警告信息 · Warn Info · ▶ 在线运行案例

警告信息

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
  • glTF/Draco 模型加载与优化

效果说明

本案例演示 警告信息 效果：基于 WebGL 实现「警告信息」可视化效果，附完整可运行源码；核心用到 ShaderMaterial、OrbitControls、glTF/Draco。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

  1. 搭建 Scene、PerspectiveCamera、WebGLRenderer，挂载 canvas 并处理 resize
  2. 异步加载模型 / 3D Tiles / GeoJSON 等资源并加入 scene 或 entities
  3. 定义 uniforms / onBeforeCompile 或 ShaderMaterial，编写 GLSL 与材质参数
  4. 创建 OrbitControls（及 Raycaster 等交互控件，若源码包含）
  5. 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/addons/controls/OrbitControls.js";
import { GLTFLoader } from "three/addons/loaders/GLTFLoader.js";

const { innerWidth, innerHeight } = window;
const aspect = innerWidth / innerHeight;

class Base {
    constructor() {
        this.init();
        this.main();
    }
    main() {
        const geometry = new THREE.PlaneGeometry(10, 10, 10, 10);
        const material = new THREE.ShaderMaterial({
            side: THREE.DoubleSide,
            transparent: true,
            uniforms: {
                uTime: this.elapsedTime,
            },
            vertexShader: `
                            varying vec2 vUv;
                            void main() {
                                vUv = uv;
                                
                                gl_Position = projectionMatrix * modelViewMatrix * vec4(position,1.0);
                            }
                        `,
            fragmentShader: `
                            varying vec2 vUv;
                            uniform float uTime;

                            void main(){
                                vec3 color = vec3(1.0,0.0,0.0);

                                vec2 center = vec2(0.5,0.5);

                                float dis = distance(vUv,center);

                                float p = 6.0;

                                float r =  fract(dis* p - uTime)/3. + step(0.99, fract(dis* p - uTime));
                                
                                
                                if(dis> 0.5 ){
                                    r = 0.0;
                                } 

                                gl_FragColor = vec4(color,r);
                            }
                        `,
        });
        const mesh = new THREE.Mesh(geometry, material);
        mesh.rotation.x = Math.PI / 2;
        this.scene.add(mesh);
    }
    init() {
        this.clock = new THREE.Clock();

        this.loader = new GLTFLoader();

        this.renderer = new THREE.WebGLRenderer({
            antialias: true,
            logarithmicDepthBuffer: true,
        });
        this.renderer.setPixelRatio(window.devicePixelRatio);
        this.renderer.setSize(innerWidth, innerHeight);
        this.renderer.setAnimationLoop(this.animate.bind(this));
        document.body.appendChild(this.renderer.domElement);

        this.camera = new THREE.PerspectiveCamera(60, aspect, 0.01, 10000);
        this.camera.position.set(5, 5, 5);

        this.scene = new THREE.Scene();

        this.controls = new OrbitControls(this.camera, this.renderer.domElement);

        this.elapsedTime = { value: 0 };

        const grid = new THREE.GridHelper(100);
        this.scene.add(grid);

        const light = new THREE.AmbientLight(0xffffff, 0.5);
        this.scene.add(light);
    }
    animate() {
        this.elapsedTime.value = this.clock.getElapsedTime();
        this.controls.update();
        this.renderer.render(this.scene, this.camera);
    }
}
new Base();

完整源码：GitHub

小结