Three.js 幻影花烟教程

幻影花烟 ·Flower Smoke· ▶ 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-examples400个案例代码:网盘链接你将学到什么onBeforeCompile 注入 GLSL 改造内置材质OrbitControls 相机轨道交互监听窗口resize同步更新 camera 与 renderer效果说明本案例演示幻影花烟效果基于 WebGL 实现「幻影花烟」可视化效果附完整可运行源码核心用到 onBeforeCompile、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。onBeforeCompile在 Three 拼好内置 shader 后替换#include片段适合在 PBR 材质上叠加大屏特效。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 renderCesium 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 three/examples/jsm/libs/lil-gui.module.min.js// reference https://codepen.io/prisoner849/pen/LYmXKrr let noise // Simplex 4D Noise // by Ian McEwan, Ashima Arts // vec4 permute(vec4 x){return mod(((x34.0)1.0)x, 289.0);} float permute(float x){return floor(mod(((x34.0)1.0)x, 289.0));} vec4 taylorInvSqrt(vec4 r){return 1.79284291400159 - 0.85373472095314 * r;} float taylorInvSqrt(float r){return 1.79284291400159 - 0.85373472095314 * r;}vec4 grad4(float j, vec4 ip){ const vec4 ones vec4(1.0, 1.0, 1.0, -1.0); vec4 p,s;p.xyz floor( fract (vec3(j)ip.xyz)7.0) * ip.z - 1.0; p.w 1.5 - dot(abs(p.xyz), ones.xyz); s vec4(lessThan(p, vec4(0.0))); p.xyz p.xyz (s.xyz2.0 - 1.0)s.www;return p; }float snoise(vec4 v){ const vec2 C vec2( 0.138196601125010504, // (5 - sqrt(5))/20 G4 0.309016994374947451); // (sqrt(5) - 1)/4 F4 // First corner vec4 i floor(v dot(v, C.yyyy) ); vec4 x0 v - i dot(i, C.xxxx);// Other corners// Rank sorting originally contributed by Bill Licea-Kane, AMD (formerly ATI) vec4 i0;vec3 isX step( x0.yzw, x0.xxx ); vec3 isYZ step( x0.zww, x0.yyz ); // i0.x dot( isX, vec3( 1.0 ) ); i0.x isX.x isX.y isX.z; i0.yzw 1.0 - isX;// i0.y dot( isYZ.xy, vec2( 1.0 ) ); i0.y isYZ.x isYZ.y; i0.zw 1.0 - isYZ.xy;i0.z isYZ.z; i0.w 1.0 - isYZ.z;// i0 now contains the unique values 0,1,2,3 in each channel vec4 i3 clamp( i0, 0.0, 1.0 ); vec4 i2 clamp( i0-1.0, 0.0, 1.0 ); vec4 i1 clamp( i0-2.0, 0.0, 1.0 );// x0 x0 - 0.0 0.0 * C vec4 x1 x0 - i1 1.0 * C.xxxx; vec4 x2 x0 - i2 2.0 * C.xxxx; vec4 x3 x0 - i3 3.0 * C.xxxx; vec4 x4 x0 - 1.0 4.0 * C.xxxx;// Permutations i mod(i, 289.0); float j0 permute( permute( permute( permute(i.w) i.z) i.y) i.x); vec4 j1 permute( permute( permute( permute ( i.w vec4(i1.w, i2.w, i3.w, 1.0 ))i.z vec4(i1.z, i2.z, i3.z, 1.0 ))i.y vec4(i1.y, i2.y, i3.y, 1.0 ))i.x vec4(i1.x, i2.x, i3.x, 1.0 ));// Gradients // ( 776 points uniformly over a cube, mapped onto a 4-octahedron.) // 776 294, which is close to the ring size 17*17 289.vec4 ip vec4(1.0/294.0, 1.0/49.0, 1.0/7.0, 0.0) ;vec4 p0 grad4(j0, ip); vec4 p1 grad4(j1.x, ip); vec4 p2 grad4(j1.y, ip); vec4 p3 grad4(j1.z, ip); vec4 p4 grad4(j1.w, ip);// Normalise gradients vec4 norm taylorInvSqrt(vec4(dot(p0,p0), dot(p1,p1), dot(p2, p2), dot(p3,p3))); p0 * norm.x; p1 * norm.y; p2 * norm.z; p3 * norm.w; p4 * taylorInvSqrt(dot(p4,p4));// Mix contributions from the five corners vec3 m0 max(0.6 - vec3(dot(x0,x0), dot(x1,x1), dot(x2,x2)), 0.0); vec2 m1 max(0.6 - vec2(dot(x3,x3), dot(x4,x4) ), 0.0); m0 m0 * m0; m1 m1 * m1; return 49.0( dot(m0m0, vec3( dot( p0, x0 ), dot( p1, x1 ), dot( p2, x2 )))dot(m1*m1, vec2( dot( p3, x3 ), dot( p4, x4 ) ) ) ) ;}let innerWidth window.innerWidth; let innerHeight window.innerHeight; let scene new THREE.Scene(); let camera new THREE.PerspectiveCamera(60, innerWidth / innerHeight, 1, 1000); camera.position.set(10, 10, 7).setLength(13); let renderer new THREE.WebGLRenderer({ antialias: true }); renderer.setSize(innerWidth, innerHeight); document.body.appendChild(renderer.domElement); window.addEventListener(resize, () { camera.aspect innerWidth / innerHeight; camera.updateProjectionMatrix(); renderer.setSize(innerWidth, innerHeight); }); new OrbitControls(camera, renderer.domElement);let g new THREE.CylinderGeometry(1, 1, 10, 200, 200, true); let gu { time: { value: 0 }, color1: { value: new THREE.Color(0x00ff00) }, color2: { value: new THREE.Color(0xff0000) } }; let m new THREE.MeshBasicMaterial({ depthTest: false, depthWrite: false, side: THREE.DoubleSide, transparent: true, opacity: 0.75, onBeforeCompile: shader { shader.uniforms.time gu.time; shader.uniforms.color1 gu.color1; shader.uniforms.color2 gu.color2; shader.vertexShader #define ss(a, b, c) smoothstep(a, b, c) uniform float time; varying vec3 nView; varying vec3 nNor; ${noise} vec3 getShaped(vec3 p) { float curve ss(0., 0.2, uv.y) ss(0.5, 1., uv.y) * 2.5; p.xz * 0.75 curve; return p; } vec3 getNoised(vec3 p) { float t time * 0.5; float n snoise(vec4(p0.4 - vec3(0, t, 0), 3.14))(0.5 0.5 * uv.y); p normal * n; return p; } vec3 rotY(vec3 p, float a) { float s sin(a), c cos(a); p.xz * mat2(c, -s, s, c); return p; } ${shader.vertexShader}.replace(#include,#include vec3 pos getNoised(getShaped(position)); vec3 pos2 getNoised(getShaped(rotY(position, 3.1415926 * 0.001))); vec3 pos3 getNoised(getShaped(position vec3(0., 0.001, 0.))); transformed pos; nNor normalMatrix * cross(normalize(pos2 - pos), normalize(pos3 - pos));).replace(#include,#include nView normalize(mvPosition.xyz);); shader.fragmentShader #define ss(a, b, c) smoothstep(a, b, c) varying vec3 nView; varying vec3 nNor; uniform vec3 color1; uniform vec3 color2; ${shader.fragmentShader}.replace(#include,#include diffuseColor.rgb mix(color1, color2, pow(vUv.y, 2.)); float alpha ss(0., 0.2, vUv.y) - ss(0.8, 1., vUv.y); vec3 nor nNor * (gl_FrontFacing ? 1. : -1.); float vAlpha abs(dot(normalize(nView), nor)); float angleAlpha (1. - vAlpha) * 0.9 0.1; float totalAlpha clamp(alpha0.5 angleAlpha0.5, 0., 1.) * alpha; diffuseColor.rgb vec3(1)totalAlpha0.1; diffuseColor.a * totalAlpha;); } }); m.defines { USE_UV: } // to use vUv let o new THREE.Mesh(g, m); scene.add(o);let gui new GUI(); gui.addColor(gu.color1, value).name(Color 1); gui.addColor(gu.color2, value).name(Color 2);let clock new THREE.Clock(); renderer.setAnimationLoop(() { gu.time.value clock.getElapsedTime(); renderer.render(scene, camera); });完整源码GitHub小结本文提供幻影花烟完整 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