学习threejs，使用Lensflare模拟镜头眩光

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文章目录

一、🍀前言
- 1.1 ☘️THREE.Lensflare
二、🍀使用Lensflare模拟镜头眩光
- 1. ☘️实现思路
- 2. ☘️代码样例

一、🍀前言

本文详细介绍如何基于threejs在三维场景中使用Lensflare模拟镜头眩光，亲测可用。希望能帮助到您。一起学习，加油！加油！

1.1 ☘️THREE.Lensflare

THREE.Lensflare 是一种用来模拟镜头光晕效果的类，常用于创建光源周围的光晕或耀斑效果，特别是当镜头朝向强光源（如太阳或强烈的灯光）时。它通过一个或多个纹理贴图来实现这种效果。

构造函数：
THREE.Lensflare(texture, size, distance, blending, color )

texture：镜头炫光的纹理，决定炫光的样子
size：镜头炫光的大小，单位是像素
distance：设值炫光与当前位置的距离。
lending：融合模式决定他们将如何融合在一起,默认的融合模式是THREE.AdditiveBlending,提供半透明的炫光
color：镜头炫光显示的颜色

方法：

add(element) 向镜头眩光效果中添加一个元素。 element：一个包含 texture、color、distance、size 和 lending 属性的对象。
remove(element) 从镜头眩光效果中移除一个元素。 element：要移除的眩光元素对象。
dispose() 释放镜头眩光使用的资源。当不再需要镜头眩光效果时可以调用此方法来释放相关资源。

二、🍀使用Lensflare模拟镜头眩光

1. ☘️实现思路

1、初始化renderer渲染器
2、初始化Scene三维场景scene
3、初始化camera相机，定义相机位置 camera.position.set，设置相机方向camera.lookAt。
4、创建THREE.AmbientLight环境光源ambiLight，scene场景加入环境光源ambiLight。创建THREE.SpotLight聚光灯光源spotLight0，设置光源位置和方向，scene场景加入spotLight0。创建THREE.DirectionalLight平行光源spotLight，设置平行光源位置、投影信息，scene添加平行光源spotLight。
5、加载几何模型：创建二维平面网格对象plane，plane使用‘grasslight-big.jpg’草地贴图，设置plane的旋转角度，scene场景加入plane。创建立方体网格对象cube，设置cube的位置和投影，scene场景加入cube。创建球体网格对象sphere，设置sphere的位置和投影，scene场景加入sphere。创建THREE.LensFlare镜头炫光控件lensFlare，lensFlare添加5种炫光要素，scene场景加入lensFlare。定义render方法，实现立方体cube旋转，球体sphere跳动的方法。具体代码参考下面代码样例。
6、加入stats监控器，监控帧数信息。

2. ☘️代码样例

<!DOCTYPE html><html><head><title>学习threejs，使用Lensflare模拟镜头眩光</title><script type="text/javascript" src="../libs/three.js"></script><script type="text/javascript" src="../libs/stats.js"></script><script type="text/javascript" src="../libs/dat.gui.js"></script><style>body {/* set margin to 0 and overflow to hidden, to go fullscreen */margin: 0;overflow: hidden;}</style>
</head>
<body><div id="Stats-output">
</div>
<!-- Div which will hold the Output -->
<div id="WebGL-output">
</div><!-- js 代码 -->
<script type="text/javascript">// 初始化function init() {var stats = initStats();// 创建场景，设置场景云雾效果var scene = new THREE.Scene();scene.fog = new THREE.Fog(0xaaaaaa, 0.010, 200);// 创建投影相机var camera = new THREE.PerspectiveCamera(45, window.innerWidth / window.innerHeight, 0.1, 1000);// 创建渲染器，并设置大小var renderer = new THREE.WebGLRenderer({antialias: true, alpha: true});renderer.setClearColor(new THREE.Color(0xaaaaff, 1.0));renderer.setSize(window.innerWidth, window.innerHeight);renderer.shadowMapEnabled = true;// 创建草地地面var textureGrass = THREE.ImageUtils.loadTexture("../assets/textures/ground/grasslight-big.jpg");textureGrass.wrapS = THREE.RepeatWrapping;textureGrass.wrapT = THREE.RepeatWrapping;textureGrass.repeat.set(4, 4);var planeGeometry = new THREE.PlaneGeometry(1000, 200, 20, 20);var planeMaterial = new THREE.MeshLambertMaterial({map: textureGrass});var plane = new THREE.Mesh(planeGeometry, planeMaterial);plane.receiveShadow = true;// 旋转草地平面角度plane.rotation.x = -0.5 * Math.PI;plane.position.x = 15;plane.position.y = 0;plane.position.z = 0;// 场景中添加草地平面scene.add(plane);// 创建立方体几何体var cubeGeometry = new THREE.BoxGeometry(4, 4, 4);var cubeMaterial = new THREE.MeshLambertMaterial({color: 0xff3333});var cube = new THREE.Mesh(cubeGeometry, cubeMaterial);cube.castShadow = true;// 设置立方体位置cube.position.x = -4;cube.position.y = 3;cube.position.z = 0;// 三维场景中添加立方体scene.add(cube);// 创建球体几何体var sphereGeometry = new THREE.SphereGeometry(4, 25, 25);var sphereMaterial = new THREE.MeshLambertMaterial({color: 0x7777ff});var sphere = new THREE.Mesh(sphereGeometry, sphereMaterial);// 设置球体位置和投影sphere.position.x = 10;sphere.position.y = 5;sphere.position.z = 10;sphere.castShadow = true;// 三维场景中添加球体scene.add(sphere);// 设置相机位置和方向camera.position.x = -20;camera.position.y = 15;camera.position.z = 45;camera.lookAt(new THREE.Vector3(10, 0, 0));// 创建并添加环境光var ambiColor = "#1c1c1c";var ambientLight = new THREE.AmbientLight(ambiColor);scene.add(ambientLight);// 创建并添加聚光灯光源var spotLight0 = new THREE.SpotLight(0xcccccc);spotLight0.position.set(-40, 60, -10);spotLight0.lookAt(plane);scene.add(spotLight0);var target = new THREE.Object3D();target.position = new THREE.Vector3(5, 0, 0);var pointColor = "#ffffff";
//    var spotLight = new THREE.SpotLight( pointColor);// 创建平行光源var spotLight = new THREE.DirectionalLight(pointColor);spotLight.position.set(30, 10, -50);spotLight.castShadow = true;spotLight.shadowCameraNear = 0.1;spotLight.shadowCameraFar = 100;spotLight.shadowCameraFov = 50;spotLight.target = plane;spotLight.distance = 0;spotLight.shadowCameraNear = 2;spotLight.shadowCameraFar = 200;spotLight.shadowCameraLeft = -100;spotLight.shadowCameraRight = 100;spotLight.shadowCameraTop = 100;spotLight.shadowCameraBottom = -100;spotLight.shadowMapWidth = 2048;spotLight.shadowMapHeight = 2048;scene.add(spotLight);// renderer渲染器绑定页面要素document.getElementById("WebGL-output").appendChild(renderer.domElement);// call the render functionvar step = 0;// used to determine the switch point for the light animationvar invert = 1;var phase = 0;var controls = new function () {this.rotationSpeed = 0.03;this.bouncingSpeed = 0.03;this.ambientColor = ambiColor;this.pointColor = pointColor;this.intensity = 0.1;this.distance = 0;this.exponent = 30;this.angle = 0.1;this.debug = false;this.castShadow = true;this.onlyShadow = false;this.target = "Plane";};var gui = new dat.GUI();gui.addColor(controls, 'ambientColor').onChange(function (e) {ambientLight.color = new THREE.Color(e);});gui.addColor(controls, 'pointColor').onChange(function (e) {spotLight.color = new THREE.Color(e);});gui.add(controls, 'intensity', 0, 5).onChange(function (e) {spotLight.intensity = e;});var textureFlare0 = THREE.ImageUtils.loadTexture("../assets/textures/lensflare/lensflare0.png");var textureFlare3 = THREE.ImageUtils.loadTexture("../assets/textures/lensflare/lensflare3.png");var flareColor = new THREE.Color(0xffaacc);var lensFlare = new THREE.LensFlare(textureFlare0, 350, 0.0, THREE.AdditiveBlending, flareColor);lensFlare.add(textureFlare3, 60, 0.6, THREE.AdditiveBlending);lensFlare.add(textureFlare3, 70, 0.7, THREE.AdditiveBlending);lensFlare.add(textureFlare3, 120, 0.9, THREE.AdditiveBlending);lensFlare.add(textureFlare3, 70, 1.0, THREE.AdditiveBlending);lensFlare.position.copy(spotLight.position);scene.add(lensFlare);render();function render() {stats.update();// 动画旋转立方体cube.rotation.x += controls.rotationSpeed;cube.rotation.y += controls.rotationSpeed;cube.rotation.z += controls.rotationSpeed;// 动画实现球体跳动step += controls.bouncingSpeed;sphere.position.x = 20 + ( 10 * (Math.cos(step)));sphere.position.y = 2 + ( 10 * Math.abs(Math.sin(step)));requestAnimationFrame(render);renderer.render(scene, camera);}function initStats() {var stats = new Stats();stats.setMode(0);stats.domElement.style.position = 'absolute';stats.domElement.style.left = '0px';stats.domElement.style.top = '0px';document.getElementById("Stats-output").appendChild(stats.domElement);return stats;}};window.onload = init;</script>
</body>
</html>