Three.js 环形着色器教程

环形着色器 ·Ring 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

本案例演示环形着色器效果：基于 WebGL 实现「环形着色器」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, 15) 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 M_PI = 3.1415926; float M_TWO_PI = 6.28318530718; vec3 iMouse = vec3(0.0, 0.0 ,0.0 ); uniform float iTime; uniform vec2 iResolution; varying vec2 vUv; float rand(vec2 n) { return fract(sin(dot(n, vec2(12.9898,12.1414))) * 83758.5453); } float noise(vec2 n) { const vec2 d = vec2(0.0, 1.0); vec2 b = floor(n); vec2 f = smoothstep(vec2(0.0), vec2(1.0), fract(n)); return mix(mix(rand(b), rand(b + d.yx), f.x), mix(rand(b + d.xy), rand(b + d.yy), f.x), f.y); } vec3 ramp(float t) { return t <= .5 ? vec3( 1. - t1.4, .2, 1.05 ) / t : vec3( .3(1. - t) * 2., .2, 1.05 ) / t; } vec2 polarMap(vec2 uv, float shift, float inner) { uv = vec2(0.5) - uv; float px = 1.0 - fract(atan(uv.y, uv.x) / 6.28 + 0.25) + shift; float py = (sqrt(uv.xuv.x + uv.yuv.y)(1.0 + inner2.0) - inner) * 2.0; return vec2(px, py); } float fire(vec2 n) { return noise(n) + noise(n2.1).6 + noise(n5.4).42; } float shade(vec2 uv, float t) { uv.x += uv.y < .5 ? 23.0 + t.035 : -11.0 + t.03; uv.y = abs(uv.y - .5); uv.x *= 35.0; float q = fire(uv - t * .013) / 2.0; vec2 r = vec2(fire(uv + q / 2.0 + t - uv.x - uv.y), fire(uv + q - t)); return pow((r.y + r.y) * max(.0, uv.y) + .1, 4.0); } vec3 color(float grad) { float m2 = iMouse.z < 0.0001 ? 1.15 : iMouse.y * 3.0 / iResolution.y; grad =sqrt( grad); vec3 color = vec3(1.0 / (pow(vec3(0.5, 0.0, .1) + 2.61, vec3(2.0)))); vec3 color2 = color; color = ramp(grad); color /= (m2 + max(vec3(0), color)); return color; } float distanceTo(vec2 src, vec2 dst) { float dx = src.x - dst.x; float dy = src.y - dst.y; float dv = dxdx + dydy; return sqrt(dv); }
  void main() { float m1 = iMouse.z < 0.0001 ? 3.6 : iMouse.x * 5.0 / iResolution.x; float t = iTime; vec2 uv = vUv; float ff = 1.0 - uv.y; uv.x -= (iResolution.x / iResolution.y - 1.0) / 2.0; vec2 uv2 = uv; uv2.y = 1.0 - uv2.y; uv = polarMap(uv, 1.3, m1); uv2 = polarMap(uv2, 1.9, m1);
  vec3 c1 = color(shade(uv, t)) * ff; vec3 c2 = color(shade(uv2, t)) * (1.0 - ff);
  gl_FragColor = vec4(c1 + c2, 1.0);; }}) const mesh = new THREE.Mesh(geometry, material);
  return { mesh, uniforms } }

  完整源码：GitHub

  小结

  • 本文提供环形着色器完整 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