Three.js之相机、渲染器、光源、动画、性能监测

参考资料

知识点

透视投影相机PerspectiveCamera
WebGL渲染器WebGLRenderer
辅助观察坐标系AxesHelper
漫反射网格材质MeshLambertMaterial
点光源PointLight
点光源辅助观察PointLightHelper
环境光AmbientLight
平行光DirectionalLight
平行光辅助观察DirectionalLightHelper
相机控件OrbitControls
请求动画帧window.requestAnimationFrame
canvas画布宽高度动态变化
性能监控Stats

代码实现

相机、渲染器、光

javascript 复制代码

<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>Three.js</title>
</head>
  <body>
  </body>
  <!-- 具体路径配置，你根据自己文件目录设置，我的是课件中源码形式 -->
  <script type="importmap">
    {
      "imports": {
        "three": "./js/three.module.js",
        "three/addons/": "../three.js/examples/jsm/"
      }
    }
  </script>
  <script type="module">
    import * as THREE from 'three';
    import { OrbitControls } from 'three/addons/controls/OrbitControls.js';

    const width = 800
    const height = 500

    // 场景
    const scene = new THREE.Scene();
    // 几何体
    const geometry = new THREE.BoxGeometry(100, 100, 100);
    // 材质 
    // MeshBasicMaterial：不受光
    // MeshLambertMaterial：受光
    const material = new THREE.MeshLambertMaterial({
      color:0x0000ff,
    });
    // 网格模型：物体
    const mesh = new THREE.Mesh(geometry, material);
    mesh.position.set(0, 0, 0);
    scene.add(mesh);

    // 坐标系
    const axes = new THREE.AxesHelper(200);
    scene.add(axes);

    // // 点光源
    // const pointLight = new THREE.PointLight( 0xffffff, 1.0, 0, 0);
    // pointLight.position.set(-200, 200, 200 );
    // scene.add( pointLight );

    // // 辅助点光源
    // const pointLightHelper = new THREE.PointLightHelper( pointLight, 10 );
    // scene.add( pointLightHelper );

    // 环境光
    const ambientLight = new THREE.AmbientLight( 0xffffff, 0.2);
    scene.add( ambientLight );

    // 平行光
    const directionalLight = new THREE.DirectionalLight( 0xffffff, 1, 0, 0);
    // directionalLight.position.set(100, 0, 0);
    // directionalLight.position.set(0, 100, 0);
    // directionalLight.position.set(100, 100, 100);
    directionalLight.position.set(100, 60, 50);
    directionalLight.target = mesh;
    scene.add( directionalLight );

    // 辅助平行光
    const directionalLightHelper = new THREE.DirectionalLightHelper( directionalLight, 10 );
    scene.add( directionalLightHelper );

    // 相机
    const camera = new THREE.PerspectiveCamera(75, width/height, 0.1, 1000);
    camera.position.set(200, 200, 200);
    camera.lookAt(scene.position);

    // 渲染器
    const renderer = new THREE.WebGLRenderer();
    renderer.setSize(width, height);
    renderer.render(scene, camera);
    document.body.appendChild(renderer.domElement);

    // 控制器
    const controls = new OrbitControls(camera, renderer.domElement);
    controls.addEventListener('change', () => {
      renderer.render(scene, camera);
    });
  </script>
</html>

动画

javascript 复制代码

<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>Three.js</title>
</head>
  <body>
  </body>
  <!-- 具体路径配置，你根据自己文件目录设置，我的是课件中源码形式 -->
  <script type="importmap">
    {
      "imports": {
        "three": "./js/three.module.js",
        "three/addons/": "../three.js/examples/jsm/"
      }
    }
  </script>
  <script type="module">
    import * as THREE from 'three';
    import { OrbitControls } from 'three/addons/controls/OrbitControls.js';

    const width = 800
    const height = 500

    // 场景
    const scene = new THREE.Scene();
    // 几何体
    const geometry = new THREE.BoxGeometry(100, 100, 100);
    // 材质
    const material = new THREE.MeshBasicMaterial({
      color: 0x00ff00,
      transparent: true,
      opacity: 0.5
    });
    // 网格模型：物体
    const mesh = new THREE.Mesh(geometry, material);
    mesh.position.set(0, 0, 0);
    scene.add(mesh);

    // 坐标系
    const axes = new THREE.AxesHelper(200);
    scene.add(axes);

    // 相机
    const camera = new THREE.PerspectiveCamera(75, width/height, 0.1, 1000);
    camera.position.set(200, 200, 200);
    camera.lookAt(scene.position);

    // 渲染器
    const renderer = new THREE.WebGLRenderer();
    renderer.setSize(width, height);
    renderer.render(scene, camera);
    document.body.appendChild(renderer.domElement);

    // 动画渲染
    // 跟踪时间
    var clock = new THREE.Clock();
    function render() {
      const spt = clock.getDelta() * 1000;
      console.log('🚀 ~ file: animation.html:59 ~ render ~ spt:', spt)
      requestAnimationFrame(render);
      mesh.rotation.y += 0.01;
      renderer.render(scene, camera);
    }

    render();

    // 控制器
    const controls = new OrbitControls(camera, renderer.domElement);
    controls.addEventListener('change', () => {
      // 因为动画渲染了，所以这里可以省略
      // renderer.render(scene, camera);
    });
  </script>
</html>

画布动态变化

javascript 复制代码

<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>Three.js</title>
  <style>
    body {
      margin: 0;
      overflow: hidden;
    }
  </style>
</head>
  <body>
  </body>
  <!-- 具体路径配置，你根据自己文件目录设置，我的是课件中源码形式 -->
  <script type="importmap">
    {
      "imports": {
        "three": "./js/three.module.js"
      }
    }
  </script>
  <script type="module">
    import * as THREE from 'three';

    let width = window.innerWidth;
    let height = window.innerHeight;

    // 场景
    const scene = new THREE.Scene();
    // 几何体
    const geometry = new THREE.BoxGeometry(100, 100, 100);
    // 材质
    const material = new THREE.MeshBasicMaterial({
      color: 0x00ff00,
      transparent: true,
      opacity: 0.5
    });
    // 网格模型：物体
    const mesh = new THREE.Mesh(geometry, material);
    mesh.position.set(0, 0, 0);
    scene.add(mesh);

    // 坐标系
    const axes = new THREE.AxesHelper(200);
    scene.add(axes);

    // 相机
    const camera = new THREE.PerspectiveCamera(75, width/height, 0.1, 1000);
    camera.position.set(200, 200, 200);
    camera.lookAt(scene.position);

    // 渲染器
    const renderer = new THREE.WebGLRenderer();
    renderer.setSize(width, height);
    renderer.render(scene, camera);
    document.body.appendChild(renderer.domElement);

    // 填满浏览器
    window.onresize = function () {
      width = window.innerWidth;
      height = window.innerHeight;
      renderer.setSize(width, height);
      camera.aspect = width / height;
      camera.updateProjectionMatrix();
    }
  </script>
</html>

性能监控

javascript 复制代码

<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>Three.js</title>
</head>
  <body>
  </body>
  <!-- 具体路径配置，你根据自己文件目录设置，我的是课件中源码形式 -->
  <script type="importmap">
    {
      "imports": {
        "three": "./js/three.module.js",
        "three/addons/": "../three.js/examples/jsm/"
      }
    }
  </script>
  <script type="module">
    import * as THREE from 'three';
    import { OrbitControls } from 'three/addons/controls/OrbitControls.js';
    import Stats from 'three/addons/libs/stats.module.js';

    const width = 800
    const height = 500

    // 场景
    const scene = new THREE.Scene();
    // 几何体
    const geometry = new THREE.BoxGeometry(100, 100, 100);
    // 材质
    const material = new THREE.MeshBasicMaterial({
      color: 0x00ff00,
      transparent: true,
      opacity: 0.5
    });
    // 网格模型：物体
    const mesh = new THREE.Mesh(geometry, material);
    mesh.position.set(0, 0, 0);
    scene.add(mesh);

    for (let i = 0; i < 1000; i++) {
      // 几何体
      const geometry = new THREE.BoxGeometry(5, 5, 5);
      // 材质
      const material = new THREE.MeshBasicMaterial({
        color: 0x00ff00,
        transparent: true,
        opacity: 0.5
      });
      // 网格模型：物体
      const mesh = new THREE.Mesh(geometry, material);
      mesh.position.set((Math.random() - 0.5) * 200, (Math.random() - 0.5) * 200, (Math.random() - 0.5) * 200);
      scene.add(mesh);
    }

    // 坐标系
    const axes = new THREE.AxesHelper(200);
    scene.add(axes);

    // 相机
    const camera = new THREE.PerspectiveCamera(75, width/height, 0.1, 1000);
    camera.position.set(200, 200, 200);
    camera.lookAt(scene.position);

    // 渲染器
    const renderer = new THREE.WebGLRenderer();
    renderer.setSize(width, height);
    renderer.render(scene, camera);
    document.body.appendChild(renderer.domElement);

    // 性能监控
    const stats = new Stats()
    document.body.appendChild(stats.domElement);

    // 动画渲染
    // 跟踪时间
    var clock = new THREE.Clock();
    function render() {
      stats.update()
      const spt = clock.getDelta() * 1000;
      requestAnimationFrame(render);
      mesh.rotation.y += 0.01;
      renderer.render(scene, camera);
    }

    render();
  </script>
</html>