Three.js開發指南---粒子和粒子系統（第七章）

時間  2019-12-11
標籤 three.js 開發 指南 粒子 系統 第七 欄目 JavaScript 简体版
原文   原文鏈接

使用粒子能夠很容易的建立不少細小的物體，例如雨滴雪花等javascript

本章主要內容：html

　　1 使用ParticleBasicMaterial(基礎粒子材質)來建立和設計粒子java

　　2 使用ParticleSystem來建立一個粒子集合web

　　3 使用已有的幾何體來建立一個粒子系統canvas

　　4 讓粒子和粒子系統動起來數組

　　5 用紋理給粒子造型緩存

　　6 使用ParticleCanvasMaterial在畫布上爲粒子造型併發

名稱 描述
Sprite粒子

參數是material，生成的sprite能夠設置position和scale等屬性直接添加到場景中app

 var sprite = new THREE.Sprite(material); sprite.position.set(x * 10, y * 10, 0); scene.add(sprite);
SpriteMaterial粒子的基本材質

粒子的基本材質，將在本章第7部分重點講解其參數dom

 var material = new THREE.SpriteMaterial();
PointCloud粒子系統

參數幾何體和材質

var cloud = new THREE.PointCloud(geom, material);

scene.add(cloud);
PointCloudMaterial粒子系統的材質

 設置全部粒子的大小，顏色，頂點顏色，透明度，是否根據相機距離的遠近改變大小等屬性

var material = new THREE.PointCloudMaterial({size: 4, vertexColors: true, color: 0xffffff});
SpriteCanvasMaterial  專門爲CanvasRenderer渲染器建立的材質，該材質的program屬性輸出的是粒子的紋理

1 粒子-----THREE.Particle

　　注意：新的THREE.js已經定義了Sprite對象，即THREE.Sprite，向後兼容THREE.Particle = THREE.Sprite;粒子Particle已經改名爲精靈Sprite

　　THREE.js源碼中有這樣一行代碼

 

　　THREE.Sprite跟THREE.Mesh同樣，都是THREE.Object3D對象的擴展，Sprite的參數是材質material，

　　另外CanvasRenderer對象已經不存在了，只有WebGLRenderer（已經找到緣由，three.js中只有WebGLRenderer，要引入CanvasRenderer.js才能夠）

<!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雖然書中介紹的CanvasRenderer，可是THREE.CanvasRenderer的值是undefined，尚未找到緣由
        //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已經改名爲PointCloudMaterial 
console.warn( 'THREE.ParticleSystemMaterial has been renamed to THREE.PointCloudMaterial.' );//THREE.ParticleSystemMaterial已經改名爲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.' );
            
            //建立一個點雲材質
            //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 粒子材質PointCloudMaterial和粒子系統PointCloud

 

PointCloudMaterial的屬性 描述
color

PointCloud中全部的粒子的顏色都相同，

除非設置了vertexColors且該幾何體的colors屬性不爲空，纔會使用colors顏色，不然都使用該屬性
map 在粒子上應用某種材質
size 粒子的大小
sizeAnnutation

false：不管相機的位置，全部的粒子大小一致；

true：離相機近的粒子更大一些，離相機越遠越小
vetexColors true：且該幾何體的colors屬性有值，則該粒子會捨棄第一個屬性--color，而應用該幾何體的colors屬性的顏色
opacity 透明度
transparent 是否透明
blending 渲染粒子時的融合模式
fog 是否受場景的霧化影響

 

<!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(); //設置粒子材質的屬性
            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, /*一般狀況下，全部的粒子應用同一種顏色，可是若該值設置爲true， 且幾何體的colors數組也有值，則會使用colors數組的顏色*/ sizeAttenuation: sizeAttenuation, /*false:無論粒子距離相機的遠近，它們都擁有相同的尺寸 true:粒子的大小取決於它們距離相機的遠近 */ color: color//粒子系統中全部粒子的顏色  }); 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);

            }
            //粒子系統PointCloud與網格Mesh相同，只接受幾何體和材質兩個參數
 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 使用畫布格式化粒子---針對CanvasRenderer渲染器所建立的材質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，繪製吃豆人中幽靈的身體
            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
            //繪製其眼睛
            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
            //繪製其眼珠
            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的擴展
                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 基於WebGLRenderer渲染器使用的粒子材質----PointCloudMaterial

　　PointCloudMaterial材質的map屬性使用的是THREE.Texture紋理，該紋理是畫布canvas做爲參數傳遞給紋理構造函數獲得的

 

   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 引入外部圖片造成紋理，而後利用該紋理格式化粒子

　　引入外部圖片造成紋理var texture=new THREE.ImageUtils.loadTexture("../img/rain.jpg");

　　格式化粒子的材質var material = new THREE.PiontCloudMaterial({map:texture});

　　利用該材質生成粒子系統 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 () {
            //有兩個粒子系統
                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) {
            //引入外部圖片生成紋理
            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, /*這種融合方式：在畫新的像素時，背景像素的顏色會被添加到新像素上*/
                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 經過模擬下雪，學習多個粒子系統併發進行
 

 
 

 
 
<!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,/*該屬性決定了這個對象是否影響WebGL的深度緩存，將其設置爲false，則各個粒子系統之間互不干涉*/
                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粒子的基本材質
 

 
  
  
 
   SpriteMaterial屬性 
   描述 
  
 
  
 
   color 
   粒子的顏色 
  
 
  
 
   map 
   粒子的紋理 
  
 
  
 
   sizeAnnutation 
   相機的遠近是否影響粒子的大小 
  
 
  
 
   opacity 
   透明度 
  
 
  
 
   transparent 
   是否透明 
  
 
  
 
   blending 
   融合方式 
  
 
  
 
   fog 
   是否受場景霧化的影響 
  
 
  
 
   useScreenCoordinates 
   true:粒子的位置是絕對位置，原點是屏幕的左上角 
  
 
  
 
   scaleByViewport 
    
true：粒子的大小取決於視窗的尺寸，粒子的寬=圖片的寬/窗口的高
 
false：粒子的寬=圖片的寬/1.0
 		 
  
 
  
 
   alignment 
    
當粒子被縮放的時候，指定從哪裏開始縮放，
 
THREE.SpriteAlignment.topLeft左上角保持不動，進行縮放
 		 
  
 
  
 
   uvOffset 
   當載入的圖片是一個精靈圖片，即不少小圖組成一張大圖，取大圖上具體某個小圖時，使用該屬性，進行偏移獲得具體的小圖 
  
 
  
 
   uvScale 
   對根據uvOffset獲取到的小圖進行縮放 
  
 
  

 

 
 
<!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() {
        //只須要載入一張大圖，該大圖由5個小圖組成
            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 將canvas做爲紋理，其中canvas上繪製了一條放射顏色漸變,扭結環幾何體的各個頂點和canvas紋理做爲參數傳遞粒子系統的構造函數，生成一個粒子系統
 

　　 var gradient = context.createRadialGradient()//canvas上繪製一條放射顏色漸變
 

 
 

  var texture = new THREE.Texture(canvas);//canvas做爲參數傳遞給紋理構造函數，生成一個紋理
 

 var material = new THREE.PointCloudMaterial({map: generateSprite()});// 利用粒子基本材質的map屬性應用該紋理，生成材質
 

 
 

     var geom = new THREE.TorusKnotGeometry()//扭結環構造函數，生成一個幾何體
 

 
 

   var cloud = new THREE.PointCloud(geom, material);//利用上面獲得的幾何體和材質獲得一個粒子系統
 

 
 

 

 
 

 
 
<!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>
 



        

            

        	





    

		

            
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