方块着色器 ·Shader Block· ▶ 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

本案例演示方块着色器效果：基于 WebGL 实现「方块着色器」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, 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() }
  const uniforms = { iResolution: { type: 'v2', value: new THREE.Vector2(box.clientWidth, box.clientHeight) }, iTime: { type: 'f', value: 1.0 } } animate() function animate() { uniforms.iTime.value += 0.01 requestAnimationFrame(animate) renderer.render(scene, camera) }
  let geometry = new THREE.PlaneGeometry(2, 2);
  let material = new THREE.ShaderMaterial({ uniforms: uniforms, vertexShader:void main() { gl_Position = vec4( position, 1.0 ); }, fragmentShader:// 屏幕尺寸 precision highp float; uniform vec2 iResolution; uniform float iTime;
  float gTime = 0.; const float REPEAT = 5.0;
  // 回転行列 mat2 rot(float a) { float c = cos(a), s = sin(a); return mat2(c,s,-s,c); }
  float sdBox( vec3 p, vec3 b ) { vec3 q = abs(p) - b; return length(max(q,0.0)) + min(max(q.x,max(q.y,q.z)),0.0); }
  float box(vec3 pos, float scale) { pos *= scale; float base = sdBox(pos, vec3(.4,.4,.1)) /1.5; pos.xy *= 5.; pos.y -= 3.5; pos.xy *= rot(.75); float result = -base; return result; }
  float box_set(vec3 pos, float iTime) { vec3 pos_origin = pos; pos = pos_origin; pos .y += sin(gTime0.4)2.5; pos.xy *= rot(.8); float box1 = box(pos,2. - abs(sin(gTime0.4))1.5); pos = pos_origin; pos .y -=sin(gTime0.4)2.5; pos.xy *= rot(.8); float box2 = box(pos,2. - abs(sin(gTime0.4))1.5); pos = pos_origin; pos .x +=sin(gTime0.4)2.5; pos.xy *= rot(.8); float box3 = box(pos,2. - abs(sin(gTime0.4))1.5); pos = pos_origin; pos .x -=sin(gTime0.4)2.5; pos.xy *= rot(.8); float box4 = box(pos,2. - abs(sin(gTime0.4))1.5); pos = pos_origin; pos.xy *= rot(.8); float box5 = box(pos,.5) * 6.; pos = pos_origin; float box6 = box(pos,.5) * 6.; float result = max(max(max(max(max(box1,box2),box3),box4),box5),box6); return result; }
  float map(vec3 pos, float iTime) { vec3 pos_origin = pos; float box_set1 = box_set(pos, iTime);
  return box_set1; } void main() { vec2 p = (gl_FragCoord.xy * 1. - iResolution.xy) / min(iResolution.x, iResolution.y); vec3 ro = vec3(0., -0.2 ,iTime * 4.); vec3 ray = normalize(vec3(p, 1.5)); ray.xy = ray.xyrot(sin(iTime.03) * 5.); ray.yz = ray.yzrot(sin(iTime.05) * .2); float t = 0.1; vec3 col = vec3(0.); float ac = 0.0;
  for (int i = 0; i < 99; i++){ vec3 pos = ro + ray * t; pos = mod(pos-2., 4.) -2.; gTime = iTime -float(i) * 0.01; float d = map(pos, iTime);
  d = max(abs(d), 0.01); ac += exp(-d*23.);
  t += d* 0.55; }
  col = vec3(ac * 0.02);
  col +=vec3(0.,0.2abs(sin(iTime)),0.5 + sin(iTime)0.2);
  gl_FragColor = vec4(col ,1.0 - t(0.02 + 0.02sin (iTime))); }});
  let mesh = new THREE.Mesh(geometry, material); scene.add(mesh);

  完整源码：GitHub

  小结

  • 本文提供方块着色器完整 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