fix(shape node): Fix merge group and skinned mesh export

Fix a regression introduced in fbec170, which renamed the `ShapeNode` constructor parameter `mesh_object` to `shape_object` without updating the super class constructor call for merge groups and skinned meshes.

addon/i3dio/node_classes/merge_group.py

@@ -23,7 +23,7 @@ def __init__(self, id_: int, merge_group_object: [bpy.types.Object, None], i3d:
                  parent: [SceneGraphNode or None] = None):
         self.merge_group_name = i3d.merge_groups[merge_group_object.i3d_merge_group_index].name
         self.skin_bind_ids = f"{id_:d} "
-        super().__init__(id_=id_, mesh_object=merge_group_object, i3d=i3d, parent=parent)
+        super().__init__(id_=id_, shape_object=merge_group_object, i3d=i3d, parent=parent)
 
     # Override default shape behaviour to use the merge group mesh name instead of the blender objects name
     def add_shape(self):

addon/i3dio/node_classes/node.py

@@ -154,7 +154,9 @@ def _write_user_attributes(self):
             pass
 
     def _add_reference_file(self):
-        if self.blender_object.i3d_reference_path == "" or not self.blender_object.i3d_reference_path.endswith('.i3d'):
+        if 'i3d_reference_path' not in self.blender_object.keys():
+            return
+        elif self.blender_object.i3d_reference_path == "" or not self.blender_object.i3d_reference_path.endswith('.i3d'):
             return
         self.logger.debug(f"Adding reference file")
         file_id = self.i3d.add_file_reference(self.blender_object.i3d_reference_path)

addon/i3dio/node_classes/skinned_mesh.py

@@ -99,7 +99,7 @@ def __init__(self, id_: int, skinned_mesh_object: bpy.types.Object, i3d: I3D,
             if modifier.type == 'ARMATURE':
                 self.armature_nodes.append(i3d.add_armature(modifier.object))
         self.bone_mapping = ChainMap(*[armature.bone_mapping for armature in self.armature_nodes])
-        super().__init__(id_=id_, mesh_object=skinned_mesh_object, i3d=i3d, parent=parent)
+        super().__init__(id_=id_, shape_object=skinned_mesh_object, i3d=i3d, parent=parent)
 
     def add_shape(self):
         # Use a ChainMap to easily combine multiple bone mappings and get around any problems with multiple bones