如何在three.js中使立方体的内色可见？

// 引入three.js库
import * as THREE from 'three';

// 创建场景、相机和渲染器
const scene = new THREE.Scene();
const camera = new THREE.PerspectiveCamera(75, window.innerWidth / window.innerHeight, 0.1, 1000);
const renderer = new THREE.WebGLRenderer();
renderer.setSize(window.innerWidth, window.innerHeight);
document.body.appendChild(renderer.domElement);

// 创建立方体
const geometry = new THREE.BoxGeometry(1, 1, 1);
const material = new THREE.MeshBasicMaterial({ color: 0x00ff00, transparent: true, opacity: 0.5 });
const cube = new THREE.Mesh(geometry, material);

// 将立方体添加到场景中
scene.add(cube);

// 设置相机位置
camera.position.z = 5;

// 渲染循环
function animate() {
  requestAnimationFrame(animate);

  // 旋转立方体
  cube.rotation.x += 0.01;
  cube.rotation.y += 0.01;

  // 渲染场景
  renderer.render(scene, camera);
}
animate();