使用vue学习three.js之粒子和粒子系统-THREE.PointCloudMaterial材质属性介绍与使用

1.THREE.PointCloudMaterial材质属性介绍

我们已经知道创建粒子系统需要两个参数，一个几何体和一个材质。接下来主要介绍一下THREE.PointCloudMaterial的属性。

属性	描述
color	粒子系统中所有粒子颜色，当vertexColors属性值为true，而且也指定了几何体的colors属性。那么color属性指定的颜色会被忽略，使用几何体colors属性中的颜色。当vertexColors属性值为false，所有粒子会渲染成该属性定义颜色。该属性的默认值是0xFFFFFF
map	通过该属性可以在粒子上应用某种材质。例如看起来像雪花的材质
size	通过该属性指定粒子的大小，默认值是1
sizeAnnutation	该属性是一个布尔值，若为true表示粒子的大小由粒子到相机的距离决定，若为false表示无论粒子到相机的距离是多少，粒子都会有相同的尺寸
vertexColors	该属性是一个布尔值，决定粒子渲染时使用哪里的颜色。当值为true，也指定了几何体的colors属性。就会使用几何体colors属性定义的颜色渲染粒子。当值为false，所有粒子都会渲染成color属性定义的颜色。该属性的默认值是false，即默认所有粒子会渲染成相同颜色。什么颜色由color属性决定
transparent	该属性决定粒子是否透明，通常和opacity属性配合使用。默认值是false，即粒子默认不透明
opacity	该属性用来指定粒子的透明度，取值范围0~1，当transparent属性值为true时，该属性才能生效。默认值是1(不透明)
blending	该属性指定粒子渲染时的融合模式
fog	该属性指定粒子是否受雾化影响，默认为true

2.THREE.PointCloudMaterial材质使用

使用THREE.PointCloudMaterial类创建粒子材质和创建其他材质一样。具体看示例代码

// 创建几何体
const geom = new THREE.Geometry()
// 创建粒子材质
const material = new THREE.PointCloudMaterial({
    
    
  size: this.properties.size.value,
  transparent: this.properties.transparent,
  opacity: this.properties.opacity.value,
  vertexColors: this.properties.vertexColors,
  sizeAttenuation: this.properties.sizeAttenuation,
  color: this.properties.color
})

const range = 500
for (let i = 0; i < 15000; i++) {
    
    
  const particle = new THREE.Vector3(
    Math.random() * range - range / 2,
    Math.random() * range - range / 2,
    Math.random() * range - range / 2
  )
  // 给几何体添加顶点坐标
  geom.vertices.push(particle)
  const color = new THREE.Color(0xffffff * Math.random())
  // 给几何体添加顶点颜色
  geom.colors.push(color)
}

// 创建粒子系统对象
this.cloud = new THREE.PointCloud(geom, material)
this.cloud.name = 'particles'
// 将粒子系统对象添加到场景
this.scene.add(this.cloud)

3.demo效果

4.demo代码

<template>
  <div>
    <div id="container"></div>
    <div class="controls-box">
      <section>

        <el-row>
          <el-checkbox v-model="properties.transparent" @change="redraw">transparent</el-checkbox>
        </el-row>
        <el-row>
          <div v-for="(item,key) in properties" :key="key">
            <div v-if="item&&item.name!=undefined">
              <el-col :span="8">
                <span class="vertice-span">{
    
    {
    
    item.name}}</span>
              </el-col>
              <el-col :span="13">
                <el-slider v-model="item.value" :min="item.min" :max="item.max" :step="item.step" :format-tooltip="formatTooltip" @change="redraw"></el-slider>
              </el-col>
              <el-col :span="3">
                <span class="vertice-span">{
    
    {
    
    item.value}}</span>
              </el-col>
            </div>
          </div>
        </el-row>
        <el-row>
          <el-checkbox v-model="properties.vertexColors" @change="redraw">vertexColors</el-checkbox>
        </el-row>
        <el-row>
          <el-col :span="8" class="label-col"><label> color</label></el-col>
          <el-col :span="16">
            <div @click="inputClick">
              <el-input :value="properties.color"></el-input>
            </div>
            <div v-show="isShowColors" class="color-select-layer">
              <sketch-picker v-model="properties.color" @input="colorChange"></sketch-picker>
            </div>
          </el-col>
        </el-row>
        <el-row>
          <el-checkbox v-model="properties.sizeAttenuation" @change="redraw">sizeAttenuation</el-checkbox>
        </el-row>
        <el-row>
          <el-checkbox v-model="properties.rotateSystem" @change="redraw">rotateSystem</el-checkbox>
        </el-row>

      </section>

    </div>
  </div>
</template>

<script>
import * as THREE from 'three'
import {
    
     OrbitControls } from 'three/examples/jsm/controls/OrbitControls.js'
import {
    
     Sketch } from 'vue-color'
export default {
    
    
  components: {
    
    
    'sketch-picker': Sketch
  },
  data () {
    
    
    return {
    
    
      properties: {
    
    
        size: {
    
    
          name: 'size',
          value: 4,
          min: 0,
          max: 20,
          step: 0.1
        },
        opacity: {
    
    
          name: 'opacity',
          value: 0.6,
          min: 0,
          max: 1,
          step: 0.1
        },
        transparent: true,
        vertexColors: true,
        sizeAttenuation: true,
        rotateSystem: true,
        color: '#ccffcc'
      },
      isShowColors: false,
      cloud: null,
      camera: null,
      scene: null,
      renderer: null,
      controls: null
    }
  },
  mounted () {
    
    
    this.init()
  },
  methods: {
    
    
    formatTooltip (val) {
    
    
      return val
    },
    inputClick () {
    
    
      this.isShowColors = !this.isShowColors
    },
    colorChange (val) {
    
    
      this.properties.color = val.hex
      this.redraw()
    },
    // 初始化
    init () {
    
    
      this.createScene() // 创建场景
      this.createParticles() // 创建粒子系统
      this.createCamera() // 创建相机
      this.createRender() // 创建渲染器
      this.createControls() // 创建控件对象
      this.render() // 渲染
    },
    // 创建场景
    createScene () {
    
    
      this.scene = new THREE.Scene()
    },
    // 创建粒子系统
    createParticles () {
    
    
      // 创建几何体
      const geom = new THREE.Geometry()
      // 创建粒子材质
      const material = new THREE.PointCloudMaterial({
    
    
        size: this.properties.size.value,
        transparent: this.properties.transparent,
        opacity: this.properties.opacity.value,
        vertexColors: this.properties.vertexColors,
        sizeAttenuation: this.properties.sizeAttenuation,
        color: this.properties.color
      })

      const range = 500
      for (let i = 0; i < 15000; i++) {
    
    
        const particle = new THREE.Vector3(
          Math.random() * range - range / 2,
          Math.random() * range - range / 2,
          Math.random() * range - range / 2
        )
        // 给几何体添加顶点坐标
        geom.vertices.push(particle)
        const color = new THREE.Color(0xffffff * Math.random())
        // 给几何体添加顶点颜色
        geom.colors.push(color)
      }

      // 创建粒子系统对象
      this.cloud = new THREE.PointCloud(geom, material)
      this.cloud.name = 'particles'
      // 将粒子系统对象添加到场景
      this.scene.add(this.cloud)
    },

    // 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()
      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)
    },

    // 重新绘制
    redraw () {
    
    
      this.scene.remove(this.cloud)
      this.createParticles()
    },

    render () {
    
    
      if (this.properties.rotateSystem) {
    
    
        this.cloud.rotation.y += 0.01
      }
      this.renderer.render(this.scene, this.camera)
      requestAnimationFrame(this.render)
    },
    // 创建控件对象
    createControls () {
    
    
      this.controls = new OrbitControls(this.camera, this.renderer.domElement)
    }
  }
}
</script>

<style>
#container {
    
    
  position: absolute;
  width: 100%;
  height: 100%;
}
.controls-box {
    
    
  position: absolute;
  right: 5px;
  top: 5px;
  width: 300px;
  padding: 10px;
  background-color: #fff;
  border: 1px solid #c3c3c3;
}
.label-col {
    
    
  padding: 8px 5px;
}
.color-select-layer {
    
    
  position: relative;
  left: -20px;
  padding: 15px 0;
}
.vertice-span {
    
    
  line-height: 38px;
  padding: 0 2px 0 10px;
}
</style>