如何在three.js球体内获得一种距离的感觉？

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

// 创建球体
const radius = 5;
const widthSegments = 32;
const heightSegments = 32;
const sphereGeometry = new THREE.SphereGeometry(radius, widthSegments, heightSegments);
const sphereMaterial = new THREE.MeshBasicMaterial({ color: 0xff0000 }); // 设置球体材质
const sphere = new THREE.Mesh(sphereGeometry, sphereMaterial);

// 设置相机
const fov = 75;
const aspect = window.innerWidth / window.innerHeight;
const near = 0.1;
const far = 1000;
const camera = new THREE.PerspectiveCamera(fov, aspect, near, far);
camera.position.set(0, 0, 10); // 将相机放置在球体内部

// 创建光源
const light = new THREE.PointLight(0xffffff, 1, 100);
light.position.set(0, 0, 10);

// 添加对象到场景
scene.add(sphere);
scene.add(light);

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

// 渲染循环
function animate() {
  requestAnimationFrame(animate);
  
  // 调整相机视角
  camera.lookAt(sphere.position);
  
  renderer.render(scene, camera);
}
animate();