WIP allow partial mesh geometry editing to preserve style assignments. See #1222.

src/ifcblenderexport/blenderbim/bim/import_ifc.py

@@ -256,6 +256,7 @@ class MaterialCreator:
 
     def create_new_single(self, material):
         self.materials[material.Name] = obj = bpy.data.materials.new(material.Name)
+        obj.BIMMaterialProperties.ifc_definition_id = int(material.id())
         self.ifc_importer.add_element_attributes(material, obj.BIMMaterialProperties)
         for pset in getattr(material, "HasProperties", ()):
             self.ifc_importer.add_pset(pset, obj.BIMMaterialProperties)
@@ -286,6 +287,7 @@ class MaterialCreator:
         for style in styles:
             if not style.is_a("IfcSurfaceStyle"):
                 continue
+            material.BIMMaterialProperties.ifc_style_id = int(style.id())
             external_style = None
             for surface_style in style.Styles:
                 if surface_style.is_a("IfcSurfaceStyleShading"):

src/ifcblenderexport/blenderbim/bim/module/geometry/add_shape_representation.py

@@ -18,7 +18,6 @@ class Usecase:
         self.ifc_vertices = []
         for key, value in settings.items():
             self.settings[key] = value
-        self.context_of_items = None
 
     def execute(self):
         if self.settings["unit_scale"] is None:

src/ifcblenderexport/blenderbim/bim/module/geometry/assign_styles.py

@@ -0,0 +1,22 @@
+class Usecase:
+    def __init__(self, file, settings=None):
+        self.file = file
+        self.settings = {"shape_representation": None, "styles": []}
+        for key, value in settings.items():
+            self.settings[key] = value
+
+    def execute(self):
+        self.results = []
+        for element in self.file.traverse(self.settings["shape_representation"]):
+            if not element.is_a("IfcShapeRepresentation"):
+                continue
+            for item in element.Items:
+                if not item.is_a("IfcGeometricRepresentationItem"):
+                    continue
+                style = self.settings["styles"].pop(0)
+                self.results.append(
+                    self.file.createIfcStyledItem(
+                        item, [style], style.Name
+                    )
+                )
+        return self.results

src/ifcblenderexport/blenderbim/bim/operator.py

@@ -4347,10 +4347,11 @@ class BakeParametricGeometry(bpy.types.Operator):
     bl_label = "Bake Parametric Geometry"
 
     def execute(self, context):
-        import blenderbim.bim.module.geometry.add_shape_representation as add_shape_representation
         obj = bpy.context.active_object
         self.file = ifc.IfcStore.get_file()
         element = self.file.by_id(obj.data.BIMMeshProperties.ifc_definition_id)
+
+        import blenderbim.bim.module.geometry.add_shape_representation as add_shape_representation
         usecase = add_shape_representation.Usecase(self.file, {
             "context": element.ContextOfItems,
             "geometry": obj.data,
@@ -4360,10 +4361,17 @@ class BakeParametricGeometry(bpy.types.Operator):
         if not result:
             print("Failed to write shape representation")
             return {"FINISHED"}
+
+        import blenderbim.bim.module.geometry.assign_styles as assign_styles
+        usecase = assign_styles.Usecase(self.file, {
+            "shape_representation": result,
+            "styles": [self.file.by_id(s.material.BIMMaterialProperties.ifc_style_id) for s in obj.material_slots if s.material]
+        })
+        usecase.execute()
+
         for inverse in self.file.get_inverse(element):
             ifcopenshell.util.element.replace_attribute(inverse, element, result)
         obj.data.BIMMeshProperties.ifc_definition_id = int(result.id())
-        print(result)
         return {"FINISHED"}
 
 

src/ifcblenderexport/blenderbim/bim/prop.py

@@ -1525,6 +1525,9 @@ class BIMMaterialProperties(PropertyGroup):
     psets: CollectionProperty(name="Psets", type=PsetQto)
     attributes: CollectionProperty(name="Attributes", type=Attribute)
     applicable_attributes: EnumProperty(items=getApplicableMaterialAttributes, name="Attribute Names")
+    ifc_definition_id: IntProperty(name="IFC Definition ID")
+    # In Blender, a material object can map to an IFC material, IFC surface style, or both
+    ifc_style_id: IntProperty(name="IFC Style ID")
 
 
 class SweptSolid(PropertyGroup):