学习threejs，实现几何体阴影效果

news2024/11/17 0:04:24

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👨‍⚕️ 收录于专栏：threejs gis工程师

文章目录

一、🍀前言
二、🍀绘制任意字体模型
- 1. ☘️实现思路
- 2. ☘️代码样例

一、🍀前言

本文详细介绍基于threejs如何绘制任意文字模型，亲测可用。希望能帮助到您。一起学习，加油！加油！

二、🍀绘制任意字体模型

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light灯光，定义灯光位置，开启light.castShadow灯光阴影，Scene场景加入灯光
5、加载几何模型：创建SphereGeometry球体、BoxGeometry立方体、PlaneGeometry地面几何体以及AxisHelper辅助工具坐标系，Scene场景加入以上几何体和工具。
6、加入controls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>learn9(实现阴影效果)</title>
    <script src="lib/threejs/127/three.js-master/build/three.js"></script>
    <script src="lib/threejs/127/three.js-master/examples/js/controls/TrackballControls.js"></script>
    <script src="lib/threejs/127/three.js-master/examples/js/libs/stats.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 = () => {
    // 抗锯齿
    renderer = new THREE.WebGLRenderer({antialias: true})
    renderer.setSize(window.innerWidth, window.innerHeight)
    renderer.shadowMap.enabled = true
    // 默认的是，没有设置的这个清晰 THREE.PCFShadowMap
    renderer.shadowMap.type = THREE.PCFSoftShadowMap
    document.body.appendChild(renderer.domElement)
  }
  var camera
  var initCamera = () => {
    camera = new THREE.PerspectiveCamera(45, window.innerWidth / window.innerHeight, 0.1, 1000)
    camera.position.set(0, 40, 100)
    camera.lookAt(new THREE.Vector3(0, 0, 0))
  }
  var scene
  var initScene = () => {
    scene = new THREE.Scene()
    // scene.fog = new THREE.FogExp2(0xffffff,0.02)
    scene.fog = new THREE.Fog(0xffffff, 100, 120)
  }
  var light
  var initLight = () => {
    scene.add(new THREE.AmbientLight(0x444444))

    light = new THREE.SpotLight(0xffffff)
    light.position.set(60, 30, 0)

    //告诉平行光需要开启阴影投射
    light.castShadow = true

    scene.add(light)
  }

  var initModel = () => {
    // 球
    var sphereGemometry = new THREE.SphereGeometry(5, 20, 20)
    var sphereMatarial = new THREE.MeshStandardMaterial({color: 0x7777ff})
    var sphere = new THREE.Mesh(sphereGemometry, sphereMatarial)
    sphere.position.set(0, 5, 0)
    sphere.castShadow = true
    scene.add(sphere)

    //辅助工具
    var helper = new THREE.AxisHelper(10)
    scene.add(helper)

    //立方体
    var cubeGeometry = new THREE.BoxGeometry(10, 10, 8)
    var cubeMaterial = new THREE.MeshLambertMaterial({color: 0x00ffff})
    var cube = new THREE.Mesh(cubeGeometry, cubeMaterial)
    cube.position.x = 25
    cube.position.y = 5
    cube.position.z = -5
    //告诉立方体需要投射阴影
    cube.castShadow = true
    scene.add(cube)

    // 底面
    var planeGeometry = new THREE.PlaneGeometry(100, 100)
    var planeMatarial = new THREE.MeshStandardMaterial({color: 0xaaaaaa})
    var plane = new THREE.Mesh(planeGeometry, planeMatarial)
    plane.rotation.x = -0.5 * Math.PI
    plane.position.y = -0
    plane.receiveShadow = true
    scene.add(plane)
  }

  var stats
  var initStats = () => {
    stats = new Stats()
    document.body.appendChild(stats.dom)
  }
  var controls
  var initControle = () => {
    controls = new THREE.TrackballControls(camera, renderer.domElement)
    controls.addEventListener('change', render)
  }
  var render = () => {
    renderer.render(scene, camera)
  }
  var onWindwosResize = () => {
    camera.aspect = window.innerWidth / window.innerHeight
    camera.updateProjectionMatrix()
    controls.handleResize()
    render()
    renderer.setSize(window.innerWidth, window.innerHeight)
  }

  var animate = () => {
    render()
    stats.update()
    controls.update()
    requestAnimationFrame(animate)
  }

  var draw = () => {
    initRender()
    initScene()
    initCamera()
    initLight()
    initModel()
    initControle()
    initStats()
    animate()

    window.onresize = onWindwosResize
  }

</script>
</html>