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();

  完整源码：GitHub

  小结

  • 本文提供人物虚化完整 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