学习threejs，拉伸几何体THREE.TubeGeometry管道

news2024/10/17 14:11:50

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文章目录

一、🍀前言
- 1.1 ☘️拉伸几何体THREE.TubeGeometry管道概念
二、🍀生成拉伸几何体THREE.TubeGeometry管道
- 1. ☘️实现思路
- 2. ☘️代码样例

一、🍀前言

本文详细介绍如何基于threejs在三维场景中实现生成拉伸几何体THREE.TubeGeometry管道，亲测可用。希望能帮助到您。一起学习，加油！加油！

1.1 ☘️拉伸几何体THREE.TubeGeometry管道概念

THREE.TubeGeometry 沿着一条三维的样条曲线拉伸出一根管。
创建方法：
构造函数 new THREE.TubeGeometry(new THREE.CatmullRomCurve3(points), segments, radius, radiusSegments, closed)
参数说明
path：该属性用一个 THREE.SplineCurve3 对象来指定管道应当遵循的路径。
segments：该属性指定构建这个管所用的分段数。默认值为 64.路径越长，指定的分段数应该越多。
radius：该属性指定管的半径。默认值为 1.
radiusSegments：该属性指定管道圆周的分段数。默认值为 8，分段数越多，管道看上去越圆。
closed：如果该属性设置为 true，管道的头和尾会连起来，默认值为 false。

二、🍀生成拉伸几何体THREE.TubeGeometry管道

1. ☘️实现思路

1、初始化renderer渲染器
2、初始化Scene三维场景
3、初始化camera相机，定义相机位置 camera.position.set
4、初始化THREE.AmbientLight环境光源，scene场景加入环境光源，初始化THREE.DirectionalLight平行光源，设置平行光源位置，scene添加平行光源。
5、加载几何模型：生成管道路径THREE.CatmullRomCurve3，并设置segments、radius、radiusSegments、closed参数生成THREE.TubeGeometry管道，创建THREE.MeshBasicMaterial基本材质，生成mesh物体，scene场景加入mesh。
6、加入controls、gui控制，加入stats监控器，监控帧数信息。

2. ☘️代码样例

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>learn24(拉伸几何体THREE.TubeGeometry管道)</title>
    <script src="lib/threejs/127/three.js-master/build/three.js"></script>
    <script src="lib/threejs/127/three.js-master/examples/js/utils/SceneUtils.js"></script>
    <script src="lib/threejs/127/three.js-master/examples/js/geometries/ConvexGeometry.js"></script>
    <script src="lib/threejs/127/three.js-master/examples/js/math/ConvexHull.js"></script>
    <script src="lib/threejs/127/three.js-master/examples/js/controls/OrbitControls.js"></script>
    <script src="lib/threejs/127/three.js-master/examples/js/libs/stats.min.js"></script>
    <script src="lib/threejs/127/three.js-master/examples/js/libs/dat.gui.min.js"></script>
</head>
<style>
    body {
        margin: 0;
    }

    canvas {
        width: 100%;
        height: 100%;
        display: block;
    }
</style>
<body onload="draw()">

</body>
<script>
  var renderer
  var initRender = () => {
    renderer = new THREE.WebGLRenderer({antialias: true})
    renderer.setSize(window.innerWidth, window.innerHeight)
    document.body.appendChild(renderer.domElement)
  }

  var camera
  var initCamera = () => {
    camera = new THREE.PerspectiveCamera(45, window.innerWidth / window.innerHeight, 1, 10000)
    camera.position.set(0, 0, 100)
  }

  var scene
  var initScene = () => {
    scene = new THREE.Scene()
  }
  var light
  var initLight = () => {
    scene.add(new THREE.AmbientLight(0x404040))

    light = new THREE.DirectionalLight(0xffffff)
    light.position.set(1, 1, 1)
    scene.add(light)
  }
  // var initModel = () => {
  //   var shape = new THREE.ShapeGeometry()
  // }
  var stats
  var initStats = () => {
    stats = new Stats()
    document.body.appendChild(stats.dom)
  }
  var controls
  var initControls = () => {
    controls = new THREE.OrbitControls(camera, renderer.domElement)
    controls.enableDamping = true
  }
  var gui, spGroup, tubeMesh
  var initGui = () => {
    gui = {
      numberOfPoints: 5,
      segments: 64,
      radius: 1,
      radiusSegments: 8,
      closed: false,
      points: [],
      newPoints: function () {
        //生成一些随机点放置到数组当中
        var points = []
        for (var i = 0; i < gui.numberOfPoints; i++) {
          var randomX = -20 + Math.round(Math.random() * 50)
          var randomY = -15 + Math.round(Math.random() * 40)
          var randomZ = -20 + Math.round(Math.random() * 40)

          points.push(new THREE.Vector3(randomX, randomY, randomZ))
        }
        gui.points = points
        gui.redraw()
      },
      redraw: function () {
        //清楚掉场景中原来的模型对象
        scene.remove(spGroup)
        scene.remove(tubeMesh)
        //重新绘制模型
        generatePoints(gui.points, gui.segments, gui.radius, gui.radiusSegments, gui.closed)
      }
    }
    var datGui = new dat.GUI()
    //将设置属性添加到gui当中，gui.add(对象，属性，最小值，最大值）
    datGui.add(gui, 'newPoints')
    datGui.add(gui, 'numberOfPoints', 2, 15).step(1).onChange(gui.newPoints)
    datGui.add(gui, 'segments', 0, 200).step(1).onChange(gui.redraw)
    datGui.add(gui, 'radius', 0, 10).onChange(gui.redraw)
    datGui.add(gui, 'radiusSegments', 0, 100).step(1).onChange(gui.redraw)
    datGui.add(gui, 'closed').onChange(gui.redraw)

    gui.newPoints()
  }
  var generatePoints = (points, segments, radius, radiusSegments, closed) => {
    spGroup = new THREE.Object3D()
    var material = new THREE.MeshBasicMaterial({color: 0xff0000, transparent: false})
    points.forEach(point => {
      var spGeom = new THREE.SphereGeometry(0.2)
      var spMesh = new THREE.Mesh(spGeom, material)
      spMesh.position.copy(point)
      spGroup.add(spMesh)
    })
    scene.add(spGroup)
    var tubeGeometry = new THREE.TubeGeometry(new THREE.CatmullRomCurve3(points), segments, radius, radiusSegments, closed)
    tubeMesh = createMesh(tubeGeometry)
    scene.add(tubeMesh)
  }

  var createMesh = (geom) => {
    var meshMaterial = new THREE.MeshBasicMaterial({color: 0x00ff00, transparent: true, opacity: 0.3})

    var wireFrameMat = new THREE.MeshBasicMaterial()
    wireFrameMat.wireframe = true
    var mesh = THREE.SceneUtils.createMultiMaterialObject(geom, [meshMaterial, wireFrameMat])
    return mesh
  }

  var render = () => {
    renderer.render(scene, camera)
  }
  var onWindowResize = () => {
    camera.aspect = window.innerWidth / window.innerHeight
    camera.updateProjectionMatrix()
    render()
    renderer.setSize(window.innerWidth, window.innerHeight)
  }
  var animate = () => {
    render()
    stats.update()
    controls.update()
    requestAnimationFrame(animate)
  }
  var draw = () => {
    initRender()
    initScene()
    initCamera()
    initLight()
    initControls()
    initStats()
    initGui()

    animate()
    window.onresize = onWindowResize
  }
</script>
</html>