Three.js 马赛克教程

马赛克 ·Mosaic 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

本案例演示马赛克效果:基于 WebGL 实现「马赛克」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)
  • 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, 0, 1)

    const renderer = new THREE.WebGLRenderer()

    renderer.setSize(box.clientWidth, box.clientHeight)

    box.appendChild(renderer.domElement)

    new OrbitControls(camera, renderer.domElement)

    animate()

    function animate() {

    requestAnimationFrame(animate)

    renderer.render(scene, camera)

    }

    window.onresize = () => {

    renderer.setSize(box.clientWidth, box.clientHeight)

    camera.aspect = box.clientWidth / box.clientHeight

    camera.updateProjectionMatrix()

    }

    const vertexShader =varying vec2 vUv; void main(){ vUv = uv; gl_Position = projectionMatrixmodelViewMatrixvec4(position, 1.0); }

    const fragmentShader =varying vec2 vUv; uniform sampler2D tDiffuse; uniform vec2 vScreenSize; uniform float fMosaicScale; void main() { vec2 vUv2 = vUv; vUv2.x = floor(vUv2.x * vScreenSize.x / fMosaicScale) / (vScreenSize.x / fMosaicScale) + (fMosaicScale / 2.0) / vScreenSize.x; vUv2.y = floor(vUv2.y * vScreenSize.y / fMosaicScale) / (vScreenSize.y / fMosaicScale) + (fMosaicScale / 2.0) / vScreenSize.y;

    vec4 color = texture2D(tDiffuse, vUv2); gl_FragColor = color; }

    const uniforms = {

    tDiffuse: { type: 't', value: new THREE.TextureLoader().load(HOST + 'files/author/z2586300277.png') },

    vScreenSize: { type: "v2", value: new THREE.Vector2(window.innerWidth, window.innerHeight) },

    fMosaicScale: { type: "f", value: 20.0 },

    }

    const material = new THREE.ShaderMaterial({ uniforms, vertexShader, fragmentShader });

    const geometry = new THREE.PlaneGeometry();

    const mesh = new THREE.Mesh(geometry, material);

    scene.add(mesh);

    var gui = new dat.GUI(); gui.add(uniforms['fMosaicScale'], 'value', 1.0, 100.0).step(1.0).name('mosaicScale');

    完整源码:GitHub

    小结

    • 本文提供马赛克完整 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