如果您想訂閱本博客內容，每天自動發到您的郵箱中， 請點這里
我們都知道，three.js庫里面內置了很多著色器通道對象供我們渲染場景，本文將對EffectComposer、RenderPass、FilmPass這三個通道進行學習和實現：
1.RenderPass這個通道會在當前場景（scene）和攝像機（camera）的基礎上渲染出一個新場景，新建：
-
let renderPass = new THREE.RenderPass(scene, camera);
2.FilmPass這個通道通過掃描線和失真模擬電視屏幕效果，實現的效果超有時代感，新建：
-
-
let effectFilm = new THREE.FilmPass(0.8, 0.325, 256, false);
-
-
effectFilm.renderToScreen = true;
3.EffectComposer可以理解為著色器通道容器，著色器通道按照先后順序添加進來并執行，新建：
-
-
let composer = new THREE.EffectComposer(renderer);
-
composer.addPass(renderPass);
-
composer.addPass(effectFilm);
本文實現的demo基于three.js_r86(請自行下載)，代碼所用js文件和圖片都在下載的那個包里面，請讀者自行引用。
實現效果：
代碼：
-
<!DOCTYPE html>
-
<html lang="en">
-
<head>
-
<meta charset="UTF-8">
-
<title>shader_2_earth</title>
-
<style>
-
body{
-
margin: 0;
-
overflow: hidden;
-
}
-
</style>
-
</head>
-
<body>
-
<script src="build/three.js"></script>
-
<script src="js/libs/stats.min.js"></script>
-
<script src="js/libs/dat.gui.min.js"></script>
-
<script src="js/controls/OrbitControls.js"></script>
-
<script src="js/Detector.js"></script>
-
-
<script src="js/postprocessing/EffectComposer.js"></script>
-
<script src="js/postprocessing/ShaderPass.js"></script>
-
<script src="js/postprocessing/MaskPass.js"></script>
-
<script src="js/postprocessing/FilmPass.js"></script>
-
<script src="js/postprocessing/BloomPass.js"></script>
-
<script src="js/postprocessing/RenderPass.js"></script>
-
-
<script src="js/shaders/CopyShader.js"></script>
-
<script src="js/shaders/FilmShader.js"></script>
-
-
<div id="stats"></div>
-
<div id="container"></div>
-
<script>
-
//檢測webgl的兼容性
-
if(!Detector.webgl) Detector.addGetWebGLMessage();
-
-
let scene;
-
let camera, renderer, sphere, controls, stats;
-
let ambientLight, spotLight;
-
let composer;
-
let clock;
-
-
main();
-
render();
-
-
function main() {
-
scene = new THREE.Scene();
-
-
camera = new THREE.PerspectiveCamera(45, window.innerWidth/window.innerHeight, 0.1, 1000);
-
camera.position.set(-10, 15, 25);
-
camera.lookAt(new THREE.Vector3(0, 0, 0));
-
-
renderer = new THREE.WebGLRenderer({antialias:true});
-
renderer.setClearColor(new THREE.Color(0,0,0));
-
renderer.setSize(window.innerWidth, window.innerHeight);
-
renderer.shadowMapEnabled = true;
-
-
controls = new THREE.OrbitControls(camera);
-
controls.autoRotate = false;
-
-
clock = new THREE.Clock();
-
-
ambientLight = new THREE.AmbientLight(0x181818);
-
scene.add(ambientLight);
-
-
spotLight = new THREE.SpotLight(0xffffff);
-
spotLight.position.set(550, 100, 550);
-
spotLight.intensity = 0.6;
-
scene.add(spotLight);
-
-
//創建地球
-
sphere = createMesh(new THREE.SphereGeometry(10, 60, 60));
-
scene.add(sphere);
-
-
document.getElementById("container").appendChild(renderer.domElement);
-
-
/**
-
* 添加渲染通道
-
*/
-
//在當前場景和攝像機的基礎上渲染一個新場景
-
let renderPass = new THREE.RenderPass(scene, camera);
-
//通過掃描線和失真來實現模擬電視屏幕的效果
-
let effectFilm = new THREE.FilmPass(0.8, 0.325, 256, false);
-
//將渲染結果輸出到屏幕
-
effectFilm.renderToScreen = true;
-
-
//渲染效果組合器，每個通道都按照傳入的順序執行
-
composer = new THREE.EffectComposer(renderer);
-
composer.addPass(renderPass);
-
composer.addPass(effectFilm);
-
-
//菜單欄元素
-
let guiFields = {
-
"掃描線數量": 256,
-
"灰度圖像": false,
-
"掃描線強度": 0.3,
-
"粗糙程度": 0.8,
-
"updateEffectFilm": function () {
-
effectFilm.uniforms.grayscale.value = guiFields.灰度圖像;
-
effectFilm.uniforms.nIntensity.value = guiFields.粗糙程度;
-
effectFilm.uniforms.sIntensity.value = guiFields.掃描線強度;
-
effectFilm.uniforms.sCount.value = guiFields.掃描線數量;
-
}
-
};
-
-
//新建一個菜單欄
-
let gui = new dat.GUI();
-
gui.add(guiFields, "掃描線數量", 0, 2048).onChange(guiFields.updateEffectFilm);
-
gui.add(guiFields, "掃描線強度", 0, 1).onChange(guiFields.updateEffectFilm);
-
gui.add(guiFields, "粗糙程度", 0, 3).onChange(guiFields.updateEffectFilm);
-
gui.add(guiFields, "灰度圖像").onChange(guiFields.updateEffectFilm);
-
-
stats = initStats();
-
}
-
-
//創建一個Mesh
-
function createMesh(geometry) {
-
-
//初始化紋理加載器
-
let textureLoader = new THREE.TextureLoader();
-
//加載圖片
-
let uniforms = {
-
planetTexture:{value:textureLoader.load("textures/planets/earth_atmos_2048.jpg")},
-
specularTexture:{value:textureLoader.load("textures/planets/earth_specular_2048.jpg")},
-
normalTexture:{value:textureLoader.load("textures/planets/earth_normal_2048.jpg")}
-
};
-
-
//創建phong材料，并進行相應圖片的貼圖
-
let planetMaterial = new THREE.MeshPhongMaterial();
-
planetMaterial.specularMap = uniforms.specularTexture.value;
-
planetMaterial.specular = new THREE.Color(0x4444aa);
-
-
planetMaterial.normalMap = uniforms.normalTexture.value;
-
planetMaterial.map = uniforms.planetTexture.value;
-
-
//新建一個mesh
-
let mesh = new THREE.SceneUtils.createMultiMaterialObject(geometry, [planetMaterial]);
-
-
return mesh;
-
}
-
-
//渲染更新場景
-
-
function render() {
-
stats.update();
-
let delta = clock.getDelta();
-
controls.update(delta);
-
sphere.rotation.y += 0.002;
-
requestAnimationFrame(render);
-
-
//沒有著色器通道系統默認為WebGLRenderer.render
-
//使用著色器通道后，應使用使用composer.render
-
composer.render(delta);
-
}
-
-
//左上角幀顯示
-
function initStats() {
-
let stats = new Stats();
-
stats.setMode(0);
-
stats.domElement.style.position = 'absolute';
-
stats.domElement.style.left = '0px';
-
stats.domElement.style.top = '0px';
-
document.getElementById("stats").appendChild(stats.domElement);
-
-
return stats;
-
}
-
</script>
-
</body>
-
</html>
藍藍設計( www.0391cbd.com )是一家專注而深入的界面設計公司，為期望卓越的國內外企業提供卓越的UI界面設計、BS界面設計 、 cs界面設計 、 ipad界面設計 、 包裝設計 、 圖標定制 、 用戶體驗 、交互設計、 網站建設 、平面設計服務
