Introduction and use of TorusKnotGeometry geometry
1. Introduction to TorusKnotGeometry
TorusKnotGeometry can be used to create a three-dimensional torus knot. The torus knot is a special kind of knot. It looks like a tube rotating around itself several times. You can enter the following parameters when creating it:
| Attributes | have to | description |
|---|---|---|
| radius | no | This property sets the radius of the complete circle, the default value is 1 |
| tube | no | This property sets the radius of the pipe, the default value is 0.4 |
| radialSegments | no | This attribute specifies the number of sections of the pipe section. The more sections there are, the smoother the pipe section circle will be. The default value is 8 |
| tubularSegments | no | This attribute specifies the number of segments of the pipeline, the more the number of segments, the smoother the pipeline, the default value is 64 |
| p | no | This property determines how many times the geometry will rotate around its rotational symmetry axis. The default value is 2. |
| q | no | This attribute determines how many times the geometry will rotate around its inner ring, the default value is 3 |
The way to create a three-dimensional torus knot is as follows:
const geom = new THREE.TorusKnotGeometry(radius, tube , radialSegments , tubularSegments , p,q)
Similarly, the parameters we need when creating a torus knot are all stored in a parameter attribute, if you want to get these parameter values, you can get it through this attribute
2.demo description
As shown above, this example supports the following functions
- Adjust the radius of the ring through the radius attribute
- Adjust the radius of the pipe section through the tube attribute
- Adjust the number of segments of the circular pipe section through the radialSegments property
- Adjust the number of segments of the pipeline through the tubularSegments property
- Adjust the number of torus kink rotations around the axis of symmetry through the p attribute
- Use the q attribute to adjust the number of times the torus twists rotate around the inner ring
3.demo code
<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"></el-slider>
</el-col>
<el-col :span="3">
<span class="vertice-span">{
{
item.value}}</span>
</el-col>
</div>
</div>
</el-row>
</section>
</div>
</div>
</template>
<script>
import * as THREE from 'three'
import {
OrbitControls } from 'three/examples/jsm/controls/OrbitControls.js'
import {
SceneUtils } from 'three/examples/jsm/utils/SceneUtils.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.MeshNormalMaterial({
side: THREE.DoubleSide
})
const wireFrameMat = new THREE.MeshBasicMaterial({
wireframe: true })
// 添加组合材质
this.mesh = SceneUtils.createMultiMaterialObject(geom, [
meshMaterial,
wireFrameMat
])
// 网格对象添加到场景中
this.scene.add(this.mesh)
},
// 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)
},
// 更新属性
updateFun() {
this.scene.remove(this.mesh)
this.createMesh()
},
render() {
this.updateFun()
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>