fix(exporter): handle collections and missing attributes to prevent e…

…rrors (#255)

Make sure that Collections and Bones don't cause errors since they don't have `i3d_attributes`

addon/i3dio/exporter.py

@@ -194,7 +194,7 @@ def _export(i3d: I3D, objects: List[BlenderObject], sort_alphabetical: bool = Tr
 def _add_object_to_i3d(i3d: I3D, obj: BlenderObject, parent: SceneGraphNode = None,
                        export_candidates: list = None) -> None:
     # Check if object should be excluded from export (including its children)
-    if obj.i3d_attributes.exclude_from_export:
+    if hasattr(obj, 'i3d_attributes') and obj.i3d_attributes.exclude_from_export:
         logger.info(f"Skipping [{obj.name}] and its children. Excluded from export.")
         return
 

addon/i3dio/node_classes/node.py

@@ -214,7 +214,7 @@ def populate_xml_element(self):
         self._write_properties()
         self._write_user_attributes()
         self._add_transform_to_xml_element(self._transform_for_conversion)
-        if not isinstance(self.blender_object, bpy.types.Collection):
+        if hasattr(self.blender_object, 'i3d_reference') and self.blender_object.type == 'EMPTY':
             self._add_reference_file()
 
     def add_child(self, node: SceneGraphNode):