// 创建球体
moon = new THREE.SphereGeometry(MOON_RADIUS)
const phong = new THREE.MeshPhongMaterial({ color: 0xffffff })
const mesh = new THREE.Mesh(moon, phong)
mesh.castShadow = true
mesh.position.set(-12, 0, 0)
scene.add(mesh)
animate = () => {
const elapsed = clock.getElapsedTime()
renderer.render(scene, camera)
// 设置球体转动
moon.position.set(Math.sin(elapsed) * 5, 0, Math.cos(elapsed) * 5)
}