ionBox.matrix, interactionBox.matrix, time/1500);
      leftInteractionBox.matrix = interactionBox.matrix;
      rightInteractionBox.matrix = interactionBox.matrix;
    }

    // Called every time the XRSession requests that a new frame be drawn.
    function onXRFrame(t, frame) {
      let session = frame.session;

      // Per-frame scene setup. Nothing WebXR specific here.
      scene.startFrame();

      // Inform the session that we're ready for the next frame.
      session.requestAnimationFrame(onXRF