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<head>
<title>three.js webgl - buffergeometry</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</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, 1, 3500 );
camera.position.z = 2750;
scene = new THREE.Scene();
scene.fog = new THREE.Fog( 0x050505, 2000, 3500 );
//
scene.add( new THREE.AmbientLight( 0x444444 ) );
var light1 = new THREE.DirectionalLight( 0xffffff, 0.5 );
light1.position.set( 1, 1, 1 );
scene.add( light1 );
var light2 = new THREE.DirectionalLight( 0xffffff, 1.5 );
light2.position.set( 0, -1, 0 );
scene.add( light2 );
//
var triangles = 160000;
var geometry = new THREE.BufferGeometry();
// break geometry into
// chunks of 21,845 triangles (3 unique vertices per triangle)
// for indices to fit into 16 bit integer number
// floor(2^16 / 3) = 21845
var chunkSize = 21845;
var indices = new Uint16Array( triangles * 3 );
for ( var i = 0; i < indices.length; i ++ ) {
indices[ i ] = i % ( 3 * chunkSize );
}
var positions = new Float32Array( triangles * 3 * 3 );
var normals = new Float32Array( triangles * 3 * 3 );
var colors = new Float32Array( triangles * 3 * 3 );
var color = new THREE.Color();
var n = 800, n2 = n/2; // triangles spread in the cube
var d = 12, d2 = d/2; // individual triangle size
var pA = new THREE.Vector3();
var pB = new THREE.Vector3();
var pC = new THREE.Vector3();
var cb = new THREE.Vector3();
var ab = new THREE.Vector3();
for ( var i = 0; i < positions.length; i += 9 ) {
// positions
var x = Math.random() * n - n2;
var y = Math.random() * n - n2;
var z = Math.random() * n - n2;
var ax = x + Math.random() * d - d2;
var ay = y + Math.random() * d - d2;
var az = z + Math.random() * d - d2;
var bx = x + Math.random() * d - d2;
var by = y + Math.random() * d - d2;
var bz = z + Math.random() * d - d2;
var cx = x + Math.random() * d - d2;
var cy = y + Math.random() * d - d2;
var cz = z + Math.random() * d - d2;
positions[ i ] = ax;
positions[ i + 1 ] = ay;
positions[ i + 2 ] = az;
positions[ i + 3 ] = bx;
positions[ i + 4 ] = by;
positions[ i + 5 ] = bz;
positions[ i + 6 ] = cx;
positions[ i + 7 ] = cy;
positions[ i + 8 ] = cz;
// flat face normals
pA.set( ax, ay, az );
pB.set( bx, by, bz );
pC.set( cx, cy, cz );
cb.subVectors( pC, pB );
ab.subVectors( pA, pB );
cb.cross( ab );
cb.normalize();
var nx = cb.x;
var ny = cb.y;
var nz = cb.z;
normals[ i ] = nx;
normals[ i + 1 ] = ny;
normals[ i + 2 ] = nz;
normals[ i + 3 ] = nx;
normals[ i + 4 ] = ny;
normals[ i + 5 ] = nz;
normals[ i + 6 ] = nx;
normals[ i + 7 ] = ny;
normals[ i + 8 ] = nz;
// colors
var vx = ( x / n ) + 0.5;
var vy = ( y / n ) + 0.5;
var vz = ( z / n ) + 0.5;
color.setRGB( vx, vy, vz );
colors[ i ] = color.r;
colors[ i + 1 ] = color.g;
colors[ i + 2 ] = color.b;
colors[ i + 3 ] = color.r;
colors[ i + 4 ] = color.g;
colors[ i + 5 ] = color.b;
colors[ i + 6 ] = color.r;
colors[ i + 7 ] = color.g;
colors[ i + 8 ] = color.b;
}
geometry.addAttribute( 'index', new THREE.BufferAttribute( indices, 1 ) );
geometry.addAttribute( 'position', new THREE.BufferAttribute( positions, 3 ) );
geometry.addAttribute( 'normal', new THREE.BufferAttribute( normals, 3 ) );
geometry.addAttribute( 'color', new THREE.BufferAttribute( colors, 3 ) );
var offsets = triangles / chunkSize;
for ( var i = 0; i < offsets; i ++ ) {
var offset = {
start: i * chunkSize * 3,
index: i * chunkSize * 3,
count: Math.min( triangles - ( i * chunkSize ), chunkSize ) * 3
};
geometry.offsets.push( offset );
}
geometry.computeBoundingSphere();
var material = new THREE.MeshPhongMaterial( {
color: 0xaaaaaa, specular: 0xffffff, shininess: 250,
side: THREE.DoubleSide, vertexColors: THREE.VertexColors
} );
mesh = new THREE.Mesh( geometry, material );
scene.add( mesh );
//
renderer = new THREE.WebGLRenderer( { antialias: false } );
renderer.setClearColor( scene.fog.color );
renderer.setPixelRatio( window.devicePixelRatio );
renderer.setSize( window.innerWidth, window.innerHeight );
renderer.gammaInput = true;
renderer.gammaOutput = true;
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() * 0.001;
mesh.rotation.x = time * 0.25;
mesh.rotation.y = time * 0.5;
renderer.render( scene, camera );
}
</script>
</body>
</html>