) {
          let pose = frame.getViewerPose(refSpace);
          this.scene.updateInputSources(frame, refSpace);
          if (!pose || !this.renderer) { return; }

          let gl = this.renderer.gl;
          let session = frame.session;
          // Assumed to be a XRWebGLLayer for now.
          let layer = session.renderState.baseLayer;

          // Rather than binding the layer's framebuffer like usual, bind a framebuffer using a
          // multisampled renderbuffer as the color attachment.
     