Fix #3973. Fix #4787. Clarify that you cannot have aggregated physical elements where the whole has a body representation.

src/blenderbim/blenderbim/bim/module/aggregate/operator.py

@@ -55,21 +55,24 @@ class BIM_OT_aggregate_assign_object(bpy.types.Operator, Operator):
         if not relating_obj:
             return
 
-        for obj in bpy.context.selected_objects + [bpy.context.active_object]:
+        for obj in tool.Blender.get_selected_objects():
             if obj == relating_obj:
                 continue
             element = tool.Ifc.get_entity(obj)
             if not element:
                 continue
-            result = core.assign_object(
+            try:
-                tool.Ifc,
+                core.assign_object(
-                tool.Aggregate,
+                    tool.Ifc,
-                tool.Collector,
+                    tool.Aggregate,
-                relating_obj=relating_obj,
+                    tool.Collector,
-                related_obj=obj,
+                    relating_obj=relating_obj,
-            )
+                    related_obj=obj,
-            if not result:
+                )
-                self.report({"ERROR"}, f" Cannot aggregate {obj.name} to {relating_obj.name}")
+            except core.IncompatibleAggregateError:
+                self.report({"ERROR"}, f"Cannot aggregate {obj.name} to {relating_obj.name}")
+            except core.AggregateRepresentationError:
+                self.report({"ERROR"}, f"Cannot aggregate to {relating_obj.name} with a body representation")
 
 
 class BIM_OT_aggregate_unassign_object(bpy.types.Operator, Operator):

src/blenderbim/blenderbim/core/aggregate.py

@@ -41,9 +41,12 @@ def assign_object(
     related_obj: Optional[bpy.types.Object] = None,
 ) -> Union[ifcopenshell.entity_instance, None]:
     if not aggregator.can_aggregate(relating_obj, related_obj):
-        return
+        raise IncompatibleAggregateError
+    relating_object = ifc.get_entity(relating_obj)
+    if aggregator.has_physical_body_representation(relating_object):
+        raise AggregateRepresentationError
     rel = ifc.run(
-        "aggregate.assign_object", products=[ifc.get_entity(related_obj)], relating_object=ifc.get_entity(relating_obj)
+        "aggregate.assign_object", products=[ifc.get_entity(related_obj)], relating_object=relating_object
     )
     collector.assign(relating_obj)
     collector.assign(related_obj)
@@ -84,3 +87,11 @@ def add_part_to_object(
     part_obj = blender.create_ifc_object(ifc_class=part_class, name=part_name)
     assign_object(ifc, aggregator, collector, relating_obj=obj, related_obj=part_obj)
     blender.set_active_object(obj)
+
+
+class IncompatibleAggregateError(Exception):
+    pass
+
+
+class AggregateRepresentationError(Exception):
+    pass

src/blenderbim/blenderbim/tool/aggregate.py

@@ -30,9 +30,9 @@ class Aggregate(blenderbim.core.tool.Aggregate):
         related_object = tool.Ifc.get_entity(related_obj)
         if not relating_object or not related_object:
             return False
-        if (relating_object.is_a("IfcElement") or relating_object.is_a("IfcElementType")) and related_object.is_a("IfcElement"):
+        if (relating_object.is_a("IfcElement") or relating_object.is_a("IfcElementType")) and related_object.is_a(
-            if relating_obj.data:  # See #3973
+            "IfcElement"
-                return False
+        ):
             return True
         if tool.Ifc.get_schema() == "IFC2X3":
             if relating_object.is_a("IfcSpatialStructureElement") and related_object.is_a("IfcSpatialStructureElement"):
@@ -46,6 +46,13 @@ class Aggregate(blenderbim.core.tool.Aggregate):
                 return True
         return False
 
+    @classmethod
+    def has_physical_body_representation(cls, element: ifcopenshell.entity_instance) -> bool:
+        if element.is_a("IfcElement") or element.is_a("IfcElementType"):  # See 3973
+            if ifcopenshell.util.representation.get_representation(element, "Model", "Body"):
+                return True
+        return False
+
     @classmethod
     def disable_editing(cls, obj: bpy.types.Object) -> None:
         obj.BIMObjectAggregateProperties.is_editing = False

src/blenderbim/test/tool/test_aggregate.py

@@ -18,6 +18,9 @@
 
 import bpy
 import ifcopenshell
+import ifcopenshell.api.root
+import ifcopenshell.api.unit
+import ifcopenshell.api.context
 import blenderbim.core.tool
 import blenderbim.tool as tool
 from test.bim.bootstrap import NewFile
@@ -92,16 +95,24 @@ class TestCanAggregate(NewFile):
         subelement_obj = bpy.data.objects.new("Object", None)
         assert subject.can_aggregate(element_obj, subelement_obj) is False
 
-    def test_aggregates_with_meshes_are_invalid(self):
+
+class TestHasPhysicalBodyRepresentation(NewFile):
+    def test_run(self):
         ifc = ifcopenshell.file()
-        tool.Ifc.set(ifc)
         element = ifc.createIfcElementAssembly()
-        element_obj = bpy.data.objects.new("Object", bpy.data.meshes.new("Mesh"))
+        assert subject.has_physical_body_representation(element) is False
-        tool.Ifc.link(element, element_obj)
+        ifcopenshell.api.root.create_entity(ifc, ifc_class="IfcProject")
-        subelement = ifc.createIfcBeam()
+        ifcopenshell.api.unit.assign_unit(ifc)
-        subelement_obj = bpy.data.objects.new("Object", None)
+        context = ifcopenshell.api.context.add_context(ifc, context_type="Model")
-        tool.Ifc.link(subelement, subelement_obj)
+        body = ifcopenshell.api.context.add_context(
-        assert subject.can_aggregate(element_obj, subelement_obj) is False
+            ifc, context_type="Model", context_identifier="Body", target_view="MODEL_VIEW", parent=context
+        )
+        builder = ifcopenshell.util.shape_builder.ShapeBuilder(ifc)
+        origin = builder.create_axis2_placement_3d()
+        block = ifc.createIfcCsgSolid(ifc.createIfcBlock(origin, 200, 200, 200))
+        rep = builder.get_representation(context=body, items=[block])
+        ifcopenshell.api.geometry.assign_representation(ifc, product=element, representation=rep)
+        assert subject.has_physical_body_representation(element) is True
 
 
 class TestDisableEditing(NewFile):