主要的核心代码：
var renderPass = new THREE.RenderPass(scene, camera);//renderPass 通道：它只会渲染场景，但不会把结果输出到场景上 var effectFilm = new THREE.FilmPass(0.8, 0.325, 256, false);//FilmPass通道：它可以把结果输出到场景上 effectFilm.renderToScreen = true;//设置是否渲染到场景中 /*创建一个Three.EffectComposer() 它是一个组合器*/ var composer = new THREE.EffectComposer(webGLRenderer); /*每个通道都会按照其加入EffectComposer的顺序执行。 * 第一个加入的通道是RenderPass下面这个通道会渲染场景，但不会将渲染结果输出到平面上 * * FilmPass可以将其结果输出到屏幕上。这个通道是在RenderPass后面添加 * */ composer.addPass(renderPass); composer.addPass(effectFilm);
然后：
composer.render(delta);//替代webGLRenderer.render()，渲染时，就会调用EffectComposer 中的render()进行渲染
EffectComposer 是一个组合器， 渲染通道：
BloomPass 该通道会使得明亮区域参入较暗的区域。模拟相机照到过多亮光的情形 DotScreenPass 将一层黑点贴到代表原始图片的屏幕上 FilmPass 通过扫描线和失真模拟电视屏幕 MaskPass 在当前图片上贴一层掩膜，后续通道只会影响被贴的区域 RenderPass 该通道在指定的场景和相机的基础上渲染出一个新的场景 SavePass 执行该通道时，它会将当前渲染步骤的结果复制一份，方便后面使用。这个通道实际应用中作用不大； ShaderPass 使用该通道你可以传入一个自定义的着色器，用来生成高级的、自定义的后期处理通道 TexturePass 该通道可以将效果组合器的当前状态保存为一个纹理，然后可以在其他EffectCoposer对象中将该纹理作为输入参数
<!DOCTYPE html>
<html>
<head>
<title>Example 11.01 - Effect composings</title>
<script type="text/javascript" src="../js/three.js"></script>
<script type="text/javascript" src="../js/stats.js"></script>
<script type="text/javascript" src="../js/dat.gui.js"></script>
<script type="text/javascript" src="../js/OrbitControls.js"></script>
<script type="text/javascript" src="../js/postprocessing/ShaderPass.js"></script>
<script type="text/javascript" src="../js/shaders/CopyShader.js"></script>
<!--添加后期处理的步骤-->
<script type="text/javascript" src="../js/postprocessing/EffectComposer.js"></script>
<!-- MaskPass.js、ShaderPass.js、CopyShader.js 是EffectComposer内部使用的文件，-->
<script type="text/javascript" src="../js/postprocessing/MaskPass.js"></script>
<script type="text/javascript" src="../js/postprocessing/FilmPass.js"></script>
<script type="text/javascript" src="../js/shaders/FilmShader.js"></script>
<!--RenderPass.js 可以用来在EffectComposer对象上添加渲染通道-->
<script type="text/javascript" src="../js/postprocessing/RenderPass.js"></script>
<style>
body {
/* set margin to 0 and overflow to hidden, to go fullscreen */
margin: 0;
overflow: hidden;
}
</style>
</head>
<body>
<!--
BloomPass 该通道会使得明亮区域参入较暗的区域。模拟相机照到过多亮光的情形
DotScreenPass 将一层黑点贴到代表原始图片的屏幕上
FilmPass 通过扫描线和失真模拟电视屏幕
MaskPass 在当前图片上贴一层掩膜，后续通道只会影响被贴的区域
RenderPass 该通道在指定的场景和相机的基础上渲染出一个新的场景
SavePass 执行该通道时，它会将当前渲染步骤的结果复制一份，方便后面使用。这个通道实际应用中作用不大；
ShaderPass 使用该通道你可以传入一个自定义的着色器，用来生成高级的、自定义的后期处理通道
TexturePass 该通道可以将效果组合器的当前状态保存为一个纹理，然后可以在其他EffectCoposer对象中将该纹理作为输入参数
-->
<div id="Stats-output">
</div>
<!-- Div which will hold the Output -->
<div id="WebGL-output">
</div>
<!-- Javascript code that runs our Three.js examples -->
<script type="text/javascript">
// once everything is loaded, we run our Three.js stuff.
function init() {
var stats = initStats();
// create a scene, that will hold all our elements such as objects, cameras and lights.
var scene = new THREE.Scene();
// create a camera, which defines where we're looking at.
var camera = new THREE.PerspectiveCamera(45, window.innerWidth / window.innerHeight, 0.1, 1000);
// create a render and set the size
var webGLRenderer = new THREE.WebGLRenderer();
webGLRenderer.setClearColor(new THREE.Color(0x000, 1.0));
webGLRenderer.setSize(window.innerWidth, window.innerHeight);
webGLRenderer.shadowMapEnabled = true;
var sphere = createMesh(new THREE.SphereGeometry(10, 40, 40));
// add the sphere to the scene
scene.add(sphere);
// position and point the camera to the center of the scene
camera.position.x = -10;
camera.position.y = 15;
camera.position.z = 25;
camera.lookAt(new THREE.Vector3(0, 0, 0));
var orbitControls = new THREE.OrbitControls(camera);
orbitControls.autoRotate = false;
var clock = new THREE.Clock();
var ambi = new THREE.AmbientLight(0x181818);
scene.add(ambi);
var spotLight = new THREE.DirectionalLight(0xffffff);
spotLight.position.set(550, 100, 550);
spotLight.intensity = 0.6;
scene.add(spotLight);
// add the output of the renderer to the html element
document.getElementById("WebGL-output").appendChild(webGLRenderer.domElement);
/*------------------------后期处理----------------------------------*/
var renderPass = new THREE.RenderPass(scene, camera);//renderPass 通道：它只会渲染场景，但不会把结果输出到场景上
var effectFilm = new THREE.FilmPass(0.8, 0.325, 256, false);//FilmPass通道：它可以把结果输出到场景上
effectFilm.renderToScreen = true;//设置是否渲染到场景中
/*创建一个Three.EffectComposer() 它是一个组合器*/
var composer = new THREE.EffectComposer(webGLRenderer);
/*每个通道都会按照其加入EffectComposer的顺序执行。
* 第一个加入的通道是RenderPass下面这个通道会渲染场景，但不会将渲染结果输出到平面上
*
* FilmPass可以将其结果输出到屏幕上。这个通道是在RenderPass后面添加
* */
composer.addPass(renderPass);
composer.addPass(effectFilm);
/*----------------------------------------------------------*/
// setup the control gui
var controls = new function () {
this.scanlinesCount = 256;
this.grayscale = false;
this.scanlinesIntensity = 0.3;
this.noiseIntensity = 0.8;
this.updateEffectFilm = function () {
effectFilm.uniforms.grayscale.value = controls.grayscale;
effectFilm.uniforms.nIntensity.value = controls.noiseIntensity;
effectFilm.uniforms.sIntensity.value = controls.scanlinesIntensity;
effectFilm.uniforms.sCount.value = controls.scanlinesCount;
};
};
var gui = new dat.GUI();
gui.add(controls, "scanlinesIntensity", 0, 1).onChange(controls.updateEffectFilm);
gui.add(controls, "noiseIntensity", 0, 3).onChange(controls.updateEffectFilm);
gui.add(controls, "grayscale").onChange(controls.updateEffectFilm);
gui.add(controls, "scanlinesCount", 0, 2048).step(1).onChange(controls.updateEffectFilm);
// call the render function
var step = 0;
render();
function createMesh(geom) {
var planetTexture = THREE.ImageUtils.loadTexture("../../img/textures/planets/Earth.png");
var specularTexture = THREE.ImageUtils.loadTexture("../../img/textures/planets/EarthSpec.png");
var normalTexture = THREE.ImageUtils.loadTexture("../../img/textures/planets/EarthNormal.png");
var planetMaterial = new THREE.MeshPhongMaterial();
planetMaterial.specularMap = specularTexture;
planetMaterial.specular = new THREE.Color(0x4444aa);
planetMaterial.normalMap = normalTexture;
planetMaterial.map = planetTexture;
// planetMaterial.shininess = 150;
// create a multimaterial
var mesh = THREE.SceneUtils.createMultiMaterialObject(geom, [planetMaterial]);
return mesh;
}
function render() {
stats.update();
//sphere.rotation.y=step+=0.04;
var delta = clock.getDelta();
orbitControls.update(delta);
sphere.rotation.y += 0.002;
// render using requestAnimationFrame
requestAnimationFrame(render);
// webGLRenderer.render(scene, camera);
composer.render(delta);//替代webGLRenderer.render()，渲染时，就会调用EffectComposer 中的render()进行渲染
}
function initStats() {
var stats = new Stats();
stats.setMode(0); // 0: fps, 1: ms
// Align top-left
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>