olyfill = new WebXRPolyfill();
      }

      // If requested, don't display the frame rate info.
      let hideStats = QueryArgs.getBool('hideStats', false);

      // XR globals.
      let xrButton = null;
      let xrImmersiveRefSpace = null;
      let inlineViewerHelper = null;

      // WebGL scene globals.
      let gl = null;
      let renderer = null;
      let scene = new Scene();
      if (hideStats) {
        scene.enableStats(false);
      }
      scene.addNode(new Gltf2Node({url: 'media/gltf/cu