Slabs are now first created directly in IFC instead of reverse engineering meshes

2026-08-10 01:41:57 +00:00 · 2022-09-30 12:08:57 +10:00
parent 9fc5f72831
commit a08a78b3c9
3 changed files with 140 additions and 40 deletions
@@ -0,0 +1,89 @@
+# 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/>.
+
+import ifcopenshell.util.unit
+
+
+class Usecase:
+    def __init__(self, file, **settings):
+        self.file = file
+        self.settings = {
+            "context": None,  # IfcGeometricRepresentationContext
+            "depth": 0.2,
+            # Planes are defined as a matrix. The XY plane is the clipping boundary and +Z is removed.
+            "clippings": [],  # A list of planes that define clipping half space solids
+        }
+        for key, value in settings.items():
+            self.settings[key] = value
+
+    def execute(self):
+        self.settings["unit_scale"] = ifcopenshell.util.unit.calculate_unit_scale(self.file)
+        return self.file.createIfcShapeRepresentation(
+            self.settings["context"],
+            self.settings["context"].ContextIdentifier,
+            "Clipping" if self.settings["clippings"] else "SweptSolid",
+            [self.create_item()],
+        )
+
+    def create_item(self):
+        size = self.convert_si_to_unit(1)
+        points = (
+            (0.0, 0.0, 0.0),
+            (size, 0.0, 0.0),
+            (size, size, 0.0),
+            (0.0, size, 0.0),
+            (0.0, 0.0, 0.0),
+        )
+        if self.file.schema == "IFC2X3":
+            curve = self.file.createIfcPolyline([self.file.createIfcCartesianPoint(p) for p in points])
+        else:
+            curve = self.file.createIfcIndexedPolyCurve(self.file.createIfcCartesianPointList3D(points))
+        extrusion = self.file.createIfcExtrudedAreaSolid(
+            self.file.createIfcArbitraryClosedProfileDef("AREA", None, curve),
+            None,
+            self.file.createIfcDirection((0.0, 0.0, 1.0)),
+            self.convert_si_to_unit(self.settings["depth"]),
+        )
+        if self.settings["clippings"]:
+            return self.apply_clippings(extrusion)
+        return extrusion
+
+    def apply_clippings(self, first_operand):
+        while self.settings["clippings"]:
+            clipping = self.settings["clippings"].pop()
+            second_operand = self.file.createIfcHalfSpaceSolid(
+                self.file.createIfcPlane(
+                    self.file.createIfcAxis2Placement3D(
+                        self.file.createIfcCartesianPoint(
+                            (
+                                self.convert_si_to_unit(clipping[0][3]),
+                                self.convert_si_to_unit(clipping[1][3]),
+                                self.convert_si_to_unit(clipping[2][3]),
+                            )
+                        ),
+                        self.file.createIfcDirection((clipping[0][2], clipping[1][2], clipping[2][2])),
+                        self.file.createIfcDirection((clipping[0][0], clipping[1][0], clipping[2][0])),
+                    )
+                ),
+                False,
+            )
+            first_operand = self.file.createIfcBooleanClippingResult("DIFFERENCE", first_operand, second_operand)
+        return first_operand
+
+    def convert_si_to_unit(self, co):
+        return co / self.settings["unit_scale"]