We now support separating IFC meshes.

src/blenderbim/blenderbim/bim/import_ifc.py

@@ -1939,7 +1939,7 @@ class IfcImporter:
     def setup_arrays(self):
         for element in self.file.by_type("IfcElement"):
             pset_data = ifcopenshell.util.element.get_pset(element, "BBIM_Array")
-            if pset_data or not pset_data.get("Data", None):  # skip array children
+            if not pset_data or not pset_data.get("Data", None):  # skip array children
                 continue
             for i in range(len(json.loads(pset_data["Data"]))):
                 tool.Blender.Modifier.Array.set_children_lock_state(element, i, True)

src/blenderbim/blenderbim/bim/module/geometry/__init__.py

@@ -32,6 +32,7 @@ classes = (
     operator.OverrideDuplicateMoveLinkedMacro,
     operator.OverrideDuplicateMoveMacro,
     operator.OverrideJoin,
+    operator.OverrideMeshSeparate,
     operator.OverrideModeSetEdit,
     operator.OverrideModeSetObject,
     operator.OverrideOriginSet,
@@ -53,6 +54,7 @@ classes = (
     ui.BIM_PT_mesh,
     ui.BIM_PT_workarounds,
     ui.BIM_MT_object_set_origin,
+    ui.BIM_MT_separate,
 )
 
 
@@ -73,6 +75,7 @@ def register():
     bpy.types.VIEW3D_MT_object.append(ui.object_menu)
     bpy.types.OUTLINER_MT_object.append(ui.outliner_menu)
     bpy.types.VIEW3D_MT_object_context_menu.append(ui.object_menu)
+    bpy.types.VIEW3D_MT_edit_mesh.append(ui.edit_mesh_menu)
     wm = bpy.context.window_manager
     if wm.keyconfigs.addon:
         km = wm.keyconfigs.addon.keymaps.new(name="Object Mode", space_type="EMPTY")
@@ -116,6 +119,7 @@ def unregister():
     bpy.types.OBJECT_PT_transform.remove(ui.BIM_PT_transform)
     bpy.types.OUTLINER_MT_object.remove(ui.outliner_menu)
     bpy.types.VIEW3D_MT_object_context_menu.remove(ui.outliner_menu)
+    bpy.types.VIEW3D_MT_edit_mesh.remove(ui.edit_mesh_menu)
     del bpy.types.Scene.BIMGeometryProperties
     del bpy.types.Object.BIMGeometryProperties
     wm = bpy.context.window_manager

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

@@ -57,6 +57,39 @@ class EditObjectPlacement(bpy.types.Operator, Operator):
             core.edit_object_placement(tool.Ifc, tool.Geometry, tool.Surveyor, obj=obj)
 
 
+class OverrideMeshSeparate(bpy.types.Operator, Operator):
+    bl_idname = "bim.override_mesh_separate"
+    bl_label = "IFC Mesh Separate"
+    bl_options = {"REGISTER", "UNDO"}
+    obj: bpy.props.StringProperty()
+    type: bpy.props.StringProperty()
+
+    def _execute(self, context):
+        obj = context.active_object
+
+        # You cannot separate meshes if the representation is mapped.
+        relating_type = tool.Root.get_element_type(tool.Ifc.get_entity(obj))
+        if relating_type and tool.Root.does_type_have_representations(relating_type):
+            # We toggle edit mode to ensure that once representations are
+            # unmapped, our Blender mesh only has a single user.
+            tool.Blender.toggle_edit_mode(context)
+            bpy.ops.bim.unassign_type(related_object=obj.name)
+            tool.Blender.toggle_edit_mode(context)
+
+        selected_objects = context.selected_objects
+        bpy.ops.mesh.separate(type=self.type)
+        bpy.ops.object.mode_set(mode="OBJECT", toggle=False)
+        new_objs = [obj]
+        for new_obj in context.selected_objects:
+            if new_obj == obj:
+                continue
+            # This is not very efficient, it needlessly copies the representations first.
+            blenderbim.core.root.copy_class(tool.Ifc, tool.Collector, tool.Geometry, tool.Root, obj=new_obj)
+            new_objs.append(new_obj)
+        for new_obj in new_objs:
+            bpy.ops.bim.update_representation(obj=new_obj.name)
+
+
 class OverrideOriginSet(bpy.types.Operator, Operator):
     bl_idname = "bim.override_origin_set"
     bl_label = "IFC Origin Set"

src/blenderbim/blenderbim/bim/module/geometry/ui.py

@@ -32,6 +32,21 @@ def object_menu(self, context):
     self.layout.menu("BIM_MT_object_set_origin", icon="PLUGIN")
 
 
+def edit_mesh_menu(self, context):
+    self.layout.separator()
+    self.layout.menu("BIM_MT_separate", icon="PLUGIN")
+
+
+class BIM_MT_separate(Menu):
+    bl_idname = "BIM_MT_separate"
+    bl_label = "IFC Separate"
+
+    def draw(self, context):
+        self.layout.operator("bim.override_mesh_separate", icon="PLUGIN", text="IFC Selection").type = "SELECTED"
+        self.layout.operator("bim.override_mesh_separate", icon="PLUGIN", text="IFC By Material").type = "MATERIAL"
+        self.layout.operator("bim.override_mesh_separate", icon="PLUGIN", text="IFC By Loose Parts").type = "LOOSE"
+
+
 class BIM_MT_object_set_origin(Menu):
     bl_idname = "BIM_MT_object_set_origin"
     bl_label = "IFC Set Origin"