Quiero exportar el modelo de AssimpLoader a GLTFExporter que utilicé

 const loader = new AssimpLoader(); loader.load(url, function ( result ) { const object = result.object; object.position.y = - 100; object.rotation.x = Math.PI * 2; group.add(object) animation = result.animation; export_animates = [result.animation] console.log(result.animation) } ); function ani() { if ( animation ) animation.setTime( performance.now() / 1000 ); } const gltfExporter = new GLTFExporter(); const options = { trs: document.getElementById( 'option_trs' ).checked, onlyVisible: document.getElementById( 'option_visible' ).checked, truncateDrawRange: document.getElementById( 'option_drawrange' ).checked, binary: document.getElementById( 'option_binary' ).checked, animations: export_animates, maxTextureSize: Number( document.getElementById( 'option_maxsize' ).value ) || Infinity // To prevent NaN value }; gltfExporter.parse( input, function ( result ) { if ( result instanceof ArrayBuffer ) { console.log(result) } else { const output = JSON.stringify( result, null, 2 ); // generate object output console.log(output) //saveString( output, 'scene.gltf' ); } }, options );

pero me sale error

AssimpLoader.js: 302 Uncaught (en promesa) TypeError: No se pueden leer las propiedades de undefined (leyendo 'nombre')

Cuando intento exportar de FBX a GLTF.
Eso es trabajo.
¿Qué estoy haciendo mal?