变换 Box3 ·Box3 Helper· ▶ 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

• Box3.setFromObject计算物体世界空间 AABB
• Box3Helper可视化黄色包围盒
• TransformControlschange事件驱动包围盒刷新

效果说明

Fox 模型挂载 TransformControls，拖拽时黄色线框包围盒跟随更新，直观看到物体占用空间。

核心概念

const box3 = new THREE.Box3();
const box3Helper = new THREE.Box3Helper(box3, 0xffff00); scene.add(box3Helper);
transformControls.addEventListener('change', () => { box3Helper.box = box3.setFromObject(transformControls.object); });

AABB（轴对齐包围盒）不随物体旋转而旋转，始终与世界轴平行，适合碰撞粗测、视图 fit。

代码要点

import * as THREE from 'three'
import { OrbitControls } from 'three/examples/jsm/controls/OrbitControls.js' import { GLTFLoader } from "three/addons/loaders/GLTFLoader.js" import { TransformControls } from 'three/examples/jsm/controls/TransformControls.js' import { RGBELoader } from 'three/examples/jsm/loaders/RGBELoader.js' import { GUI } from "three/addons/libs/lil-gui.module.min.js";
const box = document.getElementById('box')
const scene = new THREE.Scene()
const camera = new THREE.PerspectiveCamera(50, box.clientWidth / box.clientHeight, 0.1, 1000)
camera.position.set(0, 3, 6)
const renderer = new THREE.WebGLRenderer({ antialias: true, alpha: true, logarithmicDepthBuffer: true })
renderer.setSize(box.clientWidth, box.clientHeight)
renderer.shadowMap.needsUpdate = true
renderer.shadowMap.enabled = true
box.appendChild(renderer.domElement)
const controls = new OrbitControls(camera, renderer.domElement)
controls.enableDamping = true
const folder = new GUI()
// 变换控制器 const transformControls = new TransformControls(camera, renderer.domElement)
folder.add(transformControls, 'mode', ['translate', 'rotate', 'scale']).name('模式')
const transformControlsRoot = transformControls.getHelper()
transformControls.addEventListener('dragging-changed', event => controls.enabled = !event.value)
const box3 = new THREE.Box3()
const box3Helper = new THREE.Box3Helper(box3, 0xffff00)
scene.add(box3Helper)
transformControls.addEventListener('change', () => box3Helper.box = box3.setFromObject(transformControls.object))
scene.add(transformControlsRoot)
// 模型 const texture = new RGBELoader().load(FILE_HOST + '/files/hdr/1k.hdr', t => t.mapping = THREE.EquirectangularReflectionMapping)
new GLTFLoader().load(GLOBAL_CONFIG.getFileUrl('files/model/Fox.glb'), (gltf) => {
const model = gltf.scene
model.scale.set(0.01, 0.01, 0.01)
model.traverse((child) => child.isMesh && (child.material.envMap = texture))
scene.add(model)
transformControls.attach(model)
})
animate()
function animate() {
requestAnimationFrame(animate)
controls.update()
renderer.render(scene, camera)
}

完整源码：GitHub

小结

• 本文提供变换 Box3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