生成圆弧顶点，HTML代码在线实时编辑、实时预览

            
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            <!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <style>
    body { margin: 0; }
    canvas { display: block; }
  </style>
</head>
<body>
  <script src="./main.js"></script>
</body>
</html>

            
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            import * as THREE from 'three';
import { OrbitControls } from 'three/examples/jsm/controls/OrbitControls.js';
// 引入gltf模型加载库GLTFLoader.js
import { GLTFLoader } from 'three/addons/loaders/GLTFLoader.js';

const R = 100; //圆弧半径
const N = 50; //分段数量
const sp = 2 * Math.PI / N;//两个相邻点间隔弧度
const arr = [];
// 批量生成圆弧上的顶点数据
for (let i = 0; i < N; i++) {
    const angle =  sp * i;//当前点弧度
    // 以坐标原点为中心，在XOY平面上生成圆弧上的顶点数据
    const x = R * Math.cos(angle);
    const y = R * Math.sin(angle);
    arr.push(x, y, 0);
}
//类型数组创建顶点数据
const vertices = new Float32Array(arr);

const scene = new THREE.Scene();
const camera = new THREE.PerspectiveCamera(75, window.innerWidth / window.innerHeight, 1, 3000);
const renderer = new THREE.WebGLRenderer({ antialias: true });
const attribue = new THREE.BufferAttribute(vertices, 3); // 创建属性缓冲区对象
const geometry = new THREE.BufferGeometry();
const material = new THREE.LineBasicMaterial({
    color: 0xff0000
});
const line = new THREE.LineLoop(geometry, material);
const axesHelper = new THREE.AxesHelper(150);
const ambientLight = new THREE.AmbientLight(0x404040, 2); // 添加环境光
const directionalLight = new THREE.DirectionalLight(0xffffff, 1); // 添加方向光
const pointLight = new THREE.PointLight(0xff0000, 2, 10); // 添加点光源，红色的点光源 

const controls = new OrbitControls(camera, renderer.domElement); // 添加轨道控制器


// 设置几何体attributes属性的位置属性
geometry.attributes.position = attribue;
// console.log(geometry.attributes.position)

directionalLight.position.set(5, 5, 5).normalize();
directionalLight.castShadow = true; // 方向光投射阴影

pointLight.position.set(2, 2, 2);
pointLight.castShadow = true; // 点光源投射阴影

controls.enableDamping = true; // 启用阻尼效果
controls.dampingFactor = 0.05; // 阻尼系数

scene.add(line);
scene.add(axesHelper);
scene.add(directionalLight);
scene.add(ambientLight);
scene.add(pointLight);

// 设置相机位置
camera.position.set(300, 100, 600);
camera.lookAt(line.position);

renderer.setSize(window.innerWidth, window.innerHeight);
renderer.shadowMap.enabled = true; // 启用阴影
renderer.setClearColor(0x444444, 1);

document.body.appendChild(renderer.domElement);


// 动画循环
const animate = () => {
  requestAnimationFrame(animate);
  // 渲染场景
  renderer.render(scene, camera);
};

// 启动动画
animate();

// 窗口大小调整时更新相机和渲染器
window.addEventListener('resize', () => {
  camera.aspect = window.innerWidth / window.innerHeight;
  camera.updateProjectionMatrix();
  renderer.setSize(window.innerWidth, window.innerHeight);
});

            
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            {
  "dependencies": {
    "three": "0.173.0"
  }
}