学习threejs，使用canvas更新纹理

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文章目录

一、🍀前言
- 1.1 ☘️Texture 贴图
二、🍀使用canvas更新纹理
- 1. ☘️实现思路
- 2. ☘️代码样例

一、🍀前言

本文详细介绍如何基于threejs在三维场景中使用canvas更新纹理，亲测可用。希望能帮助到您。一起学习，加油！加油！

1.1 ☘️Texture 贴图

创建一个纹理贴图，将其应用到一个表面，或者作为反射/折射贴图。
构造函数：
Texture( image, mapping, wrapS, wrapT, magFilter, minFilter, format, type, anisotropy, encoding )
常用属性：
在这里插入图片描述
方法：

二、🍀使用canvas更新纹理

1. ☘️实现思路

1、初始化renderer渲染器
2、初始化Scene三维场景scene，创建THREE.CubeTextureLoader立方体纹理加载器cubeTextureLoader，加载cubeTextureLoader的六个方位的图片获取纹理对象cubeTexture，scene背景background设置为cubeTexture。
3、创建id为‘surface’的canvas页面元素火焰然后动画，并执行。具体实现参考下面代码样例。
4、初始化camera相机，定义相机位置 camera.position.set
5、初始化THREE.AmbientLight环境光源，scene场景加入环境光源，初始化THREE.DirectionalLight平行光源，设置平行光源位置，设置平行光源投影，scene添加平行光源。
6、加载几何模型：创建THREE.AxesHelper坐标辅助工具helper，scene场景中加入helper。创建THREE.BoxGeometry立方体几何体geometry，创建THREE.MeshBasicMaterial基础材质material，material设置map贴图（为步骤3canvas元素）、水平和垂直贴图包裹，传入geometry和material创建THREE.Mesh网格对象，scene中加入创建的网格对象。
7、加入controls控制，加入stats监控器，监控帧数信息。

2. ☘️代码样例

<!DOCTYPE html>
<html lang="en">
<head><meta charset="UTF-8"><title>learn60(使用CANVAS更新纹理)</title><script src="lib/threejs/127/three.js-master/build/three.js"></script><script src="https://cdn.bootcss.com/jquery/3.3.1/jquery.min.js"></script><script src="lib/threejs/127/three.js-master/examples/js/controls/OrbitControls.js"></script><script src="lib/threejs/127/three.js-master/examples/js/libs/stats.min.js"></script><script src="lib/threejs/127/three.js-master/examples/js/libs/dat.gui.min.js"></script><script src="lib/js/Detector.js"></script>
</head>
<style type="text/css">html, body {margin: 0;height: 100%;}canvas {display: block;}#surface {position: fixed;left: 0;bottom: 0;}
</style>
<body onload="draw()">
<canvas id="surface"></canvas>
</body>
<script>var renderer, camera, scene, gui, light, stats, controls//引入一个canvas动画function initCanvas() {$(document).ready(function () {// Set canvas drawing surfacevar space = document.getElementById("surface")var surface = space.getContext("2d")surface.scale(1, 1)// Set Particlesvar particles = []var particle_count = 150for (var i = 0; i < particle_count; i++) {particles.push(new particle())}var time = 0// Set wrapper and canvas items sizevar canvasWidth = 480var canvasHeight = 480$(".wrapper").css({width: canvasWidth, height: canvasHeight})$("#surface").css({width: canvasWidth, height: canvasHeight})// shim layer with setTimeout fallback from Paul Irishwindow.requestAnimFrame = (function () {return window.requestAnimationFrame ||window.webkitRequestAnimationFrame ||window.mozRequestAnimationFrame ||function (callback) {window.setTimeout(callback, 6000 / 60)}})()function particle() {this.speed = {x: -1 + Math.random() * 2, y: -5 + Math.random() * 5}canvasWidth = (document.getElementById("surface").width)canvasHeight = (document.getElementById("surface").height)this.location = {x: canvasWidth / 2, y: (canvasHeight / 2) + 35}this.radius = .5 + Math.random() * 1this.life = 10 + Math.random() * 10this.death = this.lifethis.r = 255this.g = Math.round(Math.random() * 155)this.b = 0}function ParticleAnimation() {surface.globalCompositeOperation = "source-over"surface.fillStyle = "black"surface.fillRect(0, 0, canvasWidth, canvasHeight)surface.globalCompositeOperation = "lighter"for (var i = 0; i < particles.length; i++) {var p = particles[i]surface.beginPath()p.opacity = Math.round(p.death / p.life * 100) / 100var gradient = surface.createRadialGradient(p.location.x, p.location.y, 0, p.location.x, p.location.y, p.radius)gradient.addColorStop(0, "rgba(" + p.r + ", " + p.g + ", " + p.b + ", " + p.opacity + ")")gradient.addColorStop(0.5, "rgba(" + p.r + ", " + p.g + ", " + p.b + ", " + p.opacity + ")")gradient.addColorStop(1, "rgba(" + p.r + ", " + p.g + ", " + p.b + ", 0)")surface.fillStyle = gradientsurface.arc(p.location.x, p.location.y, p.radius, Math.PI * 2, false)surface.fill()p.death--p.radius++p.location.x += (p.speed.x)p.location.y += (p.speed.y)//regenerate particlesif (p.death < 0 || p.radius < 0) {//a brand new particle replacing the dead oneparticles[i] = new particle()}}requestAnimFrame(ParticleAnimation)}ParticleAnimation()})}var initRender = () => {renderer = new THREE.WebGLRenderer({antialias: true})renderer.setClearColor(0xeeeeee)renderer.setSize(window.innerWidth, window.innerHeight)renderer.shadowMap.enabled = truerenderer.setPixelRatio(window.devicePixelRatio)document.body.appendChild(renderer.domElement)}var initCamera = () => {camera = new THREE.PerspectiveCamera(45, window.innerWidth / window.innerHeight, 0.1, 1000)camera.position.set(0, 0, 15)}var initScene = () => {var cubeTextureLoader = new THREE.CubeTextureLoader()cubeTextureLoader.setPath('data/texture/skybox/space/')var cubeTexture = cubeTextureLoader.load(['right.jpg', 'left.jpg','top.jpg', 'bottom.jpg','front.jpg', 'back.jpg'])scene = new THREE.Scene()scene.background = cubeTexture}var initLight = () => {scene.add(new THREE.AmbientLight(0x444444))light = new THREE.DirectionalLight(0xffffff)light.position.set(0, 20, 20)light.castShadow = truescene.add(light)}var initModel = () => {var helper = new THREE.AxesHelper(50)scene.add(helper)var geometry = new THREE.BoxBufferGeometry(5, 5, 5)var canvas = $('#surface')[0]var texture = new THREE.Texture(canvas)material = new THREE.MeshBasicMaterial({map: texture})scene.add(new THREE.Mesh(geometry, material))}var initStats = () => {stats = new Stats()document.body.appendChild(stats.dom)}var initControls = () => {controls = new THREE.OrbitControls(camera, renderer.domElement)controls.enableDamping = true}var render = () => {material.map.needsUpdate = truerenderer.render(scene, camera)}var onWindowResize = () => {camera.aspect = window.innerWidth / window.innerHeightcamera.updateProjectionMatrix()renderer.setSize(window.innerWidth, window.innerHeight)}var animate = () => {render()stats.update()controls.update()requestAnimationFrame(animate)}var draw = () => {if(!Detector.webgl)Detector.addGetWebGLMessage()initCanvas()initRender()initScene()initCamera()initLight()initModel()initStats()initControls()animate()window.onresize = onWindowResize}
</script>
</html>