Fix #5544. Assign / add of objects with styles are now supported.

src/bonsai/bonsai/bim/module/root/operator.py

@@ -210,12 +210,7 @@ class AssignClass(bpy.types.Operator, tool.Ifc.Operator):
                 ifc_representation_class=self.ifc_representation_class,
             )
             if self.should_add_representation and obj.data and len(obj.data.vertices):
-                builder = ifcopenshell.util.shape_builder.ShapeBuilder(tool.Ifc.get())
-                unit_scale = ifcopenshell.util.unit.calculate_unit_scale(tool.Ifc.get())
-                verts = [v.co / unit_scale for v in obj.data.vertices]
-                faces = [p.vertices[:] for p in obj.data.polygons]
-                item = builder.mesh(verts, faces)
-                representation = builder.get_representation(ifc_context, [item])
+                representation = tool.Geometry.export_mesh_to_tessellation(obj, ifc_context)
                 ifcopenshell.api.geometry.assign_representation(tool.Ifc.get(), element, representation)
                 bonsai.core.geometry.switch_representation(
                     tool.Ifc,
@@ -373,16 +368,7 @@ class AddElement(bpy.types.Operator, tool.Ifc.Operator):
             pass
         elif representation_template == "OBJ" and props.representation_obj:
             obj.matrix_world = props.representation_obj.matrix_world
-            builder = ifcopenshell.util.shape_builder.ShapeBuilder(tool.Ifc.get())
-            unit_scale = ifcopenshell.util.unit.calculate_unit_scale(tool.Ifc.get())
-            items = []
-            meshes = tool.Geometry.split_by_loose_parts(props.representation_obj)
-            for mesh in meshes:
-                verts = [v.co / unit_scale for v in mesh.vertices]
-                faces = [p.vertices[:] for p in mesh.polygons]
-                items.append(builder.mesh(verts, faces))
-                bpy.data.meshes.remove(mesh)
-            representation = builder.get_representation(ifc_context, items)
+            representation = tool.Geometry.export_mesh_to_tessellation(props.representation_obj, ifc_context)
             ifcopenshell.api.geometry.assign_representation(tool.Ifc.get(), element, representation)
             bonsai.core.geometry.switch_representation(
                 tool.Ifc,

src/bonsai/bonsai/tool/geometry.py

@@ -27,6 +27,7 @@ import multiprocessing
 import ifcopenshell
 import ifcopenshell.api
 import ifcopenshell.api.grid
+import ifcopenshell.api.style
 import ifcopenshell.geom
 import ifcopenshell.guid
 import ifcopenshell.util.element
@@ -1600,3 +1601,34 @@ class Geometry(bonsai.core.tool.Geometry):
     @classmethod
     def reload_representation_item_ids(cls, representation: ifcopenshell.entity_instance, data: bpy.types.Mesh) -> None:
         data["ios_item_ids"] = [i["item"].id() for i in ifcopenshell.util.representation.resolve_items(representation)]
+
+    @classmethod
+    def export_mesh_to_tessellation(cls, obj: bpy.types.Object, ifc_context) -> ifcopenshell.entity_instance:
+        builder = ifcopenshell.util.shape_builder.ShapeBuilder(tool.Ifc.get())
+        unit_scale = ifcopenshell.util.unit.calculate_unit_scale(tool.Ifc.get())
+        items = []
+        meshes = cls.split_by_loose_parts(obj)
+        for mesh in meshes:
+            verts = [v.co / unit_scale for v in mesh.vertices]
+            faces = [p.vertices[:] for p in mesh.polygons]
+            item = builder.mesh(verts, faces)
+            items.append(item)
+            material_index = mesh.polygons[0].material_index
+            if materials := list(mesh.materials):
+                material = materials[material_index]
+                if not (style := tool.Style.get_style(material)):
+                    style = ifcopenshell.api.run("style.add_style", tool.Ifc.get(), name=material.name)
+                    if material.use_nodes:
+                        ifc_class = "IfcSurfaceStyleRendering"
+                        attributes = tool.Style.get_surface_rendering_attributes(material)
+                    else:
+                        ifc_class = "IfcSurfaceStyleShading"
+                        attributes = tool.Style.get_surface_shading_attributes(material)
+                    ifcopenshell.api.style.add_surface_style(
+                        tool.Ifc.get(), style=style, ifc_class=ifc_class, attributes=attributes
+                    )
+                    tool.Ifc.link(style, material)
+                    material.use_fake_user = True
+                ifcopenshell.api.style.assign_item_style(tool.Ifc.get(), item=item, style=style)
+            bpy.data.meshes.remove(mesh)
+        return builder.get_representation(ifc_context, items)

src/bonsai/bonsai/tool/style.py

@@ -594,55 +594,9 @@ class Style(bonsai.core.tool.Style):
 
     @classmethod
     def assign_style_to_representation_item(
-        cls, representation_item: ifcopenshell.entity_instance, style: Optional[ifcopenshell.entity_instance] = None
+        cls, item: ifcopenshell.entity_instance, style: Optional[ifcopenshell.entity_instance] = None
     ) -> None:
-        """Assign specified style to a representation item and unassign all previously assigned styles."""
-        ifc_file = representation_item.file
-        if not (styled_item := next(iter(representation_item.StyledByItem), None)):
-            if style is None:
-                return
-            if ifc_file.schema == "IFC2X3":
-                style = ifc_file.create_entity("IfcPresentationStyleAssignment", (style,))
-            ifc_file.create_entity("IfcStyledItem", representation_item, (style,))
-            return
-
-        styled_item_styles = styled_item.Styles
-        if style and styled_item_styles == (style,):
-            return
-
-        if ifc_file.schema == "IFC4X3":
-            if style is None:
-                ifc_file.remove(styled_item)
-                return
-            styled_item.Styles = (style,)
-            return
-
-        # < IFC4X3
-        # Can't just remove a styled item or assign a style
-        # since we need to remove/change the possible style assignments.
-        assignment = None
-        for style_ in styled_item_styles:
-            if not style_.is_a("IfcPresentationStyleAssignment"):
-                continue
-            # Remove second assignment.
-            if style is None or assignment:
-                ifc_file.remove(style_)
-            else:
-                assignment = style_
-                if assignment.Styles != (style,):
-                    assignment.Styles = (style,)
-
-        if style is None:
-            ifc_file.remove(styled_item)
-            return
-
-        if assignment:
-            if styled_item_styles == (assignment,):
-                return
-            styled_item.Styles = (assignment,)
-            return
-
-        styled_item.Styles = (style,)
+        return ifcopenshell.api.style.assign_item_style(tool.Ifc.get(), item=item, style=style)
 
     @classmethod
     def get_representation_item_style(