Fix #3120. You can now assign styles to individual items.

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

@@ -1053,7 +1053,6 @@ class AssignStyleToSelected(bpy.types.Operator, tool.Ifc.Operator):
     bl_label = "Assign Style To Selected"
     bl_description = "Assign style to the selected objects' active representations"
     bl_options = {"REGISTER", "UNDO"}
-
     style_id: bpy.props.IntProperty(name="Style ID")
 
     @classmethod
@@ -1069,19 +1068,30 @@ class AssignStyleToSelected(bpy.types.Operator, tool.Ifc.Operator):
             return {"CANCELLED"}
         ifc_file = tool.Ifc.get()
         style = ifc_file.by_id(self.style_id)
+        material = tool.Ifc.get_object(style)
 
+        has_items = False
         representations: dict[ifcopenshell.entity_instance, bpy.types.Object] = {}
         for obj in context.selected_objects:
-            representation = tool.Geometry.get_active_representation(obj)
-            if not representation:
-                continue
-            representation = tool.Geometry.resolve_mapped_representation(representation)
-            representations.setdefault(representation, obj)
+            if tool.Geometry.is_representation_item(obj):
+                has_items = True
+                item = tool.Ifc.get().by_id(obj.data.BIMMeshProperties.ifc_definition_id)
+                tool.Style.assign_style_to_representation_item(item, style)
+                obj.data.materials.clear()
+                obj.data.materials.append(material)
+            elif representation := tool.Geometry.get_active_representation(obj):
+                representation = tool.Geometry.resolve_mapped_representation(representation)
+                representations.setdefault(representation, obj)
 
-        if not representations:
+        if not has_items and not representations:
             self.report({"INFO"}, "No IFC objects with representations selected.")
             return {"FINISHED"}
 
+        if has_items:
+            tool.Geometry.reload_representation(context.scene.BIMGeometryProperties.representation_obj)
+            bpy.ops.bim.disable_editing_representation_items()
+            bpy.ops.bim.enable_editing_representation_items()
+
         for representation in representations:
             ifcopenshell.api.style.assign_representation_styles(
                 ifc_file,

src/bonsai/bonsai/tool/geometry.py

@@ -1513,6 +1513,10 @@ class Geometry(bonsai.core.tool.Geometry):
             verts = geometry.verts
         tool.Loader.convert_geometry_to_mesh(geometry, obj.data, verts=verts)
 
+        if ios_materials := list(obj.data["ios_materials"]):
+            material = tool.Ifc.get_object(tool.Ifc.get().by_id(ios_materials[0]))
+            obj.data.materials.append(material)
+
         obj.matrix_world = rep_obj.matrix_world.copy()
 
         if (is_swept_area := item.is_a("IfcSweptAreaSolid")) or item.is_a("IfcConic"):