Minor fixes to new presentation layer features by Krande

src/ifcblenderexport/blenderbim/bim/import_ifc.py

@@ -480,6 +480,7 @@ class IfcImporter:
         self.add_project_to_scene()
         self.profile_code("Add project to scene")
         self.get_presentation_layers()
+        self.profile_code("Get presentation layers")
         if self.ifc_import_settings.should_clean_mesh and len(self.file.by_type("IfcElement")) < 10000:
             self.clean_mesh()
             self.profile_code("Mesh cleaning")
@@ -1328,23 +1329,31 @@ class IfcImporter:
         ].hide_viewport = True
 
     def get_presentation_layers(self):
-        for f in self.file.by_type("IfcPresentationLayerAssignment"):
-            pl = bpy.context.scene.BIMProperties.presentation_layers.add()
-            pl.name = f.Name
-            pl.description = f.Description
-            pl.identifier = f.Identifier
-            if f.is_a() == "IfcPresentationLayerWithStyle":
-                pl.layer_on = f.LayerOn if f.LayerOn is not None else True
-                pl.layer_frozen = f.LayerFrozen if f.LayerFrozen is not None else False
-                pl.layer_blocked = f.LayerBlocked if f.LayerBlocked is not None else False
+        for assignment in self.file.by_type("IfcPresentationLayerAssignment"):
+            layer = bpy.context.scene.BIMProperties.presentation_layers.add()
+            layer.name = assignment.Name
+            layer.description = assignment.Description or ""
+            layer.identifier = assignment.Identifier or ""
+            if assignment.is_a() == "IfcPresentationLayerWithStyle":
+                layer.layer_on = assignment.LayerOn if assignment.LayerOn is not None else True
+                layer.layer_frozen = assignment.LayerFrozen if assignment.LayerFrozen is not None else False
+                layer.layer_blocked = assignment.LayerBlocked if assignment.LayerBlocked is not None else False
 
-            for item in f.AssignedItems:
-                guid = item.OfProductRepresentation[0].ShapeOfProduct[0].GlobalId
+            for item in assignment.AssignedItems:
+                # TODO: This is a simplified and incorrect implementation of assigning presentation layers to objects
+                # themselves, and will need to be rewritten in the future. See bug #1109. This code also does not
+                # consider mapped representations.
+                guids = []
+                if not hasattr(item, "OfProductRepresentation"):
+                    continue  # TODO: At the moment we ignore representation items
+                for product_representation in item.OfProductRepresentation:
+                    for product in product_representation.ShapeOfProduct:
+                        guids.append(product.GlobalId)
                 for obj in bpy.context.selectable_objects:
                     global_id = obj.BIMObjectProperties.attributes.get("GlobalId")
-                    if global_id and global_id.string_value == guid:
-                        obj.BIMObjectProperties.presentation_layer.name = pl.name
-                        obj.hide_set(not pl.layer_on)
+                    if global_id and global_id.string_value in guids:
+                        obj.BIMObjectProperties.presentation_layer.name = layer.name
+                        obj.hide_set(not layer.layer_on)
 
     def clean_mesh(self):
         obj = None