style.assign_material_style to assign style to related shape aspects

src/ifcopenshell-python/ifcopenshell/api/style/assign_material_style.py

@@ -16,6 +16,8 @@
 # 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
+
 
 class Usecase:
     def __init__(self, file, material=None, style=None, context=None, should_use_presentation_style_assignment=False):
@@ -112,6 +114,27 @@ class Usecase:
         else:
             self.create_new_definition_representation()
 
+        material_constituents_names = []
+        for inverse in self.file.get_inverse(self.settings["material"]):
+            if inverse.is_a("IfcMaterialConstituent") and inverse.Name:
+                material_constituents_names.append(inverse.Name)
+        if not material_constituents_names:
+            return
+
+        elements = ifcopenshell.util.element.get_elements_by_material(self.file, self.settings["material"])
+        shape_aspects = []
+        for element in elements:
+            shape_aspects += ifcopenshell.util.element.get_shape_aspects(element)
+
+        for shape_aspect in shape_aspects:
+            if shape_aspect.Name not in material_constituents_names:
+                continue
+
+            for rep in shape_aspect.ShapeRepresentations:
+                ifcopenshell.api.run(
+                    "style.assign_representation_styles", self.file, shape_representation=rep, styles=[self.style]
+                )
+
     def modify_existing_definition_representation(self):
         definition_representation = self.settings["material"].HasRepresentation[0]
         representation = self.get_styled_representation(definition_representation)

src/ifcopenshell-python/test/api/style/test_assign_material_style.py

@@ -0,0 +1,56 @@
+# 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 pytest
+import test.bootstrap
+import ifcopenshell
+import ifcopenshell.api
+
+
+# TODO: test assigning styles without material constituents
+class TestAssignMaterialStyle(test.bootstrap.IFC4):
+    def test_update_shape_aspect_representaitons_items_styles_if_material_is_part_of_matching_material_constituents(
+        self,
+    ):
+        element = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcWall")
+        name = "Concrete"
+        product_shape = self.file.createIfcProductDefinitionShape()
+        element.Representation = product_shape
+        context = self.file.createIfcGeometricRepresentationContext()
+
+        representation = self.file.createIfcShapeRepresentation()
+        item = self.file.createIfcExtrudedAreaSolid()
+        representation.Items = [item]
+
+        shape_aspect = self.file.createIfcShapeAspect(ShapeRepresentations=(representation,), Name=name)
+        shape_aspect.PartOfProductDefinitionShape = product_shape
+
+        style = self.file.createIfcSurfaceStyle()
+        material = ifcopenshell.api.run("material.add_material", self.file)
+        material_set = ifcopenshell.api.run(
+            "material.add_material_set", self.file, set_type="IfcMaterialConstituentSet"
+        )
+        constituent = ifcopenshell.api.run(
+            "material.add_constituent", self.file, constituent_set=material_set, material=material
+        )
+        constituent.Name = name
+        ifcopenshell.api.run("material.assign_material", self.file, product=element, material=material_set)
+
+        ifcopenshell.api.run("style.assign_material_style", self.file, material=material, style=style, context=context)
+
+        assert item.StyledByItem[0].Styles == (style,)