场景对浏览器的自适应

window.addEventListener("resize", onResize, false);

function onResize() {
  camera.aspect = window.innerWidth / window.innerHeight; //更新屏幕的长宽比
  camera.updateProjectionMatrix();
  renderer.setSize(window.innerWidth, window.innerHeight); //改变渲染器的尺寸
}