Three.js 视频着色器教程

视频着色器 ·Video Shader· ▶ 在线运行案例

• 案例合集：三维可视化功能案例（threehub.cn）
• 开源仓库github地址：https://github.com/z2586300277/three-cesium-examples
• 400个案例代码:网盘链接

你将学到什么

• ShaderMaterial 自定义着色器实现核心视觉效果
• OrbitControls 相机轨道交互
• requestAnimationFrame渲染循环与resize自适应

效果说明

本案例演示视频着色器效果：基于 WebGL 实现「视频着色器」可视化效果，附完整可运行源码；核心用到 ShaderMaterial、OrbitControls。建议先打开文首在线案例查看动态画面，再对照下方源码逐步理解。

核心概念

• Scene / Camera / WebGLRenderer构成最小渲染闭环；大场景可开logarithmicDepthBuffer缓解 Z-fighting。
• ShaderMaterial通过uniforms+ 自定义 GLSL 控制逐像素/逐点效果；透明粒子常配合depthTest: false。
• OrbitControls提供轨道旋转/缩放；开启enableDamping后需在 animate 中controls.update()。

实现步骤

• 搭建 Scene、PerspectiveCamera、WebGLRenderer，挂载 canvas 并处理resize
• 定义 uniforms / onBeforeCompile 或 ShaderMaterial，编写 GLSL 与材质参数
• 创建 OrbitControls（及 Raycaster 等交互控件，若源码包含）
• 在requestAnimationFrame循环中更新状态并 render（Cesium 为viewer.render或自动渲染）

• 代码要点

  import * as THREE from 'three'
  import { OrbitControls } from 'three/examples/jsm/controls/OrbitControls.js' import * as dat from 'dat.gui'
  const box = document.getElementById('box')
  const scene = new THREE.Scene()
  const camera = new THREE.PerspectiveCamera(75, box.clientWidth / box.clientHeight, 0.1, 1000)
  camera.position.set(0, 10, 10)
  const renderer = new THREE.WebGLRenderer()
  renderer.setSize(box.clientWidth, box.clientHeight)
  box.appendChild(renderer.domElement)
  new OrbitControls(camera, renderer.domElement)
  window.onresize = () => {
  renderer.setSize(box.clientWidth, box.clientHeight)
  camera.aspect = box.clientWidth / box.clientHeight
  camera.updateProjectionMatrix() }
  scene.add(new THREE.AxesHelper(50000)) // 坐标轴
  const amibientLight = new THREE.AmbientLight(0xffffff, 4) // 环境光
  scene.add(amibientLight) // 添加环境光
  const geometry = new THREE.BoxGeometry(5, 5, 5) // 立方体
  const video = document.createElement('video')
  video.crossOrigin = 'anonymous' // 跨域
  video.src = 'https://z2586300277.github.io/3d-file-server/video/test.mp4'
  video.loop = true // 循环播放
  video.muted = true // 静音
  video.play()
  const texture = await new Promise(r => video.onloadeddata = () => r(new THREE.VideoTexture(video))) // 创建视频纹理
  // 使用 shader 库中的phong材质 进行修改 const shader = { uniforms: THREE.UniformsUtils.merge([
  THREE.ShaderLib['phong'].uniforms,
  { r: { type: 'v2', value: new THREE.Vector2(box.clientWidth, box.clientHeight) }, t: { type: 'f', value: 0.0 }, colorTexture: { value: texture }, calcType: { value: 2 } }
  ]),
  vertexShader: THREE.ShaderLib['phong'].vertexShader,
  fragmentShader: THREE.ShaderLib['phong'].fragmentShader,
  }
  // GUI 切换混合运算类型 const GUI = new dat.GUI()
  GUI.add(shader.uniforms.calcType, 'value', [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]).name('混合运算类型');
  // 动画 animate()
  function animate() {
  shader.uniforms.t.value += 0.1
  renderer.render(scene, camera)
  requestAnimationFrame(animate)
  }
  shader.vertexShader = shader.vertexShader.replace(/#include /,varying vec2 vUv; #include)
  shader.vertexShader = shader.vertexShader.replace('void main() {',void main() { vUv = uv;)
  shader.fragmentShader = shader.fragmentShader.replace(/#include /,precision highp float; varying vec2 vUv; uniform vec2 r; uniform float t; uniform float calcType; uniform sampler2D colorTexture; #include)
  shader.fragmentShader = shader.fragmentShader.replace('vec4 diffuseColor = vec4( diffuse, opacity );',vec3 c; float l,z=t; for(int i=0;i<3;i++) { vec2 uv,p=gl_FragCoord.xy/r/2.0; uv=p + 2.0 * vUv; p-=.5; p.x*=r.x/r.y; z+=.07; l=length(p); uv+=p/l(sin(z)+1.)abs(sin(l*9.-z-z)); c[i]=.01/length(mod(uv,1.)-.5); } vec3 color = texture2D( colorTexture, vUv ).rgb; vec3 mixedColor; if (calcType == 0.0) mixedColor = max(color, c); else if(calcType == 1.0) mixedColor = min(color, c); else if(calcType == 2.0) mixedColor = mix(color, c, 0.5); else if(calcType == 3.0) mixedColor = mod(color, c); else if(calcType == 4.0) mixedColor = pow(color, c); else if(calcType == 5.0) mixedColor = step(color, c); else if(calcType == 6.0) mixedColor = color + c; else if(calcType == 7.0) mixedColor = color - c; else if(calcType == 8.0) mixedColor = c - color; else if(calcType == 9.0) mixedColor = color + c - vec3(1.0)ccolor; else mixedColor = color; vec4 diffuseColor = vec4( diffuse * mixedColor, opacity );)
  const material = new THREE.ShaderMaterial(shader)
  material.lights = true // 光照影响
  const mesh = new THREE.Mesh(geometry, material)
  scene.add(mesh)

  完整源码：GitHub

  小结

  • 本文提供视频着色器完整 Three.js 源码与在线 Demo，建议先运行案例再改 uniform/参数做二次实验
  • 更多 Three.js 实战案例见 three-cesium-examples 合集 与 GitHub 开源仓库