275;IfcPresentableText;"

IfcPresentableText is a text string used to capture the content of a text literal for the purpose of presentation. The IfcPresentableText can include multiple lines of text, for which the line feed character LF, 0x0A, should be used to separate lines.

NOTE The non printable characters are converted within the standard exchange format ISO 10303-21 (STEP physical file format), commonly the \X\09 represents the TAB, and \X\0A the LF character.

NOTE The IfcPresentableText is an entity that had been adopted from ISO 10303, Industrial automation systems and integration—Product data representation and exchange, Part 46: Integrated generic resources: Visual presentation.

NOTE Corresponding ISO 10303 name: presentable_text. Please refer to ISO/IS 10303-46:1994, p. 133 for the final definition of the formal standard.

HISTORY New type in IFC2x2.

" 299;IfcTextFontName;"

Definition from CSS1 (W3C Recommendation): The value is a font family name and/or generic family name. Values are:

<family-name>

The name of a font family of choice. For example, ""gill"" and ""helvetica"" are font families.

<generic-family>

In the example above, the last value is a generic family name. The following generic families are defined:

'serif' (Example: Times)
'sans-serif' (Example: Helvetica)
'cursive' (Example: Zapf-Chancery)
'fantasy' (Example: Western)
'monospace' (Example: Courier)

It is encouraged to offer a generic font family as a last alternative.

NOTE Corresponding CSS1 definitions are font-family.

HISTORY New type in IFC2x2 Addendum 2.

IFC2x2 Addendum 2 CHANGE: The IfcFontFamily has been added.

" 300;IfcFontStyle;"

Definition from CSS1 (W3C Recommendation): The font-style property selects between normal (sometimes referred to as ""roman"" or ""upright""), italic and oblique faces within a font family. Values are:

normal
italic
oblique

A value of 'normal' selects a font that is classified as 'normal' in the user agents font database, while 'oblique' selects a font that is labeled 'oblique'. A value of 'italic' selects a font that is labeled 'italic', or, if that is not available, one labeled 'oblique'. The font that is labeled 'oblique' in the user agents font database may actually have been generated by electronically slanting a normal font.

Fonts with Oblique, Slanted or Incline in their names will typically be labeled 'oblique' in the user agents font database. Fonts with Italic, Cursive or Kursiv in their names will typically be labeled 'italic'.

NOTE Corresponding CSS1 definitions is font-style.

HISTORY New type in IFC2x3.

" 302;IfcFontVariant;"

Definition from CSS1 (W3C Recommendation): The font-style property selects between normal and small-caps within a font family. Values are:

normal
small-caps

Another type of variation within a font family is the small-caps. In a small-caps font the lower case letters look similar to the uppercase ones, but in a smaller size and with slightly different proportions. The 'font-variant' property selects that font.

A value of 'normal' selects a font that is not a small-caps font, 'small-caps' selects a small-caps font. It is acceptable (but not required) in CSS1 if the small-caps font is a created by taking a normal font and replacing the lower case letters by scaled uppercase characters. As a last resort, uppercase letters will be used as replacement for a small-caps font.

NOTE Corresponding CSS1 definitions is font-variant.

HISTORY New type in IFC2x3.

" 304;IfcFontWeight;"

Definition from CSS1 (W3C Recommendation): The 'font-weight' property selects the weight of the font. The values '100' to '900' form an ordered sequence, where each number indicates a weight that is at least as dark as its predecessor. The keyword 'normal' is synonymous with '400', and 'bold' is synonymous with '700'. Keywords other than 'normal' and 'bold' have been shown to be often confused with font names and a numerical scale was therefore chosen for the 9-value list. Values are:

normal
bold
100 | 200 | 300 | 400 | 500 | 600 | 700 | 800 | 900

Fonts (the font data) typically have one or more properties whose values are names that are descriptive of the ""weight"" of a font. There is no accepted, universal meaning to these weight names. Their primary role is to distinguish faces of differing darkness within a single font family. Usage across font families is quite variant; for example a font that you might think of as being bold might be described as being Regular, Roman, Book, Medium, Semi- or DemiBold, Bold, or Black, depending on how black the ""normal"" face of the font is within the design. Because there is no standard usage of names, the weight property values in CSS1 are given on a numerical scale in which the value '400' (or 'normal') corresponds to the ""normal"" text face for that family. The weight name associated with that face will typically be Book, Regular, Roman, Normal or sometimes Medium.

The association of other weights within a family to the numerical weight values is intended only to preserve the ordering of darkness within that family. However, the following heuristics tell how the assignment is done in typical cases:

If the font family already uses a numerical scale with nine values (such as with OpenType), the font weights should be mapped directly.
If there is both a face labeled Medium and one labeled Book, Regular, Roman or Normal, then the Medium is normally assigned to the '500'.
The font labeled ""Bold"" will often correspond to the weight value '700'.
If there are fewer then 9 weights in the family, the default algorithm for filling the ""holes"" is as follows. If '500' is unassigned, it will be assigned the same font as '400'. If any of the values '600', '700', '800' or '900' remains unassigned, they are assigned to the same face as the next darker assigned keyword, if any, or the next lighter one otherwise. If any of '300', '200' or '100' remains unassigned, it is assigned to the next lighter assigned keyword, if any, or the next darker otherwise.

The following two examples illustrate the process. Assume four weights in the ""Example1"" family, from lightest to darkest: Regular, Medium, Bold, Heavy. And assume six weights in the ""Example2"" family: Book, Medium, Bold, Heavy, Black, ExtraBlack. Note how in the second example it has been decided not to assign ""Example2 ExtraBlack"" to anything.

Available faces       | Assignments   | Filling the holes
----------------------+---------------+-------------------
""Example1 Regular""    | 400           | 100, 200, 300
""Example1 Medium""     | 500           |
""Example1 Bold""       | 700           | 600
""Example1 Heavy""      | 800           | 900

Available faces       | Assignments   | Filling the holes
----------------------+---------------+-------------------
""Example2 Book""       | 400           | 100, 200, 300
""Example2 Medium""     | 500           |
""Example2 Bold""       | 700           | 600 
""Example2 Heavy""      | 800           |
""Example2 Black""      | 900           |
""Example2 ExtraBlack"" | (none)        |

NOTE Corresponding CSS1 definitions is font-weight.

HISTORY New type in IFC2x2 Addendum 2.

" 3764;IfcURIReference;"

IfcURIReference provides for identifying a Uniform Resource Identifier, URI, as defined by the RFC3986 of the Network Working Group. A URI can be classified as a locator or a name or both, that is it may comprise a Uniform Resource Locator (URL) and/or a Uniform Resource Name (URN).

A Uniform Resource Locator, URL, is a string conforming to a standardized format, which refers to a resource on the internet (such as a document or an image) by its location.
A Uniform Resource Name, URN, is intended to serve as persistent, location-independent resource identifier and is designed to make it easy to map other namespaces (that share the properties of URNs) into URN-space.

HISTORY New defined datatype in IFC 2x4.

" 3869;IfcLanguageId;"

IfcLanguageId identifies the language in which a natural language text is expressed. It uses a language tag to identify the language.

The tag shall comply to the Internet Engineering Task Force (IETF) language tag as expressed in RFC 5646. A conforming program shall support the ""simple language"" subtag and the ""language-region"" tag format.

EXAMPLE for simple language tags en (English), de (German), fr (France), or ja (Japanese), and for language-region tags en-US (English as used in United States), de-CH (German as used in German speaking part of Switzerland).

Type: IfcIdentifier

NOTE The use of IfcLanguageId should conform to the use of language tags in HTML and XML as published by the W3C consortium.

HISTORY New defined datatype in IFC2x4.

" 4001;IfcDateTime;"

This lexical representation is the [ISO 8601] extended format CCYY-MM-DDThh:mm:ss where ""CC"" represents the century, ""YY"" the year, ""MM"" the month and ""DD"" the day, preceded by an optional leading ""-"" sign to indicate a negative number. If the sign is omitted, ""+"" is assumed. The letter ""T"" is the date/time separator and ""hh"", ""mm"", ""ss"" represent hour, minute and second respectively. Additional digits can be used to increase the precision of fractional seconds if desired i.e the format ss.ss... with any number of digits after the decimal point is supported. The fractional seconds part is optional; other parts of the lexical form are not optional. To accommodate year values greater than 9999 additional digits can be added to the left of this representation. Leading zeros are required if the year value would otherwise have fewer than four digits; otherwise they are forbidden. The year 0000 is prohibited.

HISTORY: New type in IFC2x4

" 4002;IfcDate;"

The lexical representation for date is the reduced (right truncated) lexical representation for dateTime: CCYY-MM-DD. No left truncation is allowed. An optional following time zone qualifier is allowed as for dateTime. To accommodate year values outside the range from 0001 to 9999, additional digits can be added to the left of this representation and a preceding ""-"" sign is allowed.

HISTORY: New type in IFC2x4

Use definitions

All given values should be provided in context and converted into a Gregorian date context and be shall be processable by a receiving application.

" 4003;IfcTime;"

The lexical representation for time is the left truncated lexical representation for dateTime: hh:mm:ss.sss with optional following time zone indicator. For example, to indicate 1:20 pm for Eastern Standard Time which is 5 hours behind Coordinated Universal Time (UTC), one would write: 13:20:00-05:00.

HISTORY: New type in IFC2x4

" 4004;IfcDuration;"

String representation of a time duration according to ISO8601:2000 ""Data elements and interchange formats - Information interchange - Representation of dates and times"" as defined in section 5.5.3 ""Representation of duration"".
It is recommended to use the alternative format (section 5.5.4.2.2) in its extended version: PYYYY-MM-DDThh:mm:ss.
EXAMPLE: P0002-10-15T10:30:20 (duration of two years, 10 months, 15 days, 10 hours, 30 minutes and 20 seconds).

HISTORY: New type in IFC2x4

" 4122;IfcDayInMonthNumber;"

Definition from IAI: The IfcDayInMonthNumber is an integer that defines the position of the specified day in a month.

Type: INTEGER

NOTE Corresponding STEP name: day_in_month_number, please refer to ISO/IS 10303-41:1994 for the final definition of the formal standard.

HISTORY New type in IFC Release 1.5.1.
IFC2x4 CHANGE Where rule ValidRange added.

" 4124;IfcDayInWeekNumber;"

Definition from IAI: The IfcDayInWeekNumber is an integer that defines the position of the specified day in a week. The positions have the following meaning (according to ISO8601 ""the calendar week"") that assigns the ordinal day number in the week to the Calender day name.

Ordinal day number	Calendar day name
01	Monday
02	Tuesday
03	Wednesday
04	Thursday
05	Friday
06	Saturday
07	Sunday

Type: INTEGER

HISTORY New type in IFC2x4.

" 4126;IfcMonthInYearNumber;"

Definition from IAI: The IfcDayInMonthNumber is an integer that defines the position of the specified month in a year. The positions have the following meaning (according to ISO8601 ""calendar month"") that assigns the Calendar month number to the Calender month name.

NOTE Refer to ISO 8601 for the definitions for using the Gregorian calendar as the standard for the identification of calendar days.

Calendar month number	Calendar month name
01	January
02	February
03	March
04	April
05	May
06	June
07	July
08	August
09	September
10	October
11	November
12	December

Type: INTEGER

NOTE Corresponding STEP name: month_in_year_number, please refer to ISO/IS 10303-41:1994 for the final definition of the formal standard.

HISTORY New type in IFC Release 1.5.1.

" 4298;IfcCardinalPointReference;"

An IfcCardinalPointReference is an index reference to significant points of a section profile. This index is used to describe the spatial relationship between the section of a member and a reference axis of the same member.

HISTORY� New Type in IFC2x4.

Indexes 1...9 refer to points at the bounding box of a profile. Indexes 10...19 refer to points defined by geometric centroid (usually centre of gravity) and shear centre, and their combinations with bounding box coordinates. In particular, the following index values are specified in this IFC Release:

bottom left
bottom centre
bottom right
mid-depth left
mid-depth centre
mid-depth right
top left
top centre
top right
geometric centroid
bottom in line with the geometric centroid
left in line with the geometric centroid
right in line with the geometric centroid
top in line with the geometric centroid
shear centre
bottom in line with the shear centre
left in line with the shear centre
right in line with the shear centre
top in line with the shear centre

Other index values are possible but outside the scope of this specification.

Figure 283 illustrates cardinal point values.

Figure 283 — Cardinal point values

Figure 284 illustrates an example extrusion shape with arbitrary profile (IfcArbitraryClosedProfileDef), aligned ""mid-depth right"" on the member axis. The line of sight follows the extrusion direction Z which points into the drawing plane of above illustration. Hence, ""left"" is in the positive X direction of the IfcProfileDef. ""Top"" is in the positive Y direction of the IfcProfileDef.

Figure 284 — Cardinal point extrusion

" 4311;IfcAmountOfSubstanceMeasure;"

Definition from ISO/CD 10303-41:1992: An amount of substance measure is the value for the quantity of a substance when compared with the number of atoms in 0.012kilogram of carbon 12.

Usually measure in mole (mol).

Type: REAL

NOTE Corresponding ISO 10303 name: amount_of_substance_measure, please refer to ISO/IS 10303-41 for the final definition of the formal standard.

HISTORY New type in IFC Release 1.5.1.

" 4312;IfcAngularVelocityMeasure;"

IfcAngularVelocityMeasure is a measure of the velocity of a body measured in terms of angle subtended per unit time.

Usually measured in radians/s.

Type: REAL

HISTORY New type in IFC Release 2.0.

" 4313;IfcAreaMeasure;"

Definition from ISO/CD 10303-41:1992: An area measure is the value of the extent of a surface.

Usually measured in square metre (m2).

Type: REAL

NOTE Corresponding ISO 10303 name: area_measure, please refer to ISO/IS 10303-41 for the final definition of the formal standard.

HISTORY New type in IFC Release 1.5.1.

" 4314;IfcBoolean;"

IfcBoolean is a defined data type of simple data type Boolean. It is required since a select type (IfcSimpleValue) cannot directly include simple types in its select list. A boolean type can have value TRUE or FALSE.

Type: BOOLEAN

HISTORY New type in IFC Release 1.5.1.

" 4315;IfcCompoundPlaneAngleMeasure;"

IfcCompoundPlaneAngleMeasure is a compound measure of plane angle in degrees, minutes, seconds, and optionally millionth-seconds of arc.

NOTE: IfcCompoundPlaneAngleMeasure is used where angles need to be described to an accuracy as fine as one millionth of a degree and expressed as parts of an arc. It may be used for angular measurement by surveyors or for other angular measurements where precision is required. Another usage is exact or approximate global positioning against a geographic coordinate systems using longitude and latitude.

NOTE: While the unit of measurement of the type IfcPlaneAngleMeasure depends on unit assignment (radian or degree or other derived units; globally at the IfcPoject or locally at an IfcMeasureWithUnit), the units of IfcCompoundPlaneAngleMeasure are always degrees, minutes, seconds, and millionth-seconds irrespective of unit assignments.

HISTORY New type in IFC Release 1.5.1.

Type: LIST [3:4] OF INTEGER

Value restrictions

The first integer measure is the number of degrees and is generally not range-restricted. However, when IfcCompoundPlaneAngleMeasure is used to express geographic coordinates, only latitudes of [-90, 90] and longitudes of [-180, 180] are used in practice.
The second integer measure is the number of minutes and shall be in the range (-60, 60).
The third integer measure is the number of seconds and shall be in the range (-60, 60).
The optional fourth integer measure is the number of millionth-seconds and shall be in the range (-1 000 000, 1 000 000).

Signedness

All measure components have the same sign (positive or negative). It is therefore trivial to convert between floating point representation (decimal degrees) and compound representation regardless whether the angle is greater or smaller than zero. Example:

LOCAL a : IfcPlaneAngleMeasure := -50.975864; (* decimal degrees, -50° 58' 33" 110400 *) b : IfcPlaneAngleMeasure; c : IfcCompoundPlaneAngleMeasure; s : IfcText; END_LOCAL; (* convert from float to compound *) c[1] := a; -- -50 c[2] := (a - c[1]) * 60; -- -58 c[3] := ((a - c[1]) * 60 - c[2]) * 60; -- -33 c[4] := (((a - c[1]) * 60 - c[2]) * 60 - c[3]) * 1.e6; -- -110400 (* convert from compound to float *) b := c[1] + c[2]/60. + c[3]/3600. + c[4]/3600.e6; -- -50.975864

Use in string representations

When a compound plane angle measure is formatted for display or printout, the signs of the fractional components will usually be discarded because, to a human reader, the sign of the first component alone already indicates the sense of the angle:

(* convert from compound to human-readable string *) s := FORMAT(c[1], '+##') + "000000B0" + FORMAT(ABS(c[2]), '##') + '''' + FORMAT(ABS(c[3]), '##') + '"' + FORMAT(ABS(c[4]), '##'); -- -50° 58' 33" 110400

Another often encountered display format of latitudes and longitudes is to omit the signs and print N, S, E, W indicators instead, for example, 50°58'33"S. When stored as IfcCompoundPlaneAngleMeasure however, a compound plane angle measure is always signed, with same sign of all components.

" 4321;IfcContextDependentMeasure;"

Definition from ISO/CD 10303-41:1992: Is the value of a physical quantity as defined by an application context.

Type: REAL

NOTE Corresponding ISO 10303 name: context_dependent_measure, please refer to ISO/IS 10303-41 for the final definition of the formal standard.

HISTORY New type in IFC Release 1.5.1.

" 4322;IfcCountMeasure;"

Definition from ISO/CD 10303-41:1992: A count measure is the value of a count.

Type: NUMBER

NOTE Corresponding ISO 10303 name: count_measure, please refer to ISO/IS 10303-41 for the final definition of the formal standard.

HISTORY New type in IFC Release 1.5.1.

" 4323;IfcDescriptiveMeasure;"

Definition from ISO/CD 10303-41:1992: A descriptive measure is a human interpretable definition of a quantifiable value.

Type: STRING

NOTE Corresponding ISO 10303 name:descriptive_measure, please refer to ISO/IS 10303-41 for the final definition of the formal standard.

HISTORY New type in IFC Release 1.5.1.

" 4324;IfcDynamicViscosityMeasure;"

IfcDynamicViscosityMeasure is a measure of the viscous resistance of a medium.

Usually measured in Pascal second (Pa s).

Type: REAL

HISTORY New type in IFC Release 2.0.

" 4325;IfcElectricCurrentMeasure;"

Definition from ISO/CD 10303-41:1992: The value for the movement of electrically charged particles.

Usually measured in Ampere (A).

Type: REAL

NOTE Corresponding ISO 10303 name: electric_current_measure, please refer to ISO/IS 10303-41 for the final definition of the formal standard.

HISTORY New type in IFC Release 1.5.1.

" 4326;IfcElectricVoltageMeasure;"

IfcElectricVoltageMeasure is a measure of electromotive force.

Usually measured in Volts (V, W/A).

Type: REAL

HISTORY New type in IFC Release 2.0.

" 4327;IfcEnergyMeasure;"

IfcEnergyMeasure is a measure of energy required or used.

Usually measured in Joules, (J, Nm).

Type: REAL

HISTORY New type in IFC Release 2.0.

" 4328;IfcFrequencyMeasure;"

IfcFrequencyMeasure is a measure of the number of times that an item vibrates in unit time.

Usually measured in cycles/s or Herz (Hz).

Type: REAL

HISTORY New type in IFC Release 2.0.

" 4329;IfcHeatFluxDensityMeasure;"

IfcHeatFluxDensityMeasure is a measure of the density of heat flux within a body.

Usually measured in W/m2 (J/s m2).

Type: REAL

HISTORY New type in IFC Release 2.0.

" 4330;IfcInteger;"

IfcInteger is a defined type of simple data type Integer. It is required since a select type (IfcSimpleValue) cannot include directly simple types in its select list.

In principle, the domain of IfcInteger (being an Integer) is all integer numbers. Here the number of bits used for the IfcInteger representation is unconstrained, but in practice it is implementation specific.

Type: INTEGER

HISTORY New type in IFC Release 1.5.1.

" 4331;IfcIntegerCountRateMeasure;"

IfcIntegerCountRateMeasure is a measure of the integer number of units flowing per unit time.

EXAMPLE: This measure may be used for measuring integer units per second or per hour. For example, it may be used to measure the number of books per hour passing along a part of a mechanical book handling system, the number of people per hour travelling along a moving walkway or the number of vehicles per hour travelling along a section of road.

Type: INTEGER

HISTORY New type in IFC Release 2.0.

" 4332;IfcKinematicViscosityMeasure;"

IfcKinematicViscosityMeasure is a measure of the viscous resistance of a medium to a moving body.

Usually measured in m2/s.

Type: REAL

HISTORY New type in IFC Release 2.0.

" 4333;IfcLengthMeasure;"

Definition from ISO/CD 10303-41:1992: A length measure is the value of a distance.

Usually measured in millimeters (mm).

Type: REAL

NOTE Corresponding ISO 10303 name: length_measure, please refer to ISO/IS 10303-41 for the final definition of the formal standard.

HISTORY New type in IFC Release 1.5.1.

" 4334;IfcLinearVelocityMeasure;"

IfcLinearVelocityMeasure is a measure of the velocity of a body measured in terms of distance moved per unit time.

Usually measured in m/s.

Type: REAL

HISTORY New type in IFC Release 2.0.

" 4335;IfcLuminousIntensityMeasure;"

Definition from ISO/CD 10303-41:1992: A luminous intensity measure is the value for the brightness of a body.

Usually measured in candela (cd).

Type: REAL

NOTE Corresponding ISO 10303 name: luminous_intensity_measure, please refer to ISO/IS 10303-41 for the final definition of the formal standard.

HISTORY New type in IFC Release 1.5.1.

" 4336;IfcMassDensityMeasure;"

IfcMassDensityMeasure is a measure of the density of a medium.

Usually measured in kg/m3.

Type: REAL

HISTORY New type in IFC Release 2.0.

" 4337;IfcMassFlowRateMeasure;"

IfcMassFlowRateMeasure is a measure of the mass of a medium flowing per unit time.

Usually measured in kg/s.

Type: REAL

HISTORY New type in IFC Release 2.0.

" 4338;IfcMassMeasure;"

Definition from ISO/CD 10303-41:1992: A mass measure is the value of the amount of matter that a body contains.

Usually measured in kilograms (kg) or grams (g).

Type: REAL

NOTE Corresponding ISO 10303 name: mass_measure, please refer to ISO/IS 10303-41 for the final definition of the formal standard.

HISTORY New type in IFC Release 1.5.1.

" 4339;IfcMonetaryMeasure;"

A monetary measure is the value of an amount of money without regard to its currency.

Type: REAL

HISTORY New type in IFC Release 2.0.

" 4340;IfcNumericMeasure;"

Definition from ISO/CD 10303-41:1992: A numeric measure is the numeric value of a physical quantity.

Type: NUMBER

NOTE Corresponding ISO 10303 name: numeric_measure, please refer to ISO/IS 10303-41 for the final definition of the formal standard.

HISTORY New type in IFC Release 1.5.1.

" 4341;IfcParameterValue;"

Definition from ISO/CD 10303-41:1992: A parameter value is the value which specifies the amount of a parameter in some parameter space.

Type: REAL

NOTE Corresponding STEP name: parameter_value, please refer to ISO/IS 10303-41 for the final definition of the formal standard.

HISTORY New type in IFC Release 1.5.1.

" 4342;IfcPlaneAngleMeasure;"

Definition from ISO/CD 10303-41:1992: A plane angle measure is the value of an angle in a plane.

Usually measured in radian (rad, m/m = 1), but also grads may be used. The grad unit may be declared as a conversion based unit based on radian unit.

NOTE IfcPlaneAngleMeasure is used where angles need to be described to an accuracy of less than one degree and expressed as decimal parts of an angle. It is widely used for angular measurement except for situations where accuracy needs to be defined using arc measurement; for which purpose the IfcCompoundPlaneAngleMeasure is provided.

Type: REAL

NOTE Corresponding ISO 10303 name: plane_angle_measure, please refer to ISO/IS 10303-41 for the final definition of the formal standard.

HISTORY New type in IFC Release 1.5.1.

" 4343;IfcPositiveLengthMeasure;"

Definition from ISO/CD 10303-41:1992: A positive length measure is a length measure that is greater than zero.

Type: IfcLengthMeasure

NOTE Corresponding ISO 10303 name: positive_length_measure, please refer to ISO/IS 10303-41 for the final definition of the formal standard.

HISTORY New type in IFC Release 1.5.1.

" 4345;IfcPositivePlaneAngleMeasure;"

Definition from ISO/CD 10303-41:1992: Positive plane angle measure is a plane angle measure that is greater than zero.

Type: IfcPlaneAngleMeasure

NOTE Corresponding STEP name: positive_plane_angle_measure, please refer to ISO/IS 10303-41 for the final definition of the formal standard.

HISTORY New type in IFC Release 1.5.1.

" 4347;IfcPositiveRatioMeasure;"

Definition from ISO/CD 10303-41:1992: A positive ratio measure is a ratio measure that is greater than zero.

Type: IfcRatioMeasure

NOTE Corresponding ISO 10303 name: positive_ratio_measure, please refer to ISO/IS 10303-41 for the final definition of the formal standard.

HISTORY New type in IFC Release 1.5.1.

" 4349;IfcRatioMeasure;"

Definition from ISO/CD 10303-41:1992: A ratio measure is the value of the relation between two physical quantities that are of the same kind.

NOTE: Input given in percent is to be divided by 100% when stored as an IfcRatioMeasure. For example, 25% becomes 0.25.

Type: REAL

NOTE Corresponding STEP name: ratio_measure, please refer to ISO/IS 10303-41 for the final definition of the formal standard.

HISTORY New type in IFC Release 1.5.1.

" 4350;IfcPowerMeasure;"

IfcPowerMeasure is a measure of power required or used.

Usually measured in Watts (W, J/s).

Type: REAL

HISTORY New type in IFC Release 2.0.

" 4351;IfcPressureMeasure;"

IfcPressureMeasure is a measure of the quantity of a medium acting on a unit area.

Usually measured in Pascals (Pa, N/m2).

Type: REAL

HISTORY New type in IFC Release 2.0.

" 4352;IfcReal;"

IfcReal is a defined type of simple data type REAL. It is required since a select type (IfcSimpleValue), cannot directly include simple types in its select list.

In principle, the domain of IfcReal (being a Real) is all rational, irrational and scientific real numbers. Here the precision is unconstrained, but in practice it is implementation specific.

Type: REAL

HISTORY: New type in IFC Release 1.5.1.

" 4353;IfcSolidAngleMeasure;"

Definition from ISO/CD 10303-41:1992: A solid angle measure is the value of an angle in a solid.

Usually measured in Steradians, (sr, m2/m2).

Type: REAL

NOTE Corresponding ISO 10303 name: solid_angle_measure, please refer to ISO/IS 10303-41 for the final definition of the formal standard.

HISTORY New type in IFC Release 1.5.1.

" 4354;IfcIdentifier;"

Definition from ISO/CD 10303-41:1992: An identifier is an alphanumeric string which allows an individual thing to be identified. It may not provide natural-language meaning.

Type: STRING of up to 255 characters

NOTE Corresponding STEP name: identifier, please refer to ISO/IS 10303-41 for the final definition of the formal standard.

HISTORY New type in IFC Release 2x.
IFC 2x4 CHANGE: Previously recommended size restriction of 255 characters is now mandatory.

As a merely machine-readable string for identification purposes, an identifier is usually machine-generated and locale-independent (in contrast to human-readable labels, IfcLabel).

Per ISO 10303-11, the set of characters that may appear in STRINGs is defined in ISO 10646. The encoding of characters in case of file-based exchange is defined in ISO 10303-21 (STEP physical files) and ISO 10303-28 (XML files). Among else, these specifications define the encoding of 8-bit characters from ISO 8859-1...-16 and of 2-byte Unicode characters.

Note that while IfcIdentifier is restricted to 255 characters, the size in exchange files after encoding may be considerably larger than 255 octets, depending on the particular encoding and on the contents of the identifier.

" 4355;IfcThermalAdmittanceMeasure;"

IfcThermalAdmittanceMeasure is the measure of the ability of a surface to smooth out temperature variations.

Usually measured in Watt / m2 Kelvin.

Type: REAL

HISTORY New type in IFC Release 2.0.

" 4356;IfcThermalResistanceMeasure;"

IfcThermalResistanceMeasure is a measure of the resistance offered by a body to the flow of energy.

Usually measured in m2 Kelvin/Watt.

HISTORY New type in IFC Release 2.0.

" 4357;IfcThermalTransmittanceMeasure;"

IfcThermalTransmittanceMeasure is a measure of the rate at which energy is transmitted through a body.

Usually measured in Watts/m2 Kelvin.

Type: REAL

HISTORY New type in IFC Release 2.0.

" 4358;IfcThermodynamicTemperatureMeasure;"

Definition from ISO/CD 10303-41:1992: A thermodynamic temperature measure is the value for the degree of heat of a body.

Usually measured in degrees Kelvin (K).

Type: REAL

NOTE Corresponding ISO 10303 name: thermodynamic_temperature_measure, please refer to ISO/IS 10303-41 for the final definition of the formal standard.

HISTORY New type in IFC Release 1.5.1.

" 4359;IfcTimeMeasure;"

Definition from ISO/CD 10303-41:1992: A time measure is the value of the duration of periods.

Measured in seconds (s) or days (d) or other units of time.

Type: REAL

NOTE Corresponding ISO 10303 name: time_measure, please refer to ISO/IS 10303-41 for the final definition of the formal standard.

HISTORY New type in IFC Release 1.5.1.

" 4360;IfcTimeStamp;"

IfcTimeStamp is an indication of date and time by measuring the number of seconds which have elapsed since the beginning of the year 1970.

Type: INTEGER

HISTORY New type in IFC Release 1.5.1.

" 4361;IfcVolumeMeasure;"

Definition from ISO/CD 10303-41:1992: A volume measure is the value of the solid content of a body.

Usually measured in cubic metre (m3).

Type: REAL

NOTE Corresponding ISO 10303 name: volume_measure, please refer to ISO/IS 10303-41 for the final definition of the formal standard.

HISTORY New type in IFC Release 1.5.1.

" 4362;IfcVolumetricFlowRateMeasure;"

IfcVolumetricFlowRateMeasure is a measure of the volume of a medium flowing per unit time.

Usually measured in m3/s.

Type: REAL

HISTORY New type in IFC Release 2.0.

" 4387;IfcLabel;"

Definition from ISO/CD 10303-41:1992: A label is the term by which something may be referred to. It is a string which represents the human-interpretable name of something and shall have a natural-language meaning.

Type: STRING of up to 255 characters

NOTE Corresponding STEP name: label, please refer to ISO/IS 10303-41 for the final definition of the formal standard.

HISTORY New type in IFC Release 2x.
IFC 2x4 CHANGE: Previously recommended size restriction of 255 characters is now mandatory.

As a human-readable string for naming purposes, a label is usually human-specified and locale-dependent (in contrast to purely machine-readable identifiers, IfcIdentifier).

Note that while IfcLabel is restricted to 255 characters, the size in exchange files after encoding may be considerably larger than 255 octets, depending on the particular encoding and on the contents of the label.

" 4426;IfcNormalisedRatioMeasure;"

IfcNormalisedRatioMeasure is a dimensionless measure to express ratio values ranging from 0.0 to 1.0.

Type: REAL

HISTORY New type in IFC Release 2x.

" 4428;IfcComplexNumber;"

IfcComplexNumber is a representation of a complex number expressed as an array with two elements. The first element (index 1) denotes the real component which is the numerical component of a complex number whose square roots can be calculated explicitly. The second element (index 2) denotes the imaginary component which is the numerical component of a complex number whose square roots cannot be determined other than through the provision of the square of the imaginary number j where j^2 = -1. Note that the imaginary component may be referred to as i in certain references.

Type: ARRAY [1:2] OF REAL

HISTORY New type in IFC Release 2x2.

" 4430;IfcNonNegativeLengthMeasure;"

A non-negative length measure is a length measure that is greater than or equal to zero.

Type: IfcLengthMeasure

HISTORY New type in IFC Release 2x4.

" 4444;IfcText;"

Definition from ISO/CD 10303-41:1992: A text is an alphanumeric string of characters which is intended to be read and understood by a human being. It is for information purposes only.

Type: STRING

NOTE Corresponding STEP name: text, please refer to ISO/IS 10303-41 for the final definition of the formal standard.

HISTORY New type in IFC Release 2x.

Note that while IfcText is not formally restricted in length, the size of a string in ISO 10303-21:2002 conforming exchange files must not exceed 32767 octets after encoding and escaping.

" 4445;IfcLogical;"

IfcLogicalIfcSimpleValue) cannot directly include simple types in its select list). Logical datatype can have values TRUE, FALSE or UNKNOWN.

Type: LOGICAL

HISTORY New type in IFC Release 2x.

" 4516;IfcThermalConductivityMeasure;"

IfcThermalConductivityMeasure is a measure of thermal conductivity.

Usually measured in Watt / m Kelvin.

Type: REAL

HISTORY New type in IFC Release 2x.

" 4517;IfcMolecularWeightMeasure;"

IfcMolecularWeightMeasure is a measure of molecular weight of material (typically gas).

Usually measured in g/mole.

Type: REAL

HISTORY New type in IFC Release 2x.

" 4518;IfcVaporPermeabilityMeasure;"

IfcVaporPermeabilityMeasure is a measure of vapor permeability.

Usually measured in kg / s m Pascal.

Type: REAL

HISTORY New type in IFC Release 2x.

" 4519;IfcMoistureDiffusivityMeasure;"

IfcMoistureDiffusivityMeasure is a measure of moisture diffusivity.

Usually measured in m3/s.

Type: REAL

HISTORY New type in IFC Release 2x.

" 4520;IfcIsothermalMoistureCapacityMeasure;"

IfcIsothermalMoistureCapacityMeasure is a measure of isothermal moisture capacity.

Usually measured in m3/kg.

Type: REAL

HISTORY New type in IFC Release 2x.

" 4521;IfcSpecificHeatCapacityMeasure;"

IfcSpecificHeatCapacityMeasure defines the specific heat of material: The heat energy absorbed per temperature unit.

Usually measured in J / kg Kelvin.

Type: REAL

HISTORY New type in IFC Release 2x.

" 4522;IfcMagneticFluxDensityMeasure;"

IfcMagneticFluxDensityMeasure is a measure of the magnetic flux density.

Usually measured in Tesla (T, Weber/m2 = V s/m2).

Type: REAL

HISTORY New type in IFC Release 2x.

" 4523;IfcMagneticFluxMeasure;"

IfcMagneticFluxMeasure is a measure of the magnetic flux.

Usually measured in Weber (Wb, V s).

Type: REAL

HISTORY New type in IFC Release 2x.

" 4524;IfcLuminousFluxMeasure;"

IfcLuminousFluxMeasure is a measure of the luminous flux.

Usually measured in Lumen (lm, Candela Steradian).

Type: REAL

HISTORY New type in IFC Release 2x.

" 4525;IfcForceMeasure;"

IfcForceMeasure is a measure of the force.

Usually measured in Newton (N, kg m/s2).

Type: REAL

HISTORY New type in IFC Release 2x.

" 4526;IfcInductanceMeasure;"

IfcInductanceMeasure is a measure of the inductance.

Usually measure in Henry (H, Weber/A = V s/A).

Type: REAL

HISTORY New type in IFC Release 2x.

" 4527;IfcIlluminanceMeasure;"

IfcIlluminanceMeasure is a measure of the illuminance.

Usually measured in Lux (lx, Lumen/m2 = Candela Steradian/m2).

Type: REAL

HISTORY New type in IFC Release 2x.

" 4528;IfcElectricResistanceMeasure;"

IfcElectricResistanceMeasure is a measure of the electric resistance.

Usually measured in Ohm (V/A).

Type: REAL

HISTORY New type in IFC Release 2x.

" 4529;IfcElectricConductanceMeasure;"

IfcElectricConductanceMeasure is a measure of the electric conductance.

Usually measured in Siemens (S, 1/Ohm = A/V).

Type: REAL

HISTORY New type in IFC Release 2x.

" 4530;IfcElectricChargeMeasure;"

IfcElectricChargeMeasure is a measure of the electric charge.

Usually measured in Coulomb (C, A s).

Type: REAL

HISTORY New type in IFC Release 2x.

" 4531;IfcDoseEquivalentMeasure;"

IfcDoseEquivalentMeasure is a measure of the radioactive dose equivalent.

Usually measured in Sievert (Sv, J/kg).

Type: REAL

HISTORY New type in IFC Release 2x.

" 4532;IfcElectricCapacitanceMeasure;"

IfcElectricCapacitanceMeasure is a measure of the electric capacitance.

Usually measured in Farad (F, C/V = A s/V).

Type: REAL

HISTORY New type in IFC Release 2x.

" 4533;IfcAbsorbedDoseMeasure;"

IfcAbsorbedDoseMeasure is a measure of the absorbed radioactivity dose.

Usually measured in Gray (Gy, J/kg).

Type: REAL

HISTORY New type in IFC Release 2x.

" 4534;IfcRadioActivityMeasure;"

IfcRadioActivityMeasure is a measure of activity of radionuclide.

Usually measured in Becquerel (Bq, 1/s).

Type: REAL

HISTORY New type in IFC Release 2x.

" 4535;IfcRotationalFrequencyMeasure;"

IfcRotationalFrequencyMeasure is a measure of the number of cycles that an item revolves in unit time.

Usually measured in cycles/s.

Type: REAL

HISTORY New type in IFC Release 2x.

" 4536;IfcTorqueMeasure;"

IfcTorqueMeasure is a measure of the torque or moment of a couple.

Usually measured in N m.

Type: REAL

HISTORY New type in IFC Release 2x.

" 4537;IfcAccelerationMeasure;"

IfcAccelerationMeasure is a measure of acceleration.

Usually measured in m/s2.

Type: REAL

HISTORY New type in IFC Release 2x.

" 4538;IfcLinearForceMeasure;"

IfcLinearForceMeasure is a measure of linear force.

Usually measured in N/m.

Type: REAL

HISTORY New type in IFC Release 2x.

" 4539;IfcLinearStiffnessMeasure;"

IfcLinearStiffnessMeasureA measure of linear stiffness.

Usually measured in N/m.

Type: REAL

HISTORY New type in IFC Release 2x.

" 4540;IfcModulusOfSubgradeReactionMeasure;"

IfcModulusOfSubgradeReactionMeasure is a geotechnical measure describing interaction between foundation structures and the soil. May also be known as bedding measure.

Usually measured in N/m3.

Type: REAL

HISTORY New type in IFC Release 2x.

Figure 290 illustrates elastic support of a planar member.

Figure 290 — Modulus of subgrade reaction measure

" 4541;IfcModulusOfElasticityMeasure;"

IfcModulusOfElasticityMeasure is a measure of modulus of elasticity.

Usually measured in N/m2.

Type: REAL

HISTORY New type in IFC Release 2x.

" 4542;IfcMomentOfInertiaMeasure;"

IfcMomentOfInertiaMeasure is a measure of moment of inertia.

Usually measured in m4.

Type: REAL

HISTORY New type in IFC Release 2x.

" 4543;IfcPlanarForceMeasure;"

IfcPlanarForceMeasure is a measure of force on an area.

Usually measured in N/m2.

Type: REAL

HISTORY New type in IFC Release 2x.

" 4544;IfcRotationalStiffnessMeasure;"

IfcRotationalStiffnessMeasure is a measure of rotational stiffness.

Usually measured in Nm/rad.

Type: REAL

HISTORY New type in IFC Release 2x.

" 4545;IfcShearModulusMeasure;"

IfcShearModulusMeasure is a measure of shear modulus.

Usually measured in N/m2.

Type: REAL

HISTORY New type in IFC Release 2x.

" 4546;IfcLinearMomentMeasure;"

IfcLinearMomentMeasure is a measure of linear moment.

Usually measured in Nm/m.

Type: REAL

HISTORY New type in IFC Release 2x.

" 4547;IfcLuminousIntensityDistributionMeasure;"

IfcLuminousIntensityDistributionMeasure is a measure of the luminous intensity of a light source that changes according to the direction of the ray. It is normally based on some standardized distribution light distribution curves.

Usually measured in Candela/Lumen (cd/lm) or (cd/klm).

Type: REAL

HISTORY New type in IFC2x2.

" 4548;IfcCurvatureMeasure;"

IfcCurvatureMeasure is a measure for curvature, which is defined as the change of slope per length. This is typically a computed value in structural analysis. It is usually measured in rad/m.

Type: REAL

HISTORY New type in IFC2x2.

" 4549;IfcMassPerLengthMeasure;"

IfcMassPerLengthMeasure is a measure for mass per length. For example for rolled steel profiles the weight of an imaginary beam is usually expressed by kg/m length for cost calculation and structural analysis purposes.

Type: REAL

HISTORY New type in IFC2x2.

" 4550;IfcModulusOfLinearSubgradeReactionMeasure;"

IfcModulusOfLinearSubgradeReactionMeasure is a measure for modulus of linear subgrade reaction, which expresses the elastic bedding of a linear structural element per length, such as for a beam. It is typically measured in N/m^2.

Type: REAL

HISTORY New type in IFC Release 2x2.

" 4551;IfcModulusOfRotationalSubgradeReactionMeasure;"

IfcModulusOfRotationalSubgradeReactionMeasure is a measure for modulus of rotational subgrade reaction, which expresses the rotational elastic bedding of a linear structural element per length, such as for a beam. It is typically measured in Nm/(m*rad).

Type: REAL

HISTORY New type in IFC2x2.

" 4552;IfcRotationalMassMeasure;"

The rotational mass measure denotes the inertia of a body with respect to angular acceleration.

It is usually measured in kg*m^2.

Type: REAL

HISTORY New type in IFC2x2.

" 4553;IfcSectionalAreaIntegralMeasure;"

The sectional area integral measure is typically used in torsional analysis. It is usually measured in m^5.

Type: REAL

HISTORY New type in IFC2x2.

" 4554;IfcSectionModulusMeasure;"

IfcSectionModulusMeasure is a measure for the resistance of a cross section against bending or torsional moment. It is usually measured in m^3.

Type: REAL

HISTORY New type in IFC Release 2x2.

" 4555;IfcTemperatureGradientMeasure;"

The temperature gradient measures the difference of a temperature per lenght, as for instance used in an external wall or its layers. It is usually measured in K/m.

Type: REAL

HISTORY New type in IFC2x2.

" 4556;IfcThermalExpansionCoefficientMeasure;"

IfcThermalExpansionCoeffientMeasure is a measure of the thermal expansion coefficient of a material, which expresses its elongation (as a ratio) per temperature difference. It is usually measured in 1/K. A positive elongation per (positive) rise of temperature is expressed by a positive value.

Type: REAL

HISTORY New type in IFC2x2.

" 4557;IfcWarpingConstantMeasure;"

IfcWarpingConstantMeasure is a measure for the warping constant or warping resistance of a cross section under torsional loading. It is usually measured in m^6.

Type: REAL

HISTORY New type in IFC2x2.

" 4558;IfcWarpingMomentMeasure;"

The warping moment measure is a measure for the warping moment, which occurs in warping torsional analysis. It is usually measured in kN*m^2.

Type: REAL

HISTORY New type in IFC2x2.

" 4559;IfcSoundPowerMeasure;"

A sound power measure is a measure of total radiated noise with units of decibels with a reference value of picowatts.

Type: REAL

HISTORY New type in IFC2x2.

" 4560;IfcSoundPressureMeasure;"

A sound pressure measure is a measure of the pressure fluctuations superimposed over the ambient pressure level with units of decibels with a reference value of micropascals.

Type: REAL

HISTORY New type in IFC2x2.

" 4561;IfcHeatingValueMeasure;"

IfcHeatingValueMeasure defines the amount of energy released (usually in MJ/kg) when a fuel is burned.

HISTORY: This is new type in IFC2x2.

" 4563;IfcPHMeasure;"

IfcPHMeasure is a measure of the molar hydrogen ion concentration in a liquid (usually defined as the measure of acidity) in a range from 0 to 14.

HISTORY: New type in IFC 2x2.

" 4565;IfcIonConcentrationMeasure;"

IfcIonConcentrationMeasure is a measure of particular ion concentration in a liquid, given in mg/L.

HISTORY: New type in IFC2x2.

" 4566;IfcTemperatureRateOfChangeMeasure;"

The temperature rate of change measures the difference of a temperature per time (positive: rise, negative: fall), as for instance used with heat sensors. It is for example measured in K/s (Kelvin per second).

Type: REAL

HISTORY New type in IFC2x4.

" 4777;IfcTextAlignment;"

Definition from CSS1 (W3C Recommendation): This property describes how text is aligned within the element. The actual justification algorithm used is user agent and human language dependent. If 'justify' is not supported, the user agent will supply a replacement. Typically, this will be 'left' for western languages. Values are:

left
right
center
justify

NOTE Corresponding CSS1 definition is text-align.

HISTORY New type in IFC2x3.

" 4779;IfcTextDecoration;"

Definition from CSS1 (W3C Recommendation): This property describes decorations that are added to the text of an element. A value of 'blink' causes the text to blink.. Values are:

none
underline
overline
line-through
blink

User agents must recognize the keyword 'blink', but are not required to support the blink effect.

NOTE Corresponding CSS1 definition is text-decoration.

HISTORY New type in IFC2x3.

" 4781;IfcTextTransformation;"

Definition from CSS1 (W3C Recommendation): This property describes how the cases of characters are handled. Values are:

capitalize: uppercases the first character of each word
uppercase: uppercases all letters of the element
lowercase: lowercases all letters of the element
none

NOTE Corresponding CSS1 definition is text-transform.

HISTORY New type in IFC2x3.

" 4865;IfcSpecularExponent;"

The IfcSpecularExponent defines the datatype for exponent determining the sharpness of the 'reflection'. reflection is made sharper with large values of the exponent, such as 10.0. Small values, such as 1.0, decrease the specular fall-off.

IfcSpecularExponent is of type REAL.

NOTE: The datatype relates to the definition of specular_exponent in ISO 10303-46 entity surface_style_reflectance_ambient_diffuse_specular.

HISTORY: New type in IFC2x2.

" 4866;IfcSpecularRoughness;"

The IfcSpecularRoughness defines the datatype for the reflection resulting from the roughness of a surface through the height of surface impurities where the specular highlight is made sharper with small values for the roughness, such as 0.1.

Applies to ""glass"", ""metal"", ""mirror"" and ""plastic"" reflection models. Larger values, close to 1.0 decrease the specular fall-off.

IfcSpecularRoughness is of type REAL. It is constraint to values between (and including) 0 and 1.

NOTE: The datatype relates to the definition of ""shiness"" in VRML97, which is the reciprocate value to the specular roughness.

HISTORY: New type in Release IFC2x2.

" 4973;IfcBoxAlignment;"

The box alignment specifies the alignment of the text box relative to its position. The following string values shall be used:

top-left
top-middle
top-right
middle-left
center
middle-right
bottom-left
bottom-middle
bottom-right

NOTE The top-left is the default value.

Figure 298 illustrates alignment values.

Figure 298 — Box alignment values

Figure 299 illustrates use of alignment values together with the placement and planar extent.

Figure 299 — Box alignment examples

HISTORY New type in IFC2x2 Addendum2.

IFC2x3 CHANGE The IfcBoxAlignment has been added.

" 5293;IfcGloballyUniqueId;"

An IfcGloballyUniqueId holds an encoded string identifier that is used to uniquely identify an IFC object. An IfcGloballyUniqueId is a Globally Unique Identifier (GUID) which is an auto-generated 128-bit number. Since this identifier is required for all IFC object instances, it is desirable to compress it to reduce overhead. The encoding of the base 64 character set is shown below:

1 2 3 4 5 6
0123456789012345678901234567890123456789012345678901234567890123
""0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz_$"";

The resulting string is a fixed 22 character length string to be exchanged within the IFC exchange file structure.

Refer to the BuildingSMART website (www.buildingsmart-tech.org) for more information and sample encoding algorithms.

HISTORY New type in IFC R1.5.1.

" 5463;IfcDimensionCount;"

Definition from ISO/CD 10303-42:1992: A dimension count is a positive integer used to define the coordinate space dimensionality.

The IfcDimensionCount is restricted to have the dimensionality of either 1, 2, or 3 - the WR1 had been added as an addition to the ISO 10303:42 entity dimension_count. In contrary to the ISO 10303:42 constraint, that all geometric representation items within a geometric representation context are forced to have the same dimension count, the IFC geometry allows mixed dimensions, particularly when defining the boundary of planar surfaces.

NOTE Corresponding ISO 10303 type: dimension_count, please refer to ISO/IS 10303-42:1994, p. 14 for the final definition of the formal standard.

HISTORY New Type in IFC Release 1.5