建筑线条 · Building Line · ▶ 在线运行案例

建筑线条

你将学到什么

  • OrbitControls 相机轨道交互
  • glTF/Draco 模型加载与优化
  • EdgesGeometry 模型边线提取
  • requestAnimationFrame 渲染循环与 resize 自适应

效果说明

本案例演示 建筑线条 效果：基于 WebGL 实现「建筑线条」可视化效果，附完整可运行源码；核心用到 OrbitControls、glTF/Draco、EdgesGeometry。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。
  • OrbitControls 提供轨道旋转/缩放；开启 enableDamping 后需在 animate 中 controls.update()。
  • 阅读下方完整源码时，建议从 init / load / animate 三条主线入手，再深入 shader 与工具函数。

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. 创建 OrbitControls（及 Raycaster 等交互控件，若源码包含）
  4. 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'
import { GLTFLoader } from 'three/examples/jsm/loaders/GLTFLoader.js'
import { LineSegments2 } from 'three/examples/jsm/lines/LineSegments2.js';
import { LineMaterial } from 'three/examples/jsm/lines/LineMaterial.js';
import { LineSegmentsGeometry } from 'three/examples/jsm/lines/LineSegmentsGeometry.js';

const box = document.getElementById('box')

const scene = new THREE.Scene()

const camera = new THREE.PerspectiveCamera(75, box.clientWidth / box.clientHeight, 0.1, 100000)

camera.position.set(1, 1, 1)

const renderer = new THREE.WebGLRenderer({ antialias: true, alpha: true })

renderer.setPixelRatio(window.devicePixelRatio * 1.3)

renderer.setSize(box.clientWidth, box.clientHeight)

box.appendChild(renderer.domElement)

new OrbitControls(camera, renderer.domElement)

scene.add(new THREE.AxesHelper(100))

animate()

function animate() {

    requestAnimationFrame(animate)

    renderer.render(scene, camera)

}

window.onresize = () => {

    renderer.setSize(box.clientWidth, box.clientHeight)

    camera.aspect = box.clientWidth / box.clientHeight

    camera.updateProjectionMatrix()

}

const urls = [0, 1, 2, 3, 4, 5].map(k => (FILE_HOST + 'files/sky/skyBox0/' + (k + 1) + '.png'));

const textureCube = new THREE.CubeTextureLoader().load(urls);

new GLTFLoader().load(FILE_HOST + 'models/whitebuild.glb', (gltf) => {

    const model = gltf.scene

    model.traverse((child) => {

        if (child.isMesh) {

            child.material.envMap = textureCube

            const { geometry } = child
            const edges = new THREE.EdgesGeometry(geometry)
            let lineGeometry = new LineSegmentsGeometry().fromEdgesGeometry(edges)
            const material = new LineMaterial({
                color: 0xfcde8c,
                linewidth: 2.5,
                envMap: textureCube,
                resolution: new THREE.Vector2(box.clientWidth, box.clientHeight)
            })

            const lines = new LineSegments2(lineGeometry, material)
            lines.computeLineDistances()
            lines.applyMatrix4(child.matrixWorld)

            scene.add(lines)
        }

    })

    scene.add(model)
})

完整源码：GitHub

小结