation.</p>
<blockquote><small>EXAMPLE A wall projection such as a pilaster
strip is handled by
<i>IfcProjectionElement</i></small></blockquote>
<blockquote><small>NOTE View definitions or implementer agreements
may restrict the types of elements to which
<i>IfcProjectionElement</i> can be applied.</small></blockquote>
<p>An <i>IfcProjectionElement</i> has to be linked to a element
(all subtypes of <i>IfcElement</i>) by using the
<i>IfcRelProjectsElement</i> relationship. Its existence depends on
the existence of the master element. The relationship implies a
Boolean union operation between the volume of the projection
element and the volume of the element.</p>
<blockquote class="history">HISTORY New entity in IFC2x2.</blockquote>
<blockquote class="change-ifc2x4">IFC2x4 CHANGE The attribute <i>PredefinedType</i> has been added at the end of attribute
list.</blockquote>
<p>The quantities relating to the <i>IfcProjectionElement</i> are
defined by the <i>IfcElementQuantity</i> and attached by the
<i>IfcRelDefinesByProperties</i> relationship. It is accessible by
the inverse <i>IsDefinedBy</i> relationship. The following base
quantities are defined and should be exchanged with the
<i>IfcElementQuantity.Name</i> = 'BaseQuantities'. Other
quantities, being subjected to local standard of measurement, can
be defined with another string value assigned to <i>Name</i>. In
this case a valid value for <i>MethodOfMeasurement</i> has to be
provided.</p>
<ul>
<li><a href=
"../../qto/IfcProductExtension/Qto_ProjectionElementBaseQuantities.xml"
target="SOURCE">Qto_ProjectionElementBaseQuantities</a>: base
quantities for all opening occurrences.</li>
</ul>
<p class="use-head">Containment Use Definition</p>
<p>The <i>IfcProjectionElement</i> shall not participate in the
containment relationship, i.e. it is not linked directly to the
spatial structure of the project. It has a mandatory
<i>ProjectsElements</i> inverse relationship pointing to the
<i>IfcElement</i> that is contained in the spatial structure.</p>
<ul>
<li>The inverse relationship <i>ContainedInStructure</i> shall be
NIL.</li>
</ul>
<p class="use-head">Geometry Use Definition</p>
<p>The geometric representation of <i>IfcProjectionElement</i> is
given by the <i>IfcProductDefinitionShape</i> and
<i>IfcLocalPlacement</i> allowing multiple geometric
representations.</p>
<p><b>Local Placement</b></p>
<p>The local placement for <i>IfcOpeningRecess</i> is defined in
its supertype <i>IfcProduct</i>. It is defined by the
<i>IfcLocalPlacement</i>, which defines the local coordinate system
that is referenced by all geometric representations.</p>
<ul>
<li>The <i>PlacementRelTo</i> relationship of
<i>IfcLocalPlacement</i> should point to the local placement of the
same element, to which the projection adds, i.e. referred to by
<i>ProjectsElement.RelatingBuildingElement</i>.</li>
</ul>
<p><b>Swept Solid Representation</b></p>
<p>The geometric representation of <i>IfcProjectionElement</i> is
defined using the swept area solid geometry. The following
attribute values for the <i>IfcShapeRepresentation</i> holding this
geometric representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'SweptSolid'</li>
</ul>
<p>The following additional constraints apply to the swept solid
representation:</p>
<ul>
<li><u>Solid</u>: <i>IfcExtrudedAreaSolid</i> is required.</li>
<li><u>Profile</u>: <i>IfcRectangleProfileDef</i>,
<i>IfcCircleProfileDef</i> and <i>IfcArbitraryClosedProfileDef</i>
shall be supported.</li>
<li><u>Extrusion</u>: The profile shall be extruded horizontally
(that is, perpendicular to the extrusion direction of the modified
element), such as for wall projections, or vertically (that is, in the
extrusion direction of the projected element), such as for floor
projections.</li>
</ul>
<p>As shown in Figure 38, the following interpretation of dimension parameter applies for
rectangular projection:</p>
<ul>
<li><i>IfcRectangleProfileDef.YDim</i> interpreted as projection
width</li>
<li><i>IfcRectangleProfileDef.XDim</i> interpreted as projection
height</li>
<li><i>IfcExtrudedAreaSolid.Depth</i> is interpreted as projection
depth</li>
</ul>
<blockquote class="note">NOTE Rectangles are now defined centric, the placement location has to be set:
<ul><li><i>IfcCartesianPoint</i>(XDim/2,YDim/2)</li></ul></blockquote>
<blockquote class="note">NOTE The local placement directions for the <i>IfcProjectionElement</i> are only given as an example, other directions are valid as well.</blockquote>
<table cellpadding="2" cellspacing="2" summary="geometry use">
<tr valign="top"><td valign="top" align="left"><img src="figures/IfcProjectionElement-Layout1.png" alt="projection" width=
"400" height="300" border="0"></td></tr>
<tr><td><p class="figure">Figure 38 — Projection representation</p></td></tr>
</table>
<p><b>Brep Representation</b></p>
<p>The general b-rep geometric representation of
<i>IfcProjectionElement</i> is defined using the Brep geometry. The
Brep representation allows for the representation of complex
element shape. The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric representation
shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'Brep'</li>
</ul>
</EPM-HTML> |
| 91 | 655 | IfcRelProjectsElement | <EPM-HTML>
<p>The <i>IfcRelProjectsElement</i> is an objectified relationship
between an element and one projection element that creates a
modifier to the shape of the element. The relationship is defined
to be a 1:1 relationship, if an element has more than one
projection, several relationship objects have to be used, each
pointing to a different projection element. The
<i>IfcRelProjectsElement</i> establishes an aggregation
relationship between the main element and a sub ordinary addition
feature.</p>
<blockquote>
<p><span style="font-size:smaller">NOTE In contrary the
<em>IfcRelAggregates</em> relationship established an aggregation
of equal parts to a whole.</span></p>
</blockquote>
<p>The <i>IfcRelProjectsElement</i> implies a Boolean operation of
addition for the geometric bodies of the element and the feature
element. As with all decomposition relationships it determines:</p>
<ul>
<li>existence dependency - the <em>RelatedFeatureElement</em>
cannot exist without the <em>RelatingElement</em></li>
<li>hierarchical and non-cyclical relationship - the
<em>IfcRelProjectsElement</em> can only alter a single
<em>IfcElement</em></li>
<li>no spatial containment - the <em>IfcFeatureElementAddition</em>
as related element never participates in the hiearchical spatial
containment relationship
<em>IfcRelContainedInSpatialStructure</em></li>
</ul>
<blockquote>
<p><span style="font-size:smaller;color=blue">HISTORY New entity in
Release IFC2x Edition 2.</span><br>
<span style="font-size:smaller;color=red">IFC2x4 CHANGE
Supertype changed to IfcRelDecomposes.</span></p>
</blockquote>
</EPM-HTML> |
| 92 | 658 | IfcRelVoidsElement | <EPM-HTML>
<p><i>IfcRelVoidsElement</i> is an objectified relationship between a building element and one opening element that creates a void in the element. It is a one-to-one relationship. This relationship implies a Boolean operation of subtraction between the geometric bodies of the element and the opening.</p>
<p>As shown in Figure 50, the insertion of a void into a wall is represented by the relationship <i>IfcRelVoidsElement</i>. The opening is created within the wall by <i>IfcWall(StandardCase) o-- IfcRelVoidsElement --o IfcOpeningElement</i>.</p>
<table border="0" cellpadding="0" cellspacing="0" width="502" summary="example for voiding">
<tr><td><img src="figures/IfcRelVoidsElements-Fig1.png" alt="relationships for voiding" width="501" height="271" border="0"></td></tr>
<tr><td><p class="figure">Figure 50 — Relationship for element voiding</p></td></tr>
</table>
<blockquote class="history">HISTORY New entity in IFC Release 1.0</blockquote>
</EPM-HTML> |
| 93 | 661 | IfcFeatureElementSubtraction | <EPM-HTML>
<p>The <em>IfcFeatureElementSubtraction</em> is specialization of
the general feature element, that represents an existence dependent
elements which modifies the shape and appearance of the associated
master element. The <i>IfcFeatureElementSubtraction</i> offers the
ability to handle shape modifiers as semantic objects within the
IFC object model that subtract from the shape of the master
element.</p>
<blockquote>
<p><span style="font-size:smaller">A single subtraction feature
such as the subtype <em>IfcOpeningElement</em> is assigned by a
single subtraction relationship <em>IfcRelVoidsElement</em> to one
occurrences of <em>IfcElement</em>. It establishes a 1:1
relationship between the opening and the element. An element may
have several <em>IfcRelVoidsElement</em> relationships, enabling
several voids.</span></p>
</blockquote>
<p>The voiding relationship between a master element and a
subtraction feature is geometrically resolved by a Boolean
difference operation.</p>
<blockquote>
<p><span style="font-size:smaller;color:blue">HISTORY New entity in
Release IFC2x Edition 2.</span><br></p>
</blockquote>
<p><b><u>Containment use definition</u></b></p>
<p>The <em>IfcFeatureElementSubtraction</em> shall have no
independent containment relationship to the spatial structure. See
explanation at supertype <i><em>IfcFeatureElement</em></i></p>
<p><b><u>Geometry Use Definitions</u></b></p>
<p>The geometric representation of
<i>IfcFeatureElementSubtraction</i> is given by the
<i>IfcProductDefinitionShape</i>, allowing multiple geometric
representations.</p>
<p><b>Local Placement</b></p>
<p>The local placement for <i>IfcFeatureElementSubtraction</i> is
defined in its supertype <i>IfcProduct</i>. It is defined by the
<i>IfcLocalPlacement</i>, which defines the local coordinate system
that is referenced by all geometric representations. The local
placement is always defined in relation to the local placement of
the building element from which the feature element substration is
substracted:</p>
<ul>
<li>The <i>PlacementRelTo</i> relationship of
<i>IfcLocalPlacement</i> shall point (if given) to the local
placement of the same <i>IfcElement</i>, which is used in the
<i>VoidsElements.RelatingElement</i> inverse attribute.</li>
</ul>
<p><b>Shape Representation</b></p>
<p>The geometry use definitions for the shape representation of the
<i>IfcFeatureElementSubtraction</i> is given at the level of its
subtypes.</p>
</EPM-HTML> |
| 94 | 666 | IfcOpeningElement | <EPM-HTML>
<p>The opening element stands for
opening, recess or chase, all reflecting voids. It represents a
void within any element that has physical manifestation. Openings
can be inserted into walls, slabs, beams, columns, or other
elements.</p>
<p>The IFC specification provides two entities for opening
elements:</p>
<ul>
<li><i>IfcOpeningStandardCase</i> is used for all openings that
have a constant profile along a linear extrusion. They are placed
relative to the voided elements and the extrusion direction is
perpendicular to the plane of the element (horizontally for
walls, vertically for slabs). Only a single extrusion body is
allowed. It cuts through the whole thickness of the voided
element, i.e. it reflects a true opening.</li>
<li><i>IfcOpeningElement</i> is used for all other occurrences of
openings and in particular also for niches or recesses.</li>
</ul>
<blockquote><small>NOTE View definitions or implementer
agreements may restrict the types of elements which can be voided
by an <i>IfcOpeningElement</i> or
<i>IfcOpeningStandardCase</i></small></blockquote>
<p>There are two different types of opening elements:</p>
<ul>
<li>an opening, where the thickness of the opening is greater or
equal to the thickness of the element;</li>
<li>a recess or niche, where the thickness of the recess is
smaller than the thickness of the element.</li>
</ul>
<p>The attribute <i>PredefinedType</i> should be used to capture
the differences,</p>
<ul>
<li>the attribute is set to OPENING for an opening or</li>
<li>the attribute is set to RECESS for a recess or niche.</li>
<li>If the value for <i>PredefinedType</i> is omitted, or the
value is set to NOTDEFINED, no specific information of whether it
is an opening or recess shall be assumed.</li>
</ul>
<blockquote><small>NOTE Until IFC2x3 the information had been
provided by the inherited attribute
<i>ObjectType</i>.</small></blockquote>
<p>An <i>IfcOpeningElement</i> has to be inserted into an
<i>IfcElement</i> by using the <i>IfcRelVoidsElement</i>
relationship. The relationship implies a Boolean subtraction
operation between the volume of the voided element and the volume
of the opening. It may be filled by an <i>IfcDoor</i>,
<i>IfcWind</i>ow, or another filling element by using the
relationship <i>IfcRelFillsElements</i>.</p>
<blockquote><small><font color="#0000FF">HISTORY New entity in
IFC Release 1.0</font></small><br>
<small><font color="#FF0000">IFC2x CHANGE The intermediate
ABSTRACT supertypes <i>IfcFeatureElement</i> and
<i>IfcFeatureSubtraction</i> have been added.</font></small><br>
<small><font color="#FF0000">IFC2x4 CHANGE The attribute
<i>PredefinedType</i> has been added at the end of attribute
list.</font></small></blockquote>
<p><u><b>Property Set Use Definition</b></u>:</p>
<p>The property sets relating to the <i>IfcOpeningElement</i> are
defined by the <i>IfcPropertySet</i> and attached by the
<i>IfcRelDefinesByProperties</i> relationship. It is accessible
by the inverse <i>IsDefinedBy</i> relationship. The following
property set definitions specific to the <i>IfcOpeningElement</i>
are part of this IFC release:</p>
<ul>
<li><a href=
"../../psd/IfcProductExtension/Pset_OpeningElementCommon.xml"
target="SOURCE">Pset_OpeningElementCommon</a>: common property
set for all opening occurrences</li>
</ul>
<p><u><b>Quantity Use Definition</b></u>:</p>
<p>The quantities relating to the <i>IfcOpeningElement</i> are
defined by the <i>IfcElementQuantity</i> and attached by the
<i>IfcRelDefinesByProperties</i> relationship. It is accessible
by the inverse <i>IsDefinedBy</i> relationship. The following
base quantities are defined and should be exchanged with the
<i>IfcElementQuantity.Name</i> = 'BaseQuantities'. Other
quantities, being subjected to local standard of measurement, can
be defined with another string value assigned to <i>Name</i>. In
this case a valid value for <i>MethodOfMeasurement</i> has to be
provided.</p>
<ul>
<li><a href=
"../../qto/IfcProductExtension/Qto_OpeningElementBaseQuantities.xml"
target="SOURCE">Qto_OpeningElementBaseQuantities</a>: base
quantities for all opening occurrences.</li>
</ul>
<p class="use-head">Containment Use Definition</p>
<p>The <i>IfcOpeningElement</i> shall not participate in the
containment relationship, i.e. it is not linked directly to the
spatial structure of the project. It has a mandatory
<i>VoidsElements</i> inverse relationship pointing to the
<i>IfcElement</i> that is contained in the spatial structure.</p>
<ul>
<li>The inverse relationship <i>ContainedInStructure</i> shall be
NIL.</li>
</ul>
<blockquote><small>NOTE See <i>IfcRelVoidsElement</i> for a
diagram on how to apply spatial containment and the voiding
relationship.</small></blockquote>
<p><b><u>Geometry Use Definitions</u></b></p>
<p>The geometric representation of <i>IfcOpeningElement</i> is
given by the <i>IfcProductDefinitionShape</i> and
<i>IfcLocalPlacement</i> allowing multiple geometric
representations.</p>
<p><b>Local Placement</b></p>
<p>The local placement for <i>IfcOpeningElement</i> is defined in
its supertype <i>IfcProduct</i>. It is defined by the
<i>IfcLocalPlacement</i>, which defines the local coordinate
system that is referenced by all geometric representations.</p>
<ul>
<li>The <i>PlacementRelTo</i> relationship of
<i>IfcLocalPlacement</i> should point to the local placement of
the same element, which is voided by the opening, i.e. referred
to by <i>VoidsElement.RelatingBuildingElement</i>.</li>
</ul>
<p><b><i>Geometric Representation</i></b></p>
<p>Currently, the 'Body', and 'Box' representations are
supported. The 'Box' representation includes the representation
type 'BoundingBox' and is explained at
<i>IfcFeatureElement</i>.</p>
<p><b>Body Representation</b></p>
<p>The 'Body' representation of <i>IfcOpeningElement</i> can be
represented using the representation types 'SweptSolid', and
'Brep'. The representation type 'Brep' is explained at
<i>IfcFeatureElement</i></p>
<p><i>Swept Solid Representation Type with Horizontal
Extrusion</i></p>
<p>The 'SweptSolid' geometric representation of
<i>IfcOpeningElement</i>, using horizontal extrusion direction
(for walls), is defined using the swept area solid geometry. The
following attribute values for the <i>IfcShapeRepresentation</i>
holding this geometric representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'SweptSolid'</li>
</ul>
<p>The following additional constraints apply to the swept solid
representation:</p>
<ul>
<li><u>Solid</u>: <i>IfcExtrudedAreaSolid</i> is required, the
set of <i>IfcShapeRepresentation.Items</i> may include a single,
or multiple, instances of <i>IfcExtrudedAreaSolid</i>.</li>
<li><u>Profile</u>: <i>IfcRectangleProfileDef</i>,
<i>IfcCircleProfileDef</i> and
<i>IfcArbitraryClosedProfileDef</i> shall be supported.</li>
<li><u>Extrusion</u>: The profile shall be extruded horizontally
(i.e. perpendicular to the extrusion direction of the voided
element), e.g. for wall openings, or vertically (i.e. in the
extrusion direction of the voided element), e.g., for floor
openings. If multiple instances of <i>IfcExtrudedAreaSolid</i>
are used, the extrusion direction of each extrusion should be
equal.</li>
</ul>
<blockquote><small>NOTE In case of non-parallel jambs, the shape
representation shall be a 'SweptSolid' representation with
vertical extrusion.</small></blockquote>
<p>Figure 34 illustrates an opening with horizontal extrusion.</p>
<blockquote class="note">NOTE The local placement directions for the <i>IfcOpeningElement</i> are only given as an example, other directions are valid as well.</blockquote>
<table cellpadding="2" cellspacing="2">
<tr valign="top"><td align="left" valign="top" width="600"><img src=
"figures/IfcOpeningElement_Horizontal-Layout1.png" alt="standard opening" border="0" height="400" width="600"></td>
<td align="left" valign="top"></td></tr>
<tr><td><p class="figure">Figure 34 — Opening with full extrusion</p></td></tr>
</table>
<p>Figure 35 illustrates an opening for a recess.</p>
<blockquote class="note">NOTE The local placement directions for the <i>IfcOpeningElement</i> are only given as an example, other directions are valid as well.</blockquote>
<blockquote class="note">NOTE Rectangles are now defined centric, the placement
location has to be set:</blockquote>
<ul>
<li><i>IfcCartesianPoint</i>(XDim/2,YDim/2)</small></li>
</ul>
<table cellpadding="2" cellspacing="2" summary="recess">
<tr valign="top"><td align="left" valign="top" width="600"><img src=
"figures/IfcOpeningElement_Recess-Layout1.png" alt="recess"
border="0" height="400" width="600"></td>
<td align="left" valign="top"></td></tr>
<tr><td><p class="figure">Figure 35 — Opening with recess extrusion</p></td></tr>
</table>
<p><i>Swept Solid Representation with Vertical Extrusion</i></p>
<p>The 'SweptSolid' geometric representation of
<i>IfcOpeningElement</i>, using vertical extrusion direction (for
walls), is defined using the swept area solid geometry, however
the extrusion direction may be vertical, i.e. in case of a wall
opening, the extrusion would be in the direction of the wall
height. The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'SweptSolid'</li>
</ul>
<p>The following additional constraints apply to the swept solid
representation:</p>
<ul>
<li><u>Solid</u>: <i>IfcExtrudedAreaSolid</i> is required, the
set of <i>IfcShapeRepresentation.Items</i> may include a single,
or multiple, instances of <i>IfcExtrudedAreaSolid</i>.</li>
<li><u>Profile</u>: <i>IfcRectangleProfileDef</i>,
<i>IfcCircleProfileDef</i> and
<i>IfcArbitraryClosedProfileDef</i> shall be supported.</li>
<li><u>Extrusion</u>: The profile shall be extruded vertically,
i.e. for wall openings along the extrusion direction of the
voided element. If multiple instances of
<i>IfcExtrudedAreaSolid</i> are used, the extrusion direction
should be equal.</li>
</ul>
<p>Vertical extrusions shall be used when an opening or recess
has a non rectangular foot print geometry that does not change
along the height of the opening or recess.</p>
<p>Figure 36 shows a vertical extrusion with multiple extrusion bodies for the opening. Each extrusion body has a different extrusion lenght.</p>
<blockquote class="note">NOTE The local placement directions for the <i>IfcOpeningElement</i> are only given as an example, other directions are valid as well.</blockquote>
<table border="0" cellpadding="2" cellspacing="2" summary="vertical extrusion">
<tr><td align="left" valign="top" width="600"><img src="figures/IfcOpeningElement_Vertical-Layout1.png" alt="vertical extrusion" border="0" height="400" width="600"></td></tr>
<tr><td><p class="figure">Figure 36 — Opening with multiple extrusions</p></td></tr>
</table>
</EPM-HTML> |
| 95 | 670 | IfcOpeningStandardCase | <EPM-HTML>
<p>The standard opening,
<i>IfcOpeningStandardCase</i>, defines an opening with certain
constraints for the dimension parameters, position within the
voided element, and with certain constraints for the geometric
representation. The <i>IfcOpeningStandardCase</i> handles all
cases of openings, that:</p>
<ul>
<li>are true openings by cutting through the body of the voided
element, i.e. where the opening depth is >= to the thickness
of the element,</li>
<li>are extruded perpendicular to the wall plane in case of
openings in a wall</li>
<li>are extruded perpendicular to the slab plane in case of
openings in a slab</li>
<li>have a local placement relative to the local placement of the
voided element</li>
<li>have a 'Body' shape representation with 'SweptSolid'
representation type</li>
<li>have only a single extrusion body within the 'Body' shape
representation</li>
</ul>
<blockquote><small><font color="#0000FF">HISTORY New entity in
IFC2x4</font></small></blockquote>
<p><u><b>Property Set Use Definition</b></u>:</p>
<p>The property sets relating to the
<i>IfcOpeningStandardCase</i> are defined at the supertype
<i>IfcOpeningElement</i>.</p>
<p><u><b>Quantity Use Definition</b></u>:</p>
<p>The quantities relating to the <i>IfcOpeningStandardCase</i>
are defined at the supertype <i>IfcOpeningElement</i>.</p>
<p><u><b>Containment Use Definition</b></u></p>
<p>The containment use definitions relating to the
<i>IfcOpeningStandardCase</i> are defined at the supertype
<i>IfcOpeningElement</i>.</p>
<p><b><u>Geometry Use Definitions</u></b></p>
<p>The geometric representation of <i>IfcOpeningStandardCase</i>
is given by the <i>IfcProductDefinitionShape</i> and
<i>IfcLocalPlacement</i> allowing multiple geometric
representations.</p>
<p><b>Local Placement</b></p>
<p>The following constraint is mandatory for
<i>IfcOpeningStandardCase</i></p>
<ul>
<li>The <i>PlacementRelTo</i> relationship of
<i>IfcLocalPlacement</i> should point to the local placement of
the same element, which is voided by the opening, i.e. referred
to by <i>VoidsElement.RelatingBuildingElement</i>.</li>
</ul>
<p><b><i>Geometric Representation</i></b></p>
<p>The geometric representation of <i>IfcOpeningStandardCase</i>
is defined using the following multiple shape representations for
its definition:</p>
<ul>
<li>Body: A SweptSolid representation defining the 3D subtraction
shape of the standard opening</li>
</ul>
<p><b>Body Representation</b></p>
<p>The body representation of <i>IfcOpeningStandardCase</i> is
represented using the representation type 'SweptSolid'.</p>
<p><i>Swept Solid Representation Type with Horizontal
Extrusion</i></p>
<p>The standard geometric representation of
<i>IfcOpeningStandardCase</i> is defined using the 'SweptSolid'
representation. The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric
representation shall be used::</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body'</li>
<li><i>RepresentationType</i> : 'SweptSolid'</li>
</ul>
<p>The following additional constraints apply to the swept solid
representation:</p>
<ul>
<li><u>Solid</u>: a single <i>IfcExtrudedAreaSolid</i> is
required</li>
<li><u>Profile</u>: <i>IfcRectangleProfileDef</i>,
<i>IfcCircleProfileDef</i> and
<i>IfcArbitraryClosedProfileDef</i> shall be supported.</li>
<li><u>Extrusion</u>: The profile shall be extruded horizontally
(i.e. perpendicular to the extrusion direction of the voided
element) for wall openings, or vertically (i.e. in the extrusion
direction of the voided element), for slab openings.</li>
</ul>
<p>As shown in Figure 37, the orientation of the opening profile that is extruded
for the opening body shall guarantee the following interpretation
of dimension parameter for rectangular openings:</p>
<ul>
<li><i>IfcRectangleProfileDef.YDim</i> interpreted as
opening width</li>
<li><i>IfcRectangleProfileDef.XDim</i> interpreted as
opening height</li>
</ul>
<table border="0" cellpadding="2" cellspacing="2">
<tr valign="top"><td align="left" valign="top" width="600"><img src=
"figures/IfcOpeningStandardCase_Wall-Layout1.png" alt=
"standard opening" border="0" height="400" width="600"></td></tr>
<tr><td><p class="figure">Figure 37 — Opening standard representation</p></td></tr>
</table>
</EPM-HTML> |
| 96 | 676 | IfcRelFillsElement | <EPM-HTML>
<p><i>IfcRelFillsElement</i> is an objectified relationship between an opening element and an element that fills (or partially fills) the opening element. It is an one-to-one relationship.</p>
<blockquote class="note">NOTE view definitions or implementer agreements may restrict an opening to be filled by one filling element only.</blockquote>
<blockquote class="history">HISTORY New entity in IFC Release 1.0</blockquote>
<p>As shown in Figure 40, the insertion of a door into a wall is represented by two separate relationships. First the door opening is created within the wall by <i>IfcWall(StandardCase) o-- IfcRelVoidsElement --o IfcOpeningElement</i>, then the door is inserted within the opening by <i>IfcOpeningElement o-- IfcRelFillsElement --o IfcDoor</i>.</p>
<table border="0" cellpadding="0" cellspacing="0" width="502" summary="example for filling">
<tr><td><img src="figures/IfcRelFillsElements-Fig1.png" alt="relationships for filling" width="501" height="401" border="0"></td></tr>
<tr><td><p class="figure">Figure 40 — Relationships for element filling</p></td></tr>
</table>
</EPM-HTML> |
| 97 | 679 | IfcElementAssembly | <EPM-HTML>
<p>The <i>IfcElementAssembly</i>
represents complex element assemblies aggregated from several
elements, such as discrete elements, building elements, or other
elements.</p>
<blockquote><small>EXAMPLE Steel construction assemblies, such as
trusses and different kinds of frames, can be represented by the
<i>IfcElementAssembly</i> entity. Other examples include slab
fields aggregated from a number of precast concrete slabs or
reinforcement units made from several reinforcement bars. Also
bathroom units, staircase sections and other premanufactured or
precast elements are examples of the general
<i>IfcElementAssembly</i> entity</small></blockquote>
<blockquote><small>NOTE The <i>IfcElementAssembly</i> is a
general purpose entity that is required to be decomposed. Also
other subtypes of IfcElement can be decomposed, with some
dedicated entities such as <i>IfcWallElementedCase</i> and
<i>IfcSlabElementedCase</i>.</small></blockquote>
<p>The assembly structure can be nested, i.e. an
<i>IfcElementAssembly</i> could be an aggregated part within
another <i>IfcElementAssembly</i>.</p>
<blockquote><small>NOTE View definitions and/or implementer
agreements may restrict the number of allowed levels of
nesting.</small></blockquote>
<blockquote class="history">HISTORY New Entity for
Release IFC2x Edition 2.</blockquote>
<p class="use-head">Containment Use Definition</p>
<p>The <i>IfcElementAssembly</i> should have (and in most
implementation scenarios it is mandatory) a relationship for its
hierachical containment in the spatial structure of the
project.</p>
<ul>
<li>The <i>IfcElementAssembly</i> is places within the project
spatial hierarchy using the objectified relationship
<i>IfcRelContainedInSpatialStructure</i>, refering to it by its
inverse attribute <i>SELF\IfcElement.ContainedInStructure</i>.
Subtypes of <i>IfcSpatialStructureElement</i> are valid spatial
containers, with <i>IfcBuildingStorey</i> being the default
container.</li>
</ul>
<p>The <i>IfcElementAssembly</i> shall represent an aggregate,
i.e. it should have other elements, being subtypes of
<i>IfcElement</i>, as contained (sub)parts.</p>
<ul>
<li>The <i>IfcElementAssembly</i> is an aggregate i.e. being
composed by other elements and acting as an assembly using the
objectified relationship <i>IfcRelAggregates</i>, refering to it
by its inverse attribute
<i>SELF\IfcObjectDefinition.IsDecomposedBy</i>. Components of an
assembly are described by instances of subtypes of
<i>IfcElement</i>.</li>
<li>In this case, the containedsubtypes of <i>IfcElement</i>
shall not be additionally contained in the project spatial
hierarchy, i.e. the inverse attribute
<i>SELF\IfcElement.ContainedInStructure</i> of those
<i>IfcElement</i>'s shall be <i>NIL.</i></li>
</ul>
<p>Figure 27 illustrates spatial containment and element aggregation relationships.</p>
<table border="0" cellpadding="2" cellspacing="2" summary=
"containment">
<tr><td><img src="figures/IfcElementAssembly-Containment.png" alt="containment relationships" width="500" height="250" border="0"></td></tr>
<tr><td><p class="figure">Figure 27 — Element assembly containment</p></td></tr>
</table>
<p class="use-head">Geometry Use Definitions</p>
<p>The geometric representation of <i>IfcElementAssembly</i> is
given by the <i>IfcProductDefinitionShape</i>, allowing multiple
geometric representations.</p>
<p><b>Local Placement</b></p>
<p>The local placement for <i>IfcElementAssembly</i> is defined
in its supertype <i>IfcProduct</i>. It is defined by the
<i>IfcLocalPlacement</i>, which defines the local coordinate
system that is referenced by all geometric representations.</p>
<ul>
<li>The <i>PlacementRelTo</i> relationship of
<i>IfcLocalPlacement</i> shall point (if given) to the local
placement of the same <i>IfcSpatialStructureElement</i> that is
used in the <i>ContainedInStructure</i> inverse attribute or to a
referenced spatial structure element at a higher level.</li>
<li>If the relative placement is not used, the absolute placement
is defined within the world coordinate system.</li>
</ul>
<p><u><b>Geometric Representations</b></u></p>
<p>The geometry of an <i>IfcElementAssembly</i> is generally
formed from its components, in which case it does not need to
have an explicit geometric representation. In some cases it may
be useful to also expose an own explicit representation of the
aggregate.</p>
<blockquote><small>NOTE View definitions or implementer
agreements may further constrain the applicability of certain
shape representations at the <i>IfcElementAssembly</i> in respect
of the shape representations of its parts.</small></blockquote>
<p><u>Informal proposition</u></p>
<ol>
<li>The <i>IfcElementAssembly</i> shall have an aggregation
relationship to the contained parts, i.e. the (INV)
<i>IsDecomposedBy</i> relationship shall be utilzed.</li>
</ol>
</EPM-HTML>
|
| 98 | 688 | IfcVirtualElement | <EPM-HTML>
<p>A virtual element is a special element used to provide imaginary boundaries, such as between two adjacent, but not separated, spaces. Virtual elements are usually not displayed and does not have quantities and other measures. Therefore <i>IfcVirtualElement</i> does not have material information and quantities attached.</p>
<blockquote class="note">NOTE The main purpose of <i>IfcVirtualElement</i> is the provision of a virtual space boundary. The <i>IfcVirtualElement</i> may provide the 2D curve or 3D surface representation of the virtual space connection and is referenced by two instances of <i>IfcRelSpaceBoundary</i>, each pointing to one of the two adjacent <i>IfcSpaces</i>.</blockquote>
<blockquote class="history">HISTORY New entity in IFC Release 2x2 Addendum.</blockquote>
<blockquote class="change-ifc2x3">IFC2x2 CHANGE: The entity <i>IfcVirtualElement</i> has been added. Upward compatibility for file based exchange is guaranteed.</blockquote>
<p class="use-head">Space Boundary Use Definition</p>
<p>The <i>IfcVirtualElement</i> is mainly used to define a virtual boundary between two spaces. Figure 63 describes how to use <i>IfcRelSpaceBoundary</i> in conjunction with <i>IfcVirtualElement</i> to define space boundaries.</p>
<table>
<tr><td><img src="figures/IfcVirtualElement_SpaceBoundaries.png" alt=
"space boundary" width="800" height="300"></td></tr>
<tr><td><p class="figure">Figure 63 — Virtual element space boundaries</p></td></tr>
</table>
<p class="use-head">Geometry Use Definition</p>
<p>The geometric representation of any <i>IfcVirtualElement</i>
is given by the <i>IfcProductDefinitionShape</i> and
<i>IfcLocalPlacement</i> allowing multiple geometric
representations. Included are:</p>
<p><b>Local Placement</b></p>
<p>The local placement for <i>IfcVirtualElement</i> is defined in
its supertype <i>IfcProduct</i>. It is defined by the
<i>IfcLocalPlacement</i>, which defines the local coordinate
system that is referenced by all geometric representations.</p>
<ul>
<li>The <i>PlacementRelTo</i> relationship of
<i>IfcLocalPlacement</i> shall point (if given) to the local
placement of the same <i>IfcSpatialStructureElement</i> that is
used in the <i>ContainedInStructure</i> inverse attribute or to a
referenced spatial structure element at a higher level.</li>
<li>If the relative placement is not used, the absolute placement
is defined within the world coordinate system.</li>
</ul>
<p><b>Geometric Representation</b></p>
<p>Currently, the use of 'FootPrint' and 'Surface' representation
is supported.</p>
<p><b>FootPrint Representation</b></p>
<p>The 2D geometric representation of <i>IfcVirtualElement</i> is
defined using the 'FootPrint' representation.</p>
<ul>
<li><i>IfcShapeRepresentation.RepresentationIdentifier</i> =
'FootPrint'.</li>
<li><i>IfcShapeRepresentation.RepresentationType</i> = 'Curve2D'
or 'GeometricCurveSet' .</li>
</ul>
<p>The following constraints apply to the 2D FootPrint
representation:</p>
<ul>
<li>'Curve2D': <i>IfcPolyline</i>, <i>IfcTrimmedCurve</i> or
<i>IfcCompositeCurve</i></li>
<li>'GeometricCurveSet': a list of 2D curves within the
constraints shown above.</li>
</ul>
<p><b>Surface Representation</b></p>
<p>The 3D geometric representation of <i>IfcVirtualElement</i> is
defined using a surface geometry.</p>
<ul>
<li><i>IfcShapeRepresentation.RepresentationIdentifier</i> =
'Surface'.</li>
<li><i>IfcShapeRepresentation.RepresentationType</i> =
'Surface3D' or 'GeometricSet .</li>
</ul>
<p>The following constraints apply to the 3D surface
representation:</p>
<ul>
<li>'Surface3D': <i>IfcSurfaceOfLinearExtrusion</i>,
<i>IfcCurveBoundedPlane</i>, <i>IfcCurveBoundedSurface</i>,
<i>IfcRectangularTrimmedSurface</i></li>
<li style="list-style-type: none;"><small>in case of an
<i>IfcSurfaceOfLinearExtrusion</i></small>
<ul>
<li><small><u>Profile</u>:
<i>IfcArbitraryOpenProfileDef</i></small></li>
<li><small><u>Extrusion</u>: The extrusion direction shall be
vertically, i.e., along the positive Z Axis of the co-ordinate
system of the containing spatial structure element.</small></li>
</ul>
</li>
<li style="list-style-type: none;"><small>in case of an
<i>IfcCurveBoundedPlane</i>, <i>IfcCurveBoundedSurface</i>,
<i>IfcRectangularTrimmedSurface</i></small>
<ul>
<li><small><u>Extrusion</u>: The <i>BasisSurface</i> shall be a
surface that is upright, i.e. standing perpendicular to the xy
place of the co-ordinate system of the containing spatial
structure element.</small></li>
</ul>
</li>
<li>'GeometricSet': a list of 3D surfaces within the constraints
shown above.</li>
</ul>
</EPM-HTML> |
| 99 | 689 | IfcGeographicElement | <EPM-HTML>
<p><u>Definition from IAI</u>: An <i>IfcGeographicElement</i> is
a generalization of all elements within a geographical landscape.
It includes occurrences of typical geographical element, often
referred to as features, such as roads, zones, trees, etc. Common
type information behind several occurrences of
<i>IfcGeographicElement</i> is provided by the
<i>IfcGeographicElementType</i>.</p>
<blockquote><small><font color="#0000FF">HISTORY New entity in
Release IFC2x4.</font></small></blockquote>
<p><u><b>Type Use Definition</b></u></p>
<p>An <i>IfcGeographicElement</i> defines the occuurence of any
element within a geographic landscape, common information about
geographic elements is handled by
<i>IfcGeographicElementType</i>. The
<i>IfcGeographicElementType</i> (if present) may establish the
commontype name, usage (or predefined) type, common set of
properties and common shape representations (using
<i>IfcRepresentationMap</i>). The <i>IfcGeographicElementType</i>
is attached using the <i>IfcRelDefinedByType.RelatingType</i>
objectified relationship and is accessible by the inverse
<i>IsDefinedBy</i> attribute.</p>
<p><b><u>Classification Use Definition</u></b></p>
<p>An <i>IfcGeographicElement</i> might be further qualified by
referencing a feature catalog as a particular classification. The
feature classification is assigned using the inverse relationship
<i>HasAssociations</i> pointing to
<i>IfcClassificationReference</i>. The attributes should have the
following meaning:</p>
<ul>
<li>Catalog : <i>IfcClassification.Name</i></li>
<li>Identity:
<i>IfcClassificationReference.ItemReference</i></li>
<li>ElementName: <i>IfcClassificationReference.Name</i></li>
<li>if there is a differentiation between an main element and a
sub element without a unique notation facet, then the main
element and sub element(s) can be established by using the
subtype
<ul>
<li style="list-style: none">
<i>IfcClassificationReferenceWithFacets.ItemReferenceFacets</i></li>
</ul>
</li>
</ul>
<p><u><b>Containment Use Definition</b></u></p>
<p>The <i>IfcGeographicElement</i>, as any subtype of
<i>IfcElement</i>, may participate in two different containment
relationships. The first (and in most implementation scenarios
mandatory) relationship is the hierachical spatial containment,
the second (optional) relationship is the aggregation within
anelement assembly.</p>
<ul>
<li>The <i>IfcGeographicElement</i> is places within the project
spatial hierarchy using the objectified relationship
<i>IfcRelContainedInSpatialStructure</i>, refering to it by its
inverse attribute <i>SELF\IfcElement.ContainedInStructure</i>.
Subtypes of<i>IfcSpatialStructureElement</i> are valid spatial
containers, with <i>IfcSite</i> being the default container.</li>
<li>The <i>IfcGeographicElement</i> may be aggregated into an
element assembly using the objectified relationship
<i>IfcRelAggregates</i>, refering to it by its inverse attribute
<i>SELF\IfcObjectDefinition.Decomposes</i>. Any subtype of
<i>IfcElement</i> can be an element assembly, with
<i>IfcElementAssembly</i> as a special focus subtype. In this
case it should not be additionally contained in the project
spatial hierarchy,
i.e.<i>SELF\IfcElement.ContainedInStructure</i> should be
<i>NIL.</i></li>
</ul>
<p><b><u>Geometry Use Definitions</u></b></p>
<p>The geometric representation of <i>IfcGeographicElement</i> is
given by the <i>IfcProductDefinitionShape</i>, allowing multiple
geometric representation.</p>
<p><b>Local Placement</b></p>
<p>The local placement for <i>IfcGeographicElement</i> is defined
in its supertype <i>IfcProduct</i>. It is defined by the
<i>IfcLocalPlacement</i>, which defines the local coordinate
system that is referenced by all geometric representations.</p>
<ul>
<li>The <i>PlacementRelTo</i> relationship of
<i>IfcLocalPlacement</i> shall point (if given) to the local
placement of the same <i>IfcSpatialStructureElement</i> , which
is used in the <i>ContainedInStructure</i> inverse attribute, or
to a spatial structure element at a higher level, referenced by
that.</li>
<li>If the relative placement is not used, the absolute placement
is defined within the world coordinate system.</li>
</ul>
<p><i><b>Geometric Representation</b></i></p>
<p><b>GeometricCurveSet and GeometricSet Representation</b></p>
<p>The standard representation of <i>IfcGeographicElement</i> is
defined using 'GeometricCurveSet' or, when including surfaces,
the 'GeometricSet' geometry. This also supports a 2D
representation of <i>IfcGeographicElement</i>.</p>
<p>The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'FootPrint' for 2D
representation</li>
<li><i>RepresentationType</i> :'GeometricCurveSet'
or'GeometricSet'</li>
</ul>
<p><b>Annotation2D Representation</b></p>
<p>Additional annotation objects, like text or hatching, and
style information to the 2D representations, may be exchanged
using the 'Annotation2D' representation. Style information is
assigned to the geometric representation items within the set of
<i>Items</i> at <i>IfcShapeRepresentation</i> using the inverse
StyledByItem relationship.</p>
<p>The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'FootPrint' for 2D
representation</li>
<li><i>RepresentationType</i> :'Annotation2D'</li>
</ul>
<p><b>SurfaceModel and Brep Representation</b></p>
<p>For full 3D representations, the use of 'SurfaceModel' and
'Brep' geometry is supported. This supports a 3D representation,
including support for 3D digital terrain models.</p>
<p>The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Body' for 3D
representation</li>
<li><i>RepresentationType</i> :'SurfaceModel' or'Brep'</li>
</ul>
<b>MappedRepresentation Representation</b><br>
<p>When using the <i>IfcGeographicElement</i> in conjunction with
the <i>IfcGeographicElementType</i> having
<i>RepresentationMaps</i> defined, the geometric representation
of<i>IfcGeographicElement</i>shall be based on
'MappedRepresentation', referencing the
<i>IfcRepresentationMap</i> given at the type object.</p>
<p>The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'FootPrint' for 2D
representation, 'Body' for 3D representation</li>
<li><i>RepresentationType</i> :'MappedRepresentation'</li>
</ul>
</EPM-HTML> |
| 100 | 693 | IfcRelInterferesElements | <EPM-HTML>
<p><u>Definition from IAI</u>: The
<i>IfcRelInterferesElements</i> objectified relationship
indicates that two elements interfere. Interference is a spatial
overlap between the two elements. It is a 1 to 1 relationship.
The concept of two elements interfering physically or logically
is described independently from the elements. The interference
may be related to the shape representation of the entities by
providing an interference geometry.</p>
<ul>
<li>When the interference geometry is available it can be passed
by the optional attribute <i>InterferenceGeometry</i> pointing to
<i>IfcConnectionGeometry</i>. The connection geometry is provided
as a point, curve, surface, or volume within the local placement
coordinate systems of the connecting elements. The
<i>IfcConnectionVolumeGeometry</i> is the default type to be used
for interference in 3D space, as indicated in e.g. clash
detections.</li>
<li>If the interference geometry is omitted then the interference
is provided as a logical relationship. Under this circumstance,
the connection point, curve, surface, or solid has to be
recalculated by the receiving application.</li>
</ul>
<p>The <i>RelatingElement</i> and <i>RelatedElement</i> define
the two elements in the relationship, that may have different
roles. This is controlled by the attribute
<i>ImpliedOrder</i>.</p>
<ul>
<li><i>ImpliedOrder</i>=TRUE The <i>RelatingElement</i>
constitutes the primary element of the interference relationship.
If the interference is to be resolved by subtracting the
overlapping part, it should be subtracted from the
<i>RelatingElement</i>. The net result would be the
<i>RelatingElement</i> subtracted by the
<i>InterferenceGeometry</i>. This would be the case in
interference relationships where the <i>RelatedElement</i>
creates a void in the <i>RelatingElement</i> dynamically.</li>
<li><i>ImpliedOrder</i>=FALSE The <i>RelatingElement</i> and
<i>RelatedElement</i> have no priority among each other. If the
interference is to be resolved then no information about whether
the <i>InterferenceGeometry</i> should be subtracted from the
<i>RelatingElement</i> or thed <i>RelatedElement</i> can be
traced. This would be the case for clash detection results.</li>
<li><i>ImpliedOrder</i>=UNKNOW No information about the
priorities is provided.</li>
</ul>
<blockquote><small><font color="#0000FF">HISTORY New entity in
IFC2x4.</font></small></blockquote>
</EPM-HTML> |
| 101 | 700 | IfcRelReferencedInSpatialStructure | <EPM-HTML>
<p>
The objectified relationship,
<i>IfcRelReferencedInSpatialStructure</i> is used to
assign elements in addition to those levels of the project
spatialstructure, in which they are referenced, but not
primarily contained.
</p>
<blockquote>
<p>
<small>NOTE The primary containment relationship between
an element and the spatial structure is handled
by<i>IfcRelContainsInSpatialStructure</i>.</small>
</p>
</blockquote>
<p>
Any element can be referencedto zero, one or several
levels of the spatial structure. Whereas the
<i>IfcRelContainsInSpatialStructure</i> relationship is
required to be hierarchical (an element can only be
contained in exactly one spatial structure element), the
<i>IfcRelReferencedInSpatialStructure</i> is not restricted
to be hierarchical.
</p>
<blockquote>
<p>
<small>EXAMPLE A wall might be normally contained within
a storey, and since it does not span through several
stories, it is not referenced in any additional storey.
However a curtain wall might span through several
stories, in this case it can be contained within the
ground floor, but it would be referenced by all
additional stories, it spans.</small>
</p>
</blockquote>
<p>
Predefined spatial structure elements to which elements can
be assigned are
</p>
<ul>
<li>site as <i>IfcSite</i>
</li>
<li>building as <i>IfcBuilding</i>
</li>
<li>storey as <i>IfcBuildingStorey</i>
</li>
<li>space as <i>IfcSpace</i>
</li>
</ul>
<p>Elements can also be references in a spatial zone that is provided as <i>IfcSpatialZone</i>.</p>
<p>
The same element can be assigned to different spatial
structure elements depending on the context.
</p>
<blockquote>
<small><font color="#0000FF">HISTORY New entity
inRelease IFC2x Edition 3.</font></small>
</blockquote>
<p class="use-head">Use Definition</p>
<p>Figure 41 shows the use of <i>IfcRelContainedInSpatialStructure</i> and <i>IfcRelReferencedInSpatialStructure</i> to assign an <i>IfcCurtainWall</i>to two different levels within the spatial structure. It is primarily contained within the ground floor, and additionally referenced within the first and second floor.</p>
<table cellpadding="2" cellspacing="2" width="80%">
<tbody>
<tr valign="top">
<td align="left" valign="top"><img alt="reference and containment" src="figures/IfcRelReferencedInSpatialStructure-Fig1.png" height="601" width="601"><br>
</td>
</tr>
<tr>
<td><p class="figure">Figure 41 — Relationship for spatial structure referencing</p></td>
</tr>
</tbody>
</table>
</EPM-HTML> |
| 102 | 704 | IfcRelConnectsWithRealizingElements | <EPM-HTML>
<p>
<u>Definition from IAI</u>:
<i>IfcRelConnectsWithRealizingElements</i> defines a
generic relationship that is made between two elements that
require the realization of that relationship by means of
further realizing elements.
</p>
<p>
An <i>IfcRelConnectsWithRealizingElements</i> is a
specialization of <i>IfcRelConnectsElement</i> where the
connecting operation has the additional attribute of (one
or many) realizing elements that may be used to realize or
further qualify the relationship. It is defined as a
ternary relationship.
</p>
<blockquote>
<p>
<font size="-1">EXAMPLE: It may be used to describe the
attachment of one element to another where the attachment
is realized by a 'fixing' element such as a bracket. It
may also be used to describe the mounting of one element
onto another such as the requirement for the mounting
major plant items onto builders work bases and/or
anti-vibration isolators.</font>
</p>
</blockquote>
<blockquote>
<p>
<small><font color="#0000FF">HISTORY: New entity in
Release IFC2x Edition 2.</font></small>
</p>
</blockquote>
</EPM-HTML> |
| 103 | 707 | IfcRelContainedInSpatialStructure | <EPM-HTML>
<p>
This objectified relationship,
<i>IfcRelContainedInSpatialStructure</i>, is used to assign
elements to a certain level of the spatial project
structure. Any element can only be assigned once to a
certain level of the spatial structure. The question, which
level is relevant for which type of element, can only be
answered within the context of a particular project and
might vary within the various regions.
</p>
<blockquote>
<p>
<small>EXAMPLE A multi-storey space is contained (or
belongs to) the building storey at which its ground level
is, but it is referenced by all the other building
storeys, in which it spans. A lift shaft might be
contained by the basement, but referenced by all storeys,
through which it spans.</small>
</p>
</blockquote>
<p>
The containment relationship of an element within a
spatial structure has to be a hierarchical relationship, an
element can only be contained within a single spatial
structure element. The reference relationship between an
element and the spatial structure may not be hierarchical,
i.e. an element can reference many spatial structure
elements.
</p>
<blockquote>
<p>
<small>NOTE The reference relationship is expressed by
<i>IfcRelReferencedInSpatialStructure</i>.</small>
</p>
</blockquote>
<p>
Predefined spatial structure elements to which elements can
be assigned are
</p>
<ul>
<li>site as <i>IfcSite</i>
</li>
<li>building as <i>IfcBuilding</i>
</li>
<li>storey as <i>IfcBuildingStorey</i>
</li>
<li>space as <i>IfcSpace</i>
</li>
</ul>
<p>
Occurrences of the same element type can be assigned to
different spatial structure elements depending on the
context of the occurrence.
</p>
<blockquote>
<p>
<font size="-1">EXAMPLE A wall might be normally assigned
to a storey, however the curtain wall might be assigned
to the building and the retaining wall in the terrain
might be assigned to the site.</font>
</p>
</blockquote>
<blockquote>
<p>
<small><font color="#0000FF">HISTORY New entity in IFC
Release 2x.</font></small>
</p>
</blockquote>
<blockquote>
<font color="#FF0000" size="-1">IFC2x PLATFORM CHANGE: The
data type of the attribute <i>RelatedElements</i> has been
changed from <i>IfcElement</i> to its supertype
<i>IfcProduct</i> with upward compatibility for file based
exchange.</font>
</blockquote>
<p class="use-head">Containment Use Definition</p>
<p>Figure 39 shows the use of <i>IfcRelContainedInSpatialStructure</i> to assign a stair and two walls to two different levels within the spatial structure.</p>
<table cellpadding="2" cellspacing="2">
<tr valign="top">
<td valign="top" align="left">
<img src=
"figures/IfcRelContainedInSpatialStructure-Fig1.png"
alt="fig1" width="556" height="556" border="0">
</td>
</tr>
<tr><td><p class="figure">Figure 39 — Relationship for spatial structure containment</p></td></tr>
</table>
</EPM-HTML> |
| 104 | 711 | IfcGrid | <EPM-HTML>
<p><i>IfcGrid</i> ia a planar design
grid defined in 3D space used as an aid in locating structural and
design elements. The position of the grid (<i>ObjectPlacement</i>)
is defined by a 3D coordinate system (and thereby the design grid
can be used in plan, section or in any position relative to the
world coordinate system). The position can be relative to the
object placement of other products or grids. The XY plane of the 3D
coordinate system is used to place the grid axes, which are 2D
curves (for example, line, circle, trimmed curve, polyline, or composite
curve).</p>
<p>The inherited attributes <i>Name</i> and <i>Description</i> can
be used to define a descriptive name of the grid and to indicate
the grid's purpose. A grid is defined by (normally) two, or
(in case of a triangular grid) three lists of grid axes. The
following table shows some examples.</p>
<p>A grid may support a rectangular layout (Figure 28), a radial layout (Figure 29), or a triangular layout (Figure 30).</p>
<table cellpadding="2" cellspacing="2">
<tbody>
<tr>
<td width="320"><img src="figures/IfcDesignGrid-Type1.gif" alt="1" border="0" height="211" width="306"></td>
<td width="320"><img src="figures/IfcDesignGrid-Type2.gif" alt="2" border="0" height="211" width="306"></td>
<td width="320"><img src="figures/IfcDesignGrid-Type3.gif" alt="3" border="0" height="211" width="306"></td>
</tr>
<tr>
<td width="320"><p class="figure">Figure 28 — Grid rectangular layout</p></td>
<td width="320"><p class="figure">Figure 29 — Grid radial layout</p></td>
<td width="320"><p class="figure">Figure 30 — Grid triangular layout</p></td>
</tr>
</tbody>
</table>
<p>The grid axes, defined within the design grid, are those
elements to which project objects will be placed relatively using
the <i>IfcGridPlacement</i>.</p>
<blockquote class="history">HISTORY New entity in IFC Release 1.0.</blockquote>
<p><u>Informal Proposition</u></p>
<ol>
<li>Grid axes, which are referenced in different lists of axes
(UAxes, VAxes, WAxes) shall not be parallel.</li>
<li>Grid axes should be defined such as there are no two grid axes
which intersect twice (see Figure 31).
<ul>
<li>left side: ambiguous intersections A1 and A2, a grid containing
such grid axes is not a valid design grid.</li>
<li>right side: the conflict can be resolved by splitting one grid
axis in a way, such as no ambiguous intersections exist.</li>
</ul>
</li>
</ol>
<table cellpadding="2" cellspacing="2">
<tbody>
<tr valign="top"><td align="left" valign="top" width="320"><img src=
"figures/IfcDesignGrid-IP2.gif" alt="IP2" border="0" height="97"
width="306"></td></tr>
<tr><td><p class="figure">Figure 31 — Grid intersections</p></td></tr>
</tbody>
</table>
<p class="use-head">Geometry Use Definitions</p>
<p>The geometric representation of <i>IfcGrid</i> is given by the
<i>IfcProductDefinitionShape</i>, allowing geometric
representations. Included are:</p>
<p><b>Local Placement</b></p>
<p>The local placement for <i>IfcGrid</i> is defined in its
supertype <i>IfcProduct</i>. It is defined by the
<i>IfcLocalPlacement</i>, which defines the local coordinate system
that is referenced by all geometric representations.</p>
<ul>
<li>The <i>PlacementRelTo</i> relationship of
<i>IfcLocalPlacement</i> shall point (if given) to the local
placement of the same <i>IfcSpatialStructureElement</i>, which is
used in the <i>ContainedInStructure</i> inverse attribute, or to a
spatial structure element at a higher level, referenced by
that.</li>
<li>If the relative placement is not used, the absolute placement
is defined within the world coordinate system.</li>
</ul>
<p><b><i>Geometric Representations</i></b></p>
<p>Currently, the use of a 2D 'FootPrint' representation of type
'GeometricCurveSet' is supported.</p>
<p><b>GeometricCurveSet representation</b></p>
<p>The 2D geometric representation of <i>IfcGrid</i> is defined
using the 'GeometricCurveSet' geometry. The following attribute
values should be inserted</p>
<ul>
<li><i>IfcShapeRepresentation.RepresentationIdentifier</i> =
'FootPrint'.</li>
<li><i>IfcShapeRepresentation.RepresentationType</i> =
'GeometricCurveSet' .</li>
</ul>
<p>The following constraints apply to the 2D representation:</p>
<ul>
<li>The <i>IfcGeometricCurveSet</i> shall be an (and the only)
<i>Item</i> of the <i>IfcShapeRepresentation</i>. It should contain
an <i>IfcGeometricCurveSet</i> containing subtypes of
<i>IfcCurve</i>, each representing a grid axis. Applicable subtypes
of <i>IfcCurve</i> are: <i>IfcPolyline</i>, <i>IfcCircle</i>,
<i>IfcTrimmedCurve</i> (based on <i>BaseCurve</i> referencing
<i>IfcLine</i> or <i>IfcCircle</i>). </li>
<li>Each subtype of <i>IfcCurve</i> may have a curve style
assigned, using <i>IfcAnnotationCurveOccurrence</i> referencing
<i>IfcCurveStyle</i>.</li>
<li>Optionally the grid axis labels may be added as
<i>IfcTextLiteral</i>, and they may have text styles assigned,
using <i>IfcAnnotationTextOccurrence</i> referencing
<i>IfcTextStyle</i>.</li>
</ul>
<p>As shown in Figure 32, the <i>IfcGrid</i> defines a placement coordinate system using the <i>ObjectPlacement</i>. The XY plane of the coordinate system is used to place the 2D grid axes. The <i>Representation</i> of <i>IfcGrid</i> is defined using <i>IfcProductRepresentation</i>, referencing an <i>IfcShapeRepresentation</i>, that includes <i>IfcGeometricCurveSet</i> as <i>Items</i>. All grid axes are added as <i>IfcPolyline</i> to the <i>IfcGeometricCurveSet</i>.</p>
<table cellpadding="2" cellspacing="2"><tbody>
<tr><td><img src="figures/IfcDesignGrid-Layout1.gif" alt="design grid" border="0" height="300" width="400"></td></tr>
<tr><td><p class="figure">Figure 32 — Grid layout</p></td></tr>
</tbody></table>
<p>As shown in Figure 33, the attributes <i>UAxes</i> and <i>VAxes</i> define lists of <i>IfcGridAxis</i> within the context of the grid. Each instance of <i>IfcGridAxis</i> refers to the same instance of <i>IfcCurve</i> (here the subtype <i>IfcPolyline</i>) that is contained within the <i>IfcGeometricCurveSet</i> that represents the <i>IfcGrid</i>.</p>
<table cellpadding="2" cellspacing="2"><tbody>
<tr><td><img src="figures/IfcGrid-Representation.png" alt="representation of a design grid" width="501" height="621" border="0"></td></tr>
<tr><td><p class="figure">Figure 33 — Grid representation</p></td></tr>
</tbody></table>
</td>
</tr>
</tbody>
</table>
</EPM-HTML> |
| 105 | 717 | IfcAnnotation | <EPM-HTML>
<p>
<u>Definition from IAI</u>: An annotation is a graphical
representation within the geometric (and spatial) context
of a project, that adds a note or meaning to the objects
which constitutes the project model. Annotations include
additional line drawings, text, dimensioning, hatching and
other forms of graphical notes.
</p>
<blockquote>
<p>
<small>NOTE Additional presentation information (often
2D) such as tag number, hatching, etc., that is directly
related to a particular product representation is
included within the <i>IfcProductDefinitionShape</i>
having various <i>IfcShapeRepresentation</i>'s of the
<i>IfcElement</i> (and its subtypes). Only those
presentation information, that cannot be directly related
to a single product, have to be wrapped within the
<i>IfcAnnotation</i>.</small>
</p>
</blockquote>
<p>
If available, the annotation should be related to the
spatial context of the project, by containing the
annotation within the appropriate level of the building
structure (site, building, storey, or space). This is
handled by the <i>IfcRelContainedInSpatialStructure</i>
relationship.
</p>
<blockquote>
<p>
<font color="#0000FF" size="-1">HISTORY: New entity in
Release IFC2x Edition 2.</font>
</p>
</blockquote>
<p>
<u><b>Use definition</b></u>
</p>
<p>
The <i>IfcAnnotation</i> can provide specific 0D, 1D, and
2D geometric items as representation of the annotation,
offering annotation point, curves, and surfaces.
</p>
<ul>
<li>
<b>'Annotation point'</b> is an annotation provided by a
point that has additional semantic. The inherited
attribute <i>ObjectType</i> should be used to capture the
type of point annotation, some predefined values are:
</li>
<li style="list-style: none">
<ul>
<li>'<b>Survey</b>': A survey point has a set of
cartesian coordinates determined by its location at
point. These coordinates are determined relative to the
coordinates of a reference point, which acts as the
datum for the survey. The difference in elevation of
the survey points enables terrain to be determined.<br>
<br>
</li>
</ul>
</li>
<li>
<b>'Annotation curve'</b> is an annotation provided by a
curve that has additional semantic. The inherited
attribute <i>ObjectType</i> should be used to capture the
type of curve annotation, some predefined values are:
</li>
<li style="list-style: none">
<ul>
<li>'<b>ContourLine</b>': A line of constant
elevation typically used on geographic maps where the
spacing of lines at constant intervals of elevation may
be used as an indication of slope.
</li>
<li>'<b>IsoBar</b>': A line of constant pressure
typically used on weather maps or to show pressure
gradient in spaces, chambers or externally.
</li>
<li>'<b>IsoLux</b>': A line of constant illumination
typically used to show the distribution of illumination
levels and/or daylighting in a space or externally.
</li>
<li>'<b>IsoTherm</b>': A line of constant temperature
typically used to show the distribution and effect of
heating or cooling within a space or to show
temperature distribution on a geographic map.<br>
<br>
</li>
</ul>
</li>
<li>
<b>'Annotation surface'</b> is an annotation provided by
a surface that has additional semantic. The inherited
attribute <i>ObjectType</i> should be used to capture the
type of surface annotation, some predefined values are:
</li>
<li style="list-style: none">
<ul>
<li>'<b>SurveyArea</b>': A surface patch based on
survey points.<br>
<br>
</li>
</ul>
</li>
</ul>
<p>
<u><b>Geometry Use Definitions</b></u>
</p>
<p>
The geometric representation of any <i>IfcAnnotation</i> is
given by the <i>IfcProductDefinitionShape</i> and
<i>IfcLocalPlacement</i> allowing multiple geometric
representations.
</p>
<p>
<b>Local Placement</b>
</p>
<p>
The local placement for any <i>IfcAnnotation</i> is defined
in its supertype <i>IfcProduct</i>. It is defined by the
<i>IfcLocalPlacement</i>, which defines the local
coordinate system that is referenced by all geometric
representations.
</p>
<ul>
<li>The <i>PlacementRelTo</i> relationship of
<i>IfcLocalPlacement</i> shall point (if given) to the
local placement of the same
<i>IfcSpatialStructureElement</i>, which is used in the <i>
ContainedInStructure</i> inverse attribute, or to a
spatial structure element at a higher level, referenced
by that.
</li>
<li>If the relative placement is not used, the absolute
placement is defined within the world coordinate system.
</li>
</ul>
<p>
<i><b>Geometric Representations</b></i>
</p>
<p>
The standard representation of <i>IfcAnnotation</i> is
defined using 'Annotation2D', when using 2D geometry,
hatching and text, 'GeometricCurveSet' when using points
and curves, or, when including als surfaces, the
'GeometricSet' geometry. Geometric representation items may
be styled items by adding the style information.
</p>
<p>
<b>Annotation2D Representation</b><br>
This representation is used, when the representation of the
<i>IfcAnnotation</i> includes specific drafting
representation elements. The Annotation may have:
</p>
<ul>
<li>subtypes of <i>IfcPoint</i>, <i>IfcCurve</i> being 2D
</li>
<li style="list-style: none">directly as <i>Items</i>, or
within an <i>IfcGeometricCurveSet</i>
</li>
<li>subtypes of <i>IfcAnnotationFillArea</i> for hatches
</li>
<li>subtypes of <i>IfcDefinedSymbol</i> for symbols
</li>
<li>subtypes of <i>IfcTextLiteral</i> for text
</li>
<li>subtypes of <i>IfcDraughtingCallout</i> for dimensions
</li>
</ul>The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:
<ul>
<li>
<i>RepresentationIdentifier</i> : 'Annotation'
</li>
<li>
<i>RepresentationType</i> : 'Annotation2D'
</li>
</ul>
<p>
<b>Annotation Curve Representation</b><br>
This representation is used, when the representation of the
<i>IfcAnnotation</i> does not includes specific drafting
representation elements. The Annotation may have:
</p>
<ul>
<li>subtypes of <i>IfcPoint</i>, <i>IfcCurve</i> being 2D
</li>
<li style="list-style: none">directly as <i>Items</i>, or
within an <i>IfcGeometricCurveSet</i>
</li>
</ul>The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:
<ul>
<li>
<i>RepresentationIdentifier</i> : 'Annotation'
</li>
<li>
<i>RepresentationType</i> : 'GeometricCurveSet'
</li>
</ul>
<p>
<b>Annotation Surface Representation</b><br>
This representation is used, when the representation of the
<i>IfcAnnotation</i> does includes surfaces. The Annotation
may have:
</p>
<ul>
<li>subtypes of <i>IfcPoint</i>, <i>IfcCurve</i>, or
<i>IfcSurface</i>
</li>
<li style="list-style: none">directly as <i>Items</i>, or
within an <i>IfcGeometricCurveSet</i>
</li>
</ul>The following attribute values for the
<i>IfcShapeRepresentation</i> holding this geometric
representation shall be used:
<ul>
<li>
<i>RepresentationIdentifier</i> : 'Annotation'
</li>
<li>
<i>RepresentationType</i> : 'GeometricSet'
</li>
</ul>
</EPM-HTML> |
| 106 | 719 | IfcSpatialZone | <EPM-HTML>
<p><u>Definition from IAI</u>: A spatial element is the
generalization of all spatial elements that might be used to
define a spatial structure or to define spatial zones.</p>
<ul>
<li>a hierarchical spatial structure element as
<i>IfcSpatialStructureElement</i>
<ul>
<li>a spatial structure is a hiearchical decomposition of the
project. That spatial structure is often used to provide a
project structure to organize a building project.</li>
<li>a spatial project structure might define as many levels of
decomposition as necessary for the building project. Elements
within the spatial project structure are site, building, storey,
and space</li>
</ul>
</li>
<li>a spatial zone as <i>IfcSpatialZone</i>
<ul>
<li>a spatial zone is a non-hierarchical and potentially
overlapping decomposition of the project under some functional
consideration.</li>
<li>a spatial zone might be used to represent a thermal zone, a
construction zone, a lighting zone, a usable area zone.</li>
<li>a spatial zone might have its independent placement and shape
representation.</li>
</ul>
</li>
</ul>
<blockquote><small>NOTE The <i>IfcSpatialZone</i> is different to
the <i>IfcZone</i> entity by allowing an own placement and shape
representation, whereas <i>IfcZone</i> is only a grouping of
<i>IfcSpace</i>'s.</small></blockquote>
<p><b>Attribute Use Definition</b></p>
<p>The <i>IfcSpatialZone</i> inherits and declares these
attributes that shall have the following meaning:</p>
<ul>
<li><i>Name</i>: A number or designator provided by the user or
system for the spatial element, e.g. a space number "1-003",
could also be a running number provided by default by the
application</li>
<li><i>LongName</i>: Name of the spatial element provided by the
user, e.g. a space name "Office".</li>
<li><i>Description</i>: Any additional description provided by
the user, e.g. a space description "Corner office with habour
view".</li>
<li><i>ObjectType</i>: reserved for typing of spatial elements in
case of <i>PredefinedType</i> = .USERDEFINED., restrictions on
applicable values might be published in view definitions or
implementer agreements.</li>
</ul>
<blockquote><small><font color="#0000FF">HISTORY New entity in
IFC Release 2x Edition 4.</font></small></blockquote>
</EPM-HTML> |
| 107 | 723 | IfcExternalSpatialStructureElement | <EPM-HTML>
<p><u>Definition from IAI</u>: The external spatial structure
element is an abstract entity provided for different kind of
external spaces, regions, and volumes.</p>
<blockquote><small><font color="#0000FF">HISTORY New entity in
IFC2x4.</font></small></blockquote>
</EPM-HTML> |
| 108 | 725 | IfcExternalSpatialElement | <EPM-HTML>
<p><u>Definition from IAI</u>: The external spatial element
defines external regions at the building site. Those regions can
be defined:</p>
<ul>
<li>logically - e.g. an instance of
<i>IfcExternalSpatialElement</i> could represent the air space
around the building without having an own shape representation,
or</li>
<li>physically - e.g. an instance of
<i>IfcExternalSpatialElement</i> could represent the sloping
ground around the building to identify the part of the external
building envelop that is below ground.</li>
</ul>
<blockquote><small><font color="#0000FF">HISTORY New entity in
IFC2x4.</font></small></blockquote>
</EPM-HTML> |
| 109 | 735 | IfcRelServicesBuildings | <EPM-HTML>
<p>
<u>Definition from IAI</u>: An objectified relationship
that defines the relationship between a system and the
sites, buildings, storeys or spaces, it serves. Examples of
systems are:
</p>
<ul>
<li>building service systems (heating, cooling, waste water
system) represented by instances of <i>IfcSystem</i>
</li>
<li>idealized structural analysis systems represented by
instances of <i>IfcStructuralAnalysisSystem</i>
</li>
</ul>
<blockquote>
<p>
<small><font color="#0000FF">HISTORY New entity in IFC
Release 1.0</font></small>
</p>
</blockquote>
<blockquote>
<small><font color="#FF0000">IFC2x PLATFORM CHANGE The
data type of the attribute<i>RelatedBuildings</i> has been
changed from <i>IfcBuilding</i> to its supertype
<i>IfcSpatialStructureElement</i> with upward compatibility
for file based exchange. The name
<i>IfcRelServicesBuildings</i> is a knownanomaly, as the
relationship is not restricted to buildings anymore.</font></small>
</blockquote>
</EPM-HTML> |
| 110 | 738 | IfcBuilding | <EPM-HTML>
<p><u>Definition from ISO 6707-1:1989</u>: Construction work that
has the provision of shelter for its occupants or contents as one
of its main purpose and is normally designed to stand permanently
in one place.</p>
<p>A building represents a structure
that provides shelter for its occupants or contents and stands in
one place. The building is also used to provide a basic element
within the spatial structure hierarchy for the components of a
building project (together with site, storey, and space).</p>
<p>A building is (if specified) associated to a site. A building
may span over several connected or disconnected buildings.
Therefore building complex provides for a collection of buildings
included in a site. A building can also be decomposed in
(vertical) parts, where each part defines a building section.
This is defined by the composition type attribute of the
supertype <i>IfcSpatialStructureElements</i> which is interpreted
as follow:</p>
<ul>
<li>COMPLEX = building complex</li>
<li>ELEMENT = building</li>
<li>PARTIAL = building section</li>
</ul>
<blockquote class="history">HISTORY New entity in IFC Release 1.0.</blockquote>
<p class="use-head">Property Set Use Definition</p>
<p>The property sets relating to the <i>IfcBuilding</i> are
defined by the <i>IfcPropertySet</i> and attached by the
<i>IfcRelDefinesByProperties</i> relationship. It is accessible
by the inverse <i>IsDefinedBy</i> relationship. The following
property set definitions specific to the <i>IfcBuilding</i> are
part of this IFC release:</p>
<ul>
<li><a href=
"../../psd/IfcProductExtension/Pset_BuildingCommon.xml" target=
"SOURCE">Pset_BuildingCommon</a>: common property set for all
types of buildings</li>
<li><a href=
"../../psd/IfcProductExtension/Pset_BuildingWaterStorage.xml"
target="SOURCE">Pset_BuildingWaterStorage</a>: specific property
set for buildings to capture the water supply requirements</li>
<li><a href="../../psd/IfcProductExtension/Pset_BuildingUse.xml"
target="SOURCE">Pset_BuildingUse</a>: specific property set for
buildings to capture the current and anticipated real estate
context.</li>
<li><a href=
"../../psd/IfcProductExtension/Pset_BuildingUseAdjacent.xml"
target="SOURCE">Pset_BuildingUseAdjacent</a>: specific property
set for buildings to capture the use information about the
adjacent buildings.</li>
</ul>
<p class="use-head">Quantity Use Definition</p>
<p>The quantities relating to the <i>IfcBuilding</i> are defined
by the <i>IfcElementQuantity</i> and attached by the
<i>IfcRelDefinesByProperties</i> relationship. It is accessible
by the inverse <i>IsDefinedBy</i> relationship. The following
base quantities are defined and should be exchanged with the
<i>IfcElementQuantity.Name</i> = 'BaseQuantities'. Other
quantities, being subjected to local standard of measurement, can
be defined with another string value assigned to <i>Name</i>. In
this case a valid value for <i>MethodOfMeasurement</i> has to be
provided.</p>
<ul>
<li><a href=
"../../qto/IfcProductExtension/Qto_BuildingBaseQuantities.xml"
target="SOURCE">Qto_BuildingBaseQuantities</a>: base quantities
for all building occurrences.</li>
</ul>
<p class="use-head">Spatial Structure Use Definition</p>
<p>The <i>IfcBuilding</i> is used to build the spatial structure
of a building (that serves as the primary project breakdown and
is required to be hierarchical). The spatial structure elements
are linked together by using the objectified relationship
<i>IfcRelAggregates</i>. The <i>IfcBuilding</i> references them
by its inverse relationships:</p>
<ul>
<li><i>IfcBuilding.Decomposes</i> -- referencing (<i>IfcSite</i>
|| <i>IfcBuilding</i>) by <i>IfcRelAggregates.RelatingObject</i>,
If it refers to another instance of <i>IfcBuilding</i>, the
referenced <i>IfcBuilding</i> needs to have a different and
higher <i>CompositionType</i>, i.e. COMPLEX (if the other
<i>IfcBuilding</i> has ELEMENT), or ELEMENT (if the other
<i>IfcBuilding</i> has PARTIAL).</li>
<li><i>IfcBuilding.IsDecomposedBy</i> -- referencing
(<i>IfcBuilding</i> || <i>IfcBuildingStorey</i>) by
<i>IfcRelAggregates.RelatedObjects</i>. If it refers to another
instance of<i>IfcBuilding</i>, the referenced <i>IfcBuilding</i>
needs to have a different and lower CompositionType, i.e. ELEMENT
(if the other <i>IfcBuilding</i> has COMPLEX), or PARTIAL (if the
other <i>IfcBuilding</i> has ELEMENT).</li>
</ul>
<p>If there are building elements and/or other elements directly
related to the <i>IfcBuilding</i>(like a curtain wall spanning
several stories), they are associated with the <i>IfcBuilding</i>
by using the objectified relationship
<i>IfcRelContainedInSpatialStructure</i>. The <i>IfcBuilding</i>
references them by its inverse relationship:</p>
<ul>
<li><i>IfcBuilding.ContainsElements</i> -- referencing any
subtype of <i>IfcProduct</i> (with the exception of other spatial
structure element) by
<i>IfcRelContainedInSpatialStructure.RelatedElements</i>.</li>
</ul>
<p>Figure 20 shows the <i>IfcBuilding</i> as part of the spatial
structure. It also serves as the spatial container for building
and other elements.</p>
<blockquote class="note">NOTE Detailed requirements on mandatory element
containment and placement structure relationships are given in
view definitions and implementer agreements.</blockquote>
<table border="0" cellpadding="2" cellspacing="2" summary="Spatial structure">
<tr><td valign="top"><img src=
"figures/IfcBuilding-SpatialStructure.png" alt=
"IfcBuildingStorey as part of a spatial structure" width="800"
height="420" border="0"></td></tr>
<tr><td><p class="figure">Figure 20 — Building composition</p></td></tr>
</table>
<p>Systems, such as building service or electrical distribution
systems, zonal systems, or structural analysis systems, relate to
<i>IfcBuilding</i> by using the objectified relationship
<i>IfcRelServicesBuildings</i>.</p>
<p class="use-head">Attribute Use Definition</p>
<p>Figure 21 describes the heights and elevations of the <i>IfcBuilding</i>. It is used to provide the height above sea level of the project height datum for this building, that is, the internal height 0.00. The height 0.00 is often used as a building internal reference height and equal to the floor finish level of the ground floor.
<ul>
<li>base elevation of building provided by: <i>IfcBuilding.ElevationOfRefHeight</i>, it is usually the top of construction slab</li>
<li>base elevation of terrain at the perimeter of the building provided by: <i>IfcBuilding.ElevationOfTerrain</i>, it is usually the minimum elevation is sloped terrain</li>
<li>total height of building, also referred to as ridge height (top of roof structure, e.g the ridge against terrain): provided by BaseQuantity with Name="TotalHeight"</li>
<li>eaves height of building (base of roof structure, e.g the eaves against terrain): provided by BaseQuantity with Name="EavesHeight"</li>
</ul>
<table border="0" cellpadding="2" cellspacing="2">
<tbody>
<tr valign="top">
<td align="left" valign="top"><img src=
"figures/IfcBuilding_Heights.png" alt="building heights" border=
"0" height="420" width="800"></td></tr>
<tr><td><p class="figure">Figure 21 — Building elevations</p></td></tr>
</tbody>
</table>
<p class="use-head">Geometry Use Definitions</p>
<p>The geometric representation of <i>IfcBuilding</i> is given by
the <i>IfcProductDefinitionShape</i> and
<i>IfcLocalPlacement</i>, allowing multiple geometric
representation.</p>
<p><b>Local Placement</b></p>
<p>The local placement for <i>IfcBuilding</i> is defined in its
supertype <i>IfcProduct</i>. It is defined by the
<i>IfcLocalPlacement</i>, which defines the local coordinate
system that is referenced by all geometric representations.</p>
<ul>
<li>The <i>PlacementRelTo</i> relationship of
<i>IfcLocalPlacement</i> shall point (if relative placement is
used) to the <i>IfcSpatialStructureElement</i> of type
<i>IfcSite</i>, or of type <i>IfcBuilding</i> (e.g. to position a
building relative to a building complex, or a building section to
a building).</li>
<li>If the relative placement is not used, the absolute placement
is defined within the world coordinate system.</li>
</ul>
<p><b><i>Geometric Representations</i></b></p>
<p>Currently, the use of a 2D 'FootPrint' representation of type
'GeometricCurveSet' and a 3D 'Body' representation of type 'Brep'
is supported.</p>
<p><b>Foot Print Representation</b></p>
<p>The foot print representation of <i>IfcBuilding</i> is given
by either a single 2D curve (such as <i>IfcPolyline</i> or
<i>IfcCompositeCurve</i>), or by a list of 2D curves (in case of
inner boundaries), if the building has an independent geometric
representation.</p>
<p>The representation identifier and type of this geometric
representation of <i>IfcBuilding</i> is:</p>
<ul>
<li><i>IfcShapeRepresentation.RepresentationIdentifier</i> =
'FootPrint'</li>
<li><i>IfcShapeRepresentation.RepresentationType</i> =
'GeometricCurveSet'</li>
</ul>
<p><b>Body Representation</b></p>
<p>The body (or solid model) geometric representation (if the
building has an independent geometric representation) of
<i>IfcBuilding</i> is defined using faceted B-Rep capabilities
(with or without voids), based on the <i>IfcFacetedBrep</i> or on
the <i>IfcFacetedBrepWithVoids</i>.</p>
<p>The representation identifier and type of this representation
of <i>IfcBuilding</i> is:</p>
<ul>
<li><i>IfcShapeRepresentation.RepresentationIdentifier</i> =
'Body'</li>
<li><i>IfcShapeRepresentation.RepresentationType</i> =
'Brep'</li>
</ul>
<p>Since the building shape is usually described by the exterior
building elements, an independent shape representation shall only
be given, if the building is exposed independently from its
constituting elements.</p>
</EPM-HTML> |
| 111 | 742 | IfcBuildingStorey | <EPM-HTML>
<p>The building storey has an
elevation and typically represents a (nearly) horizontal
aggregation of spaces that are vertically bound.</p>
<p>A storey is (if specified) associated to a building. A storey
may span over several connected storeys. Therefore storey complex
provides for a collection of storeys included in a building. A
storey can also be decomposed in (horizontical) parts, where each
part defines a partial storey. This is defihned by the composition
type attribute of the supertype
<i>IfcSpatialStructureElements</i> which is interpreted as
follow:</p>
<ul>
<li>COMPLEX = building storey complex</li>
<li>ELEMENT = building storey</li>
<li>PARTIAL = partial building storey</li>
</ul>
<blockquote class="example">EXAMPLE In split level houses, a storey is split into two or more partial storeys, each with a different elevation. It can be handled by defining a storey, which includes two or more partial storeys with the individual elevations.</blockquote>
<blockquote class="history">HISTORY New entity in IFC Release 1.0</blockquote>
<p class="use-head">Property Set Use Definition</p>
<p>The property sets relating to the <i>IfcBuildingStorey</i> are
defined by the <i>IfcPropertySet</i> and attached by the
<i>IfcRelDefinesByProperties</i> relationship. It is accessible
by the inverse <i>IsDefinedBy</i> relationship. The following
property set definitions specific to the <i>IfcBuildingStorey</i>
are part of this IFC release:</p>
<ul>
<li><a href=
"../../psd/IfcProductExtension/Pset_BuildingStoreyCommon.xml"
target="SOURCE">Pset_BuildingStoreyCommon</a>: common property
set for all types of building stories</li>
</ul>
<p><u><b>Quantity Use Definition</b></u></p>
<p>The quantities relating to the <i>IfcBuildingStorey</i> are
defined by the <i>IfcElementQuantity</i> and attached by the
<i>IfcRelDefinesByProperties</i> relationship. It is accessible
by the inverse <i>IsDefinedBy</i> relationship. The following
base quantities are defined and should be exchanged with the
<i>IfcElementQuantity.Name</i> = 'BaseQuantities'. Other
quantities, being subjected to local standard of measurement, can
be defined with another string value assigned to <i>Name</i>. In
this case a valid value for <i>MethodOfMeasurement</i> has to be
provided.</p>
<ul>
<li><a href=
"../../qto/IfcProductExtension/Qto_BuildingStoreyBaseQuantities.xml"
target="SOURCE">Qto_BuildingStoreyBaseQuantities</a>: base
quantities for all building storey occurrences.</li>
</ul>
<p class="use-head">Spatial Structure Use Definition</p>
<p>The <i>IfcBuildingStorey</i> is used to build the spatial
structure of a building (that serves as the primary project
breakdown and is required to be hierarchical). The spatial
structure elements are linked together by using the objectified
relationship <i>IfcRelAggregates</i>. The
<i>IfcBuildingStorey</i>references them by its inverse
relationships:</p>
<ul>
<li><i>IfcBuildingStorey.Decomposes</i> -- referencing
(<i>IfcBuilding</i> || <i>IfcBuildingStorey</i>) by
<i>IfcRelAggregates.RelatingObject</i>, If it refers to another
instance of<i>IfcBuildingStorey</i>, the referenced
<i>IfcBuildingStorey</i> needs to have a different and higher
<i>CompositionType</i>, i.e. COMPLEX (if the other
<i>IfcBuildingStorey</i> has ELEMENT), or ELEMENT (if the other
<i>IfcBuildingStorey</i> has PARTIAL).</li>
<li><i>IfcBuildingStorey.IsDecomposedBy</i> -- referencing
(<i>IfcBuildingStorey</i> || <i>IfcSpace</i>) by
<i>IfcRelAggregates.RelatedObjects</i>. If it refers to another
instance of<i>IfcBuildingStorey</i>, the referenced
<i>IfcBuildingStorey</i> needs to have a different and lower
CompositionType, i.e. ELEMENT (if the other
<i>IfcBuildingStorey</i> has COMPLEX), or PARTIAL (if the other
<i>IfcBuildingStorey</i> has ELEMENT).</li>
</ul>
<p>If there are building elements and/or other elements directly
related to the <i>IfcBuildingStorey</i> (like most building
elements, such as walls, columns, etc.), they are associated with
the <i>IfcBuildingStorey</i> by using the objectified
relationship <i>IfcRelContainedInSpatialStructure</i>. The
<i>IfcBuildingStorey</i> references them by its inverse
relationship:</p>
<ul>
<li><i>IfcBuildingStorey.ContainsElements</i> -- referencing any
subtype of <i>IfcProduct</i> (with the exception of other spatial
structure element) by
<i>IfcRelContainedInSpatialStructure.RelatedElements</i>.</li>
</ul>
<p>Figure 25 shows the <i>IfcBuildingStorey</i> as part of the
spatial structure. It also serves as the spatial container for
building and other elements.</p>
<blockquote class="note">NOTE Detailed requirements on mandatory element
containment and placement structure relationships are given in
view definitions and implementer agreements.</blockquote>
<table summary="Spatial structure">
<tr><td valign="top"><img src=
"figures/IfcBuildingStorey-SpatialStructure.png" alt=
"IfcBuildingStorey as part of a spatial structure" width="800"
height="420" border="0"></td></tr>
<tr><td><p class="figure">Figure 25 — Building storey composition</p></td></tr>
</table>
<p>Elements can also be referenced in an
<i>IfcBuildingStorey</i>, for example, if they span through several
storeys. This is expressed by using the objectified relationship
<i>IfcRelReferencedInSpatialStructure</i>. Systems, such as
building service or electrical distribution systems, zonal
systems, or structural analysis systems, relate to
<i>IfcBuildingStorey</i> by using the objectified relationship
<i>IfcRelServicesBuildings</i>.</p>
<p class="use-head">Attribute Use Definition</p>
<p>Figure 26 describes the heights and elevations of the <i>IfcBuildingStorey</i>.
<ul>
<li>elevation of storey provided by: <i>IfcBuildingStorey.Elevation</i> as a local height value
relative to <i>IfcBuilding.ElevationOfRefHeight</i>, it is usually the top of construction slab</li>
<li>net height of storey, also referred to as total height or system height (top of construction slab to top of construction slab above): provided by BaseQuantity with Name="GrossHeight"</li>
<li>net height of storey (top of construction slab to bottom of construction slab above): provided by BaseQuantity with Name="NetHeight"</li>
</ul>
<table summary="attributes" cellpadding="2" cellspacing="2">
<tbody>
<tr>
<td align="left" valign="top"><img src=
"figures/IfcBuildingStorey_Heights.png" alt="space heights"
border="0" height="400" width="450"></td>
<td align="left" valign="top"></td></tr>
<tr><td><p class="figure">Figure 26 — Building storey elevations</p></td></tr>
</tbody>
</table>
<p class="use-head">Geometry Use Definitions</p>
<p>The geometric representation of <i>IfcBuildingStorey</i> is
given by the <i>IfcProductDefinitionShape</i> and
<i>IfcLocalPlacement</i>, allowing multiple geometric
representation.</p>
<p><b>Local Placement</b></p>
<p>The local placement for <i>IfcBuildingStorey</i> is defined in
its supertype <i>IfcProduct</i>. It is defined by the
<i>IfcLocalPlacement</i>, which defines the local coordinate
system that is referenced by all geometric representations.</p>
<ul>
<li>The <i>PlacementRelTo</i> relationship of
<i>IfcLocalPlacement</i> shall point (if relative placement is
used) to the <i>IfcSpatialStructureElement</i> of type
<i>IfcBuilding</i>, or of type <i>IfcBuildingStorey</i> (e.g. to
position a building storey relative to a building storey complex,
or a partial building storey to a building storey).</li>
<li>If the relative placement is not used, the absolute placement
is defined within the world coordinate system.</li>
</ul>
<p><b><u>Geometric Representations</u></b></p>
<p>Currently, the use of a 2D 'FootPrint' representation of type
'GeometricCurveSet' and a 3D 'Body' representation of type 'Brep'
is supported.</p>
<blockquote>
<p><small>NOTE The independent geometric representation of
<i>IfcBuildingStorey</i> may not be required or allowed in
certain view definitions. In those cases only the contained
elements and spaces have an independent geometric
representation.</small></p>
</blockquote>
<p><b>Foot Print Representation</b></p>
<p>The foot print representation of <i>IfcBuildingStorey</i> is
given by either a single 2D curve (such as <i>IfcPolyline</i> or
<i>IfcCompositeCurve</i>), or by a list of 2D curves (in case of
inner boundaries), if the building storey has an independent
geometric representation.</p>
<p>The representation identifier and type of this geometric
representation of <i>IfcBuildingStorey</i> is:</p>
<ul>
<li><i>IfcShapeRepresentation.RepresentationIdentifier</i> =
'FootPrint'</li>
<li><i>IfcShapeRepresentation.RepresentationType</i> =
'GeometricCurveSet'</li>
</ul>
<p><b>Body Representation</b></p>
<p>The body (or solid model) geometric representation (if the
building storey has an independent geometric representation) of
<i>IfcBuildingStorey</i> is defined using faceted B-Rep
capabilities (with or without voids), based on the
<i>IfcFacetedBrep</i> or on the
<i>IfcFacetedBrepWithVoids</i>.</p>
<p>The representation identifier and type of this representation
of <i>IfcBuildingStorey</i> is:</p>
<ul>
<li><i>IfcShapeRepresentation.RepresentationIdentifier</i> =
'Body'</li>
<li><i>IfcShapeRepresentation.RepresentationType</i> =
'Brep'</li>
</ul>
<p>Since the building storey shape is usually described by the
exterior building elements, an independent shape representation
shall only be given, if the building storey is exposed
independently from its constituting elements.</p>
</EPM-HTML> |
| 112 | 744 | IfcSite | <EPM-HTML>
<p><u>Definition from ISO 6707-1:1989</u>: Area where construction
works are undertaken.</p>
<p>A site is a defined area of land, possibly
covered with water, on which the project construction is to be
completed. A site may be used to erect building(s) or other AEC
products.</p>
<p>A site (<i>IfcSite</i>) may include a definition of the single
geographic reference point for this site (global position using
WGS84 with <i>Longitude</i>, <i>Latitude</i> and <i>Elevation</i>).
The precision is provided up to millionth of a second and it
provides an absolute placement in relation to the real world as
used in exchange with geospational information systems. If
asserted, the <i>Longitude</i>, <i>Latitude</i> and
<i>Elevation</i> establish the point in WGS84 where the point
0.,0.,0. of the <i>LocalPlacement</i> of <i>IfcSite</i> is
situated.</p>
<p>The geometrical placement of the site, defined by the
<i>IfcLocalPlacement</i>, shall be always relative to the spatial
structure element, in which this site is included, or absolute,
i.e. to the world coordinate system, as established by the
geometric representation context of the project. The world
coordinate system, established at the
<i>IfcProject.RepresentationContexts</i>, may include a definition
of the true north within the XY plane of the world coordinate
system, if provided, it can be obtained at
<i>IfcGeometricRepresentationContext.TrueNorth</i>.</p>
<p>A project may span over several connected or disconnected sites.
Therefore site complex provides for a collection of sites included
in a project. A site can also be decomposed in parts, where each
part defines a site section. This is defined by the composition
type attribute of the supertype <i>IfcSpatialStructureElements</i>
which is interpreted as follow:</p>
<ul>
<li>COMPLEX = site complex</li>
<li>ELEMENT = site</li>
<li>PARTIAL = site section</li>
</ul>
<blockquote class="history">HISTORY New entity in IFC Release 1.0.</blockquote>
<p class="use-head">Property Set Use Definition</p>
<p>The property sets relating to the <i>IfcSite</i> are defined by
the <i>IfcPropertySet</i> and attached by the
<i>IfcRelDefinesByProperties</i> relationship. It is accessible by
the inverse <i>IsDefinedBy</i> relationship. The following property
set definitions specific to the <i>IfcSite</i> are part of this IFC
release:</p>
<ul>
<li><a href="../../psd/IfcProductExtension/Pset_SiteCommon.xml"
target="SOURCE">Pset_SiteCommon</a>: common property set for all
types of site</li>
</ul>
<p class="use-head">Quantity Use Definition</p>
<p>The quantities relating to the <i>IfcSite</i> are defined by the
<i>IfcElementQuantity</i> and attached by the
<i>IfcRelDefinesByProperties</i> relationship. It is accessible by
the inverse <i>IsDefinedBy</i> relationship. The following base
quantities are defined and should be exchanged with the
<i>IfcElementQuantity.Name</i> = 'BaseQuantities'. Other
quantities, being subjected to local standard of measurement, can
be defined with another string value assigned to <i>Name</i>. In
this case a valid value for <i>MethodOfMeasurement</i> has to be
provided.</p>
<ul>
<li><a href=
"../../qto/IfcProductExtension/Qto_SiteBaseQuantities.xml" target=
"SOURCE">Qto_SiteBaseQuantities</a>: base quantities for all site
occurrences.</li>
</ul>
<p class="use-head">Spatial Structure Use Definition</p>
<p>The <i>IfcSite</i> is used to build the spatial structure of a
building (that serves as the primary project breakdown and is
required to be hierarchical). The spatial structure elements are
linked together by using the objectified relationship
<i>IfcRelAggregates</i>. The <i>IfcSite</i> references them by its
inverse relationships:</p>
<ul>
<li><i>IfcSite.Decomposes</i> -- referencing (<i>IfcProject</i> ||
<i>IfcSite</i>) by <i>IfcRelAggregates.RelatingObject</i>, If it
refers to another instance of <i>IfcSite</i>, the referenced
<i>IfcSite</i> needs to have a different and higher
<i>CompositionType</i>, i.e. COMPLEX (if the other <i>IfcSite</i>
has ELEMENT), or ELEMENT (if the other <i>IfcSite</i> has
PARTIAL).</li>
<li><i>IfcSite.IsDecomposedBy</i> -- referencing (<i>IfcSite</i> ||
<i>IfcBuilding</i> || <i>IfcSpace</i>) by
<i>IfcRelAggregates.RelatedObjects</i>. If it refers to another
instance of <i>IfcSite</i>, the referenced <i>IfcSite</i> needs to
have a different and lower CompositionType, i.e. ELEMENT (if the
other <i>IfcSite</i> has COMPLEX), or PARTIAL (if the other
<i>IfcSite</i> has ELEMENT).</li>
</ul>
<p>If there are building elements and/or other elements directly
related to the <i>IfcSite</i> (like a fence, or a shear wall), they
are associated with the <i>IfcSite</i> by using the objectified
relationship <i>IfcRelContainedInSpatialStructure</i>. The
<i>IfcIfcSite</i> references them by its inverse relationship:</p>
<ul>
<li><i>IfcSite.ContainsElements</i> -- referencing any subtype of
<i>IfcProduct</i> (with the exception of other spatial structure
element) by
<i>IfcRelContainedInSpatialStructure.RelatedElements</i>.</li>
</ul>
<p>Figure 51 shows the <i>IfcSite</i> as part of the spatial structure. In addition to the logical spatial structure, also the placement hierarchy is shown. In this example the spatial structure hierarchy and the placement hierarchy are identical.</p>
<blockquote class="note">NOTE Detailed requirements on mandatory element containment and placement structure relationships are given in view definitions and implementer agreements.</blockquote>
<table summary="Spatial and placement structure">
<tr><td valign="top"><img src="figures/IfcSite-SpatialStructure.png" alt="IfcSite as part of a spatial structure" width="800" height="420" border="0"></tr>
<tr><td><p class="figure">Figure 51 — Site composition</p></td></tr>
</table>
<p class="use-head">Attribute Use Definition</p>
<p>Figure 52 describes the heights and elevations of the <i>IfcSite</i>. It is used to provide the geographic longitude, latitude, and height above sea level for the origin of the site. The origin of the site is the local placement.</p>
<p>The provision of longitude, latitude, height at the <i>IfcSite</i> for georeferencing is provided for upward compatibility reasons. It requires a single instance of <i>IfcSite</i> and WGS84 as coordinate reference system.</p>
<P>For exact georeferencing the new entities <i>IfcCoordinateReferenceSystem</i> and <i>IfcMapConversion</i> should be used.</p>
<ul>
<li><small>reference height of site is provided by: <i>IfcSite.RefElevation</i>, it is given according to the height datum used at this location.</small></li>
<li><small>the reference height of each building situated at the site is given againt the same height datum used at this location.</small></li>
<li><small>the elevations of each storey belonging to each building are given as local height relative to the reference height of the building.</small></li>
</ul>
<table border="0" cellpadding="2" cellspacing="2" summary=
"attribute use">
<tbody>
<tr valign="top"><td align="left" valign="top"><img src="figures/IfcSite_Heights.png" alt="building heights" border="0" height="400" width="500"> </td></tr>
<tr><td><p class="figure">Figure 52 — Site elevations</p></td></tr>
</tbody>
</table>
<p class="use-head">Geometry Use Definitions</p>
<p>The geometric representation of <i>IfcSite</i> is given by the
<i>IfcProductDefinitionShape</i> and <i>IfcLocalPlacement</i>
allowing multiple geometric representations.</p>
<p><b>Local placement</b></p>
<p>The local placement for <i>IfcSite</i> is defined in its
supertype <i>IfcProduct</i>. It is defined by the
<i>IfcLocalPlacement</i>, which defines the local coordinate system
that is referenced by all geometric representations.</p>
<ul>
<li>The <i>PlacementRelTo</i> relationship of
<i>IfcLocalPlacement</i> shall point to the
<i>IfcSpatialStructureElement</i> of type "<i>IfcSite</i>", if
relative placement is used (e.g. to position a site relative a a
site complex, or a site section to a site).</li>
<li>If the relative placement is not used, the absolute placement
is defined within the world coordinate system. If there is only one
site object, then this is the default situation.</li>
</ul>
<p><b>Foot Print Representation</b></p>
<p>The foot print representation of <i>IfcSite</i> is given by
either a single 2D curve (such as <i>IfcPolyline</i> or
<i>IfcCompositeCurve</i>), or by a list of 2D curves (in case of
inner boundaries).</p>
<p>The representation identifier and type of this geometric
representation of <i>IfcSite</i> is:</p>
<ul>
<li><i>IfcShapeRepresentation.RepresentationIdentifier</i> =
'FootPrint'</li>
<li><i>IfcShapeRepresentation.RepresentationType</i> =
'GeometricCurveSet', or 'Annotation2D'</li>
</ul>
<p><b>Survey Points Representation</b></p>
<p>The survey point representation of <i>IfcSite</i> is defined
using a set of survey points and optionally breaklines. The
breaklines are restricted to only connect points given in the set
of survey points. Breaklines, if given, are used to constrain the
triangulation.</p>
<p>The representation identifier and type of this geometric
representation of <i>IfcSite</i> is:</p>
<ul>
<li><i>IfcShapeRepresentation.RepresentationIdentifier</i> =
'SurveyPoints'</li>
<li><i>IfcShapeRepresentation.RepresentationType</i> =
'GeometricCurveSet'</li>
</ul>
<p>Figure 53 shows a set of survey points, given as 3D Cartesian points within the object coordinate system of the site. Figure 54 shows the result after facetation.</p>
<p>The set of <i>IfcCartesianPoint</i> is included in the set of <i>IfcGeometricCurveSet.Elements</i>.</p>
<table cellpadding="2" cellspacing="2" summary="survey points representation">
<tr>
<td><img src="figures/IfcSite-Standard-points.gif" alt="points only" border="0" height="300" width="400"></td>
<td><img src="figures/IfcSite-Standard-facets-points.gif" alt="facetation of points" border="0" height="300" width="400"></td>
</tr>
<tr>
<td width="400"><p class="figure">Figure 53 — Site survey points</p></td>
<td width="400"><p class="figure">Figure 54 — Site survey points facetation</p></td>
</tr>
</table>
<p>Figure 55 shows A set of survey points, given as 3D Cartesian points, and a set of break points, given as a set of lines, connecting some survey points, within the object coordinate system of the site. Figure 56 shows the result after facetation.</p>
<p>The set of <i>IfcCartesianPoint</i> and the set of <i>IfcPolyline</i> are included in the set of <i>IfcGeometricCurveSet.Elements</i>.</p>
<table cellpadding="2" cellspacing="2" summary="survey points representation">
<tr>
<td><img src="figures/IfcSite-Standard-breaklines.gif" alt="breaklines" border="0" height="300" width="400"></td>
<td><img src="figures/IfcSite-Standard-facets-breaklines.gif" alt="facetation with breakpoints" border="0" height="300" width=
"400"></td>
</tr>
<tr>
<td width="400"><p class="figure">Figure 55 — Site breaklines</p></td>
<td width="400"><p class="figure">Figure 56 — Site breaklines facetation</p></td>
</tr>
</table>
<blockquote class="note">NOTE The geometric representation of the site has been based on the ARM level description of the site_shape_representation given within the ISO 10303-225 "Building Elements using explicit shape representation".</blockquote>
<p><b>Body Representation</b></p>
<p>The body representation of <i>IfcSite</i> is defined using a
solid or surface model. Applicable solids are the
<i>IfcFacetedBrep</i> or on the <i>IfcFacetedBrepWithVoids</i>,
applicable surface models are the <i>IfcFaceBasedSurfaceModel</i>
and the <i>IfcShellBasedSurfaceModel</i>.</p>
<p>The representation identifier and type of this representation of
<i>IfcSite</i> is:</p>
<ul>
<li><i>IfcShapeRepresentation.RepresentationIdentifier</i> =
'Body'</li>
<li><i>IfcShapeRepresentation.RepresentationType</i> = 'Brep', or
'SurfaceModel'</li>
</ul>
</EPM-HTML> |
| 113 | 765 | IfcElementQuantity | <EPM-HTML>
<p><u>Definition from IAI</u>: An <i>IfcElementQuantity</i>
defines a set of derived measures of an element's physical
property. Elements could be spatial structure elements (like
buildings, storeys, or spaces) or building elements (like walls,
slabs, finishes). The <i>IfcElementQuantity</i> gets assigned to
the element by using the <i>IfcRelDefinesByProperties</i>
relationship.</p>
<p>The optional <i>MethodOfMeasurement</i> attribute defines the
code, e.g. from a standard method of measurement, which had been
used to calculate the element quantity.</p>
<blockquote>
<p><small>NOTE The recognizable values for the name and the
method of measurement attributes have to be agreed upon in
further agreement documents, such as implementers agreements.
Some of these agreements might be limited to a certain region, to
which the method of measurement applies.</small></p>
</blockquote>
<p>The name attribute, given at the individual <i>Quantities</i>
provides a recognizable semantic meaning of the element quantity.
Both information is needed to establish a precise meaning for the
measure value. An optional description may be assigned to each of
the <i>Quantities</i>. All quantities assigned by a single
instance of <i>IfcElementQuantity</i> are deemed to have been
generated according to the same method of measurement. However
several instances of <i>IfcElementQuantity</i> are assignable to
an element, thus allowing for an element having quantities
generated according to several methods of measurement.</p>
<blockquote>
<p><small>EXAMPLE1 To exchange the net floor area of spaces in
the German region (as <i>IfcSpace</i>), the name might be
'Netto-Grundfläche' (net floor area), and the method of
measurement might be accordingly 'DIN277-2' (German industry norm
no. 277 edition 2)</small></p>
</blockquote>
<blockquote>
<p><small>EXAMPLE2 The same instance of <i>IfcSpace</i> may have
a different area measure assigned in the German region according
to a housing regulation, the name would be 'Wohnfläche' and
the method of measurement would be '2.BV'. It would be attached
to the <i>IfcSpace</i> by a separate
<i>IfcRelDefinesByProperties</i> relationship.</small></p>
</blockquote>
<p>The <i>IfcElementQuantity</i> can have the following subtypes
of <i>IfcPhysicalQuantity</i> within its SET of
<i>Quantities</i>, which count for the basis measure types
used:</p>
<ul>
<li>count measure</li>
<li>weight measure</li>
<li>length measure</li>
<li>area measure</li>
<li>volume measure</li>
<li>time measure</li>
</ul>
<blockquote>
<p><small><font color="#0000FF">HISTORY New entity in IFC Release
2x. NOTE: It replaces the calcXxx attributes used in previous IFC
Releases.</font></small><br>
<small><font color="#FF0000">IFC2x4 CHANGE Subtyped from new
intermediate <i>IfcPreDefinedPropertySet</i>
supertype.</font></small></p>
</blockquote>
<p><b><u>Quantity Use Defintion</u></b></p>
<p>Base quantities are quantity definitions that are independent
of a particular method of measurement and therefore
internationally applicable. Base quantities are defined as gross
and net values and provided by measurement of the correct
geometric shape representation of the element. The IFC
specification includes a set of base quantity definition. See
each subtype of <i>IfcElement</i> for applicable base
quantities.</p>
<p>The following general agreements apply for each base quantity
set</p>
<ul>
<li><i>IfcElementQuantity.Name</i> = 'BaseQuantities'</li>
<li><i>IfcElementQuantity.MethodOfMeasurement</i> = NIL</li>
<li><i>IfcElementQuantity.Quantities</i> = SET of subtypes of
<i>IfcPhysicalSimpleQuantity</i> with values for the <i>Name</i>
attribute as published as part of the IFC specifciation.</li>
</ul>
</EPM-HTML> |
| 114 | 770 | IfcRelAssociatesMaterial | <EPM-HTML>
<p><u>Definition from IAI</u>: Objectified relationship between a
material definition and elements or element types to which this
material definition applies.</p>
<p>The material definition can be:</p>
<ul>
<li>assigned to an element occurrence as a specific usage of a
layer set or profile set</li>
<li>assigned to an element occurrence or element type as a layer
set, profile set, constituent set or a single material</li>
</ul>
<p>Materials can be arranged by layers and applied to layered
elements. Typical elements are walls and slabs.</p>
<ul>
<li>An <i>IfcMaterialLayerSet</i>, for layered elements with an
indication of the layering direction and individual layer
thicknesses</li>
<li>An <i>IfcMaterialLayerSetUsage</i>, i.e. a material layer set
with positioning information along the reference axis or surface
of the element.
<blockquote><small>NOTE As a material layer set usage is an
occurrence based information, that applies to each individual
element, it cannot be assigned to an element
type.</small></blockquote>
</li>
</ul>
<p>Material can be applied to profiles. Typical elements using
profile material are beam, column, member</p>
<ul>
<li>An <i>IfcMaterialProfileSet</i>, i.e. a set of material
assigned to a set of profiles, with a single material assigned to
a single profile as the default.</li>
<li>An <i>IfcMaterialProfileSetUsage</i>, i.e. a material profile
set with positioning information relative to the element axis,
also refered to as cardinal point.
<blockquote><small>NOTE As a material profile set usage is an
occurrence based information, that applies to each individual
element, it cannot be assigned to an element
type.</small></blockquote>
</li>
</ul>
<p>Materials can be arranged by identified parts of a component
based element. Typical elements are dorrs/windows (with
components such as lining, framing and glazing), or distribution
elements.</p>
<ul>
<li>An <i>IfcMaterialConstituentSet</i>, for component based
elements with an indication of the component by keyword to which
the material consituent applies.
<blockquote><small>NOTE See the material use definitions at each
applicable subtype of <i>IfcElement</i> or <i>IfcElementType</i>
for a provision of these keywords.</small></blockquote>
</li>
</ul>
<p>As a fallback, or in cases where only a single material
information is needed, material information can be directly
associated</p>
<ul>
<li>A single <i>IfcMaterial</i> for any element where the
material use definition does not prohibits its direct
association</li>
<li>An <i>IfcMaterialList</i>, e.g. for composite elements,
without an information, how the different materials are arranged.
<blockquote><small><font color="#FF0000">NOTE The use of
<i>IfcMaterialList</i> is deprecated in IFC2x4 onwards. Use
<i>IfcMaterialConstituentSet</i>
instead.</font></small></blockquote>
</li>
</ul>
<p>The <i>IfcRelAssociatesMaterial</i> relationship is a special
type of the <i>IfcRelAssociates</i> relationship. It can be
applied to subtypes of <i>IfcElement</i> and subtypes of
<i>IfcElementType</i>.</p>
<ul>
<li>The <i>IfcElement</i> has an inverse relation to its material
definition by the <i>HasAssociations</i> attribute, inherited
from <i>IfcObject</i>.</li>
<li>The <i>IfcElementType</i> has an inverse relation to its
material definition by the <i>HasAssociations</i> attribute,
inherited from <i>IfcPropertyDefinition</i>.</li>
</ul>
<p>If both, the element occurrence (by an instance of
<i>IfcElement</i>) and the element type (by an instance of
<i>IfcElementType</i>, connected through
<i>IfcRelDefinesByType</i>) have an associated material, then the
material associated to the element occurrence overrides the
material associated to the element type.</p>
<blockquote>
<p><small><font color="#0000FF">HISTORY New entity in IFC Release
2.x.</font></small></p>
</blockquote>
<p><u>Informal proposition</u></p>
<ol>
<li>An <i>IfcMaterialLayerSetUsage</i> shall not be associated
with a subtype of <i>IfcElementType</i>, it should only be
associated with individual occurrences</li>
<li>An <i>IfcMaterialProfileSetUsage</i> shall not be associated
with a subtype of <i>IfcElementType</i>, it should only be
associated with individual occurrences</li>
</ol>
</EPM-HTML> |
| 115 | 776 | IfcProduct | <EPM-HTML>
<p>Any object that relates to a
geometric or spatial context. Subtypes of <i>IfcProduct</i>
usually hold a shape representation and a object placement within
the project structure.</p>
<p>This includes manufactured, supplied or created objects
(referred to as elements) for incorporation into an AEC/FM
project. This also includes objects that are created indirectly
by other products, as spaces are defined by bounding elements.
Products can be designated for permanent use or temporary use, an
example for the latter is formwork. Products are defined by their
properties and representations.</p>
<p>In addition to physical products (covered by the subtype
<i>IfcElement</i>) and spatial items (covered by the subtype
<i>IfcSpatialElement</i>) the <i>IfcProduct</i> also includes
non-physical items, that relate to a geometric or spatial
contexts, such as grid, port, annotation, structural actions,
etc.</p>
<p>The inherited <i>ObjectType</i> attribute can be used to
designate a particular type of the product instance. If subtypes
of <i>IfcProduct</i> have a <i>PredefinedType</i> defined, the
<i>ObjectType</i> is used to provide the user defined, particular
type of the product instance, if the <i>PredefinedType</i> is set
to <small>USERDEFINED</small>.</p>
<blockquote class="history">
HISTORY New Entity in IFC Release 1.0
</blockquote>
<p class="use-head">Relationship use definition</p>
<p>On a generic level products can be assigned to processes,
controls, resources, project by using the relationship objects
that refer to the corresponding object:</p>
<ul>
<li><b>Having a control applied</b>: assigned using
<i>IfcRelAssignsToControl</i> linking the <i>IfcProduct</i> to an
<i>IfcControl</i>
<ul>
<li style="list-style-type:none"><small>An example of this
relationship is the assignment of a performance history to a
distribution element.</small></li>
</ul>
</li>
<li><b>Being assigned to a process</b>: assigned using
<i>IfcRelAssignsToProcess</i> linking the <i>IfcProduct</i> to an
<i>IfcProcess</i>
<ul>
<li style="list-style-type:none"><small>An example of this
relationship is the assignment of products like wall, slab,
column to a contruction task for construction
planning.</small></li>
</ul>
</li>
<li><b>Being assigned to a resource</b>: assigned using
<i>IfcRelAssignsToResource</i> linking the <i>IfcProduct</i> to
an <i>IfcResource</i>
<ul>
<li style="list-style-type:none"><small>An example of this
relationship is the assignment of products to a construction
resource that consumes the product.</small></li>
</ul>
</li>
</ul>
<p class="use-head">Type use definition</p>
<p>Any instance of <i>IfcProduct</i> defines a particular
occurrence of a product, the common type information, that
relates to many similar (or identical) occurrences of
<i>IfcProduct</i>, is handled by the <i>IfcTypeProduct</i> (and
its subtypes), assigned to one or many occurrences of
<i>IfcProduct</i> by using the objectified relationship
<i>IfcRelDefinesByType</i>. The <i>IfcTypeProduct</i> may
provide, in addition to common properties, also a common
geometric representation for all occurrences.</p>
<blockquote><small>See <i>IfcTypeProduct</i> for how to use a
common geometric representation and <i>IfcRelDefinesByType</i>
for using and overriding common properties.</small></blockquote>
<p class="use-head">Representation use definition</p>
<p>An <i>IfcProduct</i> occurs at a specific location in space if
it has a geometric representation assigned. It can be placed
relatively to other products, but ultimately relative to the
world coordinate system defined for this project. The
<i>ObjectPlacement</i> attribute establishes the coordinate
system in which all points and directions used by the geometric
representation items under <small>Representation</small> are
founded. The placement can either be:</p>
<ul>
<li><b>a relative placement</b>: by <i>IfcLocalPlacement</i> with
<i>PlacementRelTo</i> pointing to a parent placement</li>
<li><b>an absolute placement</b>: by <i>IfcLocalPlacement</i>
with <i>PlacementRelTo</i> being NIL</li>
<li><b>a placement relative to a grid</b>: by
<i>IfcGridPlacement</i></li>
</ul>
<p>The <i>Representation</i> is provided by an
<i>IfcProductDefinitionShape</i> being either a geometric shape
representation, or a topology representation (with or without
underlying geometry of the topological items).</p>
</EPM-HTML> |
| 116 | 782 | IfcObject | <EPM-HTML>
<p>An <i>IfcObject</i> is the
generalization of any semantically treated thing or process.
Objects are things as they appear - i.e. occurrences.</p>
<blockquote><small>NOTE Examples of <i>IfcObject</i> include
physically tangible items, such as wall, beam or covering,
physically existing items, such as spaces, or conceptual items,
such as grids or virtual boundaries. It also stands for
processes, such as work tasks, for controls, such as cost items,
for actors, such as persons involved in the design process,
etc.</small></blockquote>
<p>Objects can be named, using the inherited <i>Name</i>
attribute, which should be a user recognizable label for the
object occurrance. Further explanations to the object can be
given using the inherited <i>Description</i> attribute. The
<i>ObjectType</i> attribute is used:</p>
<ul>
<li>to store the user defined value for all subtypes of
<i>IfcObject</i>, where a <i>PredefinedType</i> attribute is
given, and its value is set to USERDEFINED.</li>
<li>to provide a type information (could be seen as a very
lightweight classifier) of the subtype of <i>IfcObject</i>, if no
<i>PredefinedType</i> attribute is given. This is often the case,
if no comprehensive list of predefined types is available.</li>
</ul>
<p>Objects are independent pieces of information that might
contain or reference other pieces of information. There are
several relationships in which objects can be involved:</p>
<ul>
<li><b>Association to external/internal resource information</b>
- an association relationship that refers to external/internal
sources of information. See supertype <i>IfcObjectDefinition</i>
for more information.</li>
<li><b>Assignment of other objects</b> - an assignment
relationship that refers to other types of objects. See supertype
<i>IfcObjectDefinition</i> for more information.</li>
<li><b>Aggregation of other objects</b> - an aggregation
relationship that establishes a whole/part relation. Objects can
either be a whole, or a part, or both. See supertype
<i>IfcObjectDefinition</i> for more information.<br>
<br></li>
<li><b>Assignment of a type</b> : <i>IsTypedBy</i> - a definition
relationship <i>IfcRelDefinesByType</i> that uses a type
definition to define the common characteristics of this
occurrences, potentially including the common shape
representation and common properties of all object occurrences
assigned to this type. It is a specific - occurrence relationship
with implied dependencies (as the occurrence properties depend on
the properties of the type, but may override them).</li>
<li style="list-style-type:none">
<blockquote><small>NOTE See <i>IfcRelDefinesByType</i> for an
explanatory figure. Also see for how to override type properties
by occurrence properties</small></blockquote>
</li>
<li><b>Assignment of a partial type</b> : <i>IsDeclaredBy</i>,
<i>Declares</i> - a definition relationship
<i>IfcRelDefinesByObject</i> that uses a component of a type
definition (a part of a type, called the "declaring part") to
define a component of an occurence (part of occurrence, called
the "reflected part"). This is also refered to as a "deep copy".
The common characteristics of all parts in the occurrence are
defined by parts in the type. It is a specific - occurrence
relationship with implied dependencies (as the occurrence
properties depend on the properties of the type, but may override
them).<br></li>
<li style="list-style-type:none">
<blockquote><small>NOTE See <i>IfcRelDefinesByObject</i> for an
explanatory figure.</small></blockquote>
</li>
<li><b>Assignment of property sets</b> : <i>IsDefinedBy</i> - a
definition relationship <i>IfcRelDefinesByProperties</i> that
assignes property set definitions to the object occurrence.</li>
</ul>
<blockquote class="history">
HISTORY New Entity in IFC Release 1.0
</blockquote>
<blockquote class="change-ifc2x4">
IFC2x4 CHANGE The inverse relationships <i>Declares</i>, <i>IsDeclaredBy</i>, and <i>IsTypedBy</i> have been added, types are not longer included in the <i>IsDefinesBy</i> relationship. <i>IfcProject</i> has been promoted to be a subtype of <i>IfcObjectDefinition</i> -> <i>IfcContext</i>.
</blockquote>
<p><u>Informal Proposition</u></p>
<ol>
<li>A partial type assignment, i.e. the inverse attribute
<i>IsDeclaredBy</i>, or <i>Declares</i> shall only be used, if
the object is part of a decomposition, i.e. if either
<i>IsDecomposedBy</i>, or <i>Decomposes</i> is exerted.</li>
</ol>
</EPM-HTML> |
| 117 | 794 | IfcObjectDefinition | <EPM-HTML>
<p>An <em>IfcObjectDefinition</em> is the generalization of any
semantically treated thing or process, either being a type or an
occurrences. Object defintions can be named, using the inherited
<em>Name</em> attribute, which should be a user recognizable label
for the object occurrance. Further explanations to the object can
be given using the inherited <em>Description</em> attribute. A
context is a specific kind of object definition as it provides the
project or library context in which object types and object
occurrences are defined.</p>
<p>Objects are independent pieces of information that might contain
or reference other pieces of information. There are four essential
kinds of relationships in which object definitons (by their
instantiable subtypes) can be involved:</p>
<ul>
<li><b>Assignment of other objects</b> - an assignment relationship
(<em>IfcRelAssigns</em>) that refers to other types of objects and
creates a bi-directional association. The semantic of the
assignment is established at the level of the subtypes of the
general <em>IfcRelAssigns</em> relationship. There is no dependency
implied a priori by the assignment.</li>
<li><b>Association to external resources</b> - an association
relationship (<em>IfcRelAssociates</em>) that refers to external
sources of information (most notably a classification or document)
and creates a uni-directional association. There is no dependency
implied by the association.</li>
<li><b>Aggregation of other objects</b> - an aggregation
relationship (<em>IfcRelAggregates</em>) that establishes an
unordered, spatial whole/part relation and creates a bi-directional
relation. There is an implied dependency established.</li>
<li><b>Nesting of other objects</b> - a nesting relationship
(<em>IfcRelNests</em>) that establishes an ordered, non-spatial
whole/part relation and creates a bi-directional relation. There is
an implied dependency established.</li>
<li><b>Declaration within a context</b> - a relationship
(<em>IfcRelDeclares</em>) of the uppermost object definition within
the object definition tree (e.g. the summary object within an
object nesting tree) to the context (a project or project library).
It applies the units, representation context and other context
information to this object definition and all dependent ones.
<ul>
<li style="list-type-type:none"><small>EXCEPTION The link
between the uppermost object in the spatial structure tree, that is
<em>IfcSite</em> or <em>ifcBuilding</em>, and the context provided
by <em>IfcProject</em> is created using the
<em>IfcRelAggregates</em> relationship. See <em>IfcProject</em> for
more information.</small></li>
</ul>
</li>
</ul>
<blockquote class="history">
HISTORY New abstract entity in IFC2x3.
</blockquote>
<blockquote class="change-ifc2x4">
IFC2x4 CHANGE The new subtype <em>IfcContext</em> and the relationship to context <em>HasContext</em> has been added . The decomposition relationship is split into ordered nesting (<em>Nests</em>, <em>IsNestedBy</em>) and un-ordered aggregating (<em>Decomposes</em>, <em>IsDecomposedBy</em>).
</blockquote>
</EPM-HTML> |
| 118 | 805 | IfcRoot | <EPM-HTML>
<p><i>IfcRoot</i> is the most abstract and root class for all IFC entity definitions that roots in the kernel or in subsequent layers of the IFC object model. It is therefore the common supertype of all IFC entities, beside those defined in an IFC resource schema. All entities that are subtypes of <i>IfcRoot</i> can be used independently, whereas resource schema entities, that are not subtypes of <i>IfcRoot</i>, are not supposed to be independent entities.</p>
<p><i>IfcRoot</i> assigns the globally unique ID, and the ownership and history information to the entity. In addition it may provide for a name and a description about the concept.</p>
<blockquote class="note">
NOTE View definitions and implementation agreement may impose additional restrictions on the use of the <i>OwnerHistory</i> to handle object versioning.
</blockquote>
<blockquote class="history">
HISTORY New entity in IFC Release 1.0
</blockquote>
<blockquote class="change-ifc2x4">
IFC2x4 CHANGE The attribute <i>OwnerHistory</i> has been made OPTIONAL.
</blockquote>
</EPM-HTML> |
| 119 | 815 | IfcPropertyDefinition | <EPM-HTML>
<p><em>IfcPropertyDefinition</em> defines the generalization of
all characteristics (i.e. a grouping of individual properties),
that may be assigned to objects. Currently, subtypes of
<i>IfcPropertyDefinition</i> include property set occurrences,
property set templates, and property templates.</p>
<blockquote>
<p><strong>Property set template</strong> -
<em>IfcPropertySetTemplate</em>, a collection of property templates
that determine the definition of properties used within a project
context.</p>
<p><strong>Property template</strong> -
<em>IfcPropertyTemplate</em>, a single template that determines the
definition of a particular property used in the same project
context. The template may determine the name, description, data
type, the unit, or a standard expression for each property that is
based on that template.</p>
<p><strong>Property set occurrence</strong> -
<em>IfcPropertySet</em>, a set of individual properties (that may
or may not be determined by a property template) holding individual
values, measure types and units, and are associated to an object
occurrence or object type.</p>
</blockquote>
<blockquote class="note">
NOTE 1 The subtype hierarchy of <em>IfcPropertyDefinition</em> also includes statically defined property sets as <em>IfcPreDefinedPropertySet</em>. Those are rarely used collections of fixed attributes combined in an entity definition. The <em>IfcPreDefinedPropertySet</em> can not be determined by an <em>IfcPropertySetTemplate</em>.
</blockquote>
<blockquote class="note">
NOTE 2 Individual properties, (subtypes of <em>IfcProperty</em>), are currently not included in the subtype hierarchy of <em>IfcPropertyDefinition</em>. This anomaly is due to upward compatibility reasons with earlier releases of this
standard.
</blockquote>
<blockquote class="history">
HISTORY New Entity in IFC2.0
</blockquote>
<p class="use-head">Relationship use definition</p>
<p>Property definitions define information that is shared among
multiple instances of objects, either object occurrences or object
types. <em>IfcPropertyDefinition</em>'s (by their instantiable
subtypes) can participated within the following relationships:</p>
<ul>
<li><strong>Assignment to a project context</strong> - an
<em>HasContext</em> relationship to <em>IfcRelDeclares</em> that
establishes the project context in which this property definition
is declared. This relationship is predominately applicable to
subtypes of <em>IfcPropertyTemplateDefinition</em>.</li>
<li><strong>Association to external resources</strong> - an
<em>HasAssociation</em> relationship to <em>IfcRelAssociates</em>
that refers to external sources of information (most notably a
classification or document) and creates a uni-directional
association. There is no dependency implied by the
association.</li>
</ul>
<p>Subtypes are included in more specific relationships, see
<em>IfcPropertySetDefinition</em> and
<em>IfcPropertyTemplateDefinition</em> for details.</p>
</EPM-HTML> |
| 120 | 820 | IfcPropertySetDefinition | <EPM-HTML>
<p><em>IfcPropertySetDefinition</em> is a generalization of all
individual property sets that can be assigned to an object or type
object. The property set definition can be either:</p>
<blockquote>
<p><strong>Dynamically extendable property sets</strong> -
<em>IfcPropertySet</em>, a set of properties for which the IFC
model only provides a kind of "meta model", to be further declared
by agreement. This means no entity definition of the properties
exists within the IFC model. The declaration is done by assigning a
significant string value to the <em>Name</em> attribute of the
entity as defined in the entity <em>IfcPropertySet</em> and at each
subtype of <em>IfcProperty</em>, referenced by the property set.
Dynamically defined property sets may have an underlying template
provided by <em>IfcPropertySetTemplate</em>.</p>
<p><strong>Statically defined property sets</strong> -
<em>IfcPreDefinedPropertySet</em>, a property set entity that
exists within the IFC specification. The semantic meaning of each
statically defined property set is declared by its entity type and
the meaning of the properties is defined by the name and data type
of the explicit attribute representing it.</p>
</blockquote>
<blockquote class="history">
HISTORY New Entity in IFC Release 2x
</blockquote>
<blockquote class="change-ifc2x4">
IFC2x4 CHANGE The subtype <em>IfcPreDefinedPropertySet</em> has been added.
</blockquote>
<p class="use-head">Relationship use definition</p>
<p>Property set definitions define information that is shared among
multiple instances of objects, either object occurrences or object
types. <em>IfcPropertySetDefinition</em>'s (by their instantiable
subtypes) can participated within the following relationships:</p>
<ul>
<li><strong>Assignment to object types</strong> - an
<em>DefinesType</em> direct relationship to <em>IfcTypeObject</em>
that applies the property set, with all included properties, to the
object type. Those properties apply to all object occurrences
having the same object type.</li>
<li><strong>Assignment to object occurrences</strong> - an
<em>DefinesOccurrence</em> relationship to
<em>IfcRelDefinesByProperties</em> that applies the property set,
with all included properties, to the object occurrence.</li>
</ul>
<blockquote class="note">
NOTE Properties assigned to object occurrences may override properties assigned to the object type. See <em>IfcRelDefinesByType</em> for further information.
</blockquote>
</EPM-HTML> |
| 121 | 825 | IfcPropertySet | <EPM-HTML>
<p><em>IfcPropertySet</em> defines all dynamically extensible
properties. The property set is a container class that holds
properties within a property tree. These properties are interpreted
according to their name attribute.</p>
<p>The same <em>IfcPropertySet</em> can be assignd to multiple
object occurrences, it should then be assigned by a single instance
of <em>IfcRelDefinedByProperties</em> to a set of related objects.
Those property sets are referred to as shared property sets. It can
also be assigned to an object type.</p>
<p>The underlying structure, i.e. the required name, the applicable
object or object types to which the property set can be attached
and the individual properties that maybe included can be assigned
using the property set template.</p>
<blockquote class="note">
NOTE See <em>IfcRelDefinesByType</em> for how to override property sets assigned to an object type within the object occurrence.
</blockquote>
<blockquote class="history">
HISTORY New Entity in IFC Release 1.0
</blockquote>
<blockquote class="change-ifc2x4">
IFC2x4 CHANGE All statically defined property set entities are no longer subtypes of
<em>IfcPropertySet</em>.
</blockquote>
<p class="use-head">Relationship use definition</p>
<p>Property sets are related to other objects by using the
relationship object that refers to the corresponding object:</p>
<ul>
<li><b>Occurrence Object</b>: <em>IfcRelDefinesByProperties</em>
using the inverse attribute <em>DefinesOccurrence</em>.</li>
<li><b>Type Object</b>: using a direct link by inverse attribute
<em>DefinesType</em>.</li>
<li><b>External reference</b>: subtypes of
<em>IfcRelAssociates</em> are used to provide a link to a
classification system, or external library providing further
reference to the property set. Accessible by inverse attribute
<em>HasAssociations</em>.</li>
<li><b>Underlying template</b>: <em>IfcRelDefinesByTemplate</em>
using the inverse attribute <em>IsDefinedBy</em>.</li>
</ul>
<p class="use-head">Attribute use definition</p>
<p>Instances of <em>IfcPropertySet</em> are used to assign named
sets of individual properties (complex or single properties). Each
individual property has a significant name string. Some property
sets are included in the IFC specification and have a
predefined set of properties indicated by assigning a significant
name. These property sets are listed under "property sets" main
menu item within this specification and from the object
documentation sheet for those object to which they are applicable.
The naming convention "Pset_Xxx" applies to all those property sets
that are defined as part of the IFC specification and it shall be
used as the value of the <em>Name</em> attribute.</p>
<p>In addition any user defined property set can be captured.
Property sets that are not declared as part of the IFC
specification shall have a <em>Name</em> value not including the
"Pset_" prefix.</p>
</EPM-HTML> |
| 122 | 830 | IfcRelDefinesByTemplate | <EPM-HTML>
<p>The objectified relationship
<i>IfcRelDefinesByTemplate</i> defines the relationships between
property set template and property sets. Common information about
property sets, e.g. the applicable name, description, contained
properties, is defined by the property set template and assigned
to all property sets.</p>
<p>The <i>IfcRelDefinesByTemplate</i> is a 1-to-N relationship,
as it allows for the assignment of one property set template to a
single or to many property sets. Those property sets then share
the same property set template definition.</p>
<blockquote class="history">
HISTORY New Entity in IFC2x4.
</blockquote>
</EPM-HTML> |
| 123 | 833 | IfcRelDefines | <EPM-HTML>
<p>A generic and abstract relationship which subtypes are used to:</p>
<ul>
<li>assign a object type to an object occurrence</li>
<li>assign a property set to an object instance</li>
<li>assign a property set template to a property set</li>
</ul>
<blockquote><small>EXAMPLE Several instances of windows within
the IFC project model may be of the same (catalogue or
manufacturer) type. Thereby they share the same properties. This
relationship is established by the subtype
<i>IfcRelDefinesByType</i> of <i>IfcRelDefines</i> relationship
assigning an <i>IfcWindowStyle</i> to multiple occurrences
<i>IfcWindow</i>.<br>
<br>
EXAMPLE The (same) property set, e.g.
Pset_ProductManufacturerInfo, keeping the manufacturer name,
label and production year of a product, can be assigned to one,
or many instances of furnishing. This relationship is established
by the subtype <i>IfcRelDefinesByProperties</i> of
<i>IfcRelDefines</i> relationship assigning an
<i>IfcPropertySet</i> to one or more instances of
<i>IfcFurnishingElement</i>.</small></blockquote>
<blockquote class="history">
HISTORY New entity in IFC2x.
</blockquote>
<blockquote class="change-ifc2x4">
IFC2x4 CHANGE The attribute <i>RelatedObjects</i> had been demoted to the subtypes <i>IfcRelDefinesByProperties</i> and
<i>IfcRelDefinesByType</i>.
</blockquote>
</EPM-HTML> |
| 124 | 838 | IfcRelationship | <EPM-HTML>
<p><i>IfcRelationship</i> is the abstract generalization of all objectified relationships in IFC. Objectified relationships are the preferred way to handle relationships among objects. This allows to keep relationship specific properties directly at the relationship and opens the possibility to later handle relationship specific behavior. </p>
<p>There are two different types of relationships, 1-to-1 relationships and 1-to-many relationship. used within the subtypes of <i>IfcRelationship</i>. The following convention applies to all subtypes:</p>
<ul>
<li>The two sides of the objectified relationship are named <br>- Relating+<name of relating object> and <br>- Related+<name of related object></li>
<li>In case of the 1-to-many relationship, the related side of the relationship shall be an aggregate SET 1:N</li>
</ul>
<blockquote class="history">
HISTORY: New entity in IFC Release 1.0.
</blockquote>
</EPM-HTML> |
| 125 | 845 | IfcRelAssigns | <EPM-HTML>
<p>The assignment relationship, <i>IfcRelAssigns</i>, is a generalization of "link" relationships among instances of <i>IfcObject</i> and its various 1<sup>st</sup> level subtypes. A link denotes the specific association through which one object (the client) applies the services of other objects (the suppliers), or through which one object may navigate to other objects.</p>
<p>The client is denoted as the relating object and is established at the level of the specific, instantiable subtypes of <i>IfcRelAssigns</i>. The suppliers are denoted as the related objects and they are established by the <i>RelatedObjects</i> attribute.</p>
<blockquote class="note">
NOTE: The terms "client" and "supplier" are used in a general concept and do not imply any meaning for implementations of systems (like client-server).
</blockquote>
<blockquote class="example">
EXAMPLE: A resource may receive information about its nature of representing real building products by establishing a link between <i>IfcResource</i> and <i>IfcBuildingElement</i> (subtype of <i>IfcProduct</i>) through the assignment relationship <i>IfcRelAssignsToResource</i>. The resource is then the client that applies the services of other objects (here building elements) to express the particular view of elements to be consumed as a resource in a process.
</blockquote>
<p>The assignment relationship establishs a bi-directional relationship among the participating objects and does not imply any dependency. The subtypes of <i>IfcRelAssigns</i> establishes the particular semantic meaning of the assignment relationship.</p>
<blockquote class="history">
HISTORY: New entity in IFC Release 2x.
</blockquote>
</EPM-HTML> |
| 126 | 855 | IfcRelAssignsToProcess | <EPM-HTML>
<p>The objectified relationship <i>IfcRelAssignsToProcess</i> handles the assignment of one or many objects to a process or activity. An object can be a product that is the item the process operates on. Processes and activities can operate on things other than products, and can operate in ways other than input and output.</p>
<blockquote><small>EXAMPLE It may be common to define processes
during estimating or scheduling that describe design tasks
(resulting in documents), procurement tasks (resulting in
construction materials), planning tasks (resulting in processes),
etc. Furthermore, the ways in which process can operate on
something might include "installs", "finishes", "transports",
"removes", etc. The ways are described as operation
types.</small></blockquote>
<p>The inherited attribute <i>RelatedObjects</i> gives the
references to the objects, or object type, which the process
operates on. The <i>RelatingProcess</i> is the process or process
type, that operates on the object. The operation types are
captured in the inherited attribute <i>Name</i>.</p>
<blockquote><small>NOTE The agreement on valid and recognizable
values for the <i>Name</i> attribute is part of view definitions
and implementer agreements.</small></blockquote>
<blockquote class="history">
HISTORY New entity in IFC Release 1.5. Has been renamed from IfcRelProcessOperatesOn in IFC Release 2x.
</blockquote>
<blockquote class="change-ifc2x4">
IFC2x4 CHANGE The data type <i>RelatingProcess</i> has been extended to cover also <i>IfcTypeProcess</i>
</blockquote>
</EPM-HTML> |
| 127 | 862 | IfcProcess | <EPM-HTML>
<p><u>Definition from ISO9000</u>: A process is a set of
activities that are interrelated or that interact with one
another. Processes use resources to transform inputs into
outputs. Processes are interconnected because the output from one
process becomes the input for another process. In effect,
processes are "glued" together by means of such input output
relationships.</p>
<p><i>IfcProcess</i> is defined as
one individual activity or event, that is ordered in time, that
has sequence relationships with other processes, which transforms
input in output, and may connect to other other processes through
input output relationships. An <i>IfcProcess</i> can be an
activity (or task), or an event. It takes usually place in
building construction with the intent of designing, costing,
acquiring, constructing, or maintaining products or other and
similar tasks or procedures.</p>
<table summary="">
<tr valign="top">
<td><img src="figures/IfcProcess_icon_fig.png" alt="icon diagram"
border="0"></td>
</tr>
<tr valign="top">
<td>
<p class="figure">Figure 2 — Process relationships and the ICON process diagram.</p>
</td>
</tr>
</table>
<blockquote class="history">
HISTORY New entity in IFC Release 1.0.
</blockquote>
<blockquote class="change-ifc2x">
IFC2x PLATFORM CHANGE The attribute <i>Productivity</i> has been removed.
</blockquote>
<blockquote class="change-ifc2x4">
IFC2x4 CHANGE The attribute <i>Identification</i> has been promoted from subtypes <i>IfcTask</i> and others.
</blockquote>
<p class="use-head">Relationship use definition</p>
<p>Process information relates to other objects by establishing the following relationships:</p>
<ul>
<li><b>Nesting of processes</b> : <i>IfcRelNests</i> - A process can contain sub processes and thereby be nested.</li>
<li><b>Sequencing of processes</b> : <i>IfcRelSequence</i> - Processes can be placed in sequence (including overlapping for parallel tasks), and have predecessors and successors.</li>
<li><b>Assigning process to schedules</b> : <i>IfcRelAssignsToControl</i> - Activities such as tasks, and predominately summary tasks, are assigned to a work schedule.</li>
<li><b>Having a product assigned to the process as input</b> :
<i>IfcRelAssignsToProcess</i> - Products can be assigned as input to a process, such as for construction process planning.</li>
<li><b>Having a product assigned to the process as output</b> :
<i>IfcRelAssignsToProduct</i> - Products can be assigned as output to a process, such as for construction process planning.</li>
<li><b>Having a control assigned to the process as process control</b> : <i>IfcRelAssignsToProcess</i> - Items that act as a
control onto the process can be assigned to a process, such as for cost management (a cost item assigned to a work task).</li>
<li><b>Having a resource assigned to the process as consumed by the process</b> : <i>IfcRelAssignsToProcess</i> - Items that act
as a mechanism to a process, such as labor, material and equipment in cost calculations.</li>
</ul>
</EPM-HTML> |
| 128 | 868 | IfcTypeProcess | <EPM-HTML>
<p><i>IfcTypeProcess</i> defines a
specific (or type) definition of a process or activity without
being assigned to a schedule or a time.It is used to define a
process or activity specification, that is, the specific process or
activity information that is common to all occurrences that are
defined for that process or activity type.</p>
<p>An <i>IfcTypeProcess</i> may have a list of property set
attached. Values of these properties are common to all
occurrences of that process or activity type. The type occurrence
relationship is realized using the objectified relationship
<i>IfcRelDefinesByType</i>.</p>
<p>Subtypes of <i>IfcTypeProcess</i> may be exchanged without
being already assigned to subtypes of <i>IfcProcess</i>.</p>
<blockquote class="history">
HISTORY New entity in IFC2x4.
</blockquote>
<p class="use-head">Property set use definition</p>
<p>An <i>IfcTypeProcess</i> may have a list of property sets
attached, accessible by the attribute
<i>SELF\IfcTypeObject.HasPropertySets</i>. Currently there are no
predefined property sets defined as part of the IFC
specification.</p>
<blockquote><small>NOTE: For property sets, a property within an
occurrence property set that is assigned at the process
occurrence, overrides the same property assigned to the process
type.</small></blockquote>
</EPM-HTML> |
| 129 | 873 | IfcTypeObject | <EPM-HTML>
<p>The object type defines the
specific information about a type, being common to all
occurrences of this type. It refers to the specific level of the
well recognized <i>generic - specific - occurrance</i> modeling
paradigm. The <i>IfcTypeObject</i> gets assigned to the
individual object instances (the occurrences) via the
<i>IfcRelDefinesByType</i> relationship.</p>
<blockquote><small>NOTE The terms 'Type' and 'Style' are often
used interchangeably.</small></blockquote>
<p>The object type is represented by a set of property set
definitions. The attached property sets describe the available
alpha-numeric information about the object type. and are used to
define all common properties that apply to all object occurrences
of that type.</p>
<blockquote><small>NOTE If a property having having the same name
is used within the <i>IfcPropertySet</i> assigned to an
<i>IfcTypeObject</i> (and subtypes) and to an occurrence of that
type, then the occurrence property overrides the type property.
See <i>IfcRelDefinesByType</i> for an explanatory
figure.</small></blockquote>
<p>Object types may be exchanged without being already assigned
to objects. An object type may have an indication of the library
(or catalogue) from which its definition originates. This
association is handled by the inherited <i>HasAssociations</i>
relationship pointing to <i>IfcRelAssociatesLibrary</i>.</p>
<blockquote class="history">
HISTORY New entity in IFC Release 2x
</blockquote>
<blockquote class="change-ifc2x3">
IFC2x3 CHANGE The <i>IfcTypeObject</i> is now subtyped from the new supertype <i>IfcObjectDefinition</i>, and the attribute <i>HasPropertySets</i> has been changed from a LIST into a SET.
</blockquote>
<blockquote class="change-ifc2x4">
IFC2x4 CHANGE (1) The entity <i>IfcTypeObject</i> shall not be instantiated from IFC2x4 onwards. It will be changed into an ABSTRACT supertype in future releases of IFC. (2) The inverse attribute <i>Types</i> has been renamed from <i>ObjectTypeOf</i>.
</blockquote>
</EPM-HTML> |
| 130 | 881 | IfcTypeProduct | <EPM-HTML>
<p><i>IfcTypeProduct</i> defines a type
definition of a product without being already inserted into a
project structure (without having a placement), and not being
included into the geometric representation context of the
project.It is used to define a product specification, that is, the
specific product information that is common to all occurrences
of that product type.</p>
<p>An <i>IfcTypeProduct</i> may have a list of property set
attached and an optional set of product representations. Values
of these properties and the representation maps are common to all
occurrencesof that product type.The type occurrence
relationship is realized using the objectified relationship
<i>IfcRelDefinesByType</i>.</p>
<blockquote><small>NOTE 1 The product representations are
defined as representation maps, which gets assigned by a product
instance through the representation item(s) being an
<i>IfcShapeRepresentation</i> and having <i>Items</i> of
type<i>IfcMappedItem</i>.</small></blockquote>
<blockquote><small>NOTE 2 The representations at the occurrence
level (represented by subtypes of <i>IfcProduct</i>) can override
the specific representations at the type level, <br></small>
<blockquote>
<ol>
<li><small>for geometric representations: a Cartesian
transformation operator can be applied at the occurrence level,
and</small></li>
<li><small>for property sets: A property within an occurrence
property set, assigned at the product occurrence, overrides the
same property assigned to the product type.</small></li>
</ol>
</blockquote>
</blockquote>
<p>An <i>IfcTypeProduct</i> may be exchanged without being
already assigned to subtypes of <i>IfcProduct</i>.</p>
<blockquote class="history">
HISTORY New entity in IFC Release 2x.
</blockquote>
<blockquote class="change-ifc2x4">
IFC2x4 CHANGE The entity <i>IfcTypeProduct</i> shall not be instantiated from IFC2x4 onwards. It will be changed into an ABSTRACT supertype in future releases of IFC.
</blockquote>
<p class="use-head">Geometry use definition</p>
<p>The <i>RepresentationMaps</i> define the type product shape
and multiple geometric representations can be assigned. If a
product occurrence is assigned to the type by using the
<i>IfcRelDefinesByType</i> relationship, then these occurrences
have to reference the representation maps. The reference is
created by one or multiple <i>IfcShapeRepresentation</i>'s having
an <i>IfcMappedItem</i> as <i>Items</i>, that places the
<i>IfcRepresentationMap</i> of the type product into the spatial
contexts, i.e. by using an Cartesian transformation operator to
transform the <i>IfcRepresentationMap</i> into the object
coordinate system of the product occurrence.</p>
<p>Figure 10 illustrates an example of referencing a representation map by
the shape representation of a product occurrence. Here the
Cartesian transformation operator only uses translation, but no
rotation, mirroring, or scaling.</p>
<table border="0" cellpadding="2" cellspacing="2" summary="representation map">
<tr><td valign="top"><img src="figures/IfcTypeProduct_RepresentationMap-1.png" alt="representation map" border="0"></td></tr>
<tr><td><p class="figure">Figure 10 — Product type geometry with single placement</p></td></tr>
</table>
<p>Figure 11 illustrates an example of referencing a representation
multiple times map by the shape representation of a product
occurrence. Here the Cartesian transformation operator only uses
translation, but no rotation, mirroring, or scaling. The
different translation values determine the pattern of the
multiple placement.</p>
<table border="0" cellpadding="2" cellspacing="2" summary="representation map">
<tr><td valign="top"><img src="figures/IfcTypeProduct_RepresentationMap-2.png" alt="representation map" border="0"></td></tr>
<tr><td><p class="figure">Figure 11 — Product type geometry with multiple placement</td></tr>
</table>
</EPM-HTML> |
| 131 | 886 | IfcRelAssignsToProduct | <EPM-HTML>
<p>The objectified relationship<i>IfcRelAssignsToProduct</i> handles the assignment of objects (subtypes of <i>IfcObject</i>) to a product (subtypes of <i>IfcProduct</i>). The <i>Name</i> attribute should be used to classify the usage of the <i>IfcRelAssignsToProduct</i> objectified relationship. The following <i>Name</i> values are proposed:</p>
<ul>
<li>'Context' : Assignment of a context specific representation, such as of structural members to a different context representation (with potentially different decomposition breakdown) such as of building elementsfor a specificcontext specific representation.</li>
<li>'View' : Assignment of a product (via <i>RelatingProduct</i>) that is decomposed according to a discipline view, to another product (via <i>RelatedObjects</i>) that is decomposed according to a different discipline view. An example is the assignment of the architectural slab to a different decomposition of the pre manufactured sections of a slab (under a precast concrete discipline view).</li>
</ul>
<blockquote class="history">
HISTORY New Entity in IFC Release 2x
</blockquote>
<blockquote class="change-ifc2x3">
IFC2x3 CHANGE The reference of a product within a spatial structure is now handled by a new relationship object <i>IfcRelReferencedInSpatialStructure</i>. The <i>IfcRelAssignsToProduct</i> shall not be used to represent this relation from IFC2x3 onwards.
</blockquote>
</EPM-HTML> |
| 132 | 892 | IfcTypeResource | <EPM-HTML>
<p><i>IfcTypeResource</i> defines a specific (or type) definition of a resource.It is used to define a resource specification (the specific resource, that is common to all occurrences that are defined for that resource) and could act as a resource template.</p>
<p>An <i>IfcTypeResource</i> may have a list of property sets attached. Values of these properties are common to all occurrences of that resource type. The type occurrence relationship is realized using the objectified relationship <i>IfcRelDefinesByType</i>.</p>
<p>Subtypes of <i>IfcTypeResource</i> may be exchanged without being already assigned to subtypes of <i>IfcResource</i>.</p>
<blockquote class="history">
HISTORY New entity in IFC2x4.
</blockquote>
<p class="use-head">Property set use definition</p>
<p>An <i>IfcTypeResource</i> may have a list of property sets attached, accessible by the attribute <i>SELF\IfcTypeObject.HasPropertySets</i>. Currently there are no predefined property sets defined as part of the IFC specification.</p>
<blockquote class="note">
NOTE: For property sets, a property within an occurrence property set that is assigned at the resource occurrence, overrides the same property assigned to the resource type.
</blockquote>
</EPM-HTML> |
| 133 | 897 | IfcRelAssignsToResource | <EPM-HTML>
<p>The objectified relationship <i>IfcRelAssignsToResource</i> handles the assignment of objects
(as subtypes of <i>IfcObject</i>), acting as a resource usage or consumption, to a resource (as subtypes of <i>IfcResource</i>).</p>
<blockquote class="example">
EXAMPLE The assignment of a resource usage to a construction resource is an application of this generic relationship. It could be an actor, as person or organization assigned to a labor resource, or a raw product assigned to a construction product or material resource).
</blockquote>
<blockquote class="history">
HISTORY New Entity in IFC Release 2x.
</blockquote>
</EPM-HTML> |
| 134 | 903 | IfcResource | <EPM-HTML>
<p><i>IfcResource</i> contains the information needed to represent the costs, schedule, and other impacts from the use of a thing in a process. It is not intended to use <i>IfcResource</i> to model the general properties of the things themselves, while an optional linkage from <i>IfcResource</i> to the things to be used can be specified (specifically, the relationship from subtypes of <i>IfcResource</i> to <i>IfcProduct</i> through the <i>IfcRelAssignsToResource</i> relationship). </p>
<p>There are two basic intended uses of <i>IfcResource</i>. First, if the attributes of the thing are not needed for the purpose of the use of <i>IfcResource</i>, or the types of things are not explicitly modeled in IFC yet, then the linkage between the resource and the thing doesn't have to be instantiated in the system. That is, the attributes of <i>IfcResource</i> (or its subtypes) alone are sufficient to represent the use of the thing as a resource for the purpose of the project. </p>
<blockquote class="example">
EXAMPLE: construction equipment such as earth-moving vehicles or tools are not currently modeled within the IFC. For the purpose of estimating and scheduling, these can be represented using subtypes of <i>IfcResource</i> alone.
</blockquote>
<p>Second, if the attributes of the thing are needed for the use of <i>IfcResource</i> objects, and they are modeled explicitly as objects, then the <i>IfcResource</i> instances can be linked to the instances of the type of the things being referenced. Things that might be used as resources and that are already modeled in the IFC include physical products, people and organizations, and materials. The relationship object <i>IfcRelAssignsToResource</i> is provided for this approach.</p>
<p>The inherited attribute <i>ObjectType</i> is used as a textual code that identifies the resource type. </p>
<blockquote class="history">
HISTORY New entity in IFC Release 1.0
</blockquote>
<blockquote class="change-ifc2x">
IFC2x PLATFORM CHANGE: The attributes BaseUnit and ResourceConsumption have been removed from the abstract entity; they are reintroduced at a lower level in the hierarchy.
</blockquote>
</EPM-HTML> |
| 135 | 907 | IfcRelDefinesByType | <EPM-HTML>
<p>The objectified relationship
<i>IfcRelDefinesByType</i> defines the relationship between an
object type and object occurrences.</p>
<p>The <i>IfcRelDefinesByType</i> is a 1-to-N relationship, as it
allows for the assignment of one type information to a single or
to many objects. Those objects then share the same object type,
and the property sets and properties assigned to the object
type.</p>
<blockquote class="history">
HISTORY New entity in IFC2x.
</blockquote>
<blockquote class="change-ifc2x4">
IFC2x4 CHANGE The attribute <i>RelatedObjects</i> had been demoted from the supertype <i>IfcRelDefines</i> to <i>IfcRelDefinesByType</i>.
</blockquote>
<p class="use-head">Relationship use definition</p>
<p>The <i>IfcRelDefinesByType</i> links the object type
definition with the object occurrence. Both may define properties
by assigning an <i>IfcPropertySet</i>, including one or many
subtypes of <i>IfcProperty</i> to either the object type or
object occurrence, as shown in Figure 8.</p>
<p>There are several scenarios to define the same property
set on the object type definition and object occurrence
side:</p>
<ol>
<li>All properties for all object occurrences of a common
object type have the same value - then only the object type
definition has a property set assigned.</li>
<li>All properties for all object occurrences are
different, that is there are no common property values for the
object type definition - then each of the object occurrence has a
property set assigned.</li>
<li>Some properties within the same property set have
common values and are assigned to the object type definition and
some are occurrence specific and assigned (with potentially
different values) to the object occurrences - then:
<ul>
<li>The sum of all properties within a given property set
applicable to an object occurrence is the union of properties
assigned to the object type definition plus the properties
assigned to the object occurrence.</li>
<li>If the object occurrence has a property with the same
<i>IfcProperty.Name</i> in an <i>IfcPropertySet</i>, as the
corresponding object type definition, then the occurrence
property value overrides the type property value.</li>
</ul>
</li>
</ol>
<table border="0" cellpadding="0" cellspacing="0" summary=
"relationship usage">
<tr><td valign="top"><img src="figures/IfcRelDefinesByType_fig-1.png"
alt="instance diagram" border="0"></td></tr>
<td valign="top"><p class="figure">Figure 8 — Type definition relationships</p></td></tr>
</table>
<p>The following table provides an example of assigning</p>
<table border="1" cellpadding="2" cellspacing="2" summary=
"example for property assignment">
<tr valign="top">
<td><small><b>properties assigned to
<i>IfcWall</i></b></small></td>
<td><small><b>properties assigned to
<i>IfcWallType</i></b></small></td>
<td><small><b>resulting property value for individual
wall</b></small></td>
</tr>
<tr valign="top">
<td><small><i>Pset_WallCommon</i></small></td>
<td><small><i>Pset_WallCommon</i></small></td>
<td></td>
</tr>
<tr valign="top">
<td><i><small>-ExtendToStructure</small> = TRUE</i></td>
<td></td>
<td><small>TRUE</small></td>
</tr>
<tr valign="top">
<td></td>
<td><small><i>-ThermalTransmittance</i> = 0.375</small></td>
<td><small>0.375</small></td>
</tr>
<tr valign="top">
<td><small><i>-ExtendToStructure</i> = FALSE</small></td>
<td><small><i>-ExtendToStructure</i> = TRUE</small></td>
<td><small>FALSE</small></td>
</tr>
</table>
</EPM-HTML> |
| 136 | 910 | IfcRelAssignsToControl | <EPM-HTML>
<p>The objectified relationship <i>IfcRelAssignsToControl</i> handles the assignment of a control (represented by subtypes of <i>IfcControl</i>) to other objects (represented by subtypes of <i>IfcObject</i>, with the exception of controls).</p>
<blockquote class="example">
EXAMPLE The assignment of a performance history (as subtype of <i>IfcControl</i>) for a building service element (as subtype of <i>IfcObject</i>) is an application of this generic relationship.
</blockquote>
<blockquote>
HISTORY New Entity in IFC Release 2.0. Has been renamed from <i>IfcRelControls</i> in IFC Release 2x.
</blockquote>
</EPM-HTML> |
| 137 | 913 | IfcControl | <EPM-HTML>
<p><i>IfcControl</i> is the abstract generalization of all concepts that control or constrain the utilization of products, processes, or resources in general. It can be seen as a regulation, cost schedule, request or order, or other requirements applied to a product, process or resource whose requirements and provisions must be fulfilled.</p>
<blockquote class="example">
EXAMPLE Controls include action requests, cost schedules, project orders, work plans, and work calendars.
</blockquote>
<blockquote class="history">
HISTORY New entity in IFC Release 1.0.
</blockquote>
<blockquote class="change-ifc2x4">
IFC2x4 CHANGE Attribute <i>Identification</i> added.
</blockquote>
<p class="use-head">Relationship use definition</p>
<p>Controls have assignments from products, processes, or other objects by using the relationship object <i>IfcRelAssignsToControl</i>.</p>
</EPM-HTML> |
| 138 | 916 | IfcRelAssignsToActor | <EPM-HTML>
<p>The objectified relationship <i>IfcRelAssignsToActor</i> handles the assignment of objects (subtypes of <i>IfcObject</i>) to an actor (subtypes of <i>IfcActor</i>).</p>
<p>The <i>IfcRelAssignsToActor</i> objectified relationship defines a relationship between an <i>IfcActor</i> and one or many objects. A particular role of the actor played in that relationship can be associated. If specified, it takes priority over the role that may be directly assigned to the person or organization.</p>
<blockquote class="example">EXAMPLE: An occupant (as an actor) may rent a flat (as a collection of spaces or a zone). This would be an application of this generic relationship.
</blockquote>
<p>Reference to the objects (or single object) on which the actor acts upon in a certain role (if given) is specified in the inherited <i>RelatedObjects</i> attribute. </p>
<blockquote class="history">
HISTORY New Entity in IFC Release 2.0. Has been renamed from IfcRelActsUpon in IFC Release 2x.
</blockquote>
</EPM-HTML> |
| 139 | 920 | IfcActor | <EPM-HTML>
<p>The <i>IfcActor</i> defines all actors or human agents involved in a project during its full life cycle. It facilitates the use of person and organization definitions in the resource part of the IFC object model. This includes name, address, telecommunication addresses, and roles.</p>
<blockquote>
HISTORY New Entity in IFC Release 2.0
</blockquote>
<p class="use-head">Relationship use definition</p>
<p>Actors are assigned (such as to a process or a resource) by the relationship object that refers to the corresponding object:</p>
<ul>
<li>Process: assigned using <i>IfcRelAssignsToProcess</i></li>
<li>Resource: assigned using <i>IfcRelAssignsToResource</i></li>
</ul>
<p class="use-head">Property set use definition</p>
<p>The property sets relating to the <i>IfcActor</i> are defined by <i>IfcPropertySet</i> and attached by the
<i>IfcRelDefinesByProperties</i> relationship. They are accessible by the inverse <i>IsDefinedBy</i> relationship. The following property set definitions specific to <i>IfcActor</i> are part of this IFC release:</p>
<ul>
<li><a href="../../psd/IfcKernel/Pset_ActorCommon.xml" target="SOURCE">Pset_ActorCommon</a>: common property set for all actor occurrences</li>
</ul>
</EPM-HTML> |
| 140 | 923 | IfcRelAssignsToGroup | <EPM-HTML>
<p>The objectified relationship <i>IfcRelAssignsToGroup</i> handles the assignment of object definitions (individual object occurrences as subtypes of <i>IfcObject</i>, and object types as subtypes of <i>IfcTypeObject</i>) to a group (subtypes of <i>IfcGroup</i>).</p>
<p>The relationship handles the assignment of group members to the group object. It allows for grouping arbitrary objects within a group, including other groups. The grouping relationship can be applied in a recursive manner. The resulting group is of type <i>IfcGroup</i>.</p>
<blockquote class="note">
NOTE Examples of groups include zones as a grouping of spaces, distribution systems as a grouping of building service components, or structural analysis models as a grouping of structural items.
</blockquote>
<p>The inherited attribute <i>RelatedObjects</i> gives the references to the objects, which are the elements within the group. The <i>RelatingGroup</i> is the group that comprises all elements. The same object or object type can be included in zero, one or many groups. Grouping relationships are not hierarchical.</p>
<p><u>Informal proposition</u>:</p>
<ol>
<li>The group assignment relationship shall be acyclic, that is, a group shall not participate in its own grouping relationship.</li>
</ol>
<blockquote class="history">
HISTORY New entity in IFC Release 1.0. It has been renamed from IfcRelGroups in IFC Release 2x.
</blockquote>
</EPM-HTML> |
| 141 | 927 | IfcRelAssignsToGroupByFactor | <EPM-HTML>
<p>The objectified relationship <i>IfcRelAssignsToGroupByFactor</i> is a specialization of the general grouping mechanism. It allows to add a factor to define the ratio that applies to the assignment of object definitions (individual object occurrences as subtypes of <i>IfcObject</i> and object types as subtypes of <i>IfcTypeObject</i>) to a group (subtypes of <i>IfcGroup</i>).</p>
<p>The ratio can be used to define a percentage assignment. For example, a <i>Factor</i> of 0.8 would indicate that the object is assigned by 80% to the group, or a <i>Factor</i> of 2.5 would indicate the object is assigned with a weight factor of 2.5 to the group.</p>
<blockquote class="note">
NOTE Examples of factored groups include the assignment of load cases in a load combination in structural analysis, or the assignment of spaces by percentage to different rental zones.
</blockquote>
<p>The same object or object type may be included with the same or different <i>Factor</i> values to many groups. Grouping relationships are not hierarchical.</p>
<blockquote class="history">
HISTORY New entity in IFC2x4.
</blockquote>
</EPM-HTML> |
| 142 | 929 | IfcGroup | <EPM-HTML>
<p><i>IfcGroup</i> is an generalization of any arbitrary group. A group is a logical collection of objects. It does not have its own position, nor can it hold its own shape representation. Therefore a group is an aggregation under some non-geometrical / topological grouping aspects.</p>
<blockquote class="note">
NOTE Use <i>IfcRelDecomposes</i> together with the appropriate subtypes of <i>IfcProduct</i> to define an aggregation of products that may have its own position and shape representation.
</blockquote>
<blockquote class="example">
EXAMPLE An example for a group is a system, since it groups elements under the aspect of their role, regardless of their position in a building.</small></blockquote>
<p>A group can hold any collection of objects (beingproducts, processes, controls, resources, actors or other groups). Thus groups can be nested. An object can be part of zero, one, or many groups. Grouping relationships are not required to be hierarchical nor do they imply a dependency.</p>
<blockquote><small>NOTE Use <i>IfcRelDecomposes</i> together with the appropriate subtypes of <i>IfcProduct</i> to define an hierarchical aggregation of products.</small></blockquote>
<p>A group can be exchanged without having already objects within the group collection.</p>
<blockquote class="history">
HISTORY New entity in IFC Release 1.0.
</blockquote>
<blockquote class="change-ifc2x4">
IFC2x4 CHANGE The inverse <i>IsGroupedBy</i> relationship is set to 0..n
</blockquote>
<p class="use-head">Relationship use definition</p>
<p>The group collection is handled by an instance of <i>IfcRelAssignsToGroup</i>, which assigns all group members to the <i>IfcGroup</i>.</p>
<ul>
<li>Objects: included in group using <i>IfcRelAssignsToGroup</i></li>
</ul>
<p>Groups are assigned to other objects (such as a process or a resource) by the relationship object that refers to the corresponding
object:</p>
<ul>
<li>Process: assigned using <i>IfcRelAssignsToProcess</i></li>
<li>Resource: assigned using <i>IfcRelAssignsToResource</i></li>
</ul>
<p>Groups can be subjected to a control. The control information is then assigned:</p>
<ul>
<li>Controls: affecting the group using <i>IfcRelAssignsToControl</i></li>
</ul>
</EPM-HTML> |
| 143 | 940 | IfcRelDecomposes | <EPM-HTML>
<p>The decomposition relationship,
<i>IfcRelDecomposes</i>, defines the general concept of elements
being composed or decomposed. The decomposition relationship
denotes a whole/part hierarchy with the ability to navigate from
the whole (the composition) to the parts and vice versa.</p>
<p>Decompositions may be constrained by requiring both, the whole
and its parts, to be of the same type - thus establishing a
nesting relationship. Or they may require some form of physical
containment, thus establishing special types of aggregation
relationships.</p>
<blockquote><small>NOTE There are two special names for
decomposition, which are linguistically distinguished, nesting
and aggregation. The subtypes of <i>IfcRelDecomposes</i> will
introduce either the nesting or aggregation convention (see
<i>IfcRelNests</i> and
<i>IfcRelAggregates</i>).</small></blockquote>
<blockquote><small>EXAMPLE A cost element is a nest of other cost
elements. Or a structural frame is an aggregation of beams and
columns. Both are applications of decomposition
relationship.</small></blockquote>
<p>Decompositions imply a dependency, i.e. the definition of the
whole depends on the definition of the parts and the parts depend
on the existence of the whole. The decomposition relationship can
be applied in a recursive manner, i.e. a decomposed element can
be part in another decomposition. Cyclic references have to be
prevented at application level.</p>
<blockquote class="history">
HISTORY New entity in IFC Release 1.5, it is a generalisation of the IFC2.0 entity <i>IfcRelNests</i>.
</blockquote>
<blockquote class="change-ifc2x4">
IFC2x4 CHANGE The differentiation between the aggregation and nesting is determined to be a non-ordered or an ordered collection of parts. The attributes <i>RelatingObject</i> and <i>RelatedObjects</i> have been demoted to the subtypes.
</blockquote>
</EPM-HTML> |
| 144 | 943 | IfcRelAggregates | <EPM-HTML>
<p>The aggregation relationship
<i>IfcRelAggregates</i> is a special type of the general
composition/decomposition (or whole/part) relationship
<i>IfcRelDecomposes</i>. The aggregation relationship can be
applied to all subtypes of <i>IfcObjectDefinition</i>.</p>
<p>In cases of aggregation of physical elements into a physical
aggregate the shape representation of the whole (within the same
representation identifier) can be taken from the sum of the shape
representations of the parts.</p>
<blockquote><small>EXAMPLE A roof is the aggregation of the roof
elements, such as roof slabs, rafters, purlins, etc. Within the
same representation identifier, e.g. the body geometric
representation, the shape representation of the roof is given by
the shape representation of its parts</small></blockquote>
<p>Decompositions imply a dependency, i.e. the definition of the
whole depends on the definition of the parts and the parts depend
on the existence of the whole. The behaviour that is implied from
the dependency has to be established inside the applications.</p>
<blockquote class="history">
HISTORY New entity in IFC Release 2x.
</blockquote>
<blockquote class="change-ifc2x4">
IFC2x4 CHANGE The attributes <i>RelatingObject</i> and <i>RelatedObjects</i> are demoted from the supertype <i>IfcRelDecomposes</i>.
</blockquote>
<EPM-HTML> |
| 145 | 947 | IfcRelNests | <EPM-HTML>
<p>The nesting relationship
<i>IfcRelNests</i> is a special type of the general
composition/decomposition (or whole/part) relationship
<i>IfcRelDecomposes</i>. The nesting relationship can be applied
to all non physical subtypes of object and object types, namely
processes, controls (like cost items), and resources. The nesting
implies an order among the nested parts.</p>
<blockquote><small>EXAMPLE1 A nesting of costs items in a cost
schedule is the composition of complex cost items from other cost
items. The order of the nested cost items underneath the parent
cost item is determined by the order of the list of
<i>RelatedObjects</i>.</small></blockquote>
<blockquote><small>EXAMPLE2 A nesting of work tasks within a work
schedule is the composition of a parent work task from more
specific sub work tasks. The order of the sub tasks underneath
the parent task is determined by the order of the list of
<i>RelatedObjects</i>..</small></blockquote>
<p>Decompositions imply a dependency, i.e. the definition of the
whole depends on the definition of the parts and the parts depend
on the existence of the whole. The behaviour that is implied from
the dependency has to be established inside the applications.</p>
<blockquote class="history">
HISTORY New entity in IFC Release 2.0
</blockquote>
<blockquote class="change-ifc2x4">
IFC2x4 CHANGE The attributes <i>RelatingObject</i> and <i>RelatedObjects</i> are demoted from the supertype <i>IfcRelDecomposes</i>, and <i>RelatedObjects</i> is refined to be a list. The use of <i>IfcRelNests</i> is repurposed to be a nesting of an ordered collections of parts.
</blockquote>
</EPM-HTML> |
| 146 | 951 | IfcRelAssociates | <EPM-HTML>
<p>
The association relationship
<i>IfcRelAssociates</i> refers to external sources of
information (most notably a classification, library or
document). There is no dependency implied by the
association.
</p>
<blockquote>
<small>EXAMPLE Further information may be given
to the tank equipment (as subtype of <i>IfcProduct</i>) in
terms of its classification and instruction documents, the
source of the additional information is held external to
the IFC project model.</small>
</blockquote>
<p>
Association relationships can be established to objects
(occurrences as subtypes of <i>IfcObject</i>) or to types
(as subtypes of <i>IfcTypeObject</i>).
</p>
<blockquote>
<small>EXAMPLE 1 The classification information
for the storage tank equipment may be associated to the
<i>IfcTankType</i> (subtype of <i>IfcTypeObject</i>),
defining the specific information for all occurencies of
that tank in the project. Therefore the association of the
(e.g.) Uniclass notation 'L6814' may be associated by a
subtype of <i>IfcRelAssociates</i> to the type
information.</small>
</blockquote>
<blockquote>
<small>EXAMPLE 2 The classification information
for a particular space within a building may the associated
to the <i>IfcSpace</i> object (subtype of
<i>IfcObject</i>), defining a particular occurrence of
space. Therefore the association of the (e.g.) DIN notation
'HNF 1.5' may be associated by a subtype of
<i>IfcRelAssociates</i> to the object.</small>
</blockquote>
<p>
The association relationship establishs a uni-directional
association. The subtypes of <i>IfcRelAssociates</i>
establishes the particular semantic meaning of the
association relationship.
</p>
<blockquote class="history">
HISTORY New entity in IFC Release 2x.
</blockquote>
<blockquote class="change-ifc2x4">
IFC2x4 CHANGE Entity has been changed into an ABSTRACT supertype
</blockquote>
</EPM-HTML> |
| 147 | 956 | IfcRelAssociatesClassification | <EPM-HTML>
<p>The objectified relationship
<i>IfcRelAssociatesClassification</i> handles the assignment of a
classification item (items of the select
<i>IfcClassificationSelect</i>) to objects occurrences (subtypes of
<i>IfcObject</i>) or object types (subtypes of
<i>IfcTypeObject</i>).</p>
<p>The relationship is used to assign a classification item, or a
classification system itself to objects. Depending on the type of
the <i>RelatingClassification</i> it is either:</p>
<ul>
<li>a reference to an classification item within an external
classification system, or</li>
<li>a reference to the classification system itself</li>
</ul>
<blockquote>
<p><small>NOTE The reference to a classification item
includes a link to the classification system within which the item
is declared. It assigns the meaning of the classification item to
the object (ocurrence or type). The reference to the classification
system provides the information that the object (occurrence or
type) is governed by the classification system but no assignment of
a particular items has been done yet.</small></p>
</blockquote>
<p>The inherited attribute <i>RelatedObjects</i> define the objects
or object types to which the classification is applied. The
attribute <i>RelatingClassification</i> is the reference to a
classification, applied to the object(s). A single
<i>RelatingClassification</i> can thereby be applied to one or
multiple objects.</p>
<blockquote class="history">
HISTORY New entity in IFC Release 2x.
</blockquote>
</EPM-HTML> |
| 148 | 958 | IfcRelAssociatesDocument | <EPM-HTML>
<p>The objectified relationship (<i>IfcRelAssociatesDocument</i>) handles the assignment of a document information (items of the select <i>IfcDocumentSelect</i>) to objects occurrences (subtypes of <i>IfcObject</i>) or object types (subtypes of <i>IfcTypeObject</i>).</p>
<p>The relationship is used to assign a document reference or a more detailed document information to objects. A single document reference can be applied to multiple objects.</p>
<p>The inherited attribute <i>RelatedObjects</i> define the objects to which the document association is applied. The attribute <i>RelatingDocument</i> is the reference to a document reference, applied to the object(s).</p>
<blockquote class="history">
HISTORY: New entity in IFC Release 2x.
</blockquote>
</EPM-HTML> |
| 149 | 960 | IfcRelAssociatesLibrary | <EPM-HTML>
<p>The objectified relationship (<i>IfcRelAssociatesLibrary</i>) handles the assignment of a library item (items of the select <i>IfcLibrarySelect</i>) to subtypes of <i>IfcObjectDefinition</i> or <i>IfcPropertyDefinition</i>.</p>
<p>The relationship is used to assign a library reference or a more detailed link to a library information to objects, property sets or types. A single library reference can be applied to multiple items.</p>
<p>The inherited attribute <i>RelatedObjects</i> define the items to which the library association is applied. The attribute <i>RelatingLibrary</i> is the reference to a library reference, applied to the item(s).</p>
<blockquote class="history">
HISTORY: New entity in IFC Release 2x.
</blockquote>
</EPM-HTML> |
| 150 | 965 | IfcRelConnects | <EPM-HTML>
<p><i>IfcRelConnects</i> is a connectivity relationship that connects objects under some criteria. As a general connectivity it does not imply constraints, however subtypes of the relationship define the applicable object types for the connectivity relationship and the semantics of the particular connectivity.</p>
<blockquote class="history">
HISTORY: New entity in IFC Release 2x.
</blockquote>
</EPM-HTML> |
| 151 | 966 | IfcRelDeclares | <EPM-HTML>
<p>The objectified relationship <i>IfcRelDeclares</i> handles the declaration of objects (subtypes of <i>IfcObject</i>) or properties (subtypes of <i>IfcPropertyDefinition</i>) to a project or project library (represented by <i>IfcProject</i>, or <i>IfcProjectLibrary</i>).</p>
<p>The relationship handles the assignment of other objects, like <i>IfcActor</i>, or <i>IfcTypeObject</i> to the project, or project libary. The attribute <i>RelatedDefinitions</i> provides the references to the first level objects, that are the elements within the context. All other objects that relate to the first level objects are also defined in the context.</p>
<blockquote>
<p><small>NOTE 1 Every object (as subtype of <em>IfcObject</em>) has to be declared within the context of a single <em>IfcProject</em>, or of a <em>IfcProjectLibrary</em> assigned to a single <em>IfcProject</em>. This declaration is transitive. For example: the <em>IfcWorkPlan</em> as first level object is declared within the context of <em>IfcProject</em> via <em>IfcRelDeclares</em>, all related <em>IfcWorkSchedule</em>'s are related to the context in a transitive way through <em>IfcWorkPlan</em>.</small></p>
</blockquote>
<blockquote>
<p><small>NOTE 2 The assignment excludes subtypes of <em>IfcProduct</em>'s, these are assigned to the <i>IfcProject</i> using the spatial structure approach through <i>IfcSpatialStructureElement</i>(s), where the outer container element such as <em>IfcSite</em> or <em>IfcBuilding</em> has an <i>IfcRelAggregates</i> relationship with the <i>IfcProject</i>.</small></p>
</blockquote>
<p>The <i>RelatingContext</i> is the project, or project library that comprises all elements. The unit assignments and the presentation contexts defined at <em>IfcProject</em> or <em>IfcProjectLibrary</em> apply to all these elements.</p>
<blockquote class="history">
HISTORY New entity in Release IFC2x4.
</blockquote>
</EPM-HTML> |
| 152 | 970 | IfcContext | <EPM-HTML>
<p><em>IfcContext</em> is the generalization of a project context in which objects, type objects, property sets, and properties are defined. The <em>IfcProject</em> as subtype of <em>IfcContext</em> provides the context for all information on a construction project, it may include one or several <em>IfcProjectLibrary</em> as subtype of <em>IfcContext</em> to register the included libraries for the project.</p>
<p>Context definitions can be named, using the inherited <em>Name</em> attribute, which should be a user recognizable key or number for the context. The <em>LongName</em> can add a full name. Further explanations to the context can be given using the inherited <em>Description</em> attribute.</p>
<blockquote class="history">
HISTORY New abstract entity in IFC2x4.
</blockquote>
<p class="use-head">Relationship use definition</p>
<p>Contexts are declared by the relationship object that refers to the corresponding object:</p>
<ul>
<li>Project library to project: <em>IfcProjectLibrary</em> is assigned to <em>IfcProject</em> (both subtypes of using
<em>IfcContext</em>) by using <em>IfcRelDeclares</em></li>
</ul>
<p>More specific relationships are introduced at the level of subtypes.</p>
</EPM-HTML> |
| 153 | 979 | IfcProject | <EPM-HTML>
<p><i>IfcProject</i> indicates the undertaking of some design, engineering, construction, or
maintenance activities leading towards a product. The project establishes the context for information to be exchanged or shared, and it may represent a construction project but does not have to. The <em>IfcProject</em>'s main purpose in an exchange structure is to provide the root instance and the context for all other information items included.</p>
<p>The context provided by the <em>IfcProject</em> includes:</p>
<ul>
<li>the default units</li>
<li>the geometric representation context for exchange structures including shape representations
<ul>
<li>the world coordinate system</li>
<li>the coordinate space dimension</li>
<li>the precision used within the geometric representations, and</li>
<li>optionally the indication of the true north relative to the world coordinate system</li>
</ul>
</li>
</ul>
<blockquote class="history">HISTORY New Entity in IFC Release 1.0</blockquote>
<blockquote class="change-ifc2x4">
IFC2x4 CHANGE The attributes <em>RepresentationContexts</em> and <em>UnitsInContext</em> are made optional and are promoted to supertype <em>IfcContext</em>.
</blockquote>
<p class="use-head">Relationship use definition</p>
<p>The <em>IfcProject</em> is used to reference the root of the spatial structure of a building (that serves as the primary project breakdown and is required to be hierarchical). The spatial structure elements are linked together, and to the <em>IfcProject</em>, by using the objectified relationship <em>IfcRelAggregates</em>. The <em>IfcProject</em> references them by its inverse relationship:</p>
<ul>
<li><em>IfcProject.Decomposes</em> -- it shall be NIL, i.e. the
<em>IfcProject</em> shall not be decomposed into any parts.</li>
<li><em>IfcProject.IsDecomposedBy</em> -- referencing
(<em>IfcSite</em> || <em>IfcBuilding</em>) by
<em>IfcRelAggregates.RelatingObject</em>. The <em>IfcSite</em> or
<em>IfcBuilding</em> referenced shall be the root of the spatial
structure.</li>
</ul>
<p>The <em>IfcProject</em> is also the context for other information about the construction project such as a work plan. Non-product structures are assigned by their first level object to <em>IfcProject</em> using the <em>IfcRelDeclares</em> relationship.</p>
<p>The <em>IfcProject</em> provides the context for spatial elements and the associated products, and for work plans (or other non-product based) descriptions of the construction project. It is handled by two distinct relationship objects as shown in Figure 3.</p>
<blockquote class="note">NOTE The spatial structure and the schedule structure can be decomposed. For example the <em>IfcBuilding</em> can be decomposed into <em>IfcBuildingStorey</em>'s, and the <em>IfcWorkPlan</em> can be decomposed into <em>IfcWorkSchedule</em>'s.</blockquote>
<blockquote class="note">NOTE The products and tasks can be decomposed further. For example the <em>IfcCurtainWall</em> can be decomposed into <em>IfcMember</em> and <em>IfcPlate</em>, the <em>IfcTask</em> can be decomposed into other <em>IfcTask</em>'s.</blockquote>
<blockquote class="note">NOTE The products and tasks can have direct linking relationships. For example the <em>IfcCurtainWall</em> can be assigned to a <em>IfcTask</em> as an input or output for a construction schedule.</blockquote>
<blockquote class="note">NOTE The anomaly to use the composition structure through <em>IfcRelAggregates</em> for assigning the uppermost spatial container to <em>IfcProject</em> is due to upward compatibility reasons with earlier releases of this standard.</blockquote>
<table summary="project relationships">
<tr valign="top"><td><img src="figures/IfcProject_fig-1.png" alt="project relationships" /></td></tr>
<tr valign="top"><td colspan="2">
<p class="figure">Figure 3 — Project spatial and work plan structure</p></td></tr>
</table>
<p>As shown in Figure 4, the <em>IfcProject</em> provides the context for project libraries that in return provide a context to the library items assigned to it. Product types are an example for items that can be included in a project library.</p>
<table summary="project relationships">
<tr><td><img src="figures/IfcProject_fig-2.png" alt="project relationships" /></td></tr>
<tr><td><p class="figure">Figure 4 — Project spatial structure, products and product type library</p></td></tr>
</table>
<p><u>Informal propositions</u>:</p>
<ol>
<li>There shall only be one project within the exchange context. This is enforced by the global rule <em>IfcSingleProjectInstance</em>.</li>
</ol>
</EPM-HTML> |
| 154 | 984 | IfcProjectLibrary | <EPM-HTML>
<p><i>IfcProjectLibrary</i> collects all library elements that are included within a referenced project data set.</p>
<p>Examples for project libraries include:</p>
<ul>
<li>type libraries (also called style or family libraries): a collection of subtypes of <em>IfcTypeObject</em></li>
<li>property definition libraries: a collections of <em>IfcPropertySetTemplate</em> or <em>IfcPropertyTemplates</em></li>
</ul>
<blockquote class="history">
HISTORY New entity in IFC2x4.
</blockquote>
<p class="use-head">Attribute use definition</p>
<dl>
<dt><em>SELF\IfcContext.RepresentationContext</em></dt>
<dd>Context of the representations used within the project library. When the project library includes shape representations for its library type objects, one or several geometric representation contexts need to be included that define the coordinate system, the coordinate space dimensions, and/or the precision factor.<br>
<br></dd>
<dt><em>SELF\IfcContext.UnitsInContext</em></dt>
<dd>Units locally assigned to measure types used within the context of this project library.
<blockquote><small>NOTE It is generally discouraged to use a different length measure and plane angle measure in an included project library compared with the project itself. It may lead to unexpected results for the shape representation of items included in the project library.</small></blockquote>
</dd>
</dl>
<p class="use-head">Relationship use definition</p>
<p>Instances of <em>IfcProjectLibrary</em> are assigned to the project context using the <em>IfcRelDeclares</em> relationship and accessible through the inverse attribute <em>HasContext</em>. Individual object types and property (set) templates are assigned to the <em>IfcProjectLibrary</em> using the <em>IfcRelDeclares</em> relationship and are accessible through the inverse attribute <em>Declares</em>.</p>
<p>An <em>IfcProjectLibrary</em> may be decomposed into sub libraries using the relationship <em>IfcRelNests</em>. Sub libraries are accessed by the <em>IfcProjectLibrary</em> through the inverse attribute <em>IsNestedBy</em>.</p>
</EPM-HTML> |
| 155 | 985 | IfcRelDefinesByProperties | <EPM-HTML>
<p>The objectified relationship
<i>IfcRelDefinesByProperties</i> defines the relationships
between property set definitions and objects. Properties are
aggregated in property sets. Property sets can be either directly
assigned to occurrence objects using this relationship, or
assigned to an object type and assigned via that type to
occurrence objects.</p>
<p>The <i>IfcRelDefinesByProperties</i> is a 1-to-N relationship,
as it allows for the assignment of one property set to a single
or to many objects. Those objects then share the same property
definition.</p>
<blockquote class="history">
HISTORY New Entity in IFC Release 2.0. Has been renamed from <i>IfcRelAssignsProperties</i> in IFC Release 2x.
</blockquote>
<blockquote class="change-ifc2x4">
IFC2x4 CHANGE The attribute <i>RelatedObjects</i> had been demoted from the supertype <i>IfcRelDefines</i> to <i>IfcRelDefinesByProperties</i>.
</blockquote>
</EPM-HTML> |
| 156 | 988 | IfcRelDefinesByObject | <EPM-HTML>
<p>The objectified relationship <i>IfcRelDefinesByObject</i> defines the relationship between an object taking part in an object type decomposition and an object occurrences taking part in an occurrence decomposition of that type.</p>
<p>The <i>IfcRelDefinesByObject</i> is a 1-to-N relationship, as it allows for the assignment of one declaring object information to a single or to many reflected objects. Those objects then share the same object property sets and, for subtypes of <i>IfcProduct</i>, the eventually assigned representation maps.</p>
<p>Only objects that take part in a type decomposition and in an occurrence decomposition of the same type can be connected by the <i>IfcRelDefinesByObject</i> relationship.</p>
<blockquote class="history">
HISTORY New entity in IFC2x4.
</blockquote>
<p class="use-head">Relationship use definition</p>
<p>The <i>IfcRelDefinesByObject</i> links the decomposed object type part, also called the "declaring part" with the occurrence of that part inside the occurrence of the decomposed type, also called the "reflected part", as shown in Figure 6.</p>
<table border="0" cellpadding="0" cellspacing="0" summary="relationship usage">
<tr><td><img src="figures/IfcRelDefinesByObject_fig-1.png" alt="instance diagram" border="0"></td></tr>
<tr><td><p class="figure">Figure 6 — Part definition relationships</p></td></tr>
</table>
<p>The <i>IfcRelDefinesByObject</i> can be used together with the shape representations of the product type as shown in Figure 7. The <i>IfcShapeRepresentation</i> of the "declaring part" is referenced by the "reflected part". The <i>IfcObjectPlacement</i> of the model occurrence (the whole) determines the position within the project context.</p>
<table border="0" cellpadding="0" cellspacing="0" summary="relationship usage">
<tr><td><img src="figures/IfcRelDefinesByObject_fig-2.png" alt="geometry diagram" border="0"></td></tr>
<tr><td><p class="figure">Figure 7 — Part definition relationships with shape representation</td></tr>
</table>
</EPM-HTML> |
| 157 | 991 | IfcPropertySetTemplate | <EPM-HTML>
<p><em>IfcPropertySetTemplate</em> defines the template for all
dynamically extensible property sets represented by
<em>IfcPropertySet</em>. The property set template is a container
of property templates within a property tree. The individual
property templates are interpreted according to their <em>Name</em>
attribute and shall have no values assigned.</p>
<blockquote><span style="font-size:smaller">NOTE By
convention an <em>IfcPropertySetTemplate</em> can also be used as a
template for an <em>IfcElementQuantity</em>, being a particular
type of a property set definition.</span></blockquote>
<p>Property set templates can form part of a property library used
and declared within a project. Depending on the
<em>TemplateType</em> the <em>IfcPropertySetTemplate</em> defines a
template for:</p>
<ul>
<li>"Pset_" - occurrences of <em>IfcPropertySet</em></li>
<li>"QTO_" - occurrences of <em>IfcElementQuantity</em></li>
</ul>
<blockquote class="history">
HISTORY New Entity in IFC2x4.
</blockquote>
<p class="use-head">Relationship use definition</p>
<p>The inherited <em>HasContext</em> inverse relation to <em>IfcRelDeclares</em> is used to declare the <em>IfcPropertySetTemplate</em> within a project library. If included in an exchange data set it can then be traversed through the <em>IfcProjectLibrary</em>.</p>
<p>The <em>Defines</em> inverse relation to <em>IfcRelDefinesByTemplate</em> is provided to keep the definition relationship between the <em>IfcPropertySetTemplate</em> and the one to many <em>IfcPropertySet</em>'s, for which it provides the template.</p>
<p>Between <em>IfcProperty</em>'s within the <em>HasProperties</em> set of <em>IfcPropertySet</em> having the same <em>Name</em> attribute value as the <em>IfcPropertyTemplate</em>'s within the <em>HasPropertyTemplates</em> set of <em>IfcPropertySetTemplate</em> an implicit definition relationship is established that assigns the template to the individual properties.</p>
<p>Figure 5 illustrates relationships used for property set templates.</p>
<table summary="relationships used for property set templates">
<tr>
<td valign="top"><img src=
"figures/IfcPropertySetTemplate_fig-1.png" alt=
"property set template"></td>
</tr>
<tr><td><p class="figure">Figure 5 — Property set template relationships</p></td>
</tr>
</table>
</EPM-HTML> |
| 158 | 998 | IfcPropertyTemplateDefinition | <EPM-HTML>
<p><em>IfcPropertyTemplateDefinition</em> is a generalization of
all property and property set templates. Templates define the
collection, types, names, applicable measure types and units of
individual properties used in a project. The property template
definition can be either:</p>
<blockquote>
<p><strong>Property set template</strong> -
<em>IfcPropertySetTemplate</em>, a collection of property templates
that determine the definition of properties used within a project
context.</p>
<p><strong>Property template</strong> -
<em>IfcPropertyTemplate</em>, a single template that determines the
definition of a particular property used in the same project
context. The template may determine the name, description, data
type, the unit, or a standard expression for each property that is
based on that template.</p>
</blockquote>
<p>The subtypes of <em>IfcPropertyTemplateDefinition</em> are
declared within a project context. The uppermost template
definition (e.g. the <em>IfcPropertySetTemplate</em> including
several <em>IfcPropertyTemplate</em>'s) should be related to the
context, either <em>IfcProject</em>, or <em>IfcProjectLibrary</em>,
using the inherited <em>HasContext</em> inverse attribute.</p>
<blockquote class="history">
HISTORY New Entity in IFC2x4.
</blockquote>
</EPM-HTML> |
| 159 | 1001 | IfcPropertyTemplate | <EPM-HTML>
<p>The <i>IfcPropertyTemplate</i> is an abstract supertype
comprising the templates for all dynamically extensible properties,
either as an <em>IfcComplexPropertyTemplate</em>, or an
<em>IfcSimplePropertyTemplate</em>. These templates determine the
structure of:</p>
<ul>
<li>in case of <em>IfcComplexPropertyTemplate</em>
<ul>
<li>an <em>IfcComplexProperty</em></li>
<li>an <em>IfcPhysicalComplexQuantity</em></li>
</ul>
</li>
<li>in case of <em>IfcSimplePropertyTemplate</em>
<ul>
<li>a subtype of <em>IfcSimpleProperty</em></li>
<li>a subtype of <em>IfcPhysicalSimpleQuantity</em></li>
</ul>
</li>
</ul>
<p>The individual property templates are interpreted according to
their <i>Name</i> attribute and may have a predefined property
type, property unit, and property data type. A template however
shall not have measure values, or quantity values assigned. .</p>
<blockquote class="note">
NOTE Property templates can form part of a property library used and attached as part of a project library. In general the <em>IfcPropertySetTemplate</em>, containing the subtypes of <em>IfcPropertyTemplate</em> would be directly linked to the <em>IfcProjectLibrary</em>.
</blockquote>
<blockquote class="history">
HISTORY New Entity in IFC2x4.
</blockquote>
</EPM-HTML> |
| 160 | 1006 | IfcComplexPropertyTemplate | <EPM-HTML>
<p>The <em>IfcComplexPropertyTemplate</em> defines the template for
all complex properties, either the <em>IfcComplexProperty</em>'s,
or the <em>IfcPhysicalComplexQuantity</em>'s. The individual
complex property templates are interpreted according to their
<em>Name</em> attribute and and optional <em>UsageName</em>
attribute.</p>
<blockquote class="history">
HISTORY New entity in IFC2x4.
</blockquote>
</EPM-HTML> |
| 161 | 1015 | IfcSimplePropertyTemplate | <EPM-HTML>
<p>The <em>IfcSimplePropertyTemplate</em> defines the template for
all dynamically extensible properties, either the subtypes of
<em>IfcSimpleProperty</em>, or the subtypes of
<em>IfcPhysicalSimpleQuantity</em>. The individual property
templates are interpreted according to their <em>Name</em>
attribute and may have a predefined template type, property units,
and property data types. The correct interpretation of the
attributes:</p>
<ul>
<li><em>PrimaryUnit</em></li>
<li><em>SecondaryUnit</em></li>
<li><em>PrimaryDataType</em></li>
<li><em>SecondaryDataType</em></li>
</ul>
<p>is determined by the <em>TemplateType</em>. The
<em>TemplateType</em> also controls, which subtype of either
<em>IfcSimpleProperty</em> or <em>IfcPhysicalSimpleQuantity</em>
shall be used for property occurrences corresponding to this
template.</p>
<blockquote class="history">
HISTORY New entity in IFC2x4.
</blockquote>
<p class="use-head">Relationship use definition</p>
<p>The <em>IfcSimplePropertyTemplate</em> is part of the set of
templates included in the <em>IfcPropertySetTemplate</em>. The
template can be accessed throught the inverse attribute
<em>PartOfPsetTemplate</em> The <em>IfcPropertySetTemplate</em> may
define one or several instances of <em>IfcPropertySet</em> (or
<em>IfcElementQuantity</em>). The definition assignment is
established by the objectified relationship
<em>IfcRelDefinesByTemplate</em>.</p>
<p>There is no direct link between an
<em>IfcSimplePropertyTemplate</em> and a subtype of either
<em>IfcSimpleProperty</em> or <em>IfcPhysicalSimpleQuantity</em>.
The definition relationship between the template and the individual
properties (or quantities) is established by the <em>Name</em>
attributes.</p>
<blockquote>
<p><span style="font-size:smaller">Constraints at
<em>IfcPropertySetTemplate</em> and <em>IfcPropertySet</em> (and
<em>IfcElementQuantity</em>) guarantee that the <em>Name</em>
attributes of included property templates and individual properties
are unique.</span></p>
</blockquote>
<table>
<tr><td><img src="figures/IfcSimplePropertyTemplate_fig-1.png" alt=
"IfcSimplePropertyTemplate figure 1"></td></tr>
<tr><td><p class="figure">Figure 9 — Property template relationships</p></td></tr>
</table>
</EPM-HTML> |
| 162 | 1045 | IfcPreDefinedPropertySet | <EPM-HTML>
<p><i>IfcPreDefinedPropertySet</i>
is a generalization of all statically defined property sets that
are assigned to an object or type object. The statically or
pre-defined property sets are entities with a fixed list of
attributes having particular defined data types.</p>
<p><i>IfcPreDefinedPropertySet</i>'s can be assigned to objects
and object types but do not have a defining property set
template.</p>
<blockquote class="history">
HISTORY New Entity in IFC2x4
</blockquote>
<p class="use-head">Relationship use definition</p>
<p>Property sets are related to other objects by using the
relationship object that refers to the corresponding object:</p>
<ul>
<li><b>Occurrence Object</b>: <i>IfcRelDefinesByProperties</i>
using the inverse attribute <i>DefinesOccurrence</i>.</li>
<li><b>Type Object</b>: using a direct link by inverse attribute
<i>DefinesType</i>.</li>
</ul>
</EPM-HTML> |
| 163 | 1046 | IfcProxy | <EPM-HTML>
<p><i>IfcProxy</i> is intended to be a kind of a container for wrapping objects which are defined by associated properties, which may or may not have a geometric representation and placement in space. A proxy may have a semantic meaning, defined by the <i>Name</i> attribute, and property definitions, attached through the property assignment relationship, which definition may be outside of the definitions given by the current release of IFC.</p>
<p>The <i>ProxyType</i> may give an indication to which high level semantic breakdown of object the semantic definition of the proxy relates to. the <i>Tag</i> attribute may be used to assign a human or system interpretable identifier (such as a serial number or bar code).</p>
<blockquote>
<p><small>NOTE 1 Given that only a
limited number of semantic constructs can be formally defined within
IFC (and it will never be possible to define all), there has to be a
mechanism for capturing those constructs that are not (yet) defined by
IFC. <br>
<br>
NOTE 2 Product proxies are a
mechanism that allows to exchange data that is part of the project but
not necessarily part of the IFC model. Those proxies may have geometric
representations assigned.</small></p>
</blockquote>
<blockquote class="history">
HISTORY New entity in IFC Release 1.5.
</blockquote>
</EPM-HTML> |
| 164 | 1055 | IfcRelFlowControlElements | <EPM-HTML>
<p>Objectified relationship between a distribution flow element occurrence instance and one-to-many control element occurrence instances indicating that the control element(s) sense or control some aspect of the flow element. It is applied to <i>IfcDistributionFlowElement</i> and <i>IfcDistributionControlElement</i>.</p>
<p>This relationship may be used to indicate an operation relationship such as an actuator operating a valve, damper, or switch. It may also be used to indicate a sensing relationship such as a sensor detecting conditions of fluid flow.</p>
<p>This relationship implies a sensing or controlling relationship; if elements are merely connected without any control relationship, then <i>IfcRelConnectsElements</i> should be used.</p>
<blockquote>
<font color="#0000ff" size="-1">
HISTORY: New entity in IFC R2x.<br>
</font>
</blockquote>
</EPM-HTML>
|
| 165 | 1058 | IfcDistributionControlElement | <EPM-HTML>
<p>The distribution element <i>IfcDistributionControlElement</i> defines occurrence elements of a building automation control system that are used to impart control over elements of a distribution system.</p>
<p>This class defines elements of a building automation control system. These are typically used to control distribution system elements to maintain variables such as temperature, humidity, pressure, flow, power, or lighting levels, through the modulation, staging or sequencing of mechanical or electrical devices. The three general functional categories of control elements are as follows:</p>
<ul>
<li>Impart control over flow control elements (<i>IfcFlowController</i>) in a distribution system such as dampers, valves, or relays, typically through the use of actuation (<i>IfcActuator</i>).</li>
<li>Sensing elements (<i>IfcSensor</i>) that measure changes in the controlled variable such as temperature, humidity, pressure, or flow.</li>
<li>Controllers (<i>IfcController</i>) typically classified according to the control action they seek to perform and generally responsible for making decisions about the elements under control.</li>
</ul>
<p>Since this class and its subtypes typically relate to many different distribution flow elements (<i>IfcDistributionFlowElement</i>), the objectified relationship <i>IfcRelFlowControlElements</i> has been provided to relate control and flow elements as required.</p>
<blockquote>
<font color="#ff0000" size="-1">IFC2x4 CHANGE: ControlElementId attribute deleted; replaced by classification usage.</font>
<font color="#0000ff" size="-1">HISTORY: New entity in IFC R2.0.<br></font>
</blockquote>
<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcDistributionControlElement</b> defines the occurrence of any distribution control element; common information about distribution control element types is handled by <a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributioncontrolelementtype.htm">IfcDistributionControlElementType</a>. The <a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributioncontrolelementtype.htm">IfcDistributionControlElementType</a> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. The <a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributioncontrolelementtype.htm">IfcDistributionControlElementType</a> is attached using the <a href="../../ifckernel/lexical/ifcreldefinesbytype.htm">IfcRelDefinesByType</a> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. If the <a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributioncontrolelementtype.htm">IfcDistributionControlElementType</a> has ports or aggregated elements, such objects are reflected at the <b>IfcDistributionControlElement</b> occurrence using the <a href="../../ifckernel/lexical/ifcreldefinesbyobject.htm">IfcRelDefinesByObject</a> relationship. Direct instantiation of <i>IfcDistributionControlElement</i> with <i>IfcObject.ObjectType</i> asserted provides the meaning of a distribution control element proxy.</p>
<p><b><u>Property Set Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <a href="../../ifckernel/lexical/ifcpropertyset.htm">IfcPropertySet</a> and attached by the <a href="../../ifckernel/lexical/ifcreldefinesbyproperties.htm">IfcRelDefinesByProperties</a> relationship. They are accessible by the <i>IsDefinedBy</i> inverse attribute. Property sets may also be specified at the <a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributioncontrolelementtype.htm">IfcDistributionControlElementType</a>, defining the common property data for all occurrences of the same type. They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcDistributionControlElementType.HasPropertySets</i>. If both are given, then the properties directly defined at <b>IfcDistributionControlElement</b> override the properties defined at <a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributioncontrolelementtype.htm">IfcDistributionControlElementType</a>. Refer to the documentation at the supertype <a href="../../ifcproductextension/lexical/ifcdistributionelement.htm">IfcDistributionElement</a> and ancestors for inherited property set definitions.</p>
<p><b><u>Classification Use Definition</u></b></p>
<p>In addition to general product and project classification (UniFormat, etc.), classifications may also be applied to indicate a device address or addressing scheme using <a href="../../ifckernel/lexical/ifcrelassociatesclassification.htm">IfcRelAssociatesClassification</a> where <i>RelatedObjects</i> contains the <b>IfcDistributionControlElement</b> and <i>RelatingClassification</i> refers to an <a href="../../ifcexternalreferenceresource/lexical/ifcclassification.htm">IfcClassification</a> or <a href="../../ifcexternalreferenceresource/lexical/ifcclassificationreference.htm">IfcClassificationReference</a>.</p>
<ul>
<li><a href="../../ifcexternalreferenceresource/lexical/ifcclassification.htm">IfcClassification</a>: Indicates an addressing scheme managed by the device where <i>ReferenceTokens</i> defines the format of the address to be specified at <i>IfcClassificationReference.ItemReference</i>. A classification hierarchy may optionally be provided indicating detected or provisioned device addresses.</li>
<li><a href="../../ifcexternalreferenceresource/lexical/ifcclassificationreference.htm">IfcClassificationReference</a>: Indicates the address of the control element where <i>Identification</i> uniquely identifies the element within the control system as determined by the <i>ClassificationSource</i>. Several examples are illustrated:
<ul>
<li><b>'BACnet'</b>: BACnetObjectIdentifier in the decimal form '12.15' (Digital Input #15) indicating type ID and instance ID.</li>
<li><b>'IP'</b>: IP Address in the decimal form '192.168.1.2' such as for an IPv4 network.</li>
<li><b>'OPC'</b>: Hierarchical ItemID in the alphanumeric form 'B204.Tank2.Temperature'</li>
<li><b>'X-10'</b>: Alphabetic and numeric code in the form 'B12' (House B, Device 12) indicating House Code and Device Code.</li>
</ul>
</li>
</ul>
<p>Figure 147 illustrates classification usage.</p>
<table>
<tr><td><img alt="Classification Use Definition" src="figures/IfcDistributionControlElement-Classification.png"></td></tr>
<tr><td><p class="figure">Figure 147 — Distribution control classification</p></td></tr>
</table>
<p><b><u>Composition Use Definition</u></b></p>
<p>The <b>IfcDistributionControlElement</b> may be decomposed into components using <a href="../../ifckernel/lexical/ifcrelaggregates.htm">IfcRelAggregates</a> where <i>RelatingObject</i> refers to the enclosing <b>IfcDistributionControlElement</b> and <i>RelatedObjects</i> contains one or more components. Likewise, a control element may be aggregated within another element. For example, a thermostat may contain temperature sensors, and a programmable logic controller may contain virtual (software-based) control elements. Standard types for composition are defined at subtypes.</p>
<p><b><u>Connection Use Definition</u></b></p>
<p>The <b>IfcDistributionControlElement</b> may be connected to other objects as follows using the indicated relationship:</p>
<ul>
<li><a href="../../ifcproductextension/lexical/ifcspatialstructureelement.htm">IfcSpatialStructureElement</a> (<a href="../../ifcproductextension/lexical/ifcrelcontainedinspatialstructure.htm">IfcRelContainedInSpatialStructure</a>) : Indicates the spatial location containing the element. If an element is aggregated within another element, then only the top-level element participates in this relationship.</li>
<li><a href="../../ifcproductextension/lexical/ifcelement.htm">IfcElement</a> (<a href="../../ifcproductextension/lexical/ifcrelconnectselements.htm">IfcRelConnectsElements</a>) : Indicates physical connectivity with another element (but not embedding or flow control), such as a sensor attached to a wall. <i>IfcRelConnectsElements.RelatingElement</i> refers to the anchored side (for example, wall hosting sensor).</li>
<li><a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm">IfcDistributionPort</a> (<a href="../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm">IfcRelConnectsPortToElement</a>) : Indicates ports on the element which may be connected to other elements for control signal transmission or electric power. Standard port names, types, and directions are defined at subtypes.</li>
<li><a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionflowelement.htm">IfcDistributionFlowElement</a> (<a href="../../ifcsharedbldgserviceelements/lexical/ifcrelflowcontrolelements.htm">IfcRelFlowControlElements</a>) : Indicates a flow element is sensed or controlled by the control element, such as a tank for a level sensor or a valve for an actuator.</li>
</ul>
<p><b><u>Assignment Use Definition</u></b></p>
<p>The <b>IfcDistributionControlElement</b> may be assigned to the following entities using relationships as indicated:</p>
<ul>
<li><a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystem.htm">IfcDistributionSystem</a> (<a href="../../ifckernel/lexical/ifcrelassignstogroup.htm">IfcRelAssignsToGroup</a>): Indicates a system containing interconnected devices, where control elements are typically part of a control system having <i>PredefinedType=CONTROL</i>.</li>
<li><a href="../../ifccontrolextension/lexical/ifcperformancehistory.htm">IfcPerformanceHistory</a> (<a href="../../ifckernel/lexical/ifcrelassignstocontrol.htm">IfcRelAssignsToControl</a>): Indicates realtime or historical infomation captured for the device.</li>
</ul>
<p> The <b>IfcDistributionControlElement</b> may have assignments of its own using the <a href="../../ifckernel/lexical/ifcrelassignstoproduct.htm">IfcRelAssignsToProduct</a> relationship where <i>RelatingProduct</i> refers to the <b>IfcDistributionControlElement</b> and <i>RelatedObjects</i> contains one or more objects of the following types: </p>
<ul>
<li><a href="../../ifcprocessextension/lexical/ifctask.htm">IfcTask</a>: Indicates tasks used to purchase, install, renovate, demolish, operate, or otherwise act upon the element. If the element has a type, available task types are assigned to the element type.</li>
<li><a href="../../ifcprocessextension/lexical/ifcprocedure.htm">IfcProcedure</a>: Indicates procedures used to operate the element. If the element has a type, available procedure types are assigned to the element type.</li>
<li><a href="../../ifcprocessextension/lexical/ifcevent.htm">IfcEvent</a>: Indicates events raised by the element, sequenced by procedures to be followed. If the element has a type, available event types are assigned to the element type.</li>
</ul>
<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcDistributionControlElement</b> is defined using one of the following entities:</p>
<ul>
<li><a href="../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm">IfcMaterialConstituentSet</a>: For elements containing multiple materials, this indicates materials at named aspects.</i>
</li>
<li>
<a href="../../ifcmaterialresource/lexical/ifcmaterial.htm">IfcMaterial</a>: For elements comprised of a single material, this indicates the material.</li>
</ul>
<p>The material is attached by the <i>RelatingMaterial</i> attribute on the <a href="../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm">IfcRelAssociatesMaterial</a> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributioncontrolelementtype.htm">IfcDistributionControlElementType</a>, defining the common attribute data for all occurrences of the same type. Standard names and material types are defined at subtypes.</p>
<p><b><u>Representation Use Definition</u></b></p>
<p>The following shape representations are supported for subtypes of <i>IfcDistributionControlElement</i>, distinguished by <i>IfcShapeRepresentation.RepresentationIdentifier</i>:</p>
<ul>
<li><b>'Footprint'</b>: Represents the 2D footprint outline of the item having <i>IfcShapeRepresentation.RepresentationType</i> of 'GeometricCurveSet' and containing a single <i>IfcGeometricCurveSet</i> consisting of one or more <i>IfcCurve</i> subtypes such as <i>IfcPolyline</i>, <i>IfcTrimmedCurve</i>, <i>IfcCompositeCurve</i>, or <i>IfcCircle</i>.</li>
<li><b>'Body'</b>: Represents the 3D shape of the item having <i>IfcShapeRepresentation.RepresentationType</i> of 'SurfaceModel', 'SolidModel', or any solid model specializations including 'Brep', 'AdvancedBrep', 'SweptSolid', 'AdvancedSweptSolid', 'CSG', 'Clipping', or 'SectionedSpine').</li>
<li><b>'Clearance'</b>: Represents the 3D clearance volume of the item having <i>RepresentationType</i> of 'Surface3D'. Such clearance region indicates space that should not intersect with the 'Body' representation of other elements, though may intersect with the 'Clearance' representation of other elements. The particular use of clearance space may be for safety, maintenance, or other purpose.</li>
</ul>
<p>For all representations, if a <i>IfcDistributionControlElement</i> occurrence is defined by a <i>IfcDistributionControlElementType</i> having a representation of the same identifier, then 'MappedRepresentation' should be used at the occurrence unless overridden.</p>
<p>If materials are defined, geometry of each representation (most typically the 'Body' representation) may be organized into shape aspects where styles may be derived by correlating <i>IfcShapeAspect.Name</i> to a corresponding material (<i>IfcMaterialConstituent.Name</i>).</p>
</EPM-HTML>
|
| 166 | 1060 | IfcDistributionPort | <EPM-HTML>
<p>A distribution port is an inlet or outlet of a product through which a particular substance may flow.</p>
<p>Distribution ports are used for passage of solid, liquid, or gas substances, as well as electricity for power or communications. Flow segments (pipes, ducts, cables) may be used to connect ports across products. Distribution ports are defined by system type and flow direction such that for two ports to be connected, they must share the same system type and have opposite flow directions (one side being a <i>SOURCE</i> and the other being a <i>SINK</i>). Ports are similar to openings in that they do not have any visible geometry; such geometry is captured at the shape representation of the enclosing element or element type. Ports may have shape representations that indicate the position, orientation, and cross-section of the connection.</p>
<blockquote class="history">HISTORY: New entity in IFC2x2</blockquote>
<p><b><u>Property Set Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <a href="../../ifckernel/lexical/ifcpropertyset.htm">IfcPropertySet</a> and attached by the <a href="../../ifckernel/lexical/ifcreldefinesbyproperties.htm">IfcRelDefinesByProperties</a> relationship. They are accessible by the <i>IsDefinedBy</i> inverse attribute. Refer to the documentation at the supertype <a href="../../ifcproductextension/lexical/ifcport.htm">IfcPort</a> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p>
<ul>
<li><a href="../../psd/IfcSharedBldgServiceElements/Pset_DistributionPortCommon.xml" target="SOURCE">Pset_DistributionPortCommon</a></li>
</ul>
<p>The following property set definitions are applicable to this entity according to the <i>PredefinedType</i> attribute: </p>
<ul>
<li><a href="../../psd/IfcSharedBldgServiceElements/Pset_DistributionPortTypeAirConditioning.xml" target="SOURCE">Pset_DistributionPortTypeAirConditioning</a> (<a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm">AIRCONDITIONING</a>)</li>
<li><a href="../../psd/IfcSharedBldgServiceElements/Pset_DistributionPortTypeAudioVisual.xml" target="SOURCE">Pset_DistributionPortTypeAudioVisual</a> (<a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm">AUDIOVISUAL</a>)</li>
<li><a href="../../psd/IfcSharedBldgServiceElements/Pset_DistributionPortTypeData.xml" target="SOURCE">Pset_DistributionPortTypeData</a> (<a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm">DATA</a>)</li>
<li><a href="../../psd/IfcSharedBldgServiceElements/Pset_DistributionPortTypeDomesticColdWater.xml" target="SOURCE">Pset_DistributionPortTypeDomesticColdWater</a> (<a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm">DOMESTICCOLDWATER</a>)</li>
<li><a href="../../psd/IfcSharedBldgServiceElements/Pset_DistributionPortTypeDomesticHotWater.xml" target="SOURCE">Pset_DistributionPortTypeDomesticHotWater</a> (<a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm">DOMESTICHOTWATER</a>)</li>
<li><a href="../../psd/IfcSharedBldgServiceElements/Pset_DistributionPortTypeDrainage.xml" target="SOURCE">Pset_DistributionPortTypeDrainage</a> (<a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm">DRAINAGE</a>)</li>
<li><a href="../../psd/IfcSharedBldgServiceElements/Pset_DistributionPortTypeElectrical.xml" target="SOURCE">Pset_DistributionPortTypeElectrical</a> (<a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm">ELECTRICAL</a>)</li>
<li><a href="../../psd/IfcSharedBldgServiceElements/Pset_DistributionPortTypeFireProtection.xml" target="SOURCE">Pset_DistributionPortTypeFireProtection</a> (<a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm">FIREPROTECTION</a>)</li>
<li><a href="../../psd/IfcSharedBldgServiceElements/Pset_DistributionPortTypeGas.xml" target="SOURCE">Pset_DistributionPortTypeGas</a> (<a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm">GAS</a>)</li>
<li><a href="../../psd/IfcSharedBldgServiceElements/Pset_DistributionPortTypeHeating.xml" target="SOURCE">Pset_DistributionPortTypeHeating</a> (<a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm">HEATING</a>)</li>
<li><a href="../../psd/IfcSharedBldgServiceElements/Pset_DistributionPortTypeOil.xml" target="SOURCE">Pset_DistributionPortTypeOil</a> (<a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm">OIL</a>)</li>
<li><a href="../../psd/IfcSharedBldgServiceElements/Pset_DistributionPortTypeSewage.xml" target="SOURCE">Pset_DistributionPortTypeSewage</a> (<a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm">SEWAGE</a>)</li>
<li><a href="../../psd/IfcSharedBldgServiceElements/Pset_DistributionPortTypeSignal.xml" target="SOURCE">Pset_DistributionPortTypeSignal</a> (<a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm">SIGNAL</a>)</li>
<li><a href="../../psd/IfcSharedBldgServiceElements/Pset_DistributionPortTypeTelephone.xml" target="SOURCE">Pset_DistributionPortTypeTelephone</a> (<a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm">TELEPHONE</a>)</li>
</ul>
<p>The following property set definitions are applicable to <a href="../../ifccontrolextension/lexical/ifcperformancehistory.htm">IfcPerformanceHistory</a>, for which objects are assigned:</p>
<ul>
<li><a href="../../psd/IfcSharedBldgServiceElements/Pset_DistributionPortPHistoryAirConditioning.xml" target="SOURCE">Pset_DistributionPortPHistoryAirConditioning</a> (<a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm">AIRCONDITIONING</a>)</li>
<li><a href="../../psd/IfcSharedBldgServiceElements/Pset_DistributionPortPHistoryControl.xml" target="SOURCE">Pset_DistributionPortPHistoryControl</a> (<a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm">CONTROL</a>)</li>
<li><a href="../../psd/IfcSharedBldgServiceElements/Pset_DistributionPortPHistoryData.xml" target="SOURCE">Pset_DistributionPortPHistoryData</a> (<a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm">DATA</a>)</li>
<li><a href="../../psd/IfcSharedBldgServiceElements/Pset_DistributionPortPHistoryElectrical.xml" target="SOURCE">Pset_DistributionPortPHistoryElectrical</a> (<a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm">ELECTRICAL</a>)</li>
<li><a href="../../psd/IfcSharedBldgServiceElements/Pset_DistributionPortPHistoryGas.xml" target="SOURCE">Pset_DistributionPortPHistoryGas</a> (<a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm">GAS</a>)</li>
<li><a href="../../psd/IfcSharedBldgServiceElements/Pset_DistributionPortPHistoryHeating.xml" target="SOURCE">Pset_DistributionPortPHistoryHeating</a> (<a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm">HEATING</a>)</li>
<li><a href="../../psd/IfcSharedBldgServiceElements/Pset_DistributionPortPHistoryOil.xml" target="SOURCE">Pset_DistributionPortPHistoryOil</a> (<a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm">OIL</a>)</li>
<li><a href="../../psd/IfcSharedBldgServiceElements/Pset_DistributionPortPHistorySignal.xml" target="SOURCE">Pset_DistributionPortPHistorySignal</a> (<a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm">SIGNAL</a>)</li>
</ul>
<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcDistributionPort</b> is defined by <a href="../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm">IfcMaterialConstituentSet</a> or as a fallback by <a href="../../ifcmaterialresource/lexical/ifcmaterial.htm">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href="../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm">IfcRelAssociatesMaterial</a> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p>
<ul>
<li><b>'Media'</b>: The solid, liquid, or gas media passing through the port.</li>
</ul>
<p><b><u>Composition Use Definition</u></b></p>
<p>The <b>IfcDistributionPort</b> may be decomposed into components using <a href="../../ifckernel/lexical/ifcrelaggregates.htm">IfcRelAggregates</a> where <i>RelatingObject</i> refers to the enclosing <b>IfcDistributionPort</b> and <i>RelatedObjects</i> contains one or more components. Composition use is defined for the following predefined types:
<ul>
<li><a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm">AUDIOVISUAL</a>: May contain <b>IfcDistributionPort</b> components having <i>PredefinedType</i> <a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm">AUDIOVISUAL</a>. If needed, audio-visual ports may be aggregated into specific streams (channels).<li><a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm">CONTROL</a>: May contain <b>IfcDistributionPort</b> components having <i>PredefinedType</i> <a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm">SIGNAL</a>. If needed, control ports may be aggregated into signal lines for indicating pinout specification.<li><a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm">DATA</a>: May contain <b>IfcDistributionPort</b> components having <i>PredefinedType</i> <a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm">SIGNAL</a>. If needed, data ports may be aggregated into signal lines for indicating pinout specification.<li><a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm">ELECTRICAL</a>: May contain <b>IfcDistributionPort</b> components having <i>PredefinedType</i> <a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm">SIGNAL</a>. If needed, electrical ports may be aggregated into modulated signals for data or lighting control.<li><a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm">ELECTROACCOUSTIC</a>: May contain <b>IfcDistributionPort</b> components having <i>PredefinedType</i> <a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm">ELECTROACCOUSTIC</a>. If needed, speaker ports may be aggregated into streams (channels) for each speaker.<li><a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm">TELEPHONE</a>: May contain <b>IfcDistributionPort</b> components having <i>PredefinedType</i> <a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystemenum.htm">TELEPHONE</a>. If needed, telephone ports may be aggregated for each line.</ul>
<p><b><u>Connection Use Definition</u></b></p>
<p>The <b>IfcDistributionPort</b> may be connected to other objects as follows using the indicated relationship:</p>
<ul>
<li><a href="../../ifcproductextension/lexical/ifcdistributionelement.htm">IfcDistributionElement</a> (<a href="../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm">IfcRelConnectsPortToElement</a>) : Indicates the host element or element type containing the port.</li>
<li><b>IfcDistributionPort</b> (<a href="../../ifcproductextension/lexical/ifcrelconnectsports.htm">IfcRelConnectsPorts</a>) : Indicates a connection to another port having the same type and opposite flow direction.
For port connections between elements,
the <i>RelatingPort</i> is set to a port having <i>FlowDirection=SOURCE</i> and
the <i>RelatedPort</i> is set to a port having <i>FlowDirection=SINK</i>.
For aggregation scenarios, ports on a device may be mapped to aggregated devices within,
in which case ports on the outer device indicate a single <i>FlowDirection</i> but have an additional connection internally
to a port on an aggregated inner device.
Refer to <a href="../../ifchvacdomain/lexical/ifcunitaryequipment.htm">IfcUnitaryEquipment</a> for an example.</li>
</ul>
<p>Figure 149 illustrates distribution port connectivity.</p>
<table>
<tr><td><img alt="Connection Use Definition" src="figures/IfcDistributionPort-Connection.png"></td></tr>
<tr><td><p class="figure">Figure 149 — Distribution port connectivity</p></td></tr>
</table>
<p><b><u>Assignment Use Definition</u></b></p>
<p> The <b>IfcDistributionPort</b> may be assigned to the following entities using relationships as indicated:</p>
<ul>
<li><a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystem.htm">IfcDistributionSystem</a> (<a href="../../ifckernel/lexical/ifcrelassignstogroup.htm">IfcRelAssignsToGroup</a>): Indicates a system containing interconnected devices.</li>
<li><a href="../../ifccontrolextension/lexical/ifcperformancehistory.htm">IfcPerformanceHistory</a> (<a href="../../ifckernel/lexical/ifcrelassignstocontrol.htm">IfcRelAssignsToControl</a>): Indicates realtime or historical infomation captured for the device.</li>
</ul>
<p> The <b>IfcDistributionPort</b> may have assignments of its own using the <a href="../../ifckernel/lexical/ifcrelassignstoproduct.htm">IfcRelAssignsToProduct</a> relationship where <i>RelatingProduct</i> refers to the <b>IfcDistributionPort</b> and <i>RelatedObjects</i> contains one or more objects of the following types: </p><ul>
<li><a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystem.htm">IfcDistributionSystem</a>: Indicates a system that is hosted by the port, as the origination.
</li>
</ul>
<p><b><u>Representation Use Definition</u></b></p>
<p>The representation of <b>IfcDistributionPort</b> is given by <a href="../../ifcrepresentationresource/lexical/ifcproductdefinitionshape.htm">IfcProductDefinitionShape</a>, allowing multiple shape and topology representations. Included are:</p>
<ul>
<li><a href="../../ifcrepresentationresource/lexical/ifcshaperepresentation.htm">IfcShapeRepresentation</a>: The optional shape representation describes the connection volume and supports indication of the port position and orientation. The position is typically the midpoint of the physical connection, and the orientation points in the flow direction normal to the physical connection. Upon connecting elements through ports with rigid connections, each object is aligned such that the effective <i>Location</i>, <i>Axis</i>, and <i>RefDirection</i> of each port is aligned to be equal.
<ul>
<li><b>'Body'</b>: The shape of the port.</li>
</ul>
</li>
</ul>
</EPM-HTML> |
| 167 | 1106 | IfcDistributionControlElementType | <EPM-HTML>
<p>The element type <i>IfcDistributionControlElementType</i> defines a list of commonly shared property set definitions of an element and an optional set of product representations. It is used to define an element specification (the specific product information that is common to all occurrences of that product type).</p>
<p>Distribution control element types (or the instantiable subtypes) may be exchanged without being already assigned to occurrences.</p>
<p>The occurrences of the <i>IfcDistributionControlElementType</i> are represented by instances of <i>IfcDistributionControlElement</i> or its subtypes.</p>
<blockquote>
<font color="#0000ff" size="-1">HISTORY: New entity in IFC Release 2x2.<br></font>
</blockquote>
<p><b><u>Declaration Use Definition</u></b></p>
<p>The <b>IfcDistributionControlElementType</b> may be declared within a project or project library using <i>IfcRelDeclares</i> where <i>RelatingContext</i> refers to the project or library and <i>RelatedDefinitions</i> includes the element type. Inclusion within <i>IfcProject</i> indicates the type is editable within the direct project and may be available to other referencing projects that may incorporate the type. Inclusion within <i>IfcProjectLibrary</i> indicates the type is incorporated from a referenced project. Default units and coordinate systems (used for representations, materials, and property sets) are indicated by the declaring project or library.</p>
<p><b><u>Classification Use Definition</u></b></p>
<p>The <b>IfcDistributionControlElementType</b> may be classified using <i>IfcRelAssociatesClassification</i> where <i>RelatingClassification</i> refers to an <i>IfcClassificationReference</i> indicating a classification notation. Classifications may refer to industry standards such as MasterFormat, OmniFormat, or UniFormat. Classifications may also refer to organization-specific, project-specific, or system-specific designations. Classification reference identification schemes are described by <i>IfcClassification.ReferenceTokens</i>.</p>
<p><b><u>Document Use Definition</u></b></p>
<p>The <b>IfcDistributionControlElementType</b> may be documented using <i>IfcRelAssociatesDocument</i> where <i>RelatingDocument</i> refers to an <i>IfcDocumentReference</i> indicating content within a document, or <i>IfcDocumentInformation</i> indicating an entire document. Document information may refer to arbitrary attachments such as text or multimedia, while document references may refer to items within particular formats (such as XML element IDs) where there is need to synchronize document information with model information. Document reference identification schemes depend on the particular document format.</p>
<p><b><u>Library Use Definition</u></b></p>
<p>The <b>IfcDistributionControlElementType</b> may be published to a model server using <i>IfcRelAssociatesLibrary</i> where <i>RelatingLibrary</i> refers to an <i>IfcLibraryReference</i> indicating the unique identification within the published project. If the published project is IFC format, then <i>IfcLibraryReference.Identification</i> shall match <i>IfcRoot.GlobalID</i> of the published (master) project, using the same encoding as described for <i>IfcGloballyUniqueId</i>. Multiple library references may be provided to indicate alternate names and descriptions for particular languages. If the element type is declared within <i>IfcProject</i>, then <i>IfcLibraryInformation.Location</i> and <i>IfcLibraryInformation.Version</i> indicate the URL and version as last published. If the element type is declared within <i>IfcProjectLibrary</i>, then the library information indicates the location and version of the definition as last retrieved.</p>
<p><b><u>Composition Use Definition</u></b></p>
<p>The <b>IfcDistributionControlElementType</b> may be decomposed into components using <a href="../../ifckernel/lexical/ifcrelaggregates.htm">IfcRelAggregates</a> where <i>RelatingObject</i> refers to the enclosing <b>IfcDistributionFlowElementType</b> and <i>RelatedObjects</i> contains one or more components. For example, a thermostat type may be decomposed into temperature sensors. Standard types for composition are defined at occurrences for subtypes.</p>
<p><b><u>Connection Use Definition</u></b></p>
<p>The <b>IfcDistributionControlElementType</b> may be connected to other objects as follows using the indicated relationship:</p>
<ul>
<li><a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm">IfcDistributionPort</a> (<a href="../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm">IfcRelConnectsPortToElement</a>) : Indicates port definitions on the element to be instantiated at occurrences. Standard port names, types, and directions are defined at occurrences for subtypes.</li>
</ul>
<p><b><u>Assignment Use Definition</u></b></p>
<p> The <b>IfcDistributionControlElementType</b> may have assignments of its own using the <a href="../../ifckernel/lexical/ifcrelassignstoproduct.htm">IfcRelAssignsToProduct</a> relationship where <i>RelatingProduct</i> refers to the <b>IfcDistributionControlElementType</b> and <i>RelatedObjects</i> contains one or more objects of the following types: </p>
<ul>
<li><a href="../../ifcprocessextension/lexical/ifctasktype.htm">IfcTaskType</a>: Indicates task types available to purchase, install, renovate, demolish, operate, or otherwise act upon occurrences of the element type. Such task types may be instantiated as task occurrences assigned to occurrences of the element type. Prices (such as for purchasing or shipping) may be established by resource types assigned to task types.</li>
<li><a href="../../ifcprocessextension/lexical/ifcproceduretype.htm">IfcProcedureType</a>: Indicates procedure types available to operate occurrences of the element type. Such procedure types may be instantiated as procedure occurrences assigned to occurrences of the element type.</li>
<li><a href="../../ifcprocessextension/lexical/ifceventtype.htm">IfcEventType</a>: Indicates event types available to be raised by occurrences of the element, sequenced by procedures to be followed. Such event types may be instantiated as event occurrences assigned to occurrences of the element type.</li>
</ul>
<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcDistributionControlElementType</b> is defined using one of the following entities:</p>
<ul>
<li><a href="../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm">IfcMaterialConstituentSet</a>: For elements containing multiple materials, this indicates materials at named aspects.</i>
</li>
<li>
<a href="../../ifcmaterialresource/lexical/ifcmaterial.htm">IfcMaterial</a>: For elements comprised of a single material, this indicates the material.</li>
</ul>
<p>The material is attached by the <i>RelatingMaterial</i> attribute on the <a href="../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm">IfcRelAssociatesMaterial</a> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute.</p>
<p><b><u>Representation Use Definition</u></b></p>
<p>The following shape representations are supported for subtypes of <i>IfcDistributionControlElementType</i>, distinguished by <i>IfcShapeRepresentation.RepresentationIdentifier</i>:</p>
<ul>
<li><b>'Footprint'</b>: Represents the 2D footprint outline of the item having <i>IfcShapeRepresentation.RepresentationType</i> of 'GeometricCurveSet' and containing a single <i>IfcGeometricCurveSet</i> consisting of one or more <i>IfcCurve</i> subtypes such as <i>IfcPolyline</i>, <i>IfcTrimmedCurve</i>, <i>IfcCompositeCurve</i>, or <i>IfcCircle</i>.</li>
<li><b>'Body'</b>: Represents the 3D shape of the item having <i>IfcShapeRepresentation.RepresentationType</i> of 'SurfaceModel', 'SolidModel', or any solid model specializations including 'Brep', 'AdvancedBrep', 'SweptSolid', 'AdvancedSweptSolid', 'CSG', 'Clipping', or 'SectionedSpine').</li>
<li><b>'Clearance'</b>: Represents the 3D clearance volume of the item having <i>RepresentationType</i> of 'Surface3D'. Such clearance region indicates space that should not intersect with the 'Body' representation between element occurrences, though may intersect with the 'Clearance' representation of other element occurrences. The particular use of clearance space may be for safety, maintenance, or other purpose.</li>
</ul>
<blockquote>
<font size="-1">
NOTE: The product representations are defined as representation maps (at the level of the supertype <i>IfcTypeProduct</i>, which get assigned by an element occurrence instance through the <i>IfcShapeRepresentation.Item[1]</i> being an <i>IfcMappedItem</i>.
</font>
</blockquote>
</EPM-HTML> |
| 168 | 1107 | IfcDistributionFlowElementType | <EPM-HTML>
<p>The element type <i>IfcDistributionFlowElementType</i> defines a list of commonly shared property set definitions of an element and an optional set of product representations. It is used to define an element specification (the specific product information that is common to all occurrences of that product type).</p>
<p>Distribution flow element types (orthe instantiable subtypes) may be exchanged without being already assigned to occurrences.</p>
<p>The occurrences of the <i>IfcDistributionFlowElementType</i> are represented by instances of <i>IfcDistributionFlowElement</i> or its subtypes.</p>
<blockquote class="history">HISTORY: New entity in IFC Release 2x2.</blockquote>
<p><b><u>Declaration Use Definition</u></b></p>
<p>The <b>IfcDistributionFlowElementType</b> may be declared within a project or project library using <i>IfcRelDeclares</i> where <i>RelatingContext</i> refers to the project or library and <i>RelatedDefinitions</i> includes the element type. Inclusion within <i>IfcProject</i> indicates the type is editable within the direct project and may be available to other referencing projects that may incorporate the type. Inclusion within <i>IfcProjectLibrary</i> indicates the type is incorporated from a referenced project. Default units and coordinate systems (used for representations, materials, and property sets) are indicated by the declaring project or library.</p>
<p><b><u>Classification Use Definition</u></b></p>
<p>The <b>IfcDistributionFlowElementType</b> may be classified using <i>IfcRelAssociatesClassification</i> where <i>RelatingClassification</i> refers to an <i>IfcClassificationReference</i> indicating a classification notation. Classifications may refer to industry standards such as MasterFormat, OmniFormat, or UniFormat. Classifications may also refer to organization-specific, project-specific, or system-specific designations. Classification reference identification schemes are described by <i>IfcClassification.ReferenceTokens</i>.</p>
<p><b><u>Document Use Definition</u></b></p>
<p>The <b>IfcDistributionFlowElementType</b> may be documented using <i>IfcRelAssociatesDocument</i> where <i>RelatingDocument</i> refers to an <i>IfcDocumentReference</i> indicating content within a document, or <i>IfcDocumentInformation</i> indicating an entire document. Document information may refer to arbitrary attachments such as text or multimedia, while document references may refer to items within particular formats (such as XML element IDs) where there is need to synchronize document information with model information. Document reference identification schemes depend on the particular document format.</p>
<p><b><u>Library Use Definition</u></b></p>
<p>The <b>IfcDistributionFlowElementType</b> may be published to a model server using <i>IfcRelAssociatesLibrary</i> where <i>RelatingLibrary</i> refers to an <i>IfcLibraryReference</i> indicating the unique identification within the published project. If the published project is IFC format, then <i>IfcLibraryReference.Identification</i> shall match <i>IfcRoot.GlobalID</i> of the published (master) project, using the same encoding as described for <i>IfcGloballyUniqueId</i>. Multiple library references may be provided to indicate alternate names and descriptions for particular languages. If the element type is declared within <i>IfcProject</i>, then <i>IfcLibraryInformation.Location</i> and <i>IfcLibraryInformation.Version</i> indicate the URL and version as last published. If the element type is declared within <i>IfcProjectLibrary</i>, then the library information indicates the location and version of the definition as last retrieved.</p>
<p>Figure 148 illustrates a project containing a light fixture in a building, where the definition of the light fixture is obtained from an external project.</p>
<table>
<tr><td><img alt="Library Use Definition" src="figures/IfcDistributionFlowElement-Library.png"></td></tr>
<tr><td><p class="figure">Figure 148 — Distribution flow element library</p></td></tr>
</table>
<p><b><u>Composition Use Definition</u></b></p>
<p>The <b>IfcDistributionFlowElementType</b> may be decomposed into components using <a href="../../ifckernel/lexical/ifcrelaggregates.htm">IfcRelAggregates</a> where <i>RelatingObject</i> refers to the enclosing <b>IfcDistributionFlowElementType</b> and <i>RelatedObjects</i> contains one or more components. For example, a cable type may be decomposed into wires. Standard types for composition are defined at occurrences for subtypes.</p>
<p><b><u>Connection Use Definition</u></b></p>
<p>The <b>IfcDistributionFlowElementType</b> may be connected to other objects as follows using the indicated relationship:</p>
<ul>
<li><a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm">IfcDistributionPort</a> (<a href="../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm">IfcRelConnectsPortToElement</a>) : Indicates port definitions on the element to be instantiated at occurrences. Standard port names, types, and directions are defined at occurrences for subtypes.</li>
</ul>
<p><b><u>Assignment Use Definition</u></b></p>
<p> The <b>IfcDistributionFlowElementType</b> may have assignments of its own using the <a href="../../ifckernel/lexical/ifcrelassignstoproduct.htm">IfcRelAssignsToProduct</a> relationship where <i>RelatingProduct</i> refers to the <b>IfcDistributionFlowElementType</b> and <i>RelatedObjects</i> contains one or more objects of the following types: </p>
<ul>
<li><a href="../../ifcprocessextension/lexical/ifctasktype.htm">IfcTaskType</a>: Indicates task types available to purchase, install, renovate, demolish, operate, or otherwise act upon occurrences of the element type. Such task types may be instantiated as task occurrences assigned to occurrences of the element type. Prices (such as for purchasing or shipping) may be established by resource types assigned to task types.</li>
<li><a href="../../ifcprocessextension/lexical/ifcproceduretype.htm">IfcProcedureType</a>: Indicates procedure types available to operate occurrences of the element type. Such procedure types may be instantiated as procedure occurrences assigned to occurrences of the element type.</li>
<li><a href="../../ifcprocessextension/lexical/ifceventtype.htm">IfcEventType</a>: Indicates event types available to be raised by occurrences of the element, sequenced by procedures to be followed. Such event types may be instantiated as event occurrences assigned to occurrences of the element type.</li>
</ul>
<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcDistributionFlowElementType</b> is defined using one of the following entities:</p>
<ul>
<li><a href="../../ifcmaterialresource/lexical/ifcmaterialprofileset.htm">IfcMaterialProfileSet</a>: For elements having a constant cross-section, this defines the material profile which may be used to generate the 'Body' representation at occurrences (for parametric definitions not having representation), or for analysis purposes.</li>
<li><a href="../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm">IfcMaterialConstituentSet</a>: For elements containing multiple materials, this indicates materials at named aspects.</i>
</li>
<li>
<a href="../../ifcmaterialresource/lexical/ifcmaterial.htm">IfcMaterial</a>: For elements comprised of a single material, this indicates the material.</li>
</ul>
<p>The material is attached by the <i>RelatingMaterial</i> attribute on the <a href="../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm">IfcRelAssociatesMaterial</a> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute.</p>
<p><b><u>Representation Use Definition</u></b></p>
<p>The following shape representations are supported for subtypes of <i>IfcDistributionFlowElementType</i>, distinguished by <i>IfcShapeRepresentation.RepresentationIdentifier</i>:</p>
<ul>
<li><b>'Axis'</b>: Represents the 3D flow path of the item having <i>IfcShapeRepresentation.RepresentationType</i> of 'Curve3D' and containing a single <i>IfcBoundedCurve</i> subtype such as <i>IfcPolyline</i>, <i>IfcTrimmedCurve</i>, or <i>IfcCompositeCurve</i>. For elements containing directional ports (<i>IfcDistributionPort</i> with <i>FlowDirection</i> of <i>SOURCE</i> or <i>SINK</i>), the direction of the curve indicates direction of flow where a <i>SINK</i> port is positioned at the start of the curve and a <i>SOURCE</i> port is positioned at the end of the curve. This representation is most applicable to flow segment types (pipes, ducts, cables), however may be used at other elements to define a primary flow path if applicable.</li>
<li><b>'Footprint'</b>: Represents the 2D footprint outline of the item having <i>IfcShapeRepresentation.RepresentationType</i> of 'GeometricCurveSet' and containing a single <i>IfcGeometricCurveSet</i> consisting of one or more <i>IfcCurve</i> subtypes such as <i>IfcPolyline</i>, <i>IfcTrimmedCurve</i>, <i>IfcCompositeCurve</i>, or <i>IfcCircle</i>.</li>
<li><b>'Body'</b>: Represents the 3D shape of the item having <i>IfcShapeRepresentation.RepresentationType</i> of 'SurfaceModel', 'SolidModel', or any solid model specializations including 'Brep', 'AdvancedBrep', 'SweptSolid', 'AdvancedSweptSolid', 'CSG', 'Clipping', or 'SectionedSpine').</li>
<li><b>'Clearance'</b>: Represents the 3D clearance volume of the item having <i>RepresentationType</i> of 'Surface3D'. Such clearance region indicates space that should not intersect with the 'Body' representation between element occurrences, though may intersect with the 'Clearance' representation of other element occurrences. The particular use of clearance space may be for safety, maintenance, or other purpose.</li>
</ul>
<li><b>'Lighting'</b>: Represents the light emission of the item having <i>IfcShapeRepresentation.RepresentationType</i> of 'LightSource' and containing one or more <i>IfcLightSource</i> subtypes. This representation is most applicable to lamps and light fixtures, however may be used at other elements that emit light.
</ul>
<p>If an element type is defined parametrically (such as a flow segment type defining common material profile but no particular length or path), then no representations shall be asserted at the type.</p>
<blockquote>
<font size="-1">
NOTE: The product representations are defined as representation maps (at the level of the supertype <i>IfcTypeProduct</i>, which get assigned by an element occurrence instance through the <i>IfcShapeRepresentation.Item[1]</i> being an <i>IfcMappedItem</i>.
</font>
</blockquote>
</EPM-HTML> |
| 169 | 1117 | IfcEnergyConversionDeviceType | <EPM-HTML>
<p>The element type <i>IfcEnergyConversionType</i> defines a list of commonly shared property
set definitions of an energy conversion device and an optional set of product representations.
It is used to define an energy conversion device specification (i.e. the specific product
information, that is common to all occurrences of that product type).</p>
<blockquote>
<font size="-1">
NOTE: The product representations are defined as
representation maps (at the level of the supertype <i>IfcTypeProduct</i>, which
get assigned by an element occurrence instance through the
<i>IfcShapeRepresentation.Item[1]</i> being an
<i>IfcMappedItem</i>.
</font>
</blockquote>
<p>A energy conversion type is used to define the common properties of a
energy conversion device that may be applied to many occurrences of that type.
An energy conversion device is a building systems device that converts energy from one form into another such
as a boiler (i.e., combusting gas to heat water), chiller (i.e., using a refrigeration cycle to cool a
liquid), or a cooling coil (i.e., using the phase-change characteristics of a refrigerant to cool air).
Energy conversion types (or the instantiable subtypes) may be exchanged
without being already assigned to occurrences.</p>
<p>The occurrences of the <i>IfcEnergyConversionType</i> are represented
by instances of <i>IfcEnergyConversionDevice</i>.</p>
<blockquote>
<font color="#0000ff" size="-1">
HISTORY: New entity in IFC Release 2x2.<br>
</font>
</blockquote>
</EPM-HTML> |
| 170 | 1118 | IfcFlowMovingDeviceType | <EPM-HTML>
<p>The element type <i>IfcFlowMovingDeviceType</i> defines a list of commonly shared property
set definitions of a flow moving device and an optional set of product representations.
It is used to define a flow moving device specification (i.e. the specific product
information, that is common to all occurrences of that product type).</p>
<blockquote>
<font size="-1">
NOTE: The product representations are defined as
representation maps (at the level of the supertype <i>IfcTypeProduct</i>, which
get assigned by an element occurrence instance through the
<i>IfcShapeRepresentation.Item[1]</i> being an
<i>IfcMappedItem</i>.
</font>
</blockquote>
<p>A flow moving type is used to define the common properties of a
flow moving device that may be applied to many occurrences of that type.
A flow moving device is a device that is used to produce a pressure differential in a distribution system,
such as a pump, fan, compressor, etc.
Flow moving types (or the instantiable subtypes) may be exchanged
without being already assigned to occurrences.</p>
<p>The occurrences of the <i>IfcFlowMovingDeviceType</i> are represented
by instances of <i>IfcFlowMovingDevice</i>.</p>
<blockquote>
<font color="#0000ff" size="-1">
HISTORY: New entity in IFC Release 2x2.<br>
</font>
</blockquote>
</EPM-HTML> |
| 171 | 1119 | IfcFlowControllerType | <EPM-HTML>
<p>The element type <i>IfcFlowControllerType</i> defines a list of commonly shared property
set definitions of a flow controller and an optional set of product representations.
It is used to define a flow controller specification (i.e. the specific product
information, that is common to all occurrences of that product type).</p>
<blockquote>
<font size="-1">
NOTE: The product representations are defined as
representation maps (at the level of the supertype <i>IfcTypeProduct</i>, which
get assigned by an element occurrence instance through the
<i>IfcShapeRepresentation.Item[1]</i> being an
<i>IfcMappedItem</i>.
</font>
</blockquote>
<p>A flow controller type is used to define the common properties of a
flow controller that may be applied to many occurrences of that type.
A flow controller is a device that regulates flow within a distribution system, such as a valve in a piping
system, modulating damper in an air distribution system, or electrical switch in an electrical distribution
system. Flow controller types (or the instantiable subtypes) may be exchanged
without being already assigned to occurrences.</p>
<p>The occurrences of the <i>IfcFlowControllerType</i> are represented
by instances of <i>IfcFlowController</i> or its subtypes.</p>
<blockquote>
<font color="#0000ff" size="-1">
HISTORY: New entity in IFC Release 2x2.<br>
</font>
</blockquote>
</EPM-HTML> |
| 172 | 1120 | IfcFlowSegmentType | <EPM-HTML>
<p>The element type <i>IfcFlowSegmentType</i> defines a list of commonly shared property
set definitions of a flow segment and an optional set of product representations.
It is used to define a flow segment specification (i.e. the specific product
information, that is common to all occurrences of that product type).</p>
<blockquote>
<font size="-1">
NOTE: The product representations are defined as
representation maps (at the level of the supertype <i>IfcTypeProduct</i>, which
get assigned by an element occurrence instance through the
<i>IfcShapeRepresentation.Item[1]</i> being an
<i>IfcMappedItem</i>.
</font>
</blockquote>
<p>A flow segment type is used to define the common properties of a
flow segment that may be applied to many occurrences of that type.
A flow segment is a section of a distribution system, such as a duct, pipe, conduit, etc. that typically has
only two ports.
Flow segment types (or the instantiable subtypes) may be exchanged
without being already assigned to occurrences.</p>
<p>The occurrences of the <i>IfcFlowSegmentType</i> are represented
by instances of <i>IfcFlowSegment</i> or its subtypes.</p>
<blockquote>
<font color="#0000ff" size="-1">
HISTORY: New entity in IFC Release 2x2.<br>
</font>
</blockquote>
<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcDistributionFlowSegmentType</b> is defined using one of the following entities:</p>
<ul>
<li><a href="../../ifcmaterialresource/lexical/ifcmaterialprofileset.htm">IfcMaterialProfileSet</a> : This defines the material cross section which may be used to generate the 'Body' representation at occurrences (for parametric definitions not having representation), or for analysis purposes.</li>
<li><a href="../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm">IfcMaterialConstituentSet</a> : For elements containing multiple materials where profiles are not applicable, this indicates materials at named aspects.</i>
</li>
<li>
<a href="../../ifcmaterialresource/lexical/ifcmaterial.htm">IfcMaterial</a> : For elements comprised of a single material where profiles are not applicable, this indicates the material.</li>
</ul>
</EPM-HTML>
|
| 173 | 1121 | IfcFlowFittingType | <EPM-HTML>
<p>The element type <i>IfcFlowFittingType</i> defines a list of commonly shared property
set definitions of a flow fitting and an optional set of product representations.
It is used to define a flow fitting specification (i.e. the specific product
information, that is common to all occurrences of that product type).</p>
<blockquote>
<font size="-1">
NOTE: The product representations are defined as
representation maps (at the level of the supertype <i>IfcTypeProduct</i>, which
get assigned by an element occurrence instance through the
<i>IfcShapeRepresentation.Item[1]</i> being an
<i>IfcMappedItem</i>.
</font>
</blockquote>
<p>A flow fitting type is used to define the common properties of a
flow fitting that may be applied to many occurrences of that type.
A flow fitting is a device that is used to interconnect flow segments or other fittings within a distribution
system, such as a tee in a ducted system that branches flow into two directions, a junction box in an
electrical distribution system, etc.
Flow fitting types (or the instantiable subtypes) may be exchanged
without being already assigned to occurrences.</p>
<p>The occurrences of the <i>IfcFlowFittingType</i> are represented
by instances of <i>IfcFlowFitting</i> or its subtypes.</p>
<blockquote>
<font color="#0000ff" size="-1">
HISTORY: New entity in IFC Release 2x2.<br>
</font>
</blockquote>
</EPM-HTML> |
| 174 | 1122 | IfcFlowStorageDeviceType | <EPM-HTML>
<p>The element type <i>IfcFlowStorageDeviceType</i> defines a list of commonly shared property set definitions of a flow storage device and an optional set of product representations. It is used to define a flow storage device specification (the specific product information that is common to all occurrences of that product type).</p>
<p>A flow storage device is a device used for the temporary storage of a fluid (such as a tank) or the voltage potential induced by the induced electron flow (such as a battery). Flow storage types (or the instantiable subtypes) may be exchanged without being already assigned to occurrences.</p>
<p>The occurrences of the <i>IfcFlowStorageDeviceType</i> are represented by instances of <i>IfcFlowStorageDevice</i> or its subtypes.</p>
<blockquote>
<font color="#0000ff" size="-1">
HISTORY: New entity in IFC Release 2x2.<br>
</font>
</blockquote>
</EPM-HTML> |
| 175 | 1123 | IfcFlowTreatmentDeviceType | <EPM-HTML>
<p>The element type <i>IfcFlowTreatmentDeviceType</i> defines a list of commonly shared property set definitions of a flow treatment device and an optional set of product representations. It is used to define a flow treatment device specification (the specific product information that is common to all occurrences of that product type).</p>
<p>A flow treatment device is a device used to change the physical properties of the medium, such as an air, oil
or water filter (used to remove particulates from the fluid), or a duct silencer (used to attenuate noise). Flow treatment types (or the instantiable subtypes) may be exchanged without being already assigned to occurrences.</p>
<p>The occurrences of the <i>IfcFlowTreatmentDeviceType</i> are represented by instances of <i>IfcFlowTreatmentDevice</i> or its subtypes.</p>
<blockquote>
<font color="#0000ff" size="-1">HISTORY: New entity in IFC Release 2x2.<br></font>
</blockquote>
</EPM-HTML> |
| 176 | 1124 | IfcFlowTerminalType | <EPM-HTML>
<p>The element type <i>IfcFlowTerminalType</i> defines a list of commonly shared property set definitions of a flow terminal and an optional set of product representations. It is used to define a flow terminal specification (the specific product information that is common to all occurrences of that product type).</p>
<p>A flow terminal type is used to define the common properties of a flow terminal that may be applied to many occurrences of that type. A flow terminal acts as a terminus or beginning element in a distribution system such as a ceiling register in a ducted air distribution system, a sink in a waste-water system, or a light fixture in an electrical lighting system. Flow terminal types (or the instantiable subtypes) may be exchanged without being already assigned to occurrences.</p>
<p>The occurrences of the <i>IfcFlowTerminalType</i> are represented by instances of <i>IfcFlowTerminal</i> or its subtypes.</p>
<blockquote>
<font color="#0000ff" size="-1">HISTORY: New entity in IFC Release 2x2.<br></font>
</blockquote>
</EPM-HTML> |
| 177 | 1125 | IfcDistributionChamberElementType | <EPM-HTML>
<p>The distribution flow element type <b>IfcDistributionChamberElementType</b> defines commonly shared information for occurrences of distribution chamber elements. The set of shared information may include:</p>
<ul>
<li>common properties with shared property sets</li>
<li>common materials</li>
<li>common ports</li>
<li>common composition of elements</li>
<li>common assignment of process types</li>
<li>common representations of shape and style</li>
</ul>
<p>It is used to define a distribution chamber element specification (i.e. the specific product information, that is common to all occurrences of that product type). Distribution Chamber Element types may be exchanged without being already assigned to occurrences.
Occurrences of <b>IfcDistributionChamberElementType</b> are represented by instances of <a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionchamberelement.htm">IfcDistributionChamberElement</a>.</p>
</p>
<blockquote><font color="#0000ff" size="-1">HISTORY: New entity in IFC2x2<br></font></blockquote>
<p><b><u>Property Set Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <a href="../../ifckernel/lexical/ifcpropertyset.htm">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute. Refer to the documentation at the supertype <a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionflowelementtype.htm">IfcDistributionFlowElementType</a> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><a href="../../psd/IfcSharedBldgServiceElements/Pset_DistributionChamberElementCommon.xml" target="SOURCE">Pset_DistributionChamberElementCommon</a></li>
</ul>
The following property set definitions are applicable to this entity according to the <i>PredefinedType</i> attribute: </p>
<ul>
<li><a href="../../psd/IfcSharedBldgServiceElements/Pset_DistributionChamberElementTypeFormedDuct.xml" target="SOURCE">Pset_DistributionChamberElementTypeFormedDuct</a> (<a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionchamberelementtypeenum.htm">FORMEDDUCT</a>)</li>
<li><a href="../../psd/IfcSharedBldgServiceElements/Pset_DistributionChamberElementTypeInspectionChamber.xml" target="SOURCE">Pset_DistributionChamberElementTypeInspectionChamber</a> (<a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionchamberelementtypeenum.htm">INSPECTIONCHAMBER</a>)</li>
<li><a href="../../psd/IfcSharedBldgServiceElements/Pset_DistributionChamberElementTypeInspectionPit.xml" target="SOURCE">Pset_DistributionChamberElementTypeInspectionPit</a> (<a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionchamberelementtypeenum.htm">INSPECTIONPIT</a>)</li>
<li><a href="../../psd/IfcSharedBldgServiceElements/Pset_DistributionChamberElementTypeManhole.xml" target="SOURCE">Pset_DistributionChamberElementTypeManhole</a> (<a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionchamberelementtypeenum.htm">MANHOLE</a>)</li>
<li><a href="../../psd/IfcSharedBldgServiceElements/Pset_DistributionChamberElementTypeMeterChamber.xml" target="SOURCE">Pset_DistributionChamberElementTypeMeterChamber</a> (<a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionchamberelementtypeenum.htm">METERCHAMBER</a>)</li>
<li><a href="../../psd/IfcSharedBldgServiceElements/Pset_DistributionChamberElementTypeSump.xml" target="SOURCE">Pset_DistributionChamberElementTypeSump</a> (<a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionchamberelementtypeenum.htm">SUMP</a>)</li>
<li><a href="../../psd/IfcSharedBldgServiceElements/Pset_DistributionChamberElementTypeTrench.xml" target="SOURCE">Pset_DistributionChamberElementTypeTrench</a> (<a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionchamberelementtypeenum.htm">TRENCH</a>)</li>
<li><a href="../../psd/IfcSharedBldgServiceElements/Pset_DistributionChamberElementTypeValveChamber.xml" target="SOURCE">Pset_DistributionChamberElementTypeValveChamber</a> (<a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionchamberelementtypeenum.htm">VALVECHAMBER</a>)</li>
</ul>
<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcDistributionChamberElementType</b> is defined by <a href="../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm">IfcMaterialConstituentSet</a> or as a fallback by <a href="../../ifcmaterialresource/lexical/ifcmaterial.htm">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href="../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm">IfcRelAssociatesMaterial</a> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p>
<ul>
<li><b>'Base'</b>: The material from which the base of the duct is constructed.</li>
<li><b>'Cover'</b>: The material from which the access cover to the chamber is constructed.</li>
<li><b>'Fill'</b>: The material that is used to fill the duct (where used).</li>
<li><b>'Wall'</b>: The material from which the wall of the duct is constructed.</li>
</ul>
</EPM-HTML>
|
| 178 | 1139 | IfcDistributionSystem | <EPM-HTML>
<p>A distribution system is a network designed to receive, store, maintain, distribute, or control the flow of a distribution media. A common example is a heating hot water system that consists of a pump, a tank, and an interconnected piping system for distributing hot water to terminals.</p>
<blockquote class="history">HISTORY New entity in IFC 2x4.</blockquote>
<p>The group <i>IfcDistributionSystem</i>
defines the occurrence of a specialized system for use within the context of building services.</p>
<blockquote>
<font size="-1">
NOTE: For electrical power systems, <i>IfcElectricalCircuit</i> has been used for low-voltage (12-1000 V) power systems and has been deprecated in IFC2x4; <i>IfcDistributionSystem</i> with PredefinedType 'ELECTRICAL' should now be used instead.
</font>
</blockquote>
<p>Important functionalities for the description of a distribution system are derived from existing IFC entities:</p>
<ul><li>From <i>IfcSystem</i> it inherits the ability to couple the distribution system via <i>IfcRelServicesBuildings</i> to one or more <i>IfcSpatialElement</i> subtypes as necessary.</li></ul>
<ul><li>From <i>IfcGroup</i> it inherits the inverse attribute <i>IsGroupedBy</i>, pointing to the relationship class <i>IfcRelAssignsToGroup</i>. This allows to group distribution elements (instances of <i>IfcDistributionElement</i> subtypes), and in special cases ports directly (instances of <i>IfcDistributionPort</i>).</li></ul>
<ul><li>From <i>IfcObject</i> it inherits the inverse attribute <i>IsDecomposedBy</i> pointing to the relationship class <i>IfcRelAggregates</i>. It provides the hierarchy between the separate (partial) distribution systems. For example, an electrical main circuit may be aggregated into branch circuits.</li></ul>
<p><b><u>Property Set Use Definition</u></b>:</p>
<p>The property sets relating to this entity are defined by the <i>IfcPropertySet</i> and attached by the <i>IfcRelDefinesByProperties</i> relationship. It is accessible by the inverse <i>IsDefinedBy</i> relationship. The following property set definitions specific to this entity are part of this IFC release:
</p>
<ul>
<li><a href="../../psd/IfcSharedBldgServiceElements/Pset_DistributionSystemCommon.xml"
target=SOURCE>Pset_DistributionSystemCommon</a>: common property set for distribution system occurrences
</li>
<li><a href="../../psd/IfcSharedBldgServiceElements/Pset_DistributionSystemTypeElectrical.xml"
target=SOURCE>Pset_DistributionSystemTypeElectrical</a>: property set for electrical systems
</li>
<li><a href="../../psd/IfcSharedBldgServiceElements/Pset_DistributionSystemTypeVentilation.xml"
target=SOURCE>Pset_DistributionSystemTypeVentilation</a>: property set for ventilation systems
</li>
</ul>
<p><b><u>Assignment Use Definition</u></b>:</p>
<p>For the most common case of an <i>IfcDistributionElement</i> subtype containing ports of a particular <i>PredefinedType</i> that all belong to the same distribution system, the <i>IfcDistributionElement</i> is assigned to the <i>IfcDistributionSystem</i> via the <i>IfcRelAssignsToGroup</i> relationship, where <i>IfcDistributionPort</i>'s are implied as part of the corresponding system based on their <i>PredefinedType</i>. An <i>IfcDistributionElement</i> may belong to multiple systems, however only one <i>IfcDistributionSystem</i> of a particular <i>PredefinedType</i>.</p>
<p>For rare cases where an <i>IfcDistributionElement</i> subtype contains ports of the same <i>PredefinedType</i> yet different ports belong to different systems, alternatively each <i>IfcDistributionPort</i> may be directly assigned to a single <i>IfcDistributionSystem</i> via the <i>IfcRelAssignsToGroup</i> relationship, where the <i>PredefinedType</i> must match. Such assignment indicates that the <i>IfcDistributionSystem</i> assigned from the <i>IfcDistributionPort</i> overrides any such system of the same <i>PredefinedType</i> assigned from the containing <i>IfcDistributionElement</i>, if any.</p>
<p>Additionally, an <i>IfcDistributionSystem</i> may in turn be assigned to an <i>IfcDistributionPort</i> indicating the host or origination of the system using <i>IfcRelAssignsToProduct</i>.</p>
<blockquote>
<font size="-1">
EXAMPLE: A gas-powered hot water heater may have three ports: GAS, DOMESTICCOLDWATER, and DOMESTICHOTWATER. The heater is a member of two systems (GAS and DOMESTICCOLDWATER), and hosts one system (DOMESTICHOTWATER) at the corresponding port.
</font>
</blockquote>
<p>Figure 150 illustrates a distribution system for an electrical circuit.</p>
<table>
<tr><td><img alt="Instance diagram for electrical circuit" src="figures/IfcDistributionSystem-01.png" ></td></tr>
<tr><td><p class="figure">Figure 150 — Distribution system assignment</p></td></tr>
</table>
</p>
</EPM-HTML>
|
| 179 | 1142 | IfcDistributionFlowElement | <EPM-HTML>
<p>The distribution element <i>IfcDistributionFlowElement</i> defines occurrence elements of a distribution system that facilitate the distribution of energy or matter, such as air, water or power.</p>
<blockquote>
<font size="-1">EXAMPLEs of distribution flow elements are ducts, pipes, wires, fittings, and equipment.</font>
</blockquote>
<blockquote>
<font color="#0000ff" size="-1">HISTORY: New entity in IFC R2.0.<br></font>
</blockquote>
<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcDistributionFlowElement</b> defines the occurrence of any distribution flow element; common information about distribution flow element types is handled by <a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionflowelementtype.htm">IfcDistributionFlowElementType</a>. The <a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionflowelementtype.htm">IfcDistributionFlowElementType</a> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. The <a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionflowelementtype.htm">IfcDistributionFlowElementType</a> is attached using the <a href="../../ifckernel/lexical/ifcreldefinesbytype.htm">IfcRelDefinesByType</a> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. If the <a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionflowelementtype.htm">IfcDistributionFlowElementType</a> has ports or aggregated elements, such objects are reflected at the <b>IfcDistributionFlowElement</b> occurrence using the <a href="../../ifckernel/lexical/ifcreldefinesbyobject.htm">IfcRelDefinesByObject</a> relationship. Direct instantiation of <i>IfcDistributionFlowElement</i> with <i>IfcObject.ObjectType</i> asserted provides the meaning of a distribution flow element proxy.</p>
<p><b><u>Property Set Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <a href="../../ifckernel/lexical/ifcpropertyset.htm">IfcPropertySet</a> and attached by the <a href="../../ifckernel/lexical/ifcreldefinesbyproperties.htm">IfcRelDefinesByProperties</a> relationship. They are accessible by the <i>IsDefinedBy</i> inverse attribute. Property sets may also be specified at the <a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionflowelementtype.htm">IfcDistributionFlowElementType</a>, defining the common property data for all occurrences of the same type. They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcDistributionFlowElementType.HasPropertySets</i>. If both are given, then the properties directly defined at <b>IfcDistributionFlowElement</b> override the properties defined at <a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionflowelementtype.htm">IfcDistributionFlowElementType</a>. Refer to the documentation at the supertype <a href="../../ifcproductextension/lexical/ifcdistributionelement.htm">IfcDistributionElement</a> and ancestors for inherited property set definitions.</p>
<p><b><u>Composition Use Definition</u></b></p>
<p>The <b>IfcDistributionFlowElement</b> may be decomposed into components using <a href="../../ifckernel/lexical/ifcrelaggregates.htm">IfcRelAggregates</a> where <i>RelatingObject</i> refers to the enclosing <b>IfcDistributionFlowElement</b> and <i>RelatedObjects</i> contains one or more components. For example, a cable may be decomposed into wires. Standard types for composition are defined at subtypes.</p>
<p><b><u>Connection Use Definition</u></b></p>
<p>The <b>IfcDistributionFlowElement</b> may be connected to other objects as follows using the indicated relationship:</p>
<ul>
<li><a href="../../ifcproductextension/lexical/ifcspatialstructureelement.htm">IfcSpatialStructureElement</a> (<a href="../../ifcproductextension/lexical/ifcrelcontainedinspatialstructure.htm">IfcRelContainedInSpatialStructure</a>) : Indicates the spatial location containing the element.</li>
<li><a href="../../ifcproductextension/lexical/ifcelement.htm">IfcElement</a> (<a href="../../ifcproductextension/lexical/ifcrelconnectselements.htm">IfcRelConnectsElements</a>) : Indicates physical connectivity with another element (but not embedding or flow transmission), such as a light fixture hanging from a ceiling (<i>IfcCovering</i>), or a junction box having a cover plate (<i>IfcDiscreteAccessory</i>). <i>IfcRelConnectsElements.RelatingElement</i> refers to the anchored side (ceiling for fixture, junction box for cover).</li>
<li><a href="../../ifcproductextension/lexical/ifcelement.htm">IfcElement</a> (<a href="../../ifcproductextension/lexical/ifcrelinterfereselements.htm">IfcRelInterferesElements</a>) : Indicates interference with another element and precedence, such as a pipe going through a wall.</li>
<li><a href="../../ifcproductextension/lexical/ifcelement.htm">IfcOpening</a> (<a href="../../ifcproductextension/lexical/ifcrelfillselement.htm">IfcRelFillsElement</a>) : Indicates embedding an element within another element (implying a cutout), such as an air terminal or junction box embedded within a wall.</li>
<li><a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionport.htm">IfcDistributionPort</a> (<a href="../../ifcproductextension/lexical/ifcrelconnectsporttoelement.htm">IfcRelConnectsPortToElement</a>) : Indicates ports on the element which may be connected to other elements for flow distribution of solids, liquids, gas, or electricity. Standard port names, types, and directions are defined at subtypes.</li>
<li><a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributioncontrolelement.htm">IfcDistributionControlElement</a> (<a href="../../ifcsharedbldgserviceelements/lexical/ifcrelflowcontrolelements.htm">IfcRelFlowControlElements</a>) : Indicates a control element that senses or controls some aspect of the flow element, such as a level sensor for a tank or an actuator for a valve.</li>
</ul>
<p><b><u>Assignment Use Definition</u></b></p>
<p>The <b>IfcDistributionFlowElement</b> may be assigned to the following entities using relationships as indicated:</p>
<ul>
<li><a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystem.htm">IfcDistributionSystem</a> (<a href="../../ifckernel/lexical/ifcrelassignstogroup.htm">IfcRelAssignsToGroup</a>): Indicates a system containing interconnected devices.</li>
<li><a href="../../ifccontrolextension/lexical/ifcperformancehistory.htm">IfcPerformanceHistory</a> (<a href="../../ifckernel/lexical/ifcrelassignstocontrol.htm">IfcRelAssignsToControl</a>): Indicates realtime or historical infomation captured for the device.</li>
</ul>
<p> The <b>IfcDistributionFlowElement</b> may have assignments of its own using the <a href="../../ifckernel/lexical/ifcrelassignstoproduct.htm">IfcRelAssignsToProduct</a> relationship where <i>RelatingProduct</i> refers to the <b>IfcDistributionFlowElement</b> and <i>RelatedObjects</i> contains one or more objects of the following types: </p>
<ul>
<li><a href="../../ifcprocessextension/lexical/ifctask.htm">IfcTask</a>: Indicates tasks used to purchase, install, renovate, demolish, operate, or otherwise act upon the element. If the element has a type, available task types are assigned to the element type.</li>
<li><a href="../../ifcprocessextension/lexical/ifcprocedure.htm">IfcProcedure</a>: Indicates procedures used to operate the element. If the element has a type, available procedure types are assigned to the element type.</li>
<li><a href="../../ifcprocessextension/lexical/ifcevent.htm">IfcEvent</a>: Indicates events raised by the element, sequenced by procedures to be followed. If the element has a type, available event types are assigned to the element type.</li>
</ul>
<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcDistributionFlowElement</b> is defined using one of the following entities:</p>
<ul>
<li><a href="../../ifcmaterialresource/lexical/ifcmaterialprofilesetusage.htm">IfcMaterialProfileSetUsage</a>: For parametric segments, this defines the cross section and alignment to the 'Axis' representation, from which the 'Body' representation may be generated.</li>
<li><a href="../../ifcmaterialresource/lexical/ifcmaterialprofileset.htm">IfcMaterialProfileSet</a>: For non-parametric segments (having fixed length or path), this may define the cross section for analysis purposes, however the 'Body' representation is independently generated.</li>
<li><a href="../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm">IfcMaterialConstituentSet</a>: For elements containing multiple materials, this indicates materials at named aspects.</i>
</li>
<li>
<a href="../../ifcmaterialresource/lexical/ifcmaterial.htm">IfcMaterial</a>: For elements comprised of a single material, this indicates the material.</li>
</ul>
<p>The material is attached by the <i>RelatingMaterial</i> attribute on the <a href="../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm">IfcRelAssociatesMaterial</a> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionflowelementtype.htm">IfcDistributionFlowElementType</a>, defining the common attribute data for all occurrences of the same type. Standard names and material types are defined at subtypes.</p>
<p><b><u>Representation Use Definition</u></b></p>
<p>The following shape representations are supported for subtypes of <i>IfcDistributionFlowElement</i>, distinguished by <i>IfcShapeRepresentation.RepresentationIdentifier</i>:</p>
<ul>
<li><b>'Axis'</b>: Represents the 3D flow path of the item having <i>IfcShapeRepresentation.RepresentationType</i> of 'Curve3D' and containing a single <i>IfcBoundedCurve</i> subtype such as <i>IfcPolyline</i>, <i>IfcTrimmedCurve</i>, or <i>IfcCompositeCurve</i>. For elements containing directional ports (<i>IfcDistributionPort</i> with <i>FlowDirection</i> of <i>SOURCE</i> or <i>SINK</i>), the direction of the curve indicates direction of flow where a <i>SINK</i> port is positioned at the start of the curve and a <i>SOURCE</i> port is positioned at the end of the curve. This representation is most applicable to flow segments (pipes, ducts, cables), however may be used at other elements to define a primary flow path if applicable.</li>
<li><b>'Footprint'</b>: Represents the 2D footprint outline of the item having <i>IfcShapeRepresentation.RepresentationType</i> of 'GeometricCurveSet' and containing a single <i>IfcGeometricCurveSet</i> consisting of one or more <i>IfcCurve</i> subtypes such as <i>IfcPolyline</i>, <i>IfcTrimmedCurve</i>, <i>IfcCompositeCurve</i>, or <i>IfcCircle</i>.</li>
<li><b>'Body'</b>: Represents the 3D shape of the item having <i>IfcShapeRepresentation.RepresentationType</i> of 'SurfaceModel', 'SolidModel', or any solid model specializations including 'Brep', 'AdvancedBrep', 'SweptSolid', 'AdvancedSweptSolid', 'CSG', 'Clipping', or 'SectionedSpine').</li>
<li><b>'Clearance'</b>: Represents the 3D clearance volume of the item having <i>RepresentationType</i> of 'Surface3D'. Such clearance region indicates space that should not intersect with the 'Body' representation of other elements, though may intersect with the 'Clearance' representation of other elements. The particular use of clearance space may be for safety, maintenance, or other purpose.</li>
<li><b>'Lighting'</b>: Represents the light emission of the item having <i>IfcShapeRepresentation.RepresentationType</i> of 'LightSource' and containing one or more <i>IfcLightSource</i> subtypes. This representation is most applicable to lamps and light fixtures, however may be used at other elements that emit light.
</ul>
<p>For all representations, if a <i>IfcDistributionFlowElement</i> occurrence is defined by a <i>IfcDistributionFlowElementType</i> having a representation of the same identifier, then 'MappedRepresentation' should be used at the occurrence unless overridden.</p>
<p>If materials are defined, geometry of each representation (most typically the 'Body' representation) may be organized into shape aspects where styles may be derived by correlating <i>IfcShapeAspect.Name</i> to a corresponding material (<i>IfcMaterialConstituent.Name</i> or <i>IfcMaterialProfile.Name</i>).</p>
<p>Representations are further defined at subtypes; for example, parametric flow segments align material profiles with the 'Axis' representation.</p>
</EPM-HTML>
|
| 180 | 1153 | IfcFlowFitting | <EPM-HTML>
<p>The distribution flow element <i>IfcFlowFitting</i> defines the occurrence of a junction or transition in a flow distribution system, such as an elbow or tee. Its type is defined by <i>IfcFlowFittingType</i> or its subtypes.</p>
<blockquote>
<font color="#0000ff" size="-1">
HISTORY: New entity in IFC R2.0.<br>
</font>
<font color="#ff0000" size="-1">
IFC 2x4 NOTE: This entity has been deprecated for instantiation and will become ABSTRACT in a future release; new subtypes should now be used instead.<br>
</font>
</blockquote>
</EPM-HTML>
|
| 181 | 1154 | IfcFlowSegment | <EPM-HTML>
<p>The distribution flow element <i>IfcFlowSegment</i> defines the occurrence of a segment of a flow distribution system.</p>
<blockquote>
<font color="#0000ff" size="-1">HISTORY: New entity in IFC R2.0.<br></font>
<font color="#ff0000" size="-1">IFC 2x4 NOTE: This entity has been deprecated for instantiation and will become ABSTRACT in a future release; new subtypes should now be used instead.<br></font>
</blockquote>
<p>The <i>IfcFlowSegment</i> defines a particular occurrence of a segment inserted in the spatial context of a project. The parameters defining the type of the segment and/or its shape are defined by the <i>IfcFlowSegmentType</i>, which is related by the inverse relationship IsDefinedBy pointing to <i>IfcRelDefinesByType</i>.
<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcFlowSegment</b> is defined using one of the following entities:</p>
<ul>
<li><a href="../../ifcmaterialresource/lexical/ifcmaterialprofilesetusage.htm">IfcMaterialProfileSetUsage</a> : for parametric segments, this defines the cross section and alignment to the 'Axis' representation, from which the 'Body' representation may be generated.</li>
<li><a href="../../ifcmaterialresource/lexical/ifcmaterialprofilesetusage.htm">IfcMaterialProfileSet</a> : for non-parametric segments (having fixed length or path), this may define the cross section for analysis purposes, however the 'Body' representation is independently generated.</li>
<li><a href="../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm">IfcMaterialConstituentSet</a> : for elements containing multiple materials where profiles are not applicable, this indicates materials at named parts.</i>
</li>
<li>
<a href="../../ifcmaterialresource/lexical/ifcmaterial.htm">IfcMaterial</a> : for elements comprised of a single material where profiles are not applicable, this indicates the material.</li>
</ul>
<p>The material is attached by the <i>RelatingMaterial</i> attribute on the <a href="../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm">IfcRelAssociatesMaterial</a> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <a href="../../ifcsharedbldgserviceelements/lexical/ifcflowsegmenttype.htm">IfcFlowSegmentType</a>, defining the common attribute data for all occurrences of the same type. Standard names and material types are defined at subtypes.</p>
<p><b><u>Representation Use Definition</u></b></p>
<p>
Standard representations are defined at the supertype <i>IfcDistrubutionFlowElement</i>. For parametric flow segments where <a href="../../ifcmaterialresource/lexical/ifcmaterialprofilesetusage.htm">IfcMaterialProfileSetUsage</a> is defined and an 'Axis' representation is defined, then the 'Body' representation may be generated using the 'SweptSolid' or 'AdvancedSweptSolid' representation types by sweeping the profile(s) along the axis.
</p>
</EPM-HTML>
|
| 182 | 1155 | IfcFlowController | <EPM-HTML>
<p>The distribution flow element <i>IfcFlowController</i> defines
the occurrence of elements of a distribution system that
are used to regulate flow through a distribution system.
Examples include dampers, valves, switches, and relays. Its type is defined by
<i>IfcFlowControllerType</i> or subtypes.</p>
<blockquote>
<font color="#0000ff" size="-1">
HISTORY: New entity in IFC R2.0.<br>
</font>
<font color="#ff0000" size="-1">
IFC 2x4 NOTE: This entity has been deprecated for instantiation and will become ABSTRACT in a future release; new subtypes should now be used instead.<br>
</font>
</blockquote>
</EPM-HTML>
|
| 183 | 1156 | IfcFlowTerminal | <EPM-HTML>
<p>The distribution flow element <i>IfcFlowTerminal</i> defines the
occurrence of a permanently attached element that acts as a terminus or
beginning of a distribution system (e.g., air outlet, drain,
water closet, sink, etc.). A terminal is typically a point
at which a system interfaces with an external environment.
Its type is defined by <i>IfcFlowTerminalType</i> or
its subtypes.</p>
<blockquote>
<font color="#0000ff" size="-1">
HISTORY: New entity in IFC R2.0.<br>
</font>
<font color="#ff0000" size="-1">
IFC 2x4 NOTE: This entity has been deprecated for instantiation and will become ABSTRACT in a future release; new subtypes should now be used instead.<br>
</font>
</blockquote>
</EPM-HTML>
|
| 184 | 1157 | IfcFlowMovingDevice | <EPM-HTML>
<p>The distribution flow element <i>IfcFlowMovingDevice</i> defines the occurrence of an apparatus used to distribute, circulate or perform conveyance of fluids, including liquids and gases (such as a pump or fan), and typically participates in a flow distribution system. Its type is defined by <i>IfcFlowMovingDeviceType</i> or its subtypes.</p>
<blockquote>
<font color="#0000ff" size="-1">
HISTORY: New entity in IFC R2x.<br>
</font>
<font color="#ff0000" size="-1">
IFC 2x4 NOTE: This entity has been deprecated for instantiation and will become ABSTRACT in a future release; new subtypes should now be used instead.<br>
</font>
</blockquote>
</EPM-HTML>
|
| 185 | 1158 | IfcEnergyConversionDevice | <EPM-HTML>
<p>The distribution flow element <i>IfcEnergyConversionDevice</i> defines
the occurrence of a device used to perform
energy conversion or heat transfer and typically participates
in a flow distribution system. Its type is defined by <i>IfcEnergyConversionDeviceType</i>
or its subtypes.</p>
<blockquote>
<font color="#0000ff" size="-1">
HISTORY: New entity in IFC R2.0.<br>
</font>
<font color="#ff0000" size="-1">
IFC 2x4 NOTE: This entity has been deprecated for instantiation and will become ABSTRACT in a future release; new subtypes should now be used instead.<br>
</font>
</blockquote>
</EPM-HTML>
|
| 186 | 1159 | IfcFlowStorageDevice | <EPM-HTML>
<p>The distribution flow element <i>IfcFlowStorageDevice</i> defines
the occurrence of a device that participates in a distribution
system and is used for temporary storage of a fluid
such as a liquid or a gas (e.g., tank). Its type is defined by
<i>IfcFlowStorageDeviceType</i> or its subtypes.</p>
<blockquote>
<font color="#0000ff" size="-1">
HISTORY: New entity in IFC R2x.<br>
</font>
<font color="#ff0000" size="-1">
IFC 2x4 NOTE: This entity has been deprecated for instantiation and will become ABSTRACT in a future release; new subtypes should now be used instead.<br>
</font>
</blockquote>
</EPM-HTML>
|
| 187 | 1160 | IfcFlowTreatmentDevice | <EPM-HTML>
<p>The distribution flow element <i>IfcFlowTreatmentDevice</i> defines the occurrence of a device typically used to remove unwanted matter from a fluid, either liquid or gas, and typically participates in a flow distribution system. Its type is defined by <i>IfcFlowTreatmentDeviceType</i> or its subtypes.</p>
<blockquote>
<font color="#0000ff" size="-1">
HISTORY: New entity in IFC R2x.<br>
</font>
<font color="#ff0000" size="-1">
IFC 2x4 NOTE: This entity has been deprecated for instantiation and will become ABSTRACT in a future release; new subtypes should now be used instead.<br>
</font>
</blockquote>
</EPM-HTML>
|
| 188 | 1161 | IfcDistributionChamberElement | <EPM-HTML>
<p>A distribution chamber element defines a place at which distribution systems and their constituent elements may be inspected or through which they may travel.</p>
<p>An <b>IfcDistributionChamberElement</b> is a formed volume used in a distribution system, such as a sump, trench or manhole. Instances of <a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionsystem.htm">IfcDistributionSystem</a> or <a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionflowelement.htm">IfcDistributionFlowElement</a> may be related to the <b>IfcDistributionChamberElement</b> enabling their location in or at the chamber to be determined.</p>
<blockquote class="history">HISTORY: New entity in IFC2x2</blockquote>
<p><b><u>Type Use Definition</u></b></p>
<p><b>IfcDistributionChamberElement</b> defines the occurrence of any distribution chamber element; common information about distribution chamber element types is handled by <a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionchamberelementtype.htm">IfcDistributionChamberElementType</a>. The <a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionchamberelementtype.htm">IfcDistributionChamberElementType</a> (if present) may establish the common type name, usage (predefined type), properties, materials, ports, composition, assignments, and representations. The <a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionchamberelementtype.htm">IfcDistributionChamberElementType</a> is attached using the <a href="../../ifckernel/lexical/ifcreldefinesbytype.htm">IfcRelDefinesByType</a> objectified relationship and is accessible by the <i>IsTypedBy</i> inverse attribute. If the <a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionchamberelementtype.htm">IfcDistributionChamberElementType</a> has ports or aggregated elements, such objects are reflected at the <b>IfcDistributionChamberElement</b> occurrence using the <a href="../../ifckernel/lexical/ifcreldefinesbyobject.htm">IfcRelDefinesByObject</a> relationship.</p>
<p><b><u>Property Set Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <a href="../../ifckernel/lexical/ifcpropertyset.htm">IfcPropertySet</a> and attached by the <a href="../../ifckernel/lexical/ifcreldefinesbyproperties.htm">IfcRelDefinesByProperties</a> relationship. They are accessible by the <i>IsDefinedBy</i> inverse attribute. Property sets may also be specified at the <a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionchamberelementtype.htm">IfcDistributionChamberElementType</a>, defining the common property data for all occurrences of the same type. They are then accessible by the <i>IsTypedBy</i> inverse attribute pointing to <i>IfcDistributionChamberElementType.HasPropertySets</i>. If both are given, then the properties directly defined at <b>IfcDistributionChamberElement</b> override the properties defined at <a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionchamberelementtype.htm">IfcDistributionChamberElementType</a>. Refer to the documentation at the supertype <a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionflowelement.htm">IfcDistributionFlowElement</a> and ancestors for inherited property set definitions.</p>
<p>The following property set definitions are applicable to this entity:</p><ul>
<li><a href="../../psd/IfcSharedBldgServiceElements/Pset_DistributionChamberElementCommon.xml" target="SOURCE">Pset_DistributionChamberElementCommon</a></li>
</ul>
The following property set definitions are applicable to this entity according to the <i>PredefinedType</i> attribute: </p><ul>
<li><a href="../../psd/IfcSharedBldgServiceElements/Pset_DistributionChamberElementTypeFormedDuct.xml" target="SOURCE">Pset_DistributionChamberElementTypeFormedDuct</a> (<a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionchamberelementtypeenum.htm">FORMEDDUCT</a>)</li>
<li><a href="../../psd/IfcSharedBldgServiceElements/Pset_DistributionChamberElementTypeInspectionChamber.xml" target="SOURCE">Pset_DistributionChamberElementTypeInspectionChamber</a> (<a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionchamberelementtypeenum.htm">INSPECTIONCHAMBER</a>)</li>
<li><a href="../../psd/IfcSharedBldgServiceElements/Pset_DistributionChamberElementTypeInspectionPit.xml" target="SOURCE">Pset_DistributionChamberElementTypeInspectionPit</a> (<a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionchamberelementtypeenum.htm">INSPECTIONPIT</a>)</li>
<li><a href="../../psd/IfcSharedBldgServiceElements/Pset_DistributionChamberElementTypeManhole.xml" target="SOURCE">Pset_DistributionChamberElementTypeManhole</a> (<a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionchamberelementtypeenum.htm">MANHOLE</a>)</li>
<li><a href="../../psd/IfcSharedBldgServiceElements/Pset_DistributionChamberElementTypeMeterChamber.xml" target="SOURCE">Pset_DistributionChamberElementTypeMeterChamber</a> (<a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionchamberelementtypeenum.htm">METERCHAMBER</a>)</li>
<li><a href="../../psd/IfcSharedBldgServiceElements/Pset_DistributionChamberElementTypeSump.xml" target="SOURCE">Pset_DistributionChamberElementTypeSump</a> (<a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionchamberelementtypeenum.htm">SUMP</a>)</li>
<li><a href="../../psd/IfcSharedBldgServiceElements/Pset_DistributionChamberElementTypeTrench.xml" target="SOURCE">Pset_DistributionChamberElementTypeTrench</a> (<a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionchamberelementtypeenum.htm">TRENCH</a>)</li>
<li><a href="../../psd/IfcSharedBldgServiceElements/Pset_DistributionChamberElementTypeValveChamber.xml" target="SOURCE">Pset_DistributionChamberElementTypeValveChamber</a> (<a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionchamberelementtypeenum.htm">VALVECHAMBER</a>)</li>
</ul>
<p><b><u>Material Use Definition</u></b></p>
<p>The material of the <b>IfcDistributionChamberElement</b> is defined by <a href="../../ifcmaterialresource/lexical/ifcmaterialconstituentset.htm">IfcMaterialConstituentSet</a> or as a fallback by <a href="../../ifcmaterialresource/lexical/ifcmaterial.htm">IfcMaterial</a>, and attached by the <i>RelatingMaterial</i> attribute on the <a href="../../ifcproductextension/lexical/ifcrelassociatesmaterial.htm">IfcRelAssociatesMaterial</a> relationship. It is accessible by the <i>HasAssociations</i> inverse attribute. Material information can also be given at the <a href="../../ifcsharedbldgserviceelements/lexical/ifcdistributionchamberelementtype.htm">IfcDistributionChamberElementType</a>, defining the common attribute data for all occurrences of the same type. The following keywords for <i>IfcMaterialConstituentSet.MaterialConstituents[n].Name</i> shall be used:</p>
<ul>
<li><b>'Base'</b>: The material from which the base of the duct is constructed.</li>
<li><b>'Cover'</b>: The material from which the access cover to the chamber is constructed.</li>
<li><b>'Fill'</b>: The material that is used to fill the duct (where used).</li>
<li><b>'Wall'</b>: The material from which the wall of the duct is constructed.</li>
</ul>
</EPM-HTML>
|
| 189 | 1166 | IfcDiscreteAccessory | <EPM-HTML>
<P> <U>Definition from IAI:</U> Representation of different kinds of
accessories included in or added to elements. </P>
<BLOCKQUOTE><FONT COLOR="#0000FF" SIZE="-1"> HISTORY New entity in IFC
Release 2x2 </FONT></BLOCKQUOTE>
<blockquote><font color="#ff0000" size="-1">IFC 2x4 change:
Attribute <i>PredefinedType</i> added.
</font></blockquote>
<P><B>General usage</B></P>
<P> The exact type information of the <I>IfcDiscreteAccessory</I> is given
in the <I>ObjectType</I> attribute inherited from <I>IfcObject</I>. Standard
type designations are provided for guideline below. The list is not exhaustive
and the list of definitions may be extended based on local national extensions.
</P>
<TABLE BORDER="1">
<TR>
<TD><I><B>Accessory type</B></I></TD>
<TD><I><B>Standard type designation</B></I></TD>
<TD><I><B>Description</B></I></TD>
</TR>
<TR>
<TD>Shading devices:</TD>
<TD>'Shading device'</TD>
<TD>Elements specifically designed to provide shading, often fixed
externally and sometimes moving (e.g. by rotation)</TD>
</TR>
<TR>
<TD>Corbels as separate components:</TD>
<TD>'Hidden steel corbel'</TD>
<TD>Corbel system made from steel components embedded into the master
element</TD>
</TR>
<TR>
<TD></TD>
<TD>'Visible steel corbel'</TD>
<TD>Corbel system made from steel components protruding from the master
element</TD>
</TR>
<TR>
<TD></TD>
<TD>'Visible concrete corbel'</TD>
<TD>Corbel system made as a separate precast concrete component added
to the master element</TD>
</TR>
<TR>
<TD></TD>
<TD>'Ladder truss connector'</TD>
<TD>A fixing device in truss form with straight cross bars in ladder
form holding two precast conrete panels together in a sandwich wall panel.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Panel suspender'</TD>
<TD>A straight fixing device holding two precast conrete panels
together in a sandwich wall panel.</TD>
</TR>
<TR>
<TD>Electrical accessories for precast concrete elements:</TD>
<TD>'Protective plug'</TD>
<TD>Protective plug used in element for protecting electrical
accessories during manufacturing, transportation and assembly.</TD>
</TR>
<TR>
<TD>Fixing parts:</TD>
<TD>'Standard fixing plate'</TD>
<TD>Standard fixing plate.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Edge fixing plate'</TD>
<TD>Fixing plate attached to the edge of an element.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Corner fixing plate'</TD>
<TD>Fixing plate attached to the corner of an element.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Slab fixing plate'</TD>
<TD>Fixing plate for slabs.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Balcony hinge'</TD>
<TD>Accessory supporting and fixing balconies.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Frame shoe'</TD>
<TD>Fixing shoe for frames.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Thermo frame'</TD>
<TD>Thermo frame.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Column shoe'</TD>
<TD>Fixing shoe for columns.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Wall shoe'</TD>
<TD>Fixing shoe for walls.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Fixing socket'</TD>
<TD>Fixing socket.</TD>
</TR>
<TR>
<TD>Joint accessories:</TD>
<TD>'Neoprene bearing plate'</TD>
<TD>Rubber plate used as a bearing in, for example, joints between
column corbels and beams.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Working joint reinforcement'</TD>
<TD>Reinforcement accessory used in working joints.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Expansion joint reinforcement'</TD>
<TD>Reinforcement accessory used in expansion joints.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Ribbed steel bar extension'</TD>
<TD>Extension accessory made of a ribbed (reinforcement) bar used in
joints.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Steel pin bolt'</TD>
<TD>Pin bolt used to join together, for example, columns and
beams.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Concrete dowel'</TD>
<TD>Dowel pin used in joints.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Concrete groove'</TD>
<TD>A groove made in a joint.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Steel plate'</TD>
<TD>A steel plate used as an accessory in a joint.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Wire loop'</TD>
<TD>A joint connector accessory made from a wire loop.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Steel loop'</TD>
<TD>A joint connector accessory made from a steel bar loop.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Sealing strip'</TD>
<TD>A strip sealing the joint.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Sealing compound'</TD>
<TD>Sealing compound protecting and sealing the joint.</TD>
</TR>
<TR>
<TD>Lifting accessories:</TD>
<TD>'Wire lifting hook'</TD>
<TD>A lifting aid in the form of a wire loop.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Steel lifting hook'</TD>
<TD>A lifting aid in the form of a steel bar loop.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Lifting socket'</TD>
<TD>A lifting aid in the form of a socket.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Steel lifting anchor'</TD>
<TD>A lifting aid in the form of a steel lifting anchor.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Lifting hole'</TD>
<TD>A lifting aid in the form of a hole.</TD>
</TR>
<TR>
<TD>Accessories mainly used in the building services domain:</TD>
<TD>'Antivibration'</TD>
<TD>An isolating device to prevent other elements to be effected by
vibrations.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Drop rod'</TD>
<TD>A length of material providing a hanging support to a bracket. Note
that a drop rod is considered to include nuts and washers required for
securing.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Duct foot'</TD>
<TD>A base support used to receive a vertical pipe (BS6100 330 3309 -
duct foot).</TD>
</TR>
<TR>
<TD></TD>
<TD>'Framing'</TD>
<TD>A frame placed around a penetration to prevent scraping against the
building surface or structure.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Grommet'</TD>
<TD>An element placed within a penetration that seals the penetration
for a particular reason.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Rack'</TD>
<TD>A set of shelving for the purposes of storage that may be
freestanding or bolted to a structure.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Safety part'</TD>
<TD>A part, typically installed in vertical shafts at each level, to
ensure safety from falling when entering the shaft.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Sleeve'</TD>
<TD>A thin barrier placed between a penetration and a penetrating
element.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Support section'</TD>
<TD>A section of material that is used as an intermediate support upon
which multiple brackets can be mounted.</TD>
</TR>
</TABLE>
</EPM-HTML>
|
| 190 | 1170 | IfcElementComponent | <EPM-HTML>
<P>
An element component is a representation for minor items included in, added to or connecting to or between
elements, which usually are not of interest from the overall building structure viewpoint.
However, these small parts may have vital and load carrying functions within the construction.
These items do not provide any actual space boundaries.
Typical examples of <I>IfcElementComponent</I>s include different kinds of fasteners and various accessories.
</P>
<BLOCKQUOTE class="history">HISTORY New entity in IFC Release 2x2</BLOCKQUOTE>
<p>It is often desirable to model a number of same-shaped element components by means of a single
occurrence object, e.g. several bolts within a connection or a row of reinforcement elements.
In this IFC release, this is possible by means of multiple mapped representation as documented below.</p>
<p>To express the multiplicity of element components also on a higher semantic level,
an <i>IfcElementQuantity</i> should be provided via <i>IfcRelDefinesByProperties</i>.
The quantity should contain an <i>IfcQuantityCount</i> named 'Count' with the number of components.</p>
<P><B><U>Geometry Use Definition</U></B></P>
<P>
The geometric representation of <I>IfcElementComponent</I> is given by the <I>IfcProductDefinitionShape</I>,
allowing multiple geometric representations. Included are:
</P>
<P><B>Local Placement</B><BR>
The local placement for <I>IfcElementComponent</I> is defined in its supertype <I>IfcProduct</I>.
It is defined by the <I>IfcLocalPlacement</I>, which defines the local coordinate system that is
referenced by all geometric representations.
</P>
<UL>
<LI>The <I>PlacementRelTo</I> relationship of <I>IfcLocalPlacement</I> shall point (if given) to
the local placement of the same <I>IfcElement</I> or <I>IfcElementAssembly</I>, which is
used in the <I>Decomposes</I> inverse attribute, i.e. the local placement is defined relative to
the local placement of the element or element assembly in which the component is contained.
<LI>If the relative placement is not used, the absolute placement is defined within the world coordinate system.
</UL>
<P><B>Surface Model Representation</B></P>
<P>
Any <I>IfcElementComponent</I> (if no further constraints are defined at the level of its subtypes)
may be represented as a single or multiple surface models, based on either shell or face based models.
The following attribute values for the <I>IfcShapeRepresentation</I> holding this geometric representation
shall be used:
</P>
<UL>
<LI><I>RepresentationIdentifier</I> : 'Body'</LI>
<LI><I>RepresentationType</I> : 'SurfaceModel'</LI>
</UL>
<P>
<B>Brep Representation</B></P>
<P>
Any <I>IfcElementComponent</I> (if no further constraints are defined at the level of its subtypes)
may be represented as a single or multiple Boundary Representation elements (which are restricted to faceted
Brep with or without voids). The Brep representation allows for the representation of complex element shape.
The following attribute values for the <I>IfcShapeRepresentation</I> holding this geometric representation
shall be used:
</P>
<UL>
<LI><I>RepresentationIdentifier</I> : 'Body'</LI>
<LI><I>RepresentationType</I> : 'Brep'</LI>
</UL>
<P><B>Mapped Representation</B></P>
<P>
The mapped item, <I>IfcMappedItem</I>, should be used if appropriate as it allows for reusing the geometry
definition of a type at occurrences of the same type.
The following attribute values for the <I>IfcShapeRepresentation</I> holding this geometric representation
shall be used:
</P>
<UL>
<LI><I>RepresentationIdentifier</I> : 'Body'</LI>
<LI><I>RepresentationType</I> : 'MappedRepresentation'</LI>
</UL>
<p><b>Multiple Mapped Representation</b></p>
<p>A single instance of a subtype of <i>IfcElementComponent</i> can stand for several
actual element components at once. In this case, the <i>IfcShapeRepresentation</i>
contains as many mapped items as there are element components combined within this
occurrence object:</p>
<p>Figure 151 illustrates multiple components modeled as a single occurrence object (here: <i>IfcFastener</i>)</p>
<table>
<tr><td><img src="figures/ifcelementcomponent_multiple.png"></td></tr>
<tr><td><p class="figure">Figure 151 — Element component mapped representation</p></td></tr>
</table>
<p>Representation identifier and type are the same as in single mapped representation.
The number of mapped items in the representation corresponds with the count of
element components in the <i>IfcElementQuantity</i>.</p>
</EPM-HTML> |
| 191 | 1175 | IfcElementComponentType | <EPM-HTML>
<P><U>Definition from IAI:</U>
The element type (<I>IfcElementComponentType</I>) represents the supertype for element
types which define lists of commonly shared property set definitions of various small parts and accessories and an optional set of product
representations. It is used to define a supporting element mainly within
structural and building services domains (i.e. the specific type information
common to all occurrences of that type).</P>
<BLOCKQUOTE><FONT COLOR="#0000FF" SIZE="-1">HISTORY New entity in IFC
Release 2x2
</FONT></BLOCKQUOTE>
</EPM-HTML> |
| 192 | 1180 | IfcBuildingElementPartType | <EPM-HTML>
<p><u>Definition from IAI:</u> The building element part type defines
lists of commonly shared property set definitions and representation maps of parts of a building element.</p>
<blockquote><font color="#0000ff" size="-1">
HISTORY New entity in IFC Release 2x4
</font></blockquote>
</EPM-HTML>
|
| 193 | 1188 | IfcDiscreteAccessoryType | <EPM-HTML>
<P><U>Definition from IAI</U>: The element type
(<I>IfcDiscreteAccessoryType</I>) defines a list of commonly shared property
set definitions of a discrete accessory and an optional set of product
representations. It is used to define a supporting element mainly within
structural and building services domains (i.e. the specific type information
common to all occurrences of that type).</P>
<P>The occurrences of the <I>IfcDiscreteAccessoryType</I> are represented
by instances of <I>IfcDiscreteAccessory</I>.</P>
<P>The <I>IfcDiscreteAccessoryType</I> is a specialization of the general
building element component type to represent different type of structural and
building service related auxiliary elements.</P>
<BLOCKQUOTE><FONT COLOR="#0000FF" SIZE="-1">HISTORY New entity in IFC
Release 2x2 </FONT></BLOCKQUOTE>
<blockquote><font color="#ff0000" size="-1">IFC 2x4 change:
Attribute <i>PredefinedType</i> added.
</font></blockquote>
<P><B>General usage</B></P>
<P> The exact type information of the <I>IfcDiscreteAccessoryType</I> is
given in the <I>ElementType</I> attribute inherited from <I>IfcElementType</I>.
Standard type designations are provided for guideline below. The list is not
exhaustive and the list of definitions may be extended based on local national
extensions. </P>
<TABLE BORDER="1">
<TR>
<TD><I><B>Accessory type</B></I></TD>
<TD><I><B>Standard type designation</B></I></TD>
<TD><I><B>Description</B></I></TD>
</TR>
<TR>
<TD>Shading devices:</TD>
<TD>'Shading device'</TD>
<TD>Elements specifically designed to provide shading, often fixed
externally and sometimes moving (e.g. by rotation)</TD>
</TR>
<TR>
<TD>Corbels as separate components:</TD>
<TD>'Hidden steel corbel'</TD>
<TD>Corbel system made from steel components embedded into the master
element</TD>
</TR>
<TR>
<TD></TD>
<TD>'Visible steel corbel'</TD>
<TD>Corbel system made from steel components protruding from the master
element</TD>
</TR>
<TR>
<TD></TD>
<TD>'Visible concrete corbel'</TD>
<TD>Corbel system made as a separate precast concrete component added
to the master element</TD>
</TR>
<TR>
<TD>Connecting accessories, for example for sandwich wall panels:</TD>
<TD>'Diagonal truss connector'</TD>
<TD>A fixing device in truss form with diagonal cross bars holding two
precast conrete panels together in a sandwich wall panel.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Ladder truss connector'</TD>
<TD>A fixing device in truss form with straight cross bars in ladder
form holding two precast conrete panels together in a sandwich wall panel.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Panel suspender'</TD>
<TD>A straight fixing device holding two precast conrete panels
together in a sandwich wall panel.</TD>
</TR>
<TR>
<TD>Electrical accessories for precast concrete elements:</TD>
<TD>'Protective plug'</TD>
<TD>Protective plug used in element for protecting electrical
accessories during manufacturing, transportation and assembly.</TD>
</TR>
<TR>
<TD>Fixing parts:</TD>
<TD>'Standard fixing plate'</TD>
<TD>Standard fixing plate.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Edge fixing plate'</TD>
<TD>Fixing plate attached to the edge of an element.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Corner fixing plate'</TD>
<TD>Fixing plate attached to the corner of an element.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Slab fixing plate'</TD>
<TD>Fixing plate for slabs.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Balcony hinge'</TD>
<TD>Accessory supporting and fixing balconies.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Frame shoe'</TD>
<TD>Fixing shoe for frames.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Thermo frame'</TD>
<TD>Thermo frame.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Column shoe'</TD>
<TD>Fixing shoe for columns.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Wall shoe'</TD>
<TD>Fixing shoe for walls.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Fixing socket'</TD>
<TD>Fixing socket.</TD>
</TR>
<TR>
<TD>Joint accessories:</TD>
<TD>'Neoprene bearing plate'</TD>
<TD>Rubber plate used as a bearing in, for example, joints between
column corbels and beams.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Working joint reinforcement'</TD>
<TD>Reinforcement accessory used in working joints.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Expansion joint reinforcement'</TD>
<TD>Reinforcement accessory used in expansion joints.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Ribbed steel bar extension'</TD>
<TD>Extension accessory made of a ribbed (reinforcement) bar used in
joints.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Steel pin bolt'</TD>
<TD>Pin bolt used to join together, for example, columns and
beams.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Concrete dowel'</TD>
<TD>Dowel pin used in joints.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Concrete groove'</TD>
<TD>A groove made in a joint.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Steel plate'</TD>
<TD>A steel plate used as an accessory in a joint.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Wire loop'</TD>
<TD>A joint connector accessory made from a wire loop.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Steel loop'</TD>
<TD>A joint connector accessory made from a steel bar loop.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Sealing strip'</TD>
<TD>A strip sealing the joint.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Sealing compound'</TD>
<TD>Sealing compound protecting and sealing the joint.</TD>
</TR>
<TR>
<TD>Lifting accessories:</TD>
<TD>'Wire lifting hook'</TD>
<TD>A lifting aid in the form of a wire loop.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Steel lifting hook'</TD>
<TD>A lifting aid in the form of a steel bar loop.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Lifting socket'</TD>
<TD>A lifting aid in the form of a socket.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Steel lifting anchor'</TD>
<TD>A lifting aid in the form of a steel lifting anchor.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Lifting hole'</TD>
<TD>A lifting aid in the form of a hole.</TD>
</TR>
<TR>
<TD>Accessories mainly used in the building services domain:</TD>
<TD>'Antivibration'</TD>
<TD>An isolating device to prevent other elements to be effected by
vibrations.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Drop rod'</TD>
<TD>A length of material providing a hanging support to a bracket. Note
that a drop rod is considered to include nuts and washers required for
securing.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Duct foot'</TD>
<TD>A base support used to receive a vertical pipe (BS6100 330 3309 -
duct foot).</TD>
</TR>
<TR>
<TD></TD>
<TD>'Framing'</TD>
<TD>A frame placed around a penetration to prevent scraping against the
building surface or structure.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Grommet'</TD>
<TD>An element placed within a penetration that seals the penetration
for a particular reason.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Rack'</TD>
<TD>A set of shelving for the purposes of storage that may be
freestanding or bolted to a structure.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Safety part'</TD>
<TD>A part, typically installed in vertical shafts at each level, to
ensure safety from falling when entering the shaft.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Sleeve'</TD>
<TD>A thin barrier placed between a penetration and a penetrating
element.</TD>
</TR>
<TR>
<TD></TD>
<TD>'Support section'</TD>
<TD>A section of material that is used as an intermediate support upon
which multiple brackets can be mounted.</TD>
</TR>
</TABLE>
</EPM-HTML> |
| 194 | 1197 | IfcFastenerType | <EPM-HTML>
<P><U>Definition from IAI</U>:
The element type (<I>IfcFastenerType</I>) defines a list of commonly shared
property set definitions of a fastener and an optional set of product
representations. It is used to define fasteners mainly within
structural and building services domains (i.e. the specific type information
common to all occurrences of that type).</P>
<P>
The occurrences of the <I>IfcFastenerType</I> are represented by
instances of <I>IfcFastener</I>.
</P>
<BLOCKQUOTE><FONT COLOR="#0000FF" SIZE="-1">
HISTORY New entity in IFC Release 2x2
</FONT></BLOCKQUOTE>
<blockquote><font color="#ff0000" size="-1">IFC 2x4 change:
Attribute <i>PredefinedType</i> added.
Subtype <i>IfcMechanicalFastenerType</i> redefined as direct subtype of <i>IfcElementComponentType</i>.
</font></blockquote>
<p><b><u>Property Set Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <a href="../../ifckernel/lexical/ifcpropertyset.htm">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.</p>
<p>The following property set definitions are applicable to this entity according to the <i>PredefinedType</i> attribute:</p>
<ul>
<li><a href="../../psd/IfcSharedComponentElements/Pset_FastenerWeld.xml" target="SOURCE">Pset_FastenerWeld</a> (<a href="ifcfastenertypeenum.htm">WELD</a>)</li>
</ul>
</EPM-HTML> |
| 195 | 1206 | IfcMechanicalFastenerType | <EPM-HTML>
<p><u>Definition from IAI</u>: The element type (<i>IfcMechanicalFastenerType</i>) defines a list of commonly shared property set definitions of a fastener and an optional set of product representations. It is used to define mechanical fasteners mainly within structural and building services domains (i.e. the specific type information common to all occurrences of that type).</p>
<p>The occurrences of the <i>IfcMechanicalFastenerType</i> are represented by instances of <i>IfcMechanicalFastener</i>.</p>
<blockquote><font color="#0000ff" size="-1">HISTORY New entity in IFC Release 2x2</font></blockquote>
<blockquote><font color="#ff0000" size="-1">IFC 2x4 change:
Supertype changed from <i>IfcFastenerType</i> to <i>IfcElementComponentType</i>.
Attributes <i>PredefinedType</i>, <i>NominalDiameter</i>, <i>NominalLength</i> added.
</font></blockquote>
<p>Mechanical fasteners, especially bolts, are often standardized. To refer to a formal fastener
designation according to a standard (a product norm), <i>IfcRelAssociatesClassification</i> together
with <i>IfcClassificationReference</i> should be used.</p>
<ul>
<li><i>IfcClassificationReference.ItemReference</i>
contains a machine-readable form of the formal fastener designation from the norm.
Example: 'M16X80-10.9-HV' for a high-strength structural bolting assembly for preloading with
hexagon bolt and nut. (On the other hand, <i>IfcMechanicalFastenerType.Name</i> contains a
displayable name which may not necessarily be the same as the formal designation.)</li>
<li><i>IfcClassificationReference.Name</i> carries the short name of the fastener norm.
Example: 'EN 14399-4' as the respective European standard for high-strength hexagon bolts.</li>
<li>Optionally, the norm can be further described by
<i>IfcClassificationReference.ReferencedSource</i>, including information like publisher and
date of issue of the norm.</li>
</ul>
<p>Furthermore, <i>IfcRelAssociatesLibrary</i> together with <i>IfcLibraryReference</i> may be
used to refer to a library which contains fastener definitions.</p>
<p><b><u>Property Set Use Definition</u></b></p>
<p>The property sets relating to this entity are defined by <a href="../../ifckernel/lexical/ifcpropertyset.htm">IfcPropertySet</a> and attached by the <i>HasPropertySets</i> attribute.</p>
<p>The following property set definitions are applicable to this entity according to the <i>PredefinedType</i> attribute:</p>
<ul>
<li><a href="../../psd/IfcSharedComponentElements/Pset_MechanicalFastenerBolt.xml" target="SOURCE">Pset_MechanicalFastenerBolt</a> (<a href="ifcmechanicalfastenertypeenum.htm">BOLT</a>)</li>
</ul>
</EPM-HTML> |
| 196 | 1224 | IfcFastener | <EPM-HTML>
<P>
<U>Definition from IAI:</U>
Representations of fixing parts which are used as fasteners to connect or join elements with
other elements.
</P>
<BLOCKQUOTE><FONT COLOR="#0000FF" SIZE="-1">
HISTORY New entity in IFC Release 2x2
</FONT></BLOCKQUOTE>
<blockquote><font color="#ff0000" size="-1">IFC 2x4 change:
Attribute <i>PredefinedType</i> added.
</font></blockquote>
</EPM-HTML>
|
| 197 | 1228 | IfcBuildingElementPart | <EPM-HTML>
<p><u>Definition from IAI:</u> Layers or major components as subordinate
parts of a building element. Typical usage examples include precast concrete
sandwich walls, where the layers may have different geometry representations.
In this case the layered material representation does not sufficiently describe
the element. Each layer is represented by an own instance of the
<i>IfcBuildingElementPart</i> with its own geometry description.</p>
<p>The kind of building element part is further specified by a
corresponding instance of <i>IfcBuildingElementPartType</i>,
referred to by <i>IfcRelDefinesByType</i>.</p>
<blockquote><font color="#0000ff" size="-1">
HISTORY New entity in IFC Release 2x2
</font></blockquote>
<blockquote><font color="#ff0000" size="-1">IFC 2x4 change:
Moved from from <i>IfcStructuralElementsDomain</i> schema to
<i>IfcSharedComponentElements</i> schema, compatible change of supertype,
attribute <i>PredefinedType</i> added.
</font></blockquote>
</EPM-HTML>
|
| 198 | 1232 | IfcMechanicalFastener | <EPM-HTML>
<p><u>Definition from IAI:</u> Fasteners connecting building elements mechanically. A single instance of this class may represent one or many of actual mechanical fasteners, for example an array of bolts or a row of nails.</p>
<blockquote><font color="#0000ff" size="-1">HISTORY New entity in IFC Release 2x2</font></blockquote>
<blockquote><font color="#ff0000" size="-1">IFC 2x4 change:
Supertype changed from <i>IfcFastener</i> to <i>IfcElementComponent</i>.
Attribute <i>PredefinedType</i> added.
Attributes <i>NominalDiameter</i> and <i>NominalLength</i> moved to <i>IfcMechanicalFastenerType</i>.
</font></blockquote>
<p><u><b>Geometry Use Definition</b></u></p>
<p>See definitions at the supertype <i>IfcElementComponent</i>.</p>
<p>In addition, a symbolic representation is defined for a row of fasteners or several rows of
fasteners within a single instance of <i>IfcMechanicalFastener</i>. Such rows or arrays may
contain possibly large numbers of individual pieces. The product definition shape consists of
an <i>IfcShapeRepresentation</i> with the attribute values</p>
<ul>
<li><i>RepresentationIdentifier</i> : 'Row'</li>
<li><i>RepresentationType</i> : 'GeometricCurveSet'</li>
</ul>
<p>and one or several curves as geometric items. The curves represent where the heads of the fasteners
are located. The local placement of the <i>IfcMechanicalFastener</i> shall be located and oriented such
that the local z axis is parallel with the axes of the fasteners (bolts, nails, staples or similar).</p>
<p>In case of such a symbolic 'Row' representation, an <i>IfcElementQuantity</i> should be attached to
the <i>IfcMechanicalFastener</i> via <i>IfcRelDefinesByProperties</i>. The quantity should contain an
<i>IfcQuantityCount</i> named 'Count' with the number of fasteners and an <i>IfcQuantityLength</i>
named 'Spacing' which expresses the center-to-center distances of fasteners.</p>
</EPM-HTML>
|
