基于three.js的一个项目类的编写

淩亂°似流年 2022-04-23 17:50 109阅读 0赞

# WebVR #

这是一篇关于怎么样基于three.js进行可配置的three.js的对象创建的文章  
[项目地址][Link 1]

# 编写一个three.js的基类 #

这是创建的一个Three.js基类其中包含了场景，相机，渲染器，控制器以及一些方法

// VRcore.js
      import * as THREE from 'three';
      const OrbitControls = require('three-orbit-controls')(THREE)
      let Scene, Camera, Renderer, Controls, loopID;
    
      function createScene({domContainer = document.body, fov = 50,far = 1000}){
        if (!(domContainer instanceof HTMLElement)) {
          throw new Error('domContainer is not a HTMLElement!');
        }
        // 初始化 scene
        Scene = new THREE.Scene();
        // 初始化 camera
        Camera = new THREE.PerspectiveCamera(fov, domContainer.clientWidth / domContainer.clientHeight, 1, far);
        Camera.position.set( 200, 200, 200 );
        Camera.lookAt(Scene.position);
        Scene.add(Camera);
        // 初始化 renderer
        Renderer = new THREE.WebGLRenderer({ canvas: domContainer, antialias: true, alpha: true } );
        Renderer.clear();
        Renderer.setClearColor( 0xeeeeee, 1); // 更改渲染器颜色
        Renderer.setSize(domContainer.clientWidth, domContainer.clientHeight);
        Renderer.shadowMap.Enabled = true;
        Renderer.setPixelRatio(domContainer.devicePixelRatio);
        initVR();
      }
    
      function initVR() {
          // 初始化控制器
          Controls = new OrbitControls(Camera, Renderer.domElement);;
          Controls.addEventListener('change', render);
          Controls.enableZoom = true;
      }
    
      function render() {
        Renderer.render(Scene, Camera);
      }
    
      function renderStart(callback) {
        loopID = 0; // 记录循环几次，后面有与清除场景中的物体
        if (loopID === -1) return;
        let animate = function(){
          loopID = requestAnimationFrame(animate);
          callback();
          Controls.update();
          render();
        }
        animate();
      }
    
      // 暂停动画渲染
      function renderStop() {
        if (loopID !== -1) {
            window.cancelAnimationFrame(loopID);
            loopID = -1;
        }
      }
      // 回收当前场景
      function clearScene() {
        for(let i = Scene.children.length - 1; i >= 0; i-- ) {
            Scene.remove(Scene.children[i]);
        }
      }
      // 清理页面
      function cleanPage() {
        renderStop();
        clearScene();
      }
    
      export {
        Scene,
        Camera,
        Renderer,
        Controls,
        createScene,
        initVR,
        renderStart,
        renderStop,
        clearScene,
        cleanPage
      }

# 创建一个VRpage基类 #

这是一个VRpage的基类，所有需要创建Three项目都需要继承这个类，然后生成一个Three项目

// VRpage.js
      import * as THREE from 'three';
      import * as VRcore from './VRcore.js';
    
      export default class VRpage {
        constructor(options) {
          // 创建场景
          VRcore.createScene(options);
          this.start();
          this.loadPage();
        }
        loadPage() {
          VRcore.renderStart(() => this.update());
          this.loaded();
        }
        initPage() {
          this.loadPage();
          this.start();
        }
        start() {}
        loaded() {}
        update() {}
      }

# 生成一个Three.js的项目 #

下面的文件是一个继承了VRpage类的一个类，然后我们重写了start方法以及update方法，start方法中我们向场景中添加了一个正方体，update方法是我们给这个正方体的一个变形动画，他会结合VRcore.js里面的renderStart方法来进行动画效果

// page.js
      import * as THREE from 'three';
      import VRpage from '../../utils/VRpage.js';
      import * as VRcore from '../../utils/VRcore.js';
    
      export default class Page extends VRpage {
        start() { // 启动渲染之前，创建场景3d模型
          let geometry = new THREE.CubeGeometry(100,100,100);
          let material = new THREE.MeshLambertMaterial( { color:0x0000ff} );
          this.box = new THREE.Mesh(geometry,material);
          this.box.position.set(3, -2, -3);
          const PointLight = new THREE.PointLight(0xffffff);
          PointLight.position.set(500, 500, 500);
          const AmbientLight = new THREE.AmbientLight( 0x404040 ); // soft white light
          VRcore.Scene.add(PointLight);
          VRcore.Scene.add(AmbientLight);
          VRcore.Scene.background = new THREE.Color( 0xeeeeee ); // 更改场景背景色
          VRcore.Scene.add(this.box);
        }
        update() {
          this.box.rotation.y += 0.01;
        }
      }

这里我使用的是react的框架

// index.js
      import React, { Component } from 'react';
      import PropTypes from 'prop-types';
      import Page from './Page.js';
      class Oho extends Component {
        constructor() {
          super();
          this.init = this.init.bind(this);
        }
    
        componentDidMount() {
          const dom = document.querySelector('#Oho');
          this.init(dom);
        }
    
        init(dom) {
          const page = new Page({domContainer: dom});
        }
    
        render() {
          return (
            <div className="three-demo">
              <canvas id="Oho" ref="camera"></canvas>
            </div>
          );
        }
      }
    
      export default Oho;

[Link 1]: https://github.com/zhangzewei/Oho/blob/master/docs/WebVR.md