模型视图 ·Model Views· ▶ 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

• 用Box3 + FOV反算「刚好框住模型」的相机距离
• 绕 Y/X 轴旋转观察方向得到六视图位置
• gsap 切换camera.position与controls.target

效果说明

加载电脑模型，GUI 按钮前视图 / 右视图 / 上视图，相机平滑飞到对应标准视角，target 始终为模型中心。

核心概念

const box = new THREE.Box3().setFromObject(object);
const center = box.getCenter(new THREE.Vector3()); const radius = box.max.clone().sub(box.min).length() / 2;
// 距离 = 半径 / tan(fov/2) const distance = radius / Math.tan(Math.PI * fov / 360); const dir = object.getWorldDirection(new THREE.Vector3()); const frontView = dir.clone().multiplyScalar(distance).add(center);
// 右视图：方向绕 Y 转 90° const rightView = dir.clone() .applyAxisAngle(new THREE.Vector3(0, 1, 0), Math.PI / 2) .add(center);

这是 CAD/编辑器「正视图」「俯视图」按钮的常用算法。

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 { GUI } from 'dat.gui' import gsap from 'gsap'
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(5, 5, 5)
const renderer = new THREE.WebGLRenderer({ antialias: true, alpha: true, logarithmicDepthBuffer: true })
renderer.setSize(box.clientWidth, box.clientHeight)
box.appendChild(renderer.domElement)
const controls = new OrbitControls(camera, renderer.domElement)
controls.enableDamping = true
window.onresize = () => {
renderer.setSize(box.clientWidth, box.clientHeight)
camera.aspect = box.clientWidth / box.clientHeight
camera.updateProjectionMatrix()
}
let model
const gui = new GUI()
new GLTFLoader().load(
FILE_HOST + 'models/glb/computer.glb',
gltf => {
model = scene.add(gltf.scene)
const { frontView, target, rightView, topView, bottomView, backView, maxView } = getObjectViews(model)
const setView = view => {
createGsapAnimation(controls.object.position, view)
createGsapAnimation(controls.target, target)
}
gui.add({ '前视图': () => setView(frontView) }, '前视图')
gui.add({ '右视图': () => setView(rightView) }, '右视图')
gui.add({ '上视图': () => setView(topView) }, '上视图')
}
)
animate()
function animate() {
requestAnimationFrame(animate)
controls.update()
renderer.render(scene, camera)
}
function getObjectViews(object, fov = 50) {
const box = new THREE.Box3().setFromObject(object)
const { max, min } = box
const center = new THREE.Vector3()
box.getCenter(center)
const radius = new THREE.Vector3().subVectors(max, min).length() / 2
const dir = object.getWorldDirection(new THREE.Vector3()) // 物体方向
const distance = radius / Math.tan(Math.PI * fov / 360) // 根据半径和相机视角 计算出距离
const vector = dir.multiplyScalar(distance) // 方向距离向量
const frontView = vector.clone().add(center)
const leftView = vector.clone().applyAxisAngle(new THREE.Vector3(0, 1, 0), -Math.PI / 2).add(center)
const rightView = vector.clone().applyAxisAngle(new THREE.Vector3(0, 1, 0), Math.PI / 2).add(center)
const topView = vector.clone().applyAxisAngle(new THREE.Vector3(1, 0, 0), -Math.PI / 2).add(center)
const bottomView = vector.clone().applyAxisAngle(new THREE.Vector3(1, 0, 0), Math.PI / 2).add(center)
const backView = vector.clone().applyAxisAngle(new THREE.Vector3(0, 1, 0), Math.PI).add(center)
return { frontView, leftView, rightView, topView, bottomView, backView, target: center }
}
function createGsapAnimation(position, position_) {
return gsap.to(
position,
{
...position_,
duration: 1,
ease: 'none',
repeat: 0,
yoyo: false,
yoyoEase: true,
}
)
}

完整源码：GitHub

小结

• 本文提供模型视图完整 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