使用vue学习three.js之移动相机-使用飞行控件FlyControls控制相机

Posted 2021-06-08 点燃火柴

使用飞行控件FlyControls控制相机

• 1.demo效果
• 2.FlyControls介绍
• 3. 实现要点
• • 3.1 vue中引入FlyControls控制器
  • 3.2 创建飞行控件实例
  • 3.3 render中更新飞行控件
• 4. demo代码

1.demo效果

如上图，该demo通过飞行控件FlyControls控制相机。实现视图的上下左右前后移动，左右翻滚，跟随鼠标移动等效果

2.FlyControls介绍

通过飞行控件FlyControls 可以实现场景的前后左右移动，左右翻滚，跟随鼠标四周移动

FlyControls操控说明
以下是操控和动作的比对说明

操控	动作
按住左键	向前移动
按住右键	向后移动
移动鼠标	往四周看
方向键	向对应方向移动
R	向上移动
F	向下移动
A	向左移动
D	向右移动
W	向前移动
S	向后移动
Q	向左翻滚
E	向右翻滚

3. 实现要点

3.1 vue中引入FlyControls控制器

在项目工程中引入FlyControls控制器如下

import { FlyControls } from 'three/examples/jsm/controls/FlyControls.js'

3.2 创建飞行控件实例

// 创建飞行控件
createTrackballControls() {
  this.clock = new THREE.Clock()
  this.flyControls = new FlyControls(this.camera, this.renderer.domElement)
  this.flyControls.movementSpeed = 25 //移动速度
  this.flyControls.domElement = this.renderer.domElement //配置dom元素
  this.flyControls.rollSpeed = Math.PI / 24 //翻滚角速度
  this.flyControls.autoForward = false //自动向前关闭
  this.flyControls.dragToLook = false //拖动视图变换关闭  
}

3.3 render中更新飞行控件

render() {
  const delta = this.clock.getDelta() //获取自上次调用的时间差
  this.flyControls.update(delta) //更新飞行控件
  this.renderer.render(this.scene, this.camera)
  requestAnimationFrame(this.render)
},

4. demo代码

<template>
  <div>
    <div id="container" />
  </div>
</template>

<script>
import * as THREE from 'three'
import { FlyControls } from 'three/examples/jsm/controls/FlyControls.js'
import { OBJLoader } from 'three/examples/jsm/loaders/OBJLoader.js'

export default {
  data() {
    return {
      publicPath: process.env.BASE_URL,
      mesh: null,
      camera: null,
      scene: null,
      renderer: null,
      flyControls: null,
      clock: null
    }
  },
  mounted() {
    this.init()
  },
  methods: {
    // 初始化
    init() {
      this.createScene() // 创建场景
      this.loadObj() // 加载OBJ模型
      this.createLight() // 创建光源
      this.createCamera() // 创建相机
      this.createRender() // 创建渲染器
      this.createFlyControls() // 创建飞行控件
      this.render() // 渲染
    },
    // 创建场景
    createScene() {
      this.scene = new THREE.Scene()
    },
    loadObj() {
      const objLoader = new OBJLoader()
      const THIS = this

      objLoader.load(`${THIS.publicPath}models/city.obj`, loadedMesh => {
        THIS.mesh = loadedMesh
        loadedMesh.scale.set(0.2, 0.2, 0.2)
        THIS.setRandomColors(loadedMesh, THIS)
        THIS.scene.add(THIS.mesh)
      })
    },
    setRandomColors(object, THIS) {
      const children = object.children

      if (children && children.length > 0) {
        children.forEach(function(e) {
          THIS.setRandomColors(e, THIS)
        })
      } else {
        if (object instanceof THREE.Mesh) {
          const colorIndex = Math.floor(Math.random() * 3) // 0~2的随机数
          const colorArray = [
            new THREE.Color(0xff0000),
            new THREE.Color(0x00ff00),
            new THREE.Color(0x0000ff)
          ]
          object.material.emissive = colorArray[colorIndex]
          object.material.color = colorArray[colorIndex]
          object.material.transparent = true
          object.material.opacity = 0.3
        }
      }
    },
    // 创建光源
    createLight() {
      // 环境光
      const ambientLight = new THREE.AmbientLight(0x383838) // 创建环境光
      this.scene.add(ambientLight) // 将环境光添加到场景

      const spotLight = new THREE.SpotLight(0xffffff) // 创建聚光灯
      spotLight.position.set(200, 200, 200)
      spotLight.castShadow = true
      this.scene.add(spotLight)
    },
    // 创建相机
    createCamera() {
      const element = document.getElementById('container')
      const width = element.clientWidth // 窗口宽度
      const height = element.clientHeight // 窗口高度
      const k = width / height // 窗口宽高比
      // PerspectiveCamera( fov, aspect, near, far )
      this.camera = new THREE.PerspectiveCamera(35, k, 0.1, 1000)
      this.camera.position.set(-80, 60, 40) // 设置相机位置

      this.camera.lookAt(new THREE.Vector3(10, 0, 0)) // 设置相机方向
      this.scene.add(this.camera)
    },
    // 创建渲染器
    createRender() {
      const element = document.getElementById('container')
      this.renderer = new THREE.WebGLRenderer({ antialias: true, alpha: true })
      this.renderer.setSize(element.clientWidth, element.clientHeight) // 设置渲染区域尺寸
      this.renderer.shadowMap.enabled = true // 显示阴影
      this.renderer.shadowMap.type = THREE.PCFSoftShadowMap
      this.renderer.setClearColor(0x3f3f3f, 1) // 设置背景颜色
      element.appendChild(this.renderer.domElement)
    },

    render() {
      const delta = this.clock.getDelta() //获取自上次调用的时间差
      this.flyControls.update(delta) //更新飞行控件
      this.renderer.render(this.scene, this.camera)
      requestAnimationFrame(this.render)
    },
    // 创建飞行控件
    createFlyControls() {
      this.clock = new THREE.Clock()
      this.flyControls = new FlyControls(this.camera, this.renderer.domElement)
      this.flyControls.movementSpeed = 25 //移动速度
      this.flyControls.domElement = this.renderer.domElement //配置dom元素
      this.flyControls.rollSpeed = Math.PI / 24 //翻滚角速度
      this.flyControls.autoForward = false //自动向前关闭
      this.flyControls.dragToLook = false //拖动视图变换关闭
    }
  }
}
</script>
<style>
#container {
  position: absolute;
  width: 100%;
  height: 100%;
}
</style>