环彩虹着色器 ·Rings 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

本案例演示环彩虹着色器效果：基于 WebGL 实现「环彩虹着色器」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'
  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, 0, 10) const renderer = new THREE.WebGLRenderer() renderer.setSize(box.clientWidth, box.clientHeight) box.appendChild(renderer.domElement) new OrbitControls(camera, renderer.domElement) scene.add(new THREE.AxesHelper(50000)) window.onresize = () => { renderer.setSize(box.clientWidth, box.clientHeight) camera.aspect = box.clientWidth / box.clientHeight camera.updateProjectionMatrix() }
  const { mesh, uniforms } = getShaderMesh() scene.add(mesh)
  animate() function animate() { uniforms.iTime.value += 0.01 requestAnimationFrame(animate) renderer.render(scene, camera) }
  function getShaderMesh() {
  const uniforms = { iTime: { value: 0 }, iResolution: { value: new THREE.Vector2(1900, 1900) }, iChannel0: { value: window.iChannel0 } }
  const geometry = new THREE.PlaneGeometry(20, 20); const material = new THREE.ShaderMaterial({ uniforms, side: 2, depthWrite: false, transparent: true, vertexShader:varying vec3 vPosition; varying vec2 vUv; void main() { vUv = uv; vec4 mvPosition = modelViewMatrix * vec4(position, 1.0); gl_Position = projectionMatrix * mvPosition; }, fragmentShader:uniform float ratio;
  float PI = 3.1415926; uniform float iTime; uniform vec2 iResolution; varying vec2 vUv; void main() { vec2 p = (vUv - 0.5) * 2.0; float tau = PI * 2.0; float a = atan(p.x,p.y); float r = length(p)*0.75; vec2 uv = vec2(a/tau,r); //get the color float xCol = (uv.x - (iTime / 3.0)) * 3.0; xCol = mod(xCol, 3.0); vec3 horColour = vec3(0.25, 0.25, 0.25); if (xCol < 1.0) { horColour.r += 1.0 - xCol; horColour.g += xCol; } else if (xCol < 2.0) { xCol -= 1.0; horColour.g += 1.0 - xCol; horColour.b += xCol; } else { xCol -= 2.0; horColour.b += 1.0 - xCol; horColour.r += xCol; }
  // draw color beam uv = (2.0 * uv) - 1.0; float beamWidth = (0.7+0.5cos(uv.x10.0tau0.15clamp(floor(5.0 + 10.0cos(iTime)), 0.0, 10.0)))abs(1.0 / (30.0uv.y)); vec3 horBeam = vec3(beamWidth); gl_FragColor = vec4((( horBeam) * horColour), 1.0); }}) const mesh = new THREE.Mesh(geometry, material);
  return { mesh, uniforms } }

  完整源码：GitHub

  小结

  • 本文提供环彩虹着色器完整 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