以JSON格式保存和加载对象
1.demo效果
如上图，该demo支持以下功能：
- 可以调整参数创建不同的环面扭结。
- 可以点击saveToJSON按钮将当前的网格对象以JSON格式保存的到页面缓存
- 可以点击loadJSON将保存在页面缓存中JSON格式的网格对象加载到当前页面
2.实现要点
2.1 网格对象保存为JSON格式
这里我们首先创建了一个环面扭结的网格对象，然后将它转成JSON格式，之后保存在页面缓存，具体如下：
// 创建环面扭结
const geom = new THREE.TorusKnotGeometry(
this.properties.radius.value,
this.properties.tube.value,
this.properties.radialSegments.value,
this.properties.tubularSegments.value,
this.properties.p.value,
this.properties.q.value
)
// 创建材质
const meshMaterial = new THREE.MeshBasicMaterial({
vertexColors: THREE.VertexColors,
wireframe: true,
wireframeLinewidth: 2,
color: 0xaaaaaa
})
// 添加组合材质
this.mesh = new THREE.Mesh(geom, meshMaterial)
// 网格对象转为json格式
const json = this.mesh.toJSON()
// 保存在localStorege缓存中
localStorage.setItem('json', JSON.stringify(json))
2.2 加载JSON格式保存的网格对象
上面的步骤我们将一个网格对象转成JSON格式保存到页面缓存，这里我们需要获取到页面缓存中的内容，转成网格对象添加到场景
// 导入json格式的网格对象
loadJSON () {
this.removeMesh()
const json = localStorage.getItem('json')
if (json) {
const loadedGeometry = JSON.parse(json)
const loader = new THREE.ObjectLoader()
const loadedMesh = loader.parse(loadedGeometry)
this.scene.add(loadedMesh)
}
}
3.demo代码
<template>
<div>
<div id="container"></div>
<div class="controls-box">
<section>
<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-button @click="loadJSON">loadJSON</el-button>
</el-row>
<el-row>
<el-button @click="saveToJSON">saveToJSON</el-button>
</el-row>
</section>
</div>
</div>
</template>
<script>
import * as THREE from 'three'
import {
OrbitControls } from 'three/examples/jsm/controls/OrbitControls.js'
export default {
data () {
return {
properties: {
radius: {
name: 'radius',
value: 18,
min: 0,
max: 60,
step: 1
},
tube: {
name: 'tube',
value: 2,
min: 0,
max: 20,
step: 0.1
},
radialSegments: {
name: 'radialSegments',
value: 230,
min: 0,
max: 400,
step: 1
},
tubularSegments: {
name: 'tubularSegments',
value: 8,
min: 0,
max: 50,
step: 1
},
p: {
name: 'p',
value: 4,
min: 0,
max: 20,
step: 1
},
q: {
name: 'q',
value: 3,
min: 0,
max: 20,
step: 1
}
},
mesh: null,
camera: null,
scene: null,
renderer: null,
controls: null
}
},
mounted () {
this.init()
},
methods: {
formatTooltip (val) {
return val
},
// 初始化
init () {
this.createScene() // 创建场景
this.createMesh() // 创建网格模型
this.createLight() // 创建光源
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()
},
// 创建网格模型
createMesh () {
// 创建环面扭结
const geom = new THREE.TorusKnotGeometry(
this.properties.radius.value,
this.properties.tube.value,
this.properties.radialSegments.value,
this.properties.tubularSegments.value,
this.properties.p.value,
this.properties.q.value
)
// 创建材质
const meshMaterial = new THREE.MeshBasicMaterial({
vertexColors: THREE.VertexColors,
wireframe: true,
wireframeLinewidth: 2,
color: 0xaaaaaa
})
// 添加组合材质
this.mesh = new THREE.Mesh(geom, meshMaterial)
// 网格对象添加到场景中
this.scene.add(this.mesh)
},
// 网格对象保存为json格式
saveToJSON () {
const json = this.mesh.toJSON()
localStorage.setItem('json', JSON.stringify(json))
},
// 导入json格式的网格对象
loadJSON () {
this.removeMesh()
const json = localStorage.getItem('json')
if (json) {
const loadedGeometry = JSON.parse(json)
const loader = new THREE.ObjectLoader()
const loadedMesh = loader.parse(loadedGeometry)
this.scene.add(loadedMesh)
}
},
removeMesh () {
const toRemove = []
this.scene.traverse(e => {
if (e instanceof THREE.Mesh) toRemove.push(e)
})
toRemove.forEach(e => {
this.scene.remove(e)
})
},
// 创建光源
createLight () {
// 环境光
const ambientLight = new THREE.AmbientLight(0xffffff, 0.1) // 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(-40, 60, -10)
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)
},
// 更新
redraw () {
this.removeMesh()
this.createMesh()
},
render () {
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;
}
.vertice-span {
line-height: 38px;
padding: 0 2px 0 10px;
}
</style>