$DOCS_URL/tutorials/io/runtime_file_loading_and_saving.html Returns a [Dictionary] that maps skeleton bone indices to the indices of glTF nodes. This property is unused during import, and only set during export. In a glTF file, a bone is a node, so Godot converts skeleton bones to glTF nodes. Sets a [Dictionary] that maps skeleton bone indices to the indices of glTF nodes. This property is unused during import, and only set during export. In a glTF file, a bone is a node, so Godot converts skeleton bones to glTF nodes.