examples/webgl_buffergeometry_particles.html

<!DOCTYPE html>
<html lang="en">
	<head>
		<title>three.js webgl - buffergeometry [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: #cccccc;
				font-family:Monospace;
				font-size:13px;
				text-align:center;

				background-color: #050505;
				margin: 0px;
				overflow: hidden;
			}

			#info {
				position: absolute;
				top: 0px; width: 100%;
				padding: 5px;
			}

			a {

				color: #0080ff;
			}

		</style>
	</head>
	<body>

		<div id="container"></div>
		<div id="info"><a href="http://threejs.org" target="_blank">three.js</a> webgl - buffergeometry - particles</div>

		<script src="../build/three.min.js"></script>

		<script src="js/Detector.js"></script>
		<script src="js/libs/stats.min.js"></script>

		<script>

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

			var container, stats;

			var camera, scene, renderer;

			var mesh;

			init();
			animate();

			function init() {

				container = document.getElementById( 'container' );

				//

				camera = new THREE.PerspectiveCamera( 27, window.innerWidth / window.innerHeight, 5, 3500 );
				camera.position.z = 2750;

				scene = new THREE.Scene();
				scene.fog = new THREE.Fog( 0x050505, 2000, 3500 );

				//

				var particles = 500000;

				var geometry = new THREE.BufferGeometry();
				geometry.attributes = {

					position: {
						itemSize: 3,
						array: new Float32Array( particles * 3 ),
						numItems: particles * 3
					},
					color: {
						itemSize: 3,
						array: new Float32Array( particles * 3 ),
						numItems: particles * 3
					}

				}


				var positions = geometry.attributes.position.array;
				var colors = geometry.attributes.color.array;

				var color = new THREE.Color();

				var n = 1000, n2 = n / 2; // particles spread in the cube

				for ( var i = 0; i < positions.length; i += 3 ) {

					// positions

					var x = Math.random() * n - n2;
					var y = Math.random() * n - n2;
					var z = Math.random() * n - n2;

					positions[ i ]     = x;
					positions[ i + 1 ] = y;
					positions[ i + 2 ] = z;

					// colors

					var vx = ( x / n ) + 0.5;
					var vy = ( y / n ) + 0.5;
					var vz = ( z / n ) + 0.5;

					//color.setHSV( 0.5 + 0.5 * vx, 0.25 + 0.75 * vy, 0.25 + 0.75 * vz );
					color.setRGB( vx, vy, vz );

					colors[ i ]     = color.r;
					colors[ i + 1 ] = color.g;
					colors[ i + 2 ] = color.b;

				}

				geometry.computeBoundingSphere();

				//

				var material = new THREE.ParticleBasicMaterial( { size: 15, vertexColors: true } );

				particleSystem = new THREE.ParticleSystem( geometry, material );
				scene.add( particleSystem );

				//

				renderer = new THREE.WebGLRenderer( { antialias: false, clearColor: 0x333333, clearAlpha: 1, alpha: false } );
				renderer.setSize( window.innerWidth, window.innerHeight );
				renderer.setClearColor( scene.fog.color, 1 );

				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() {

				windowHalfX = window.innerWidth / 2;
				windowHalfY = window.innerHeight / 2;

				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() * 0.001;

				particleSystem.rotation.x = time * 0.25;
				particleSystem.rotation.y = time * 0.5;

				renderer.render( scene, camera );

			}

		</script>

	</body>
</html>