学习threejs，局部纹理刷新，实现图片分块加载

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文章目录

一、🍀前言
- 1.1 ☘️Texture 贴图
二、🍀局部纹理刷新，实现图片分块加载
- 1. ☘️实现思路
- 2. ☘️代码样例

一、🍀前言

本文详细介绍如何基于threejs在三维场景中局部纹理刷新，实现图片分块加载，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、🍀局部纹理刷新，实现图片分块加载

1. ☘️实现思路

1、初始化renderer渲染器
2、初始化Scene三维场景scene。
3、初始化camera相机，定义相机位置 camera.position.set
4、创建THREE.MeshBasicMaterial基础材质material。传入THREE.PlaneGeometry平面几何体（使用配置参数）和material创建THREE.Mesh网格对象plane，scene场景中添加plane。创建Image对象img，调用img的onload方法，实现material材质贴图的分块加载，具体代码参考下面代码样例。

2. ☘️代码样例

<!DOCTYPE html>
<html lang="en">
<head><meta charset="UTF-8"><title>learn62(实现局部纹理刷新--图片分块加载)</title><script src="lib/threejs/127/three.js-master/build/three.js"></script><!--<script src="lib/threejs/91/three.js"></script>-->
</head>
<style>body {margin: 0;}canvas {width: 100%;height: 100%;/*width: 4000px;*//*height: 2000px;*/display: block;}
</style>
<body onload="init()">
</body>
<script>var renderer, camera, scene, geometry, material, meshvar initRender = () => {renderer = new THREE.WebGLRenderer()renderer.setSize(window.innerWidth, window.innerHeight)document.body.appendChild(renderer.domElement)}var initScene = () => {scene = new THREE.Scene()}var initCamera = () => {camera = new THREE.PerspectiveCamera(45, window.innerWidth / window.innerHeight, 0.1, 20000)camera.position.set(0, 0, 3000)}var initMesh = () => {material = new THREE.MeshBasicMaterial({map: new THREE.Texture()})let sceneBlockModel = {sceneWidth: 6912,sceneHeight: 3456,fileBlockWidth: 1024,fileBlockHeight: 512,dir: 'data/img/fenge/'}let plane = new THREE.Mesh(new THREE.PlaneGeometry(sceneBlockModel.sceneWidth, sceneBlockModel.sceneHeight), material)scene.add(plane)let img = new Image()img.onload = () => {let canvas = document.createElement('canvas')let ctx = canvas.getContext('2d')canvas.width = sceneBlockModel.sceneWidthcanvas.height = sceneBlockModel.sceneHeightctx.drawImage(img, 0, 0, sceneBlockModel.sceneWidth, sceneBlockModel.sceneHeight)material.map.image = canvasmaterial.map.minFilter = THREE.LinearFiltermaterial.map.generateMipmaps = falsematerial.map.needsUpdate = true//加载分块图片let xLen = Math.ceil(sceneBlockModel.sceneWidth / sceneBlockModel.fileBlockWidth)let yLen = Math.ceil(sceneBlockModel.sceneHeight / sceneBlockModel.fileBlockHeight)setTimeout(() => {for (let x = 0; x < xLen; x++) {for (let y = 0; y < yLen; y++) {let img = new Image()img.src = sceneBlockModel.dir + x + "_" + y + ".jpg"img.onload = function () {let texture = new THREE.Texture(img)//获取渲染的起始位置let position = new THREE.Vector2()position.x = y * sceneBlockModel.fileBlockWidthif (x === yLen - 1) {position.y = 0}else {position.y = (yLen - 2 - x) * sceneBlockModel.fileBlockHeight + (sceneBlockModel.sceneHeight % sceneBlockModel.fileBlockHeight) + 125}renderer.copyTextureToTexture(position, texture, material.map)}}}}, 3000)}img.src = 'data/img/fengeyt/preview.jpg'}var animate = () => {requestAnimationFrame(animate)renderer.render(scene, camera)}var init = () => {initRender()initScene()initCamera()initMesh()animate()}
</script>
</html>