使用粒子可以很容易的创建很多细小的物体，例如雨滴雪花等
本章主要内容：
1 使用ParticleBasicMaterial(基础粒子材质)来创建和设计粒子
2 使用ParticleSystem来创建一个粒子集合
3 使用已有的几何体来创建一个粒子系统
4 让粒子和粒子系统动起来
5 用纹理给粒子造型
6 使用ParticleCanvasMaterial在画布上为粒子造型
| 名称 | 描述 |
| Sprite粒子 |
参数是material，生成的sprite可以设置position和scale等属性直接添加到场景中 var sprite = new THREE.Sprite(material); |
| SpriteMaterial粒子的基本材质 |
粒子的基本材质，将在本章第7部分重点讲解其参数 var material = new THREE.SpriteMaterial(); |
| PointCloud粒子系统 |
参数几何体和材质 var cloud = new THREE.PointCloud(geom, material); scene.add(cloud); |
| PointCloudMaterial粒子系统的材质 |
设置所有粒子的大小，颜色，顶点颜色，透明度，是否根据相机距离的远近改变大小等属性 var material = new THREE.PointCloudMaterial({size: 4, vertexColors: true, color: 0xffffff}); |
| SpriteCanvasMaterial | 专门为CanvasRenderer渲染器创建的材质，该材质的program属性输出的是粒子的纹理 |
1 粒子—–THREE.Particle
注意：新的THREE.js已经定义了Sprite对象，即THREE.Sprite，向后兼容THREE.Particle = THREE.Sprite;粒子Particle已经更名为精灵Sprite
THREE.js源码中有这样一行代码
THREE.Sprite跟THREE.Mesh一样，都是THREE.Object3D对象的扩展，Sprite的参数是材质material，
另外CanvasRenderer对象已经不存在了，只有WebGLRenderer（已经找到原因，three.js中只有WebGLRenderer，要引入CanvasRenderer.js才可以）
<!DOCTYPE html><html><head>
<title>Example 07.01 - Particles - Only works in CanvasRenderer</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;
background-color: #000000;
}
</style>
</head>
<body><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
//THREE.CanvasRenderer虽然书中介绍的CanvasRenderer，但是THREE.CanvasRenderer的值是undefined，还没有找到原因
//var canvasRenderer = new THREE.CanvasRenderer();
var canvasRenderer = new THREE.WebGLRenderer();
canvasRenderer.setClearColor(new THREE.Color(0x000000, 1.0));
canvasRenderer.setSize(window.innerWidth, window.innerHeight); // position and point the camera to the center of the scene
camera.position.x = 0;
camera.position.y = 0;
camera.position.z = 150; // add the output of the renderer to the html element
document.getElementById("WebGL-output").appendChild(canvasRenderer.domElement); createSprites();
render(); function createSprites() {
var material = new THREE.SpriteMaterial();
//var material = new THREE.ParticleBasicMaterial(); for (var x = -5; x < 5; x++) {
for (var y = -5; y < 5; y++) {
//var sprite = new THREE.Particle(material);
var sprite = new THREE.Sprite(material);
sprite.position.set(x * 10, y * 10, 0);
scene.add(sprite);
}
}
} function render() {
stats.update(); requestAnimationFrame(render);
canvasRenderer.render(scene, camera);
} 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>
console.warn( 'THREE.ParticleBasicMaterial has been renamed to THREE.PointCloudMaterial.' );
//ParticleBasicMaterial已经更名为PointCloudMaterial
console.warn( 'THREE.ParticleSystemMaterial has been renamed to THREE.PointCloudMaterial.' );//THREE.ParticleSystemMaterial已经更名为THREE.PointCloudMaterial
console.warn( 'THREE.ParticleSystem has been renamed to THREE.PointCloud.' );
<!DOCTYPE html><html><head>
<title>Example 07.02 - Particles - Only works in WebGLRenderer</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;
background-color: #000000;
}
</style>
</head>
<body><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(0x000000, 1.0));
webGLRenderer.setSize(window.innerWidth, window.innerHeight); // position and point the camera to the center of the scene
camera.position.x = 0;
camera.position.y = 0;
camera.position.z = 150; // add the output of the renderer to the html element
document.getElementById("WebGL-output").appendChild(webGLRenderer.domElement); createParticles();
render(); function createParticles() { var geom = new THREE.Geometry();
console.warn( 'THREE.ParticleBasicMaterial has been renamed to THREE.PointCloudMaterial.' );
console.warn( 'THREE.ParticleSystemMaterial has been renamed to THREE.PointCloudMaterial.' ); //创建一个点云材质
//PointCloudMaterial==ParticleBasicMaterial
var material = new THREE.PointCloudMaterial({size: 4, vertexColors: true, color: 0xffffff}); for (var x = -5; x < 5; x++) {
for (var y = -5; y < 5; y++) {
var particle = new THREE.Vector3(x * 10, y * 10, 0);
geom.vertices.push(particle);
geom.colors.push(new THREE.Color(Math.random() * 0x00ffff));
}
}
//console.warn( 'THREE.ParticleSystem has been renamed to THREE.PointCloud.' );
//PointCloud==ParticleSystem
var cloud = new THREE.PointCloud(geom, material);
scene.add(cloud);
} function render() {
stats.update(); requestAnimationFrame(render);
webGLRenderer.render(scene, camera);
} 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>
2 粒子材质PointCloudMaterial和粒子系统PointCloud
| PointCloudMaterial的属性 | 描述 |
| color |
PointCloud中所有的粒子的颜色都相同， 除非设置了vertexColors且该几何体的colors属性不为空，才会使用colors颜色，否则都使用该属性 |
| map | 在粒子上应用某种材质 |
| size | 粒子的大小 |
| sizeAnnutation |
false：无论相机的位置，所有的粒子大小一致； true：离相机近的粒子更大一些，离相机越远越小 |
| vetexColors | true：且该几何体的colors属性有值，则该粒子会舍弃第一个属性–color，而应用该几何体的colors属性的颜色 |
| opacity | 透明度 |
| transparent | 是否透明 |
| blending | 渲染粒子时的融合模式 |
| fog | 是否受场景的雾化影响 |
<!DOCTYPE html><html><head>
<title>Example 07.03 - Particle Basic Material</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;
background-color: #000000;
}
</style>
</head>
<body><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(0x000000, 1.0));
webGLRenderer.setSize(window.innerWidth, window.innerHeight); // position and point the camera to the center of the scene
camera.position.x = 20;
camera.position.y = 0;
camera.position.z = 150; // add the output of the renderer to the html element
document.getElementById("WebGL-output").appendChild(webGLRenderer.domElement); var cloud; var controls = new function () {
this.size = 4;
this.transparent = true;
this.opacity = 0.6;
this.vertexColors = true;
this.color = 0xffffff;
this.sizeAttenuation = true;
this.rotateSystem = true; this.redraw = function () {
if (scene.getObjectByName("particles")) {
scene.remove(scene.getObjectByName("particles"));
}
createParticles(controls.size, controls.transparent, controls.opacity, controls.vertexColors, controls.sizeAttenuation, controls.color);
};
}; var gui = new dat.GUI();
gui.add(controls, 'size', 0, 10).onChange(controls.redraw);
gui.add(controls, 'transparent').onChange(controls.redraw);
gui.add(controls, 'opacity', 0, 1).onChange(controls.redraw);
gui.add(controls, 'vertexColors').onChange(controls.redraw);
gui.addColor(controls, 'color').onChange(controls.redraw);
gui.add(controls, 'sizeAttenuation').onChange(controls.redraw);
gui.add(controls, 'rotateSystem'); controls.redraw();
render(); function createParticles(size, transparent, opacity, vertexColors, sizeAttenuation, color) { var geom = new THREE.Geometry();
//设置粒子材质的属性
var material = new THREE.PointCloudMaterial({
size: size,//粒子的大小
transparent: transparent,//是否透明
opacity: opacity,//透明度是多少
vertexColors: vertexColors,
/*通常情况下，所有的粒子应用同一种颜色，但是若该值设置为true，
且几何体的colors数组也有值，则会使用colors数组的颜色*/
sizeAttenuation: sizeAttenuation,
/*false:不管粒子距离相机的远近，它们都拥有相同的尺寸
true:粒子的大小取决于它们距离相机的远近
*/ color: color//粒子系统中所有粒子的颜色
}); var range = 500;
for (var i = 0; i < 15000; i++) {
var particle = new THREE.Vector3(Math.random() * range - range / 2, Math.random() * range - range / 2, Math.random() * range - range / 2);
geom.vertices.push(particle);
var color = new THREE.Color(0x00ff00);
color.setHSL(color.getHSL().h, color.getHSL().s, Math.random() * color.getHSL().l);
geom.colors.push(color); }
//粒子系统PointCloud与网格Mesh相同，只接受几何体和材质两个参数
cloud = new THREE.PointCloud(geom, material);
cloud.name = "particles";
scene.add(cloud);
} var step = 0; function render() { stats.update(); if (controls.rotateSystem) {
step += 0.01; cloud.rotation.x = step;
cloud.rotation.z = step;
} requestAnimationFrame(render);
webGLRenderer.render(scene, camera);
} 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>
3 使用画布格式化粒子—针对CanvasRenderer渲染器所创建的材质SpriteCanvasMaterial
<!DOCTYPE html><html><head>
<title>Example 07.04 - Particles - Canvas based texture</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>
<script type="text/javascript" src="../libs/CanvasRenderer.js"></script>
<script type="text/javascript" src="../libs/Projector.js"></script>
<style>
body {
/* set margin to 0 and overflow to hidden, to go fullscreen */
margin: 0;
overflow: hidden;
background-color: #000000;
}
</style>
</head>
<body><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 canvasRenderer = new THREE.CanvasRenderer();
// var canvasRenderer = new THREE.WebGLRenderer(); canvasRenderer.setClearColor(new THREE.Color(0x000000, 1.0));
canvasRenderer.setSize(window.innerWidth, window.innerHeight); // position and point the camera to the center of the scene
camera.position.x = 20;
camera.position.y = 0;
camera.position.z = 150; // add the output of the renderer to the html element
document.getElementById("WebGL-output").appendChild(canvasRenderer.domElement); var getTexture = function (ctx) { // the body，绘制吃豆人中幽灵的身体
ctx.translate(-81, -84); ctx.fillStyle = "orange";
ctx.beginPath();
ctx.moveTo(83, 116);
ctx.lineTo(83, 102);
ctx.bezierCurveTo(83, 94, 89, 88, 97, 88);
ctx.bezierCurveTo(105, 88, 111, 94, 111, 102);
ctx.lineTo(111, 116);
ctx.lineTo(106.333, 111.333);
ctx.lineTo(101.666, 116);
ctx.lineTo(97, 111.333);
ctx.lineTo(92.333, 116);
ctx.lineTo(87.666, 111.333);
ctx.lineTo(83, 116);
ctx.fill(); // the eyes
//绘制其眼睛
ctx.fillStyle = "white";
ctx.beginPath();
ctx.moveTo(91, 96);
ctx.bezierCurveTo(88, 96, 87, 99, 87, 101);
ctx.bezierCurveTo(87, 103, 88, 106, 91, 106);
ctx.bezierCurveTo(94, 106, 95, 103, 95, 101);
ctx.bezierCurveTo(95, 99, 94, 96, 91, 96);
ctx.moveTo(103, 96);
ctx.bezierCurveTo(100, 96, 99, 99, 99, 101);
ctx.bezierCurveTo(99, 103, 100, 106, 103, 106);
ctx.bezierCurveTo(106, 106, 107, 103, 107, 101);
ctx.bezierCurveTo(107, 99, 106, 96, 103, 96);
ctx.fill(); // the pupils
//绘制其眼珠
ctx.fillStyle = "blue";
ctx.beginPath();
ctx.arc(101, 102, 2, 0, Math.PI * 2, true);
ctx.fill();
ctx.beginPath();
ctx.arc(89, 102, 2, 0, Math.PI * 2, true);
ctx.fill(); }; createSprites();
render(); function createSprites() {
var material = new THREE.SpriteCanvasMaterial({
program: getTexture,
color: 0xffffff
}
); material.rotation = Math.PI; var range = 500;
for (var i = 0; i < 1500; i++) {
//Sprite是Object3D的扩展
var sprite = new THREE.Sprite(material);
sprite.position.set(Math.random() * range - range / 2, Math.random() * range - range / 2, Math.random() * range - range / 2);
sprite.scale.set(0.1, 0.1, 0.1);
scene.add(sprite);
}
} var step = 0; function render() { stats.update(); requestAnimationFrame(render);
canvasRenderer.render(scene, camera);
} 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>
4 基于WebGLRenderer渲染器使用的粒子材质—-PointCloudMaterial
PointCloudMaterial材质的map属性使用的是THREE.Texture纹理，该纹理是画布canvas作为参数传递给纹理构造函数得到的
var texture = new THREE.Texture(canvas);
<!DOCTYPE html><html><head>
<title>Example 07.05 - Particles - Canvas based texture - WebGL</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;
background-color: #000000;
}
</style>
</head>
<body><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(0x000000, 1.0));
webGLRenderer.setSize(window.innerWidth, window.innerHeight); // position and point the camera to the center of the scene
camera.position.x = 20;
camera.position.y = 0;
camera.position.z = 150; // add the output of the renderer to the html element
document.getElementById("WebGL-output").appendChild(webGLRenderer.domElement); var getTexture = function () {
var canvas = document.createElement('canvas');
canvas.width = 32;
canvas.height = 32; var ctx = canvas.getContext('2d');
// the body
ctx.translate(-81, -84); ctx.fillStyle = "orange";
ctx.beginPath();
ctx.moveTo(83, 116);
ctx.lineTo(83, 102);
ctx.bezierCurveTo(83, 94, 89, 88, 97, 88);
ctx.bezierCurveTo(105, 88, 111, 94, 111, 102);
ctx.lineTo(111, 116);
ctx.lineTo(106.333, 111.333);
ctx.lineTo(101.666, 116);
ctx.lineTo(97, 111.333);
ctx.lineTo(92.333, 116);
ctx.lineTo(87.666, 111.333);
ctx.lineTo(83, 116);
ctx.fill(); // the eyes
ctx.fillStyle = "white";
ctx.beginPath();
ctx.moveTo(91, 96);
ctx.bezierCurveTo(88, 96, 87, 99, 87, 101);
ctx.bezierCurveTo(87, 103, 88, 106, 91, 106);
ctx.bezierCurveTo(94, 106, 95, 103, 95, 101);
ctx.bezierCurveTo(95, 99, 94, 96, 91, 96);
ctx.moveTo(103, 96);
ctx.bezierCurveTo(100, 96, 99, 99, 99, 101);
ctx.bezierCurveTo(99, 103, 100, 106, 103, 106);
ctx.bezierCurveTo(106, 106, 107, 103, 107, 101);
ctx.bezierCurveTo(107, 99, 106, 96, 103, 96);
ctx.fill(); // the pupils
ctx.fillStyle = "blue";
ctx.beginPath();
ctx.arc(101, 102, 2, 0, Math.PI * 2, true);
ctx.fill();
ctx.beginPath();
ctx.arc(89, 102, 2, 0, Math.PI * 2, true);
ctx.fill(); var texture = new THREE.Texture(canvas);
texture.needsUpdate = true;
return texture;
}; var cloud; var controls = new function () {
this.size = 15;
this.transparent = true;
this.opacity = 0.6;
this.color = 0xffffff;
this.rotateSystem = true;
this.sizeAttenuation = true; this.redraw = function () {
if (scene.getObjectByName("pointcloud")) {
scene.remove(scene.getObjectByName("pointcloud"));
}
createPointCloud(controls.size, controls.transparent, controls.opacity, controls.sizeAttenuation, controls.color);
};
}; var gui = new dat.GUI();
gui.add(controls, 'size', 0, 20).onChange(controls.redraw);
gui.add(controls, 'transparent').onChange(controls.redraw);
gui.add(controls, 'opacity', 0, 1).onChange(controls.redraw);
gui.addColor(controls, 'color').onChange(controls.redraw);
gui.add(controls, 'sizeAttenuation').onChange(controls.redraw); gui.add(controls, 'rotateSystem'); controls.redraw(); render(); function createPointCloud(size, transparent, opacity, sizeAttenuation, color) { var geom = new THREE.Geometry(); var material = new THREE.PointCloudMaterial({
size: size,
transparent: transparent,
opacity: opacity,
map: getTexture(),
sizeAttenuation: sizeAttenuation,
color: color
}); var range = 500;
for (var i = 0; i < 5000; i++) {
var particle = new THREE.Vector3(Math.random() * range - range / 2, Math.random() * range - range / 2, Math.random() * range - range / 2);
geom.vertices.push(particle);
} cloud = new THREE.PointCloud(geom, material);
cloud.name = 'pointcloud';
cloud.sortParticles = true;
scene.add(cloud);
} var step = 0; function render() { stats.update();
if (controls.rotateSystem) {
step += 0.01; cloud.rotation.x = step;
cloud.rotation.z = step;
} requestAnimationFrame(render);
webGLRenderer.render(scene, camera);
} 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>
5 引入外部图片形成纹理，然后利用该纹理格式化粒子
引入外部图片形成纹理var texture=new THREE.ImageUtils.loadTexture(“../img/rain.jpg”);
格式化粒子的材质var material = new THREE.PiontCloudMaterial({map:texture});
利用该材质生成粒子系统 var cloud = new THREE.PointCloud(geom, material);
<!DOCTYPE html><html><head>
<title>Example 07.06 - Particles - Rainy scene</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;
background-color: #000000;
}
</style>
</head>
<body><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, 200); // create a render and set the size
var webGLRenderer = new THREE.WebGLRenderer();
webGLRenderer.setClearColor(new THREE.Color(0x000000, 1.0));
webGLRenderer.setSize(window.innerWidth, window.innerHeight); // position and point the camera to the center of the scene
camera.position.x = 20;
camera.position.y = 40;
camera.position.z = 110;
camera.lookAt(new THREE.Vector3(20, 30, 0)); // add the output of the renderer to the html element
document.getElementById("WebGL-output").appendChild(webGLRenderer.domElement); var system1;
var cloud; var controls = new function () {
this.size = 3;
this.transparent = true;
this.opacity = 0.6;
this.color = 0xffffff; this.sizeAttenuation = true; this.redraw = function () {
//有两个粒子系统
scene.remove(scene.getObjectByName("particles1"));
scene.remove(scene.getObjectByName("particles2")); createPointCloud(controls.size, controls.transparent, controls.opacity, controls.sizeAttenuation, controls.color);
};
}; var gui = new dat.GUI();
gui.add(controls, 'size', 0, 20).onChange(controls.redraw);
gui.add(controls, 'transparent').onChange(controls.redraw);
gui.add(controls, 'opacity', 0, 1).onChange(controls.redraw);
gui.addColor(controls, 'color').onChange(controls.redraw);
gui.add(controls, 'sizeAttenuation').onChange(controls.redraw); controls.redraw(); render(); function createPointCloud(size, transparent, opacity, sizeAttenuation, color) {
//引入外部图片生成纹理
var texture = THREE.ImageUtils.loadTexture("../assets/textures/particles/raindrop-3.png");
var geom = new THREE.Geometry(); var material = new THREE.PointCloudMaterial({
size: size,
transparent: transparent,
opacity: opacity,
map: texture,
blending: THREE.AdditiveBlending,
/*这种融合方式：在画新的像素时，背景像素的颜色会被添加到新像素上*/
sizeAttenuation: sizeAttenuation,
color: color
}); var range = 40;
for (var i = 0; i < 1500; i++) {
var particle = new THREE.Vector3(
Math.random() * range - range / 2,
Math.random() * range * 1.5,
Math.random() * range - range / 2);
particle.velocityY = 0.1 + Math.random() / 5;
particle.velocityX = (Math.random() - 0.5) / 3;
geom.vertices.push(particle);
} cloud = new THREE.PointCloud(geom, material);
cloud.sortParticles = true; scene.add(cloud);
} function render() {
stats.update();
var vertices = cloud.geometry.vertices;
vertices.forEach(function (v) {
v.y = v.y - (v.velocityY);
v.x = v.x - (v.velocityX); if (v.y <= 0) v.y = 60;
if (v.x <= -20 || v.x >= 20) v.velocityX = v.velocityX * -1;
}); requestAnimationFrame(render);
webGLRenderer.render(scene, camera);
} 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>
6 通过模拟下雪，学习多个粒子系统并发进行
<!DOCTYPE html><html><head>
<title>Example 07.07 - Particles - Snowy scene</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;
background-color: #000000;
}
</style>
</head>
<body><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, 200); // create a render and set the size
var webGLRenderer = new THREE.WebGLRenderer();
webGLRenderer.setClearColor(new THREE.Color(0x000000, 1.0));
webGLRenderer.setSize(window.innerWidth, window.innerHeight); // position and point the camera to the center of the scene
camera.position.x = 20;
camera.position.y = 40;
camera.position.z = 110;
camera.lookAt(new THREE.Vector3(20, 30, 0)); // add the output of the renderer to the html element
document.getElementById("WebGL-output").appendChild(webGLRenderer.domElement); var system1;
var system2; var controls = new function () {
this.size = 10;
this.transparent = true;
this.opacity = 0.6;
this.color = 0xffffff; this.sizeAttenuation = true; this.redraw = function () {
var toRemove = [];
scene.children.forEach(function (child) {
if (child instanceof THREE.PointCloud) {
toRemove.push(child);
}
});
toRemove.forEach(function (child) {
scene.remove(child)
});
createPointClouds(controls.size, controls.transparent, controls.opacity, controls.sizeAttenuation, controls.color);
};
}; var gui = new dat.GUI();
gui.add(controls, 'size', 0, 20).onChange(controls.redraw);
gui.add(controls, 'transparent').onChange(controls.redraw);
gui.add(controls, 'opacity', 0, 1).onChange(controls.redraw);
gui.addColor(controls, 'color').onChange(controls.redraw);
gui.add(controls, 'sizeAttenuation').onChange(controls.redraw); controls.redraw(); render(); function createPointCloud(name, texture, size, transparent, opacity, sizeAttenuation, color) {
var geom = new THREE.Geometry(); var color = new THREE.Color(color);
color.setHSL(color.getHSL().h,
color.getHSL().s,
(Math.random()) * color.getHSL().l); var material = new THREE.PointCloudMaterial({
size: size,
transparent: transparent,
opacity: opacity,
map: texture,
blending: THREE.AdditiveBlending,
depthWrite: false,/*该属性决定了这个对象是否影响WebGL的深度缓存，将其设置为false，则各个粒子系统之间互不干涉*/
sizeAttenuation: sizeAttenuation,
color: color
}); var range = 40;
for (var i = 0; i < 50; i++) {
var particle = new THREE.Vector3(
Math.random() * range - range / 2,
Math.random() * range * 1.5,
Math.random() * range - range / 2);
particle.velocityY = 0.1 + Math.random() / 5;
particle.velocityX = (Math.random() - 0.5) / 3;
particle.velocityZ = (Math.random() - 0.5) / 3;
geom.vertices.push(particle);
} var system = new THREE.PointCloud(geom, material);
system.name = name;
system.sortParticles = true;
return system;
} function createPointClouds(size, transparent, opacity, sizeAttenuation, color) { var texture1 = THREE.ImageUtils.loadTexture("../assets/textures/particles/snowflake1.png");
var texture2 = THREE.ImageUtils.loadTexture("../assets/textures/particles/snowflake2.png");
var texture3 = THREE.ImageUtils.loadTexture("../assets/textures/particles/snowflake3.png");
var texture4 = THREE.ImageUtils.loadTexture("../assets/textures/particles/snowflake5.png"); scene.add(createPointCloud("system1", texture1, size, transparent, opacity, sizeAttenuation, color));
scene.add(createPointCloud("system2", texture2, size, transparent, opacity, sizeAttenuation, color));
scene.add(createPointCloud("system3", texture3, size, transparent, opacity, sizeAttenuation, color));
scene.add(createPointCloud("system4", texture4, size, transparent, opacity, sizeAttenuation, color));
} function render() { stats.update(); scene.children.forEach(function (child) {
if (child instanceof THREE.PointCloud) {
var vertices = child.geometry.vertices;
vertices.forEach(function (v) {
v.y = v.y - (v.velocityY);
v.x = v.x - (v.velocityX);
v.z = v.z - (v.velocityZ); if (v.y <= 0) v.y = 60;
if (v.x <= -20 || v.x >= 20) v.velocityX = v.velocityX * -1;
if (v.z <= -20 || v.z >= 20) v.velocityZ = v.velocityZ * -1;
});
}
}); requestAnimationFrame(render);
webGLRenderer.render(scene, camera);
} 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>
7 Sprite粒子和SpriteMaterial粒子的基本材质
| SpriteMaterial属性 | 描述 |
| color | 粒子的颜色 |
| map | 粒子的纹理 |
| sizeAnnutation | 相机的远近是否影响粒子的大小 |
| opacity | 透明度 |
| transparent | 是否透明 |
| blending | 融合方式 |
| fog | 是否受场景雾化的影响 |
| useScreenCoordinates | true:粒子的位置是绝对位置，原点是屏幕的左上角 |
| scaleByViewport |
true：粒子的大小取决于视窗的尺寸，粒子的宽=图片的宽/窗口的高 false：粒子的宽=图片的宽/1.0 |
| alignment |
当粒子被缩放的时候，指定从哪里开始缩放， THREE.SpriteAlignment.topLeft左上角保持不动，进行缩放 |
| uvOffset | 当载入的图片是一个精灵图片，即很多小图组成一张大图，取大图上具体某个小图时，使用该属性，进行偏移得到具体的小图 |
| uvScale | 对根据uvOffset获取到的小图进行缩放 |
<!DOCTYPE html><html><head>
<title>Example 07.09 - Sprites in 3D</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;
background-color: #000000;
}
</style>
</head>
<body><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(0x000000, 1.0));
webGLRenderer.setSize(window.innerWidth, window.innerHeight); // position and point the camera to the center of the scene
camera.position.x = 20;
camera.position.y = 0;
camera.position.z = 150; // add the output of the renderer to the html element
document.getElementById("WebGL-output").appendChild(webGLRenderer.domElement); createSprites();
render(); var group; function createSprites() { group = new THREE.Object3D();
var range = 200;
for (var i = 0; i < 400; i++) {
group.add(createSprite(10, false, 0.6, 0xffffff, i % 5, range));
}
scene.add(group);
} function getTexture() {
//只需要载入一张大图，该大图由5个小图组成
var texture = new THREE.ImageUtils.loadTexture("../assets/textures/particles/sprite-sheet.png");
return texture;
} function createSprite(size, transparent, opacity, color, spriteNumber, range) { var spriteMaterial = new THREE.SpriteMaterial({
opacity: opacity,
color: color,
transparent: transparent,
map: getTexture()
}
); // we have 1 row, with five sprites
spriteMaterial.map.offset = new THREE.Vector2(0.2 * spriteNumber, 0);
spriteMaterial.map.repeat = new THREE.Vector2(1 / 5, 1);
spriteMaterial.depthTest = false; spriteMaterial.blending = THREE.AdditiveBlending; var sprite = new THREE.Sprite(spriteMaterial);
sprite.scale.set(size, size, size);
sprite.position.set(Math.random() * range - range / 2, Math.random() * range - range / 2, Math.random() * range - range / 2);
sprite.velocityX = 5; return sprite;
} var step = 0; function render() { stats.update();
step += 0.01;
group.rotation.x = step; requestAnimationFrame(render);
webGLRenderer.render(scene, camera);
} 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>
8 将canvas作为纹理，其中canvas上绘制了一条放射颜色渐变,扭结环几何体的各个顶点和canvas纹理作为参数传递粒子系统的构造函数，生成一个粒子系统
var gradient = context.createRadialGradient()//canvas上绘制一条放射颜色渐变
var texture = new THREE.Texture(canvas);//canvas作为参数传递给纹理构造函数，生成一个纹理
var material = new THREE.PointCloudMaterial({map: generateSprite()});// 利用粒子基本材质的map属性应用该纹理，生成材质
var geom = new THREE.TorusKnotGeometry()//扭结环构造函数，生成一个几何体
var cloud = new THREE.PointCloud(geom, material);//利用上面得到的几何体和材质得到一个粒子系统
<!DOCTYPE html><html><head>
<title>Example 07.10 - 3D Torusknot</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><!-- 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(0x000000, 1.0));
webGLRenderer.setSize(window.innerWidth, window.innerHeight);
webGLRenderer.shadowMapEnabled = true; // position and point the camera to the center of the scene
camera.position.x = -30;
camera.position.y = 40;
camera.position.z = 50;
camera.lookAt(new THREE.Vector3(10, 0, 0)); // add the output of the renderer to the html element
document.getElementById("WebGL-output").appendChild(webGLRenderer.domElement); // call the render function
var step = 0; var knot; // setup the control gui
var controls = new function () {
// we need the first child, since it's a multimaterial
this.radius = 13;
this.tube = 1.7;
this.radialSegments = 156;
this.tubularSegments = 12;
this.p = 5;
this.q = 4;
this.heightScale = 3.5;
this.asParticles = false;
this.rotate = false; this.redraw = function () {
// remove the old plane
if (knot) scene.remove(knot);
// create a new one
var geom = new THREE.TorusKnotGeometry(controls.radius, controls.tube, Math.round(controls.radialSegments), Math.round(controls.tubularSegments), Math.round(controls.p), Math.round(controls.q), controls.heightScale); if (controls.asParticles) {
knot = createPointCloud(geom);
} else {
knot = createMesh(geom);
} // add it to the scene.
scene.add(knot);
}; }; var gui = new dat.GUI();
gui.add(controls, 'radius', 0, 40).onChange(controls.redraw);
gui.add(controls, 'tube', 0, 40).onChange(controls.redraw);
gui.add(controls, 'radialSegments', 0, 400).step(1).onChange(controls.redraw);
gui.add(controls, 'tubularSegments', 1, 20).step(1).onChange(controls.redraw);
gui.add(controls, 'p', 1, 10).step(1).onChange(controls.redraw);
gui.add(controls, 'q', 1, 15).step(1).onChange(controls.redraw);
gui.add(controls, 'heightScale', 0, 5).onChange(controls.redraw);
gui.add(controls, 'asParticles').onChange(controls.redraw);
gui.add(controls, 'rotate').onChange(controls.redraw); controls.redraw(); render(); // from THREE.js examples
function generateSprite() { var canvas = document.createElement('canvas');
canvas.width = 16;
canvas.height = 16; var context = canvas.getContext('2d');
var gradient = context.createRadialGradient(canvas.width / 2, canvas.height / 2, 0, canvas.width / 2, canvas.height / 2, canvas.width / 2);
gradient.addColorStop(0, 'rgba(255,255,255,1)');
gradient.addColorStop(0.2, 'rgba(0,255,255,1)');
gradient.addColorStop(0.4, 'rgba(0,0,64,1)');
gradient.addColorStop(1, 'rgba(0,0,0,1)'); context.fillStyle = gradient;
context.fillRect(0, 0, canvas.width, canvas.height); var texture = new THREE.Texture(canvas);
texture.needsUpdate = true;
return texture; } function createPointCloud(geom) {
var material = new THREE.PointCloudMaterial({
color: 0xffffff,
size: 3,
transparent: true,
blending: THREE.AdditiveBlending,
map: generateSprite()
}); var cloud = new THREE.PointCloud(geom, material);
cloud.sortParticles = true;
return cloud;
} function createMesh(geom) { // assign two materials
var meshMaterial = new THREE.MeshNormalMaterial({});
meshMaterial.side = THREE.DoubleSide; // create a multimaterial
var mesh = THREE.SceneUtils.createMultiMaterialObject(geom, [meshMaterial]); return mesh;
} function render() {
stats.update(); if (controls.rotate) {
knot.rotation.y = step += 0.01;
} // render using requestAnimationFrame
requestAnimationFrame(render);
webGLRenderer.render(scene, camera);
} 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>
