clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT);

        if (vrDisplay) {
          vrDisplay.requestAnimationFrame(onAnimationFrame);

          vrDisplay.getFrameData(frameData);

          if (vrDisplay.isPresenting) {
            gl.viewport(0, 0, webglCanvas.width * 0.5, webglCanvas.height);
            cubeSea.render(frameData.leftProjectionMatrix, frameData.leftViewMatrix, stats);

            gl.viewport(webglCanvas.width * 0.5, 0, webglCanvas.width * 0.5, webglCanvas.height);
            cubeSea.