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Three.js 旋转的圆教程

news 2026/7/5 21:49:47

旋转的圆 ·Circle Rotate· ▶ 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
水面反射/镜像材质
requestAnimationFrame渲染循环与resize自适应

效果说明

本案例演示旋转的圆效果：基于 WebGL 实现「旋转的圆」可视化效果，附完整可运行源码；核心用到 ShaderMaterial、OrbitControls、水面反射/镜像材质。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, 0, 1.5)
const renderer = new THREE.WebGLRenderer({ antialias: true, alpha: true, logarithmicDepthBuffer: true })
renderer.setSize(box.clientWidth, box.clientHeight)
box.appendChild(renderer.domElement)
const controls = new OrbitControls(camera, renderer.domElement)
controls.enableDamping = true
window.onresize = () => {
renderer.setSize(box.clientWidth, box.clientHeight)
camera.aspect = box.clientWidth / box.clientHeight
camera.updateProjectionMatrix()
}
const uniforms = {
iTime: {
value: 0
},
iResolution: {
value: new THREE.Vector2(box.clientWidth, box.clientHeight)
} }
const geometry = new THREE.PlaneGeometry(1, 1)
const material = new THREE.ShaderMaterial({
uniforms,
transparent: true,
side: THREE.DoubleSide,
vertexShader:varying vec3 vPosition; varying vec2 vUv; void main() { vUv = uv; vec4 mvPosition = modelViewMatrix * vec4(position, 1.0); gl_Position = projectionMatrix * mvPosition; }, fragmentShader:uniform float iTime; uniform vec2 iResolution; varying vec2 iMouse; varying vec2 vUv;
#define PI 3.1415926 #define NUM 20. #define PALETTE vec3(.0, 1.4, 2.)+1.5
#define COLORED #define MIRROR //#define ROTATE #define ROT_OFST #define TRIANGLE_NOISE
//#define SHOW_TRIANGLE_NOISE_ONLY
mat2 mm2(in float a){float c = cos(a), s = sin(a);return mat2(c,-s,s,c);} float tri(in float x){return abs(fract(x)-.5);} vec2 tri2(in vec2 p){return vec2(tri(p.x+tri(p.y2.)),tri(p.y+tri(p.x2.)));} mat2 m2 = mat2( 0.970, 0.242, -0.242, 0.970 );
float triangleNoise(in vec2 p) { float z=1.5; float z2=1.5; float rz = 0.; vec2 bp = p; for (float i=0.; i<=3.; i++ ) { vec2 dg = tri2(bp2.).8; dg= mm2(iTime.3); p += dg/z2;
bp *= 1.6; z2 *= .6; z *= 1.8; p *= 1.2; p*= m2; rz+= (tri(p.x+tri(p.y)))/z; } return rz; } void main(void) { float time = iTime* 1.2; float aspect = iResolution.x/iResolution.y; float w = 50./sqrt(iResolution.x*aspect+iResolution.y);
vec2 p = (vUv -0.5) * 2.0 ; p.x *= aspect; p*= 1.05; vec2 bp = p; #ifdef ROTATE p= mm2(time.25); #endif float lp = length(p); float id = floor(lp*NUM+.5)/NUM; #ifdef ROT_OFST p= mm2(id11.); #endif #ifdef MIRROR p.y = abs(p.y); #endif //polar coords vec2 plr = vec2(lp, atan(p.y, p.x)); //Draw concentric circles float rz = 1.-pow(abs(sin(plr.xPINUM))*1.25/pow(w,0.25),2.5); //get the current arc length for a given id float enp = plr.y+sin((time+id5.5))1.52-1.5; rz *= smoothstep(0., 0.05, enp); //smooth out both sides of the arcs (and clamp the number) rz= smoothstep(0.,.022w/plr.x, enp)*step(id,1.); #ifndef MIRROR rz= smoothstep(-0.01,.02w/plr.x,PI-plr.y); #endif #ifdef TRIANGLE_NOISE rz= (triangleNoise(p/(ww))*0.9+0.4); vec3 col = (sin(PALETTE+id5.+time)0.5+0.5)*rz; col += smoothstep(.4,1.,rz)*0.15; col *= smoothstep(.2,1.,rz)+1.; #else vec3 col = (sin(PALETTE+id5.+time)0.5+0.5)*rz; col= smoothstep(.8,1.15,rz).7+.8; #endif #ifndef COLORED col = vec3(dot(col,vec3(.7))); #endif #ifdef SHOW_TRIANGLE_NOISE_ONLY col = vec3(triangleNoise(bp)); #endif// 剔除黑色 if (col.r < 0.1 && col.g < 0.1 && col.b < 0.1) { discard; } gl_FragColor = vec4(col,1.0); }})
const mesh = new THREE.Mesh(geometry, material)
scene.add(mesh)
animate()
function animate() {
uniforms.iTime.value += 0.01
requestAnimationFrame(animate)
controls.update()
renderer.render(scene, camera)
}