access layer assignments from inverse attribute instead of going through representation inverses

src/blenderbim/blenderbim/bim/module/layer/data.py

@@ -47,7 +47,6 @@ class LayersData:
             return []
         results = []
         shape = tool.Ifc.get().by_id(data.BIMMeshProperties.ifc_definition_id)
-        for inverse in tool.Ifc.get().get_inverse(shape):
-            if inverse.is_a("IfcPresentationLayerAssignment"):
-                results.append(inverse.id())
+        for inverse in shape.LayerAssignments:
+            results.append(inverse.id())
         return results

src/ifcopenshell-python/ifcopenshell/api/geometry/remove_representation.py

@@ -51,9 +51,8 @@ class Usecase:
                 [textures.add(t) for t in getattr(subelement, "HasTextures", []) or []]
                 [colours.add(t) for t in getattr(subelement, "HasColours", []) or []]
             elif subelement.is_a("IfcRepresentation"):
-                for inverse in self.file.get_inverse(subelement):
-                    if inverse.is_a("IfcPresentationLayerAssignment"):
-                        presentation_layer_assignments.add(inverse)
+                for layer in subelement.LayerAssignments:
+                    presentation_layer_assignments.add(layer)
 
         ifcopenshell.util.element.remove_deep2(
             self.file,