学习threejs，通过THREE.Raycaster给模型绑定点击事件

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文章目录

一、🍀前言
- 1.1 ☘️THREE.Raycaster光线投射概念
二、🍀通过THREE.Raycaster给模型绑定点击事件
- 1. ☘️实现思路
- 2. ☘️代码样例

一、🍀前言

本文详细介绍如何基于threejs在三维场景中实现通过THREE.Raycaster给模型绑定点击事件，亲测可用。希望能帮助到您。一起学习，加油！加油！

1.1 ☘️THREE.Raycaster光线投射概念

THREE.Raycaster 光线投射，常用于和3D图形之间做一些点击事件和交互操作，也可用于碰撞检测等
创建方法：
Raycaster( origin : Vector3, direction : Vector3, near : Float, far : Float )
origin：光线投射的原点向量。
direction：向射线提供方向的方向向量，应当被标准化。
near：返回的所有结果比near远。near不能为负值，其默认值为0。
far：返回的所有结果都比far近。far不能小于near，其默认值为Infinity（正无穷。）
属性
far：远距离因数（投射远点）。这个值表明哪些对象可以基于该距离而被raycaster所丢弃。这个值不应当为负，并且应当比near属性大。
near：近距离因数（投射近点）。这个值表明哪些对象可以基于该距离而被raycaster所丢弃。这个值不应当为负，并且应当比far属性小。
camera : 对依赖于视图的对象进行光线投射时使用的相机。默认为空。
layers：Raycaster 在执行相交测试时使用它来选择性地忽略 3D 对象。
ray：用于进行光线投射的射线。

二、🍀通过THREE.Raycaster给模型绑定点击事件

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，定义相机方向lookAt。
4、加载模型：添加THREE.AxesHelper坐标辅助工具，添加3000个位置随机的THREE.BoxGeometry立方体，scene场景中加入坐标辅助工具和立方体。
5、创建THREE.Raycaste光线投射对象，创建onMouseClick事件，定义THREE.Raycaster光线投射与scene中立方体交互事件。
6、加入controls，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>learn27(通过THREE.Raycaster给模型绑定点击事件)</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/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 renderervar initRender = () => {renderer = new THREE.WebGLRenderer({antialias: true})renderer.setClearColor(0xffffff)renderer.setSize(window.innerWidth, window.innerHeight)document.body.appendChild(renderer.domElement)}var scenevar initScene = () => {scene = new THREE.Scene()}var cameravar 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 initModel = () => {var helper = new THREE.AxesHelper(20)scene.add(helper)var s = 25var cube = new THREE.BoxGeometry(s, s, s)for (var i = 0; i < 3000; i++) {var material = new THREE.MeshBasicMaterial({color: randomColor()})var mesh = new THREE.Mesh(cube, material)mesh.position.x = 800 * ( 2.0 * Math.random() - 1.0 )mesh.position.y = 800 * ( 2.0 * Math.random() - 1.0 )mesh.position.z = 800 * ( 2.0 * Math.random() - 1.0 )mesh.rotation.x = Math.random() * Math.PImesh.rotation.y = Math.random() * Math.PImesh.rotation.z = Math.random() * Math.PImesh.updateMatrix()scene.add(mesh)}}var randomColor = () => {var arrHex = ["0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "a", "b", "c", "d", "e", "f"],strHex = "#",index;for (var i = 0; i < 6; i++) {index = Math.round(Math.random() * 15)strHex += arrHex[index]}return strHex}var raycaster = new THREE.Raycaster()var mouse = new THREE.Vector2()var onMouseClick = (event) => {mouse.x = (event.clientX / window.innerWidth) * 2 - 1mouse.y = -(event.clientY / window.innerHeight) *2 + 1raycaster.setFromCamera(mouse, camera)var intersects = raycaster.intersectObjects(scene.children)console.log(intersects)for (var i = 0; i < intersects.length; i++) {intersects[i].object.material.color.set(0xff0000)}}window.addEventListener('click', onMouseClick, false)var statsvar initStats = () => {stats = new Stats()document.body.appendChild(stats.dom)}var controlsvar initControls = () => {controls = new THREE.OrbitControls(camera, renderer.domElement)controls.enableDamping = true}var render = () => {renderer.render(scene, camera)}var onWindowResize = (event) => {camera.aspect = window.innerWidth / window.innerHeightcamera.updateProjectionMatrix()render()renderer.setSize(window.innerWidth, window.innerHeight)}var animate = () => {render()stats.update()controls.update()requestAnimationFrame(animate)}var draw = () => {initRender()initScene()initCamera()initModel()initStats()initControls()animate()window.onresize = onWindowResize}
</script>
</html>