如何使用三个js将对象放置在球面上

// 创建场景
var scene = new THREE.Scene();

// 创建相机
var camera = new THREE.PerspectiveCamera(75, window.innerWidth/window.innerHeight, 0.1, 1000);
camera.position.z = 5;

// 创建渲染器
var renderer = new THREE.WebGLRenderer();
renderer.setSize(window.innerWidth, window.innerHeight);
document.body.appendChild(renderer.domElement);

// 创建球体模型
var geometry = new THREE.SphereGeometry(2, 32, 32);
var material = new THREE.MeshBasicMaterial({ color: 0xffff00 });
var sphere = new THREE.Mesh(geometry, material);
scene.add(sphere);

// 创建对象
var objectGeometry = new THREE.BoxGeometry(0.2, 0.2, 0.2);
var objectMaterial = new THREE.MeshBasicMaterial({ color: 0x00ff00 });
var object = new THREE.Mesh(objectGeometry, objectMaterial);

// 计算对象的位置
var radius = 2;
var theta = 0.5; // 极角
var phi = 0.5; // 方位角

// 将对象放置在球面上
object.position.set(
  radius * Math.sin(theta) * Math.cos(phi),
  radius * Math.sin(theta) * Math.sin(phi),
  radius * Math.cos(theta)
);

// 将对象添加到场景中
scene.add(object);

// 渲染场景
function animate() {
  requestAnimationFrame(animate);
  object.rotation.x += 0.01;
  object.rotation.y += 0.01;
  renderer.render(scene, camera);
}
animate();