首先放个最终效果图:
三维(3D)概念:
三维(3D)是一个描述物体在三个空间坐标轴上的位置和形态的概念。相比于二维(2D)只有长度和宽度的平面,三维增加了高度或深度这一维度
在三维空间中,我们使用三个独立的坐标轴来描述物体的位置。通常使用笛卡尔坐标系,即X、Y和Z轴。其中,X轴表示横向,Y轴表示纵向,Z轴表示纵深或垂直方向。通过在这些轴上的不同值组合,可以确定一个点或对象在三维空间中的位置
大家可以three编辑器中感受一下三维:three.js editor
ps:默认英文,可以切换中文语言
three前提概念
以舞台展示为例:
- 场景
Sence
相当于一个舞台,在这里是布置场景物品和表演者表演的地方 - 相机
Carma
相当于观众的眼睛去观看 - 几何体
Geometry
相当于舞台的表演者 - 灯光
light
相当于舞台灯光照射控制 Controls
相当于这出舞台剧的总导演
创建场景与相机
<html><head><meta charset="utf-8"><title>My first three.js app</title>
</head><body><script src="https://code.jquery.com/jquery-3.6.0.min.js"></script><script type="importmap">{"imports": {"three": "./three.module.js"}}</script><script type="module">import { Scene, WebGLRenderer, PerspectiveCamera } from 'three'let scene,renderer,camera//创建场景const setScene = () => {scene = new Scene()renderer = new WebGLRenderer()//调用 setSize() 方法设置渲染器的大小为当前窗口的宽度和高度renderer.setSize(window.innerWidth, window.innerHeight)//将渲染器的 DOM 元素添加到页面的 <body> 元素中document.body.appendChild(renderer.domElement)}//相机的默认坐标const defaultMap = {x: 0,y: 10,z: 20,}//创建相机 const setCamera = () => {const { x, y, z } = defaultMap//创建一个 PerspectiveCamera 对象,并传入参数来设置透视相机的属性:视野角度为 45 度,宽高比为窗口的宽高比,近裁剪面为 1,远裁剪面为 1000camera = new PerspectiveCamera(45, window.innerWidth / window.innerHeight, 1, 1000)//用 position.set() 方法将相机的位置设置为之前从 defaultMap 中提取的坐标camera.position.set(x, y, z)}(function () {setScene()setCamera()})()</script>
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PerspectiveCamera的详细说明:
new THREE.PerspectiveCamera构造函数用来创建透视投影相机,该构造函数总共有四个参数,分别是fov,aspect,near,far 。
fov表示摄像机视锥体垂直视野角度,最小值为0,最大值为180,默认值为50,实际项目中一般都定义45,因为45最接近人正常睁眼角度;aspect表示摄像机视锥体长宽比,默认长宽比为1,即表示看到的是正方形,实际项目中使用的是屏幕的宽高比;near表示摄像机视锥体近端面,这个值默认为0.1,实际项目中都会设置为1;far表示摄像机视锥体远端面,默认为2000,这个值可以是无限的,说的简单点就是我们视觉所能看到的最远距离。
引入模型
国外一个3d模型下载网站,里面有很多免费的模型下载 点击红框处下载
Log in to your Sketchfab account - Sketchfab
<html><head><meta charset="utf-8"><title>My first three.js app</title>
</head><body><script src="https://code.jquery.com/jquery-3.6.0.min.js"></script><script type="importmap">{"imports": {"three": "./three.module.js"}}</script><script type="module">import { GLTFLoader } from 'three/examples/jsm/loaders/GLTFLoader'import { Scene, WebGLRenderer, PerspectiveCamera } from 'three'let scene, renderer, camera, directionalLight, dhelperlet isLoading = truelet loadingWidth = 0//创建场景const setScene = () => {scene = new Scene()renderer = new WebGLRenderer()renderer.setSize(window.innerWidth, window.innerHeight)document.body.appendChild(renderer.domElement)}//相机的默认坐标const defaultMap = {x: 0,y: 10,z: 20,}//创建相机 const setCamera = () => {const { x, y, z } = defaultMapcamera = new PerspectiveCamera(45, window.innerWidth / window.innerHeight, 1, 1000)camera.position.set(x, y, z)}//通过Promise处理一下loadfile函数const loader = new GLTFLoader() //引入模型的loader实例const loadFile = (url) => {return new Promise(((resolve, reject) => {loader.load(url,(gltf) => {resolve(gltf)}, ({ loaded, total }) => {let load = Math.abs(loaded / total * 100)loadingWidth = loadif (load >= 100) {setTimeout(() => {isLoading = false}, 1000)}console.log((loaded / total * 100) + '% loaded')},(err) => {reject(err)})}))}(async function () {const gltf = await loadFile('./assets/scene.gltf')setScene()setCamera()scene.add(gltf.scene)})()</script>
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加载模型代码讲解:
loader.load 用来加载和解析 glTF 文件,接受四个参数:
- 第一个参数
url
是要加载的 glTF 模型文件的路径。 - 第二个参数是一个回调函数,当模型加载成功时会被调用
- 第三个参数是一个回调函数,用于跟踪加载进度。回调函数的
{ loaded, total }
参数表示已加载和总共需要加载的文件数量,通过计算百分比可以得到当前加载进度。 - 第四个参数是一个回调函数,当加载出错时会被调用。
创建灯光
<html><head><meta charset="utf-8"><title>My first three.js app</title>
</head><body><script src="https://code.jquery.com/jquery-3.6.0.min.js"></script><script type="importmap">{"imports": {"three": "./three.module.js"}}</script><script type="module">import { GLTFLoader } from 'three/examples/jsm/loaders/GLTFLoader'import { Scene, WebGLRenderer, PerspectiveCamera } from 'three'let scene, renderer, camera, directionalLight, dhelperlet isLoading = truelet loadingWidth = 0//创建场景const setScene = () => {scene = new Scene()renderer = new WebGLRenderer()renderer.setSize(window.innerWidth, window.innerHeight)document.body.appendChild(renderer.domElement)}//相机的默认坐标const defaultMap = {x: 0,y: 10,z: 20,}//创建相机 const setCamera = () => {const { x, y, z } = defaultMapcamera = new PerspectiveCamera(45, window.innerWidth / window.innerHeight, 1, 1000)camera.position.set(x, y, z)}// 设置灯光const setLight = () => {// 创建一个颜色为白色(0xffffff),强度为 0.5 的平行光对象directionalLight = new DirectionalLight(0xffffff, 0.5)//设置平行光的位置,这里将其放置在三维坐标 (-4, 8, 4) 的位置directionalLight.position.set(-4, 8, 4)//创建一个平行光辅助对象,用于可视化平行光的方向和强度dhelper = new DirectionalLightHelper(directionalLight, 5, 0xff0000)//创建一个颜色为白色(0xffffff),半球颜色为白色(0xffffff),强度为 0.4 的半球光对象hemisphereLight = new HemisphereLight(0xffffff, 0xffffff, 0.4)hemisphereLight.position.set(0, 8, 0)//创建一个半球光辅助对象,用于可视化半球光的方向和强度hHelper = new HemisphereLightHelper(hemisphereLight, 5)//添加到场景scene.add(directionalLight)//添加到场景scene.add(hemisphereLight)}//使场景、照相机、模型不停调用const loop = () => {//requestAnimationFrame(loop) 是浏览器提供的方法,用于在下一次重绘页面之前调用回调函数 loop。这样可以创建一个循环,使场景、相机和模型不断被渲染更新requestAnimationFrame(loop)//使用渲染器 renderer 渲染场景 scene 中的模型,使用相机 camera 进行投影renderer.render(scene, camera)}//通过Promise处理一下loadfile函数const loader = new GLTFLoader() //引入模型的loader实例const loadFile = (url) => {return new Promise(((resolve, reject) => {// loader.load 用来加载和解析 glTF 文件loader.load(url,(gltf) => {resolve(gltf)}, ({ loaded, total }) => {let load = Math.abs(loaded / total * 100)loadingWidth = loadif (load >= 100) {setTimeout(() => {isLoading = false}, 1000)}console.log((loaded / total * 100) + '% loaded')},(err) => {reject(err)})}))}(async function () {const gltf = await loadFile('./assets/scene.gltf')setScene()setCamera()setLight()scene.add(gltf.scene)loop()})()</script>
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DirectionalLight
和 HemisphereLight
是 Three.js 中的两种灯光类型,分别表示平行光和半球光。它们用于模拟现实世界中的光照效果
此刻模型已经可以看见了,如何你只能看见黑黑的一片,无法看到模型,一般两个原因:
- 模型是否加载成功
try {gltf = await loadFile('./assets/scene.gltf');console.log('Model loading completed:', gltf);
} catch (error) {console.error('Error loading model:', error);
}
- 相机位置偏差,调整下相机(defaultMap)的位置
控制模型
这一步完成之后,模型就可以通过鼠标移动,旋转了
<html><head><meta charset="utf-8"><title>My first three.js app</title>
</head><body><script src="https://code.jquery.com/jquery-3.6.0.min.js"></script><script type="importmap">{"imports": {"three": "./three.module.js"}}</script><script type="module">import { Scene, WebGLRenderer, PerspectiveCamera, DirectionalLight, HemisphereLight, DirectionalLightHelper, HemisphereLightHelper } from 'three'import { GLTFLoader } from './jsm/loaders/GLTFLoader.js'import { OrbitControls } from './jsm/controls/OrbitControls.js'let scene, renderer, camera, directionalLight, hemisphereLight, dhelper, hHelper, controlslet isLoading = truelet loadingWidth = 0//创建场景const setScene = () => {scene = new Scene()renderer = new WebGLRenderer()renderer.setSize(window.innerWidth, window.innerHeight)document.body.appendChild(renderer.domElement)}//相机的默认坐标const defaultMap = {x: 0,y: 10,z: 20,}//创建相机 const setCamera = () => {const { x, y, z } = defaultMapcamera = new PerspectiveCamera(45, window.innerWidth / window.innerHeight, 1, 1000)camera.position.set(x, y, z)}// 设置灯光const setLight = () => {directionalLight = new DirectionalLight(0xffffff, 0.5)directionalLight.position.set(-4, 8, 4)dhelper = new DirectionalLightHelper(directionalLight, 5, 0xff0000)hemisphereLight = new HemisphereLight(0xffffff, 0xffffff, 0.4)hemisphereLight.position.set(0, 8, 0)hHelper = new HemisphereLightHelper(hemisphereLight, 5)scene.add(directionalLight)scene.add(hemisphereLight)}//使场景、照相机、模型不停调用const loop = () => {requestAnimationFrame(loop)renderer.render(scene, camera)controls.update()}// 设置模型控制const setControls = () => {// 创建一个新的 OrbitControls 对象,并将它绑定到相机 camera 和渲染器的 DOM 元素 renderer.domElement 上controls = new OrbitControls(camera, renderer.domElement)// 设置相机的最大仰角(上下旋转角度),这里将其限制为 0.9 * π / 2controls.maxPolarAngle = 0.9 * Math.PI / 2//启用相机的缩放功能,允许用户通过鼠标滚轮或触摸手势进行缩放操作controls.enableZoom = true//监听控制器的变化事件,当用户操作控制器导致相机位置发生改变时,触发渲染函数 rendercontrols.addEventListener('change', render)}//在相机位置发生变化时,将新的相机位置保存到 defaultMap 对象中const render = () => {defaultMap.x = Number.parseInt(camera.position.x)defaultMap.y = Number.parseInt(camera.position.y)defaultMap.z = Number.parseInt(camera.position.z)}//通过Promise处理一下loadfile函数const loader = new GLTFLoader() //引入模型的loader实例const loadFile = (url) => {return new Promise(((resolve, reject) => {// loader.load 用来加载和解析 glTF 文件loader.load(url,(gltf) => {resolve(gltf)}, ({ loaded, total }) => {let load = Math.abs(loaded / total * 100)loadingWidth = loadif (load >= 100) {setTimeout(() => {isLoading = false}, 1000)}console.log((loaded / total * 100) + '% loaded')},(err) => {reject(err)})}))}(async function () {setScene()setCamera()setLight()setControls()const gltf = await loadFile('./assets/scene.gltf')scene.add(gltf.scene)loop()})()</script>
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ps:这段代码没问题,可正常运行,前两三个可能会有些引入缺失或者声明变量的缺失,大家参考这个补齐,我就不去查漏补缺了
改变车身颜色
scene
有一个traverse
函数,它回调了所有模型的子模型信息,只要我们找到对应name属性,就可以更改颜色,和增加贴图等等
//设置车身颜色const setCarColor = (index) => {//Color 是 Three.js 中的一个类,用于表示颜色。它的作用是创建和管理三维场景中物体的颜色const currentColor = new Color(colorAry[index])// 使用 Three.js 中的 traverse 方法遍历场景中的每个子对象scene.traverse(child => {if (child.isMesh) {console.log(child)if (child.name) {//将当前子对象的材质颜色设置为 currentColor,实现改变颜色的效果child.material.color.set(currentColor)}}})}
整个的完整代码:
<html><head><meta charset="utf-8"><title>My first three.js app</title><style>body {margin: 0;}.maskLoading {background: #000;position: fixed;display: flex;justify-content: center;align-items: center;top: 0;left: 0;bottom: 0;right: 0;z-index: 1111111;color: #fff;}.maskLoading .loading {width: 400px;height: 20px;border: 1px solid #fff;background: #000;overflow: hidden;border-radius: 10px;}.maskLoading .loading div {background: #fff;height: 20px;width: 0;transition-duration: 500ms;transition-timing-function: ease-in;}canvas {width: 100%;height: 100%;margin: auto;}.mask {color: #fff;position: absolute;bottom: 0;left: 0;width: 100%;}.flex {display: flex;flex-wrap: wrap;padding: 20px;}.flex div {width: 10px;height: 10px;margin: 5px;cursor: pointer;}</style>
</head><body><div class="boxs"><div class="maskLoading"><div class="loading"><div class="oneDiv"></div></div><div style="padding-left: 10px;" class="twoDiv"></div></div><div class="mask"><p class="realTimeDate"></p><button class="rotatingCar">转动车</button><button class="stop">停止</button><div class="flex" id="colorContainer"></div></div></div><script src="https://code.jquery.com/jquery-3.6.0.min.js"></script><script type="importmap">{"imports": {"three": "./three.module.js"}}</script><script type="module">import {Color,DirectionalLight,DirectionalLightHelper,HemisphereLight,HemisphereLightHelper,PerspectiveCamera,Scene,WebGLRenderer} from 'three'import { GLTFLoader } from './jsm/loaders/GLTFLoader.js'import { OrbitControls } from './jsm/controls/OrbitControls.js'//车身颜色数组const colorAry = ["rgb(216, 27, 67)", "rgb(142, 36, 170)", "rgb(81, 45, 168)", "rgb(48, 63, 159)", "rgb(30, 136, 229)", "rgb(0, 137, 123)","rgb(67, 160, 71)", "rgb(251, 192, 45)", "rgb(245, 124, 0)", "rgb(230, 74, 25)", "rgb(233, 30, 78)", "rgb(156, 39, 176)","rgb(0, 0, 0)"]let scene, camera, renderer, controls, floor, dhelper, hHelper, directionalLight, hemisphereLightlet gltflet isLoading = truelet loadingWidth = 0//相机的默认坐标const defaultMap = {x: 0,y: 10,z: 20,}//遮罩层const maskLayer = () => {if (isLoading) {$('.maskLoading').hide();} else {$('.maskLoading').show()}}maskLayer()// 进度const schedule = () => {let timer = setInterval(function () {$('oneDiv').css('width', `${loadingWidth}%`);$('twoDiv').text(`${loadingWidth}%`);if (loadingWidth == 100) {clearInterval(timer);}}, 10);}schedule()//实时更新x,y,zconst realTime = () => {let timer = setInterval(function () {$('realTimeDate').text(`x:${defaultMap.x} y:${defaultMap.y} z:${defaultMap.z}`);}, 10);}// 生成颜色旋转块$.each(colorAry, function (index, item) {$('<div>').appendTo('#colorContainer') // 在 #colorContainer 中创建一个 <div> 元素.css('background-color', item) // 设置背景颜色.click(function () {setCarColor(index); // 调用 setCarColor 函数并传递索引参数});});//创建场景const setScene = () => {scene = new Scene()renderer = new WebGLRenderer()renderer.setSize(window.innerWidth, window.innerHeight)document.body.appendChild(renderer.domElement)}//创建相机 const setCamera = () => {const { x, y, z } = defaultMapcamera = new PerspectiveCamera(45, window.innerWidth / window.innerHeight, 1, 1000)camera.position.set(x, y, z)}//引入模型的loader实例const loader = new GLTFLoader()//通过Promise处理一下loadfile函数const loadFile = (url) => {return new Promise(((resolve, reject) => {loader.load(url,(gltf) => {resolve(gltf)}, ({ loaded, total }) => {let load = Math.abs(loaded / total * 100)loadingWidth = loadif (load >= 100) {setTimeout(() => {isLoading = false}, 1000)}console.log((loaded / total * 100) + '% loaded')},(err) => {reject(err)})}))}// 设置灯光const setLight = () => {directionalLight = new DirectionalLight(0xffffff, 0.8)directionalLight.position.set(-4, 8, 4)dhelper = new DirectionalLightHelper(directionalLight, 5, 0xff0000)hemisphereLight = new HemisphereLight(0xffffff, 0xffffff, 0.4)hemisphereLight.position.set(0, 8, 0)hHelper = new HemisphereLightHelper(hemisphereLight, 5)scene.add(directionalLight)scene.add(hemisphereLight)}// 设置模型控制const setControls = () => {controls = new OrbitControls(camera, renderer.domElement)controls.maxPolarAngle = 0.9 * Math.PI / 2controls.enableZoom = truecontrols.addEventListener('change', render)}//返回坐标信息const render = () => {defaultMap.x = Number.parseInt(camera.position.x)defaultMap.y = Number.parseInt(camera.position.y)defaultMap.z = Number.parseInt(camera.position.z)}(async function () {setScene()setCamera()setLight()setControls()try {gltf = await loadFile('./assets/scene.gltf');console.log('Model loading completed:', gltf);} catch (error) {console.error('Error loading model:', error);}scene.add(gltf.scene)loop()})()//使场景、照相机、模型不停调用const loop = () => {requestAnimationFrame(loop)renderer.render(scene, camera)controls.update()}//是否自动转动$('.rotatingCar').click(function () {console.log("旋转")controls.autoRotate = true})//停止转动$('.stop').click(function () {console.log("停止")controls.autoRotate = false})//设置车身颜色const setCarColor = (index) => {const currentColor = new Color(colorAry[index])scene.traverse(child => {if (child.isMesh) {console.log(child)if (child.name) {child.material.color.set(currentColor)}}})}</script>
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完结撒花*★,°*:.☆( ̄▽ ̄)/$:*.°★* 。