Three.js 溶解动画教程

溶解动画 ·Dissolve· ▶ 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

本案例演示溶解动画效果:基于 WebGL 实现「溶解动画」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 Stats from "three/examples/jsm/libs/stats.module.js"

    var scene, camera, renderer, clock, controller, stats var dissolveMaterials = []

    init(); animate();

    function init() { scene = new THREE.Scene(); clock = new THREE.Clock(); camera = new THREE.PerspectiveCamera( 45, window.innerWidth / window.innerHeight, 0.1, 1000 ); camera.position.set(15, 5, 15) renderer = new THREE.WebGLRenderer({ antialias: true, // 开启抗锯齿处理 alpha: true, }); renderer.setSize(window.innerWidth, window.innerHeight); renderer.setPixelRatio(window.devicePixelRatio)

    let shader_material = new THREE.ShaderMaterial({ uniforms: { dissolveMap: { value: new THREE.TextureLoader().load(FILE_HOST + "threeExamples/shader/tex2.png") }, texture2: { value: new THREE.TextureLoader().load(FILE_HOST + "threeExamples/shader/earth1.jpg") }, color: { value: new THREE.Color(1, 0, 0) }, time: { value: 0 }, flag: { value: true } }, vertexShader:varying vec2 vUv; varying vec3 worldPos; void main() { vUv = uv; worldPos = (modelMatrix * vec4(position, 1.0)).xyz; gl_Position = projectionMatrixmodelViewMatrixvec4(position, 1.0); }, fragmentShader:varying vec2 vUv; uniform sampler2D dissolveMap; uniform sampler2D texture2; uniform float time; varying vec3 worldPos; uniform bool flag; void main() { float bottom = -2.0; float top = 2.0; float yScale = (worldPos.y - bottom)/(top - bottom); vec4 color = texture2D( texture2, vUv); //vec4 color = vec4(1.0, 0.0, 0.0, 0.3); //float t = 1. - fract(time); float t; if(flag) { t = fract(time); }else { t = 1. - fract(time); } float h = texture2D( dissolveMap, vUv).r;

    float dissolveWidth = 4.0; // 值越大越窄

    float condition_if_1 = step(h + yScaledissolveWidth, t(dissolveWidth + 1.0) + 0.04); float condition_if_2 = step(h + yScaledissolveWidth, t(dissolveWidth + 1.0)); color = mix(color, vec4(1.0 ,1.0 , 0.0, 1.0), condition_if_1 ); color = color * (1. - condition_if_2); gl_FragColor = color; }, transparent: true, depthWrite: false }); dissolveMaterials.push(shader_material)

    var axisHelper = new THREE.AxesHelper(10); scene.add(axisHelper) stats = new Stats() document.body.appendChild(stats.dom);

    var geometry = new THREE.BoxGeometry(4, 4, 4); var cube = new THREE.Mesh(geometry, shader_material); scene.add(cube);

    controller = new OrbitControls(camera, renderer.domElement); document.body.appendChild(renderer.domElement); window.onresize = onResize; }

    function animate() { requestAnimationFrame(animate); renderer.render(scene, camera); stats.update(); controller.update(clock.getDelta()); updateMaterial() }

    function updateMaterial() { dissolveMaterials.map(m => { m.uniforms.time.value += 0.005 if (m.uniforms.time.value >= 1) { m.uniforms.time.value = 0 m.uniforms.flag.value = !m.uniforms.flag.value } }) }

    function onResize() { camera.aspect = window.innerWidth / window.innerHeight; camera.updateProjectionMatrix(); renderer.setSize(window.innerWidth, window.innerHeight); }

    完整源码:GitHub

    小结

    • 本文提供溶解动画完整 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