Three.js 蒸汽粒子教程

Three.js 蒸汽粒子教程

蒸汽粒子 ·Steam Particle· ▶ 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
  • THREE.Points 粒子点渲染
  • BufferGeometry 自定义顶点/索引数据
  • requestAnimationFrame渲染循环与resize自适应

效果说明

本案例演示蒸汽粒子效果:基于 WebGL 实现「蒸汽粒子」可视化效果,附完整可运行源码;核心用到 ShaderMaterial、OrbitControls、THREE.Points。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()
  • THREE.Points将每个顶点渲染为可控大小的粒子;可用自定义 attribute(如u_index)驱动片元/顶点动画。

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 { GUI } from 'dat.gui'

    // 初始化场景 const box = document.getElementById('box') const scene = new THREE.Scene() scene.background = new THREE.Color(0x445566)

    const camera = new THREE.PerspectiveCamera(50, box.clientWidth / box.clientHeight, 0.1, 1000) camera.position.set(0, 8, 20)

    // 设置渲染器 const renderer = new THREE.WebGLRenderer({ antialias: true, alpha: true }) renderer.setSize(box.clientWidth, box.clientHeight) box.appendChild(renderer.domElement)

    // 轨道控制器 const controls = new OrbitControls(camera, renderer.domElement) controls.enableDamping = true

    scene.add(new THREE.AmbientLight(0xffffff, 0.5))

    // 可配置参数 const config = { particleCount: 3000, particleSize: 1.2, width: 12, depth: 2, height: 15, riseSpeed: 0.4, spread: 0.3, turbulence: 0.3, density: 0.4, }

    const uniforms = { time: { value: 0 }, baseColor: { value: new THREE.Color(0xffffff) }, height: { value: config.height }, turbulence: { value: config.turbulence }, density: { value: config.density }, }

    const material = new THREE.ShaderMaterial({ uniforms, vertexShader:attribute float size; attribute float phase; attribute vec3 velocity; uniform float time; uniform float height; uniform float turbulence; varying float vAlpha; varying float vAge; void main() { float age = mod(time * 0.3 + phase, 1.0); vAge = age; vec3 pos = position + velocityageheight; pos.x += sin(age8.0 + phase20.0)turbulence(0.5 + age); pos.z += cos(age6.0 + phase15.0)turbulence(0.3 + age * 0.5); pos.x= (1.0 + age1.5); pos.z= (1.0 + age0.8); vec4 mvPosition = modelViewMatrix * vec4(pos, 1.0); gl_Position = projectionMatrix * mvPosition; gl_PointSize = size(1.0 + age3.0) * (250.0 / -mvPosition.z); float fadeIn = smoothstep(0.0, 0.1, age); float fadeOut = 1.0 - smoothstep(0.6, 1.0, age); vAlpha = fadeIn * fadeOut; }, fragmentShader:uniform vec3 baseColor; uniform float density; varying float vAlpha; varying float vAge; void main() { float dist = length(gl_PointCoord - 0.5) * 2.0; if (dist > 1.0) discard; float edge = 1.0 - smoothstep(0.3, 1.0, dist); vec3 color = mix(baseColor, vec3(0.85, 0.88, 0.92), vAge * 0.3); gl_FragColor = vec4(color, vAlphaedgedensity); }, blending: THREE.NormalBlending, depthWrite: false, transparent: true, })

    function buildGeometry() { const geo = new THREE.BufferGeometry() const positions = [], sizes = [], phases = [], velocities = [] for (let i = 0; i < config.particleCount; i++) { positions.push( (Math.random() - 0.5) * config.width, Math.random() * 0.3, (Math.random() - 0.5) * config.depth ) sizes.push(config.particleSize(0.6 + Math.random()0.8)) phases.push(Math.random()) velocities.push( (Math.random() - 0.5) * config.spread, config.riseSpeed(0.8 + Math.random()0.4), (Math.random() - 0.5)config.spread0.5 ) } geo.setAttribute('position', new THREE.Float32BufferAttribute(positions, 3)) geo.setAttribute('size', new THREE.Float32BufferAttribute(sizes, 1)) geo.setAttribute('phase', new THREE.Float32BufferAttribute(phases, 1)) geo.setAttribute('velocity', new THREE.Float32BufferAttribute(velocities, 3)) return geo }

    const steam = new THREE.Points(buildGeometry(), material) scene.add(steam)

    // GUI const gui = new GUI() gui.add(config, 'height', 5, 30).name('上升高度').onChange(v => uniforms.height.value = v) gui.add(config, 'turbulence', 0, 1).name('湍流强度').onChange(v => uniforms.turbulence.value = v) gui.add(config, 'density', 0.1, 1).name('浓度').onChange(v => uniforms.density.value = v) gui.add(config, 'width', 1, 20).name('喷口宽度').onChange(() => { steam.geometry.dispose(); steam.geometry = buildGeometry() }) gui.add(config, 'depth', 0.5, 10).name('喷口深度').onChange(() => { steam.geometry.dispose(); steam.geometry = buildGeometry() }) gui.add(config, 'riseSpeed', 0.1, 1).name('上升速度').onChange(() => { steam.geometry.dispose(); steam.geometry = buildGeometry() }) gui.add(config, 'particleCount', 500, 8000, 500).name('粒子数量').onChange(() => { steam.geometry.dispose(); steam.geometry = buildGeometry() }) gui.add(config, 'particleSize', 0.3, 3).name('粒子大小').onChange(() => { steam.geometry.dispose(); steam.geometry = buildGeometry() }) gui.addColor({ color: '#ffffff' }, 'color').name('蒸汽颜色').onChange(v => uniforms.baseColor.value.set(v))

    // 动画 const clock = new THREE.Clock()

    function animate() { requestAnimationFrame(animate) uniforms.time.value = clock.getElapsedTime() controls.update() renderer.render(scene, camera) }

    animate()

    window.onresize = () => { renderer.setSize(box.clientWidth, box.clientHeight) camera.aspect = box.clientWidth / box.clientHeight camera.updateProjectionMatrix() }

    完整源码:GitHub

    小结

    • 本文提供蒸汽粒子完整 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