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Three.js 人物虚化教程

news 2026/7/2 14:37:21

人物虚化 ·人物虚化· ▶ 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

onBeforeCompile 注入 GLSL 改造内置材质
OrbitControls 相机轨道交互
Canvas 动态纹理贴图
FBXLoader 加载 FBX 城市/角色模型
骨骼动画与 AnimationMixer
requestAnimationFrame渲染循环与resize自适应

效果说明

本案例演示人物虚化效果：用 Canvas 2D 绘制内容并实时映射为 Three.js 纹理；核心用到 onBeforeCompile、OrbitControls、Canvas。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()。
CanvasTexture每帧或按需把 2D Canvas 内容上传 GPU，适合动态文字、图表、视频帧贴图。

实现步骤

搭建 Scene、PerspectiveCamera、WebGLRenderer，挂载 canvas 并处理resize
异步加载模型 / 3D Tiles / GeoJSON 等资源并加入 scene 或 entities
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 { FBXLoader } from "three/examples/jsm/loaders/FBXLoader.js"; import { OrbitControls } from "three/examples/jsm/controls/OrbitControls.js"; import { GUI } from "dat.gui";
const modelUrl = "https://ylfq.github.io/model/walk.fbx";
const canvas = document.createElement("canvas"); canvas.style.width = "100vw !important"; canvas.style.height = "100vh !important"; document.body.appendChild(canvas);
const renderer = new THREE.WebGLRenderer({ canvas: canvas, antialias: true, alpha: true }); renderer.setClearColor(0x333333, 0); renderer.shadowMap.enabled = true; renderer.shadowMap.type = THREE.PCFShadowMap;
const scene = new THREE.Scene();
const loader_fbx = new FBXLoader();
const modelMaterialUniforms = { blur: 0.85, blockSize: 12.0, };
const model = await loader_fbx.loadAsync(modelUrl); model.traverse((obj) => { if (obj instanceof THREE.Mesh) { obj.castShadow = true; obj.receiveShadow = true;
/* @type {THREE.MeshPhongMaterial}/ const m = obj.material; m.onBeforeCompile = (shader) => { shader.uniforms.blur = { get value() { return modelMaterialUniforms.blur; }, }; shader.uniforms.blockSize = { get value() { return modelMaterialUniforms.blockSize; }, };
shader.fragmentShader = shader.fragmentShader.replace( /glsl/void main() {, /glsl/// 虚化阈值 uniform float blur; // 虚化区块大小 uniform float blockSize;// 虚化矩阵，自定义区块内的虚化顺序，当像素对应的虚化矩阵值小于blur时，该像素不进行渲染 const mat4 blurMatrix = mat4( 0.1, 0.5, 0.7, 0.3, 0.6, 0.6, 0.9, 0.8, 0.8, 1.0, 0.2, 0.6, 0.3, 0.7, 0.5, 0.4 ); void main() { ivec2 xyInBlur = ivec2(fract(gl_FragCoord.xy / blockSize) * 4.0); if (blurMatrix[xyInBlur.y][xyInBlur.x] <= blur) discard;); }; } }); const mixer = new THREE.AnimationMixer(model); const action = mixer.clipAction(model.animations[0]); action.setLoop(THREE.LoopRepeat); action.play();
const light_ambient = new THREE.AmbientLight(0xffffff, 0.7);
const light_directional = new THREE.DirectionalLight(0xffffff, 0.8); light_directional.position.set(200, 200, 200); light_directional.castShadow = true; light_directional.shadow.camera.left = -100; light_directional.shadow.camera.right = 100; light_directional.shadow.camera.top = 100; light_directional.shadow.camera.bottom = -100; light_directional.shadow.camera.near = 1; light_directional.shadow.camera.far = 1000; light_directional.shadow.mapSize.width = 1024; light_directional.shadow.mapSize.height = 1024;
scene.add(model, light_ambient, light_directional);
const camera = new THREE.PerspectiveCamera(90, 1, 0.1, 1000); camera.position.set(0, 0, 140);
const controls = new OrbitControls(camera, canvas); controls.enableDamping = true;
const timer = new THREE.Timer();
const tick = (delta, elapsed) => { controls.update(delta);
// 更新动画并限制模型不进行移动 mixer.update(delta * 0.9); model.children[2].children[0].position.set(0, 0, 0); };
const render = () => { renderer.render(scene, camera); };
const ani = () => { const elapsed = timer.getElapsed(); const delta = timer.getDelta();
timer.update();
tick(delta, elapsed); render();
requestAnimationFrame(ani); };
const data = { get blur() { return modelMaterialUniforms.blur; }, set blur(v) { modelMaterialUniforms.blur = v; },
get blockSize() { return modelMaterialUniforms.blockSize; }, set blockSize(v) { modelMaterialUniforms.blockSize = v; }, }; const gui = new GUI(); gui.add(data, "blur", 0, 1, 0.001).name("虚化强度"); gui.add(data, "blockSize", 2.0, 20.0, 4.0).name("虚化区块大小");
new ResizeObserver(() => { const rect = document.body.getBoundingClientRect(); const w = rect.width; const h = rect.height; const a = w / h; const dpr = window.devicePixelRatio * 1.25;
renderer.setSize(w, h, false); renderer.setPixelRatio(dpr);
camera.aspect = a; camera.updateProjectionMatrix(); }).observe(document.body);
ani();