3d-tiles-renderer/src/three/plugins/gltf/GLTFCesiumRTCExtension.d.ts

https://github.com/AnalyticalGraphicsInc/3d-tiles/tree/master/specification

import { GLTFLoaderPlugin } from 'three/examples/jsm/loaders/GLTFLoader.js';

export class GLTFCesiumRTCExtension implements GLTFLoaderPlugin {

	name: 'CESIUM_RTC';

}