examples/webgl_custom_attributes_particles.html

<!DOCTYPE html>
<html lang="en">
	<head>
		<title>three.js webgl - custom attributes [particles]</title>
		<meta charset="utf-8">
		<meta name="viewport" content="width=device-width, user-scalable=no, minimum-scale=1.0, maximum-scale=1.0">
		<style>
			body {
				color: #ffffff;
				font-family:Monospace;
				font-size:13px;
				text-align:center;
				font-weight: bold;

				background-color: #000000;
				margin: 0px;
				overflow: hidden;
			}
			#info {
				color: #fff;
				background-color: rgba( 0, 0, 0, 0.75 );
				position: relative;
				top: 0px; width: 100%;
				padding: 5px;
				z-index:100;
				width:33em;
				margin:0 auto -2em;
			}
			a { color: #ff0000 }
		</style>
	</head>

	<body>
		<div id="info"><a href="http://github.com/mrdoob/three.js" target="_blank">three.js</a> - custom attributes example - particles</div>
		<div id="container"></div>

		<script src="../build/Three.js"></script>

		<script src="js/Detector.js"></script>
		<script src="js/Stats.js"></script>

		<script type="x-shader/x-vertex" id="vertexshader">

			uniform float amplitude;
			attribute float size;
			attribute vec3 customColor;

			varying vec3 vColor;

			void main() {

				vColor = customColor;

				vec4 mvPosition = modelViewMatrix * vec4( position, 1.0 );

				//gl_PointSize = size;
				gl_PointSize = size * ( 300.0 / length( mvPosition.xyz ) );

				gl_Position = projectionMatrix * mvPosition;

			}

		</script>

		<script type="x-shader/x-fragment" id="fragmentshader">

			uniform vec3 color;
			uniform sampler2D texture;

			varying vec3 vColor;

			void main() {

				gl_FragColor = vec4( color * vColor, 1.0 );
				gl_FragColor = gl_FragColor * texture2D( texture, gl_PointCoord );

			}

		</script>


		<script>

		if ( ! Detector.webgl ) Detector.addGetWebGLMessage();

		var renderer, scene, camera, stats;

		var sphere, uniforms, attributes;

		var noise = [];

		var WIDTH = window.innerWidth,
			HEIGHT = window.innerHeight;

		init();
		animate();

		function init() {

			camera = new THREE.PerspectiveCamera( 40, WIDTH / HEIGHT, 1, 10000 );
			camera.position.z = 300;

			scene = new THREE.Scene();

			scene.add( camera );

			attributes = {

				size: {	type: 'f', value: [] },
				customColor: { type: 'c', value: [] }

			};

			uniforms = {

				amplitude: { type: "f", value: 1.0 },
				color:     { type: "c", value: new THREE.Color( 0xffffff ) },
				texture:   { type: "t", value: 0, texture: THREE.ImageUtils.loadTexture( "textures/sprites/spark1.png" ) },

			};

			var shaderMaterial = new THREE.ShaderMaterial( {

				uniforms: 		uniforms,
				attributes:     attributes,
				vertexShader:   document.getElementById( 'vertexshader' ).textContent,
				fragmentShader: document.getElementById( 'fragmentshader' ).textContent,

				blending: 		THREE.AdditiveBlending,
				depthTest: 		false,
				transparent:	true

			});


			var radius = 200;
			var geometry = new THREE.Geometry();

			for ( var i = 0; i < 100000; i++ ) {

				var vertex = new THREE.Vector3();
				vertex.x = Math.random() * 2 - 1;
				vertex.y = Math.random() * 2 - 1;
				vertex.z = Math.random() * 2 - 1;
				vertex.multiplyScalar( radius );

				geometry.vertices.push( vertex );

			}

			sphere = new THREE.ParticleSystem( geometry, shaderMaterial );

			sphere.dynamic = true;
			//sphere.sortParticles = true;

			var vertices = sphere.geometry.vertices;
			var values_size = attributes.size.value;
			var values_color = attributes.customColor.value;


			for( var v = 0; v < vertices.length; v++ ) {

				values_size[ v ] = 10;
				values_color[ v ] = new THREE.Color( 0xffaa00 );

				if ( vertices[ v ].x < 0 )
					values_color[ v ].setHSV( 0.5 + 0.1 * ( v / vertices.length ), 0.7, 0.9 );
				else
					values_color[ v ].setHSV( 0.0 + 0.1 * ( v / vertices.length ), 0.9, 0.9 );

			}

			scene.add( sphere );

			renderer = new THREE.WebGLRenderer( { clearColor: 0x000000, clearAlpha: 1 } );
			renderer.setSize( WIDTH, HEIGHT );

			var container = document.getElementById( 'container' );
			container.appendChild( renderer.domElement );

			stats = new Stats();
			stats.domElement.style.position = 'absolute';
			stats.domElement.style.top = '0px';
			container.appendChild( stats.domElement );

			//

			window.addEventListener( 'resize', onWindowResize, false );

		}

		function onWindowResize() {

			camera.aspect = window.innerWidth / window.innerHeight;
			camera.updateProjectionMatrix();

			renderer.setSize( window.innerWidth, window.innerHeight );

		}

		function animate() {

			requestAnimationFrame( animate );

			render();
			stats.update();

		}

		function render() {

			var time = Date.now() * 0.005;

			sphere.rotation.z = 0.01 * time;

			for( var i = 0; i < attributes.size.value.length; i++ ) {

				attributes.size.value[ i ] = 14 + 13 * Math.sin( 0.1 * i + time );


			}

			attributes.size.needsUpdate = true;

			renderer.render( scene, camera );

		}


	</script>

</body>

</html>