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2026-05-31 10:17:09 +07:00

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6.5 KiB
Python

# IfcOpenShell - IFC toolkit and geometry engine
# Copyright (C) 2022 Dion Moult <dion@thinkmoult.com>
#
# This file is part of IfcOpenShell.
#
# IfcOpenShell is free software: you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# IfcOpenShell is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with IfcOpenShell. If not, see <http://www.gnu.org/licenses/>.
from math import cos, sin
from typing import Optional, Union
import ifcopenshell.util.element
import ifcopenshell.util.unit
from ifcopenshell.util.data import Clipping
def add_slab_representation(
file: ifcopenshell.file,
context: ifcopenshell.entity_instance,
depth: float = 0.2,
# TODO: document remaining args.
direction_sense: str = "POSITIVE",
offset: float = 0.0,
x_angle: float = 0.0,
clippings: Optional[list[Union[Clipping, ifcopenshell.entity_instance]]] = None,
polyline: Optional[list[tuple[float, float]]] = None,
) -> ifcopenshell.entity_instance:
"""
Add a geometric representation for a slab.
:param context: The IfcGeometricRepresentationContext for the representation,
only Model/Body/MODEL_VIEW type of representations are currently supported.
:param depth: The slab depth, in meters.
:param x_angle: The slope angle along the slab's X-axis, in radians.
:param clippings: List of planes that define clipping half space solids.
Clippings can be `Clipping` objects or dictionaries of arguments for `Clipping.parse`.
:return: IfcShapeRepresentation.
Example:
.. code:: python
context = ifcopenshell.util.representation.get_context(ifc_file, "Model", "Body", "MODEL_VIEW")
clippings = [ifcopenshell.util.data.Clipping(location=(0.0, 0.0, 0.1), normal=(0.0, 0.0, 1.0),)]
representation = ifcopenshell.api.geometry.add_slab_representation(ifc_file, context, depth=0.2, clippings=clippings)
ifcopenshell.api.geometry.assign_representation(ifc_file, product=element, representation=representation)
"""
usecase = Usecase()
usecase.file = file
return usecase.execute(
context,
depth,
direction_sense,
offset,
x_angle,
clippings if clippings is not None else [],
polyline,
)
class Usecase:
file: ifcopenshell.file
def execute(
self,
context: ifcopenshell.entity_instance,
depth: float,
direction_sense: str,
offset: float,
x_angle: float,
clippings: list[Union[Clipping, ifcopenshell.entity_instance]],
polyline: Optional[list[tuple[float, float]]],
) -> ifcopenshell.entity_instance:
self.unit_scale = ifcopenshell.util.unit.calculate_unit_scale(self.file)
self.clippings = clippings
self.depth = depth
self.direction_sense = direction_sense
self.offset = offset
self.x_angle = x_angle
self.polyline = polyline
return self.file.create_entity(
"IfcShapeRepresentation",
context,
context.ContextIdentifier,
"Clipping" if self.clippings else "SweptSolid",
[self.create_item()],
)
def create_item(self) -> ifcopenshell.entity_instance:
size = self.convert_si_to_unit(1)
points = ((0.0, 0.0), (size, 0.0), (size, size), (0.0, size), (0.0, 0.0))
if self.polyline:
points = [
(self.convert_si_to_unit(p[0]), self.convert_si_to_unit(p[1] * abs(1 / cos(self.x_angle))))
for p in self.polyline
]
if self.file.schema == "IFC2X3":
curve = self.file.createIfcPolyline([self.file.createIfcCartesianPoint(p) for p in points])
else:
curve = self.file.createIfcIndexedPolyCurve(self.file.createIfcCartesianPointList2D(points))
if self.x_angle:
direction_ratios = (0.0, sin(self.x_angle), cos(self.x_angle))
else:
direction_ratios = (0.0, 0.0, 1.0)
offset_direction = direction_ratios # offset direction doesn't change if direction_sense is negative
extrusion_direction = self.file.createIfcDirection(direction_ratios)
if self.direction_sense == "NEGATIVE":
direction_ratios = tuple(-n for n in direction_ratios)
extrusion_direction = self.file.createIfcDirection(direction_ratios)
perpendicular_offset = self.convert_si_to_unit(self.offset) * abs(1 / cos(self.x_angle))
perpendicular_depth = self.convert_si_to_unit(self.depth) * abs(1 / cos(self.x_angle))
position = None
# default position for IFC2X3 where .Position is not optional
if self.file.schema == "IFC2X3" or self.offset != 0:
position_vector = (
offset_direction[0] * perpendicular_offset,
offset_direction[1] * perpendicular_offset,
offset_direction[2] * perpendicular_offset,
)
position = self.file.createIfcAxis2Placement3D(
self.file.createIfcCartesianPoint(position_vector),
self.file.createIfcDirection((0.0, 0.0, 1.0)),
self.file.createIfcDirection((1.0, 0.0, 0.0)),
)
extrusion = self.file.create_entity(
"IfcExtrudedAreaSolid",
self.file.createIfcArbitraryClosedProfileDef("AREA", None, curve),
position,
extrusion_direction,
perpendicular_depth,
)
if self.clippings:
return self.apply_clippings(extrusion)
return extrusion
def apply_clippings(self, first_operand: ifcopenshell.entity_instance) -> ifcopenshell.entity_instance:
while self.clippings:
clipping = self.clippings.pop()
if isinstance(clipping, ifcopenshell.entity_instance):
new = ifcopenshell.util.element.copy(self.file, clipping)
new.FirstOperand = first_operand
first_operand = new
else: # Clipping
first_operand = clipping.apply(self.file, first_operand, self.unit_scale)
return first_operand
def convert_si_to_unit(self, co: float) -> float:
return co / self.unit_scale