Three.js 罗盘教程

罗盘 ·Compass 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-examples400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罗盘效果基于 WebGL 实现「罗盘」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 threeimport { OrbitControls } from three/examples/jsm/controls/OrbitControls.jsconst 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, 0.6)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 truewindow.onresize () {renderer.setSize(box.clientWidth, box.clientHeight)camera.aspect box.clientWidth / box.clientHeightcamera.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 ratio;float PI 3.1415926; uniform float iTime; uniform vec2 iResolution; varying vec2 vUv; vec2 rotate(vec2 p, float rad) { mat2 m mat2(cos(rad), sin(rad), -sin(rad), cos(rad)); return m * p; } vec2 translate(vec2 p, vec2 diff) { return p - diff; } vec2 scale(vec2 p, float r) { return p*r; } float circle(float pre, vec2 p, float r1, float r2, float power) { float leng length(p); float d min(abs(leng-r1), abs(leng-r2)); if (r1 half1.y) ? abs(half1.x-p.x) : length(p-half1); float dx2 (p.y half2.y) ? abs(half2.x-p.x) : length(p-half2); float dy1 (p.x half1.x) ? abs(half1.y-p.y) : length(p-half1); float dy2 (p.x half2.x) ? abs(half2.y-p.y) : length(p-half2); float d min(min(dx1, dx2), min(dy1, dy2)); float res power / d; return clamp(pre res, 0.0, 1.0); } float radiation(float pre, vec2 p, float r1, float r2, int num, float power) { float angle 2.0*PI/float(num); float d 1e10; for(int i0; i360; i) { if (inum) break; float _d (r1 iTime/1.0)0.021.1); { vec2 q p; q rotate(q, iTime * PI / 6.0); dst circle(dst, q, 0.85, 0.9, 0.006); dst radiation(dst, q, 0.87, 0.88, 36, 0.0008); } { vec2 q p; q rotate(q, iTime * PI / 6.0); const int n 6; float angle PI / float(n); q rotate(q, floor(atan(q.x, q.y)/angle 0.5) * angle); for(int i0; i iTime/1.0)0.041.1); q rotate(q, -iTime * PI / 6.0); for(float i0.0; i6.0; i) { float r 0.13-i*0.01; q translate(q, vec2(0.1, 0.0)); dst circle(dst, q, r, r, 0.002); q translate(q, -vec2(0.1, 0.0)); q rotate(q, -iTime * PI / 12.0); } dst circle(dst, q, 0.04, 0.04, 0.004); } return pow(dst, 2.5) * vec3(1.0, 0.95, 0.8); } void main() { vec2 uv (vUv - 0.5) * 2.0; gl_FragColor vec4(calc(uv), 1.0);; }})const mesh new THREE.Mesh(geometry, material)scene.add(mesh)animate()function animate() {uniforms.iTime.value 0.01requestAnimationFrame(animate)controls.update()renderer.render(scene, camera)}完整源码GitHub小结本文提供罗盘完整 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