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<!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">
<link type="text/css" rel="stylesheet" href="main.css">
</head>
<body>
<div id="container"></div>
<div id="info"><a href="https://threejs.org" target="_blank" rel="noopener">three.js</a> webgl - buffergeometry - particles</div>
<!-- Import maps polyfill -->
<!-- Remove this when import maps will be widely supported -->
<script async src="https://unpkg.com/es-module-shims@1.3.6/dist/es-module-shims.js"></script>
<script type="importmap">
{
"imports": {
"three": "../build/three.module.js",
"three/addons/": "./jsm/"
}
}
</script>
<script type="module">
import * as THREE from 'three';
import Stats from 'three/addons/libs/stats.module.js';
let container, stats;
let camera, scene, renderer;
let points;
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.background = new THREE.Color( 0x050505 );
scene.fog = new THREE.Fog( 0x050505, 2000, 3500 );
//
const particles = 500000;
const geometry = new THREE.BufferGeometry();
// create a generic buffer of binary data (a single particle has 16 bytes of data)
const arrayBuffer = new ArrayBuffer( particles * 16 );
// the following typed arrays share the same buffer
const interleavedFloat32Buffer = new Float32Array( arrayBuffer );
const interleavedUint8Buffer = new Uint8Array( arrayBuffer );
//
const color = new THREE.Color();
const n = 1000, n2 = n / 2; // particles spread in the cube
for ( let i = 0; i < interleavedFloat32Buffer.length; i += 4 ) {
// position (first 12 bytes)
const x = Math.random() * n - n2;
const y = Math.random() * n - n2;
const z = Math.random() * n - n2;
interleavedFloat32Buffer[ i + 0 ] = x;
interleavedFloat32Buffer[ i + 1 ] = y;
interleavedFloat32Buffer[ i + 2 ] = z;
// color (last 4 bytes)
const vx = ( x / n ) + 0.5;
const vy = ( y / n ) + 0.5;
const vz = ( z / n ) + 0.5;
color.setRGB( vx, vy, vz );
const j = ( i + 3 ) * 4;
interleavedUint8Buffer[ j + 0 ] = color.r * 255;
interleavedUint8Buffer[ j + 1 ] = color.g * 255;
interleavedUint8Buffer[ j + 2 ] = color.b * 255;
interleavedUint8Buffer[ j + 3 ] = 0; // not needed
}
const interleavedBuffer32 = new THREE.InterleavedBuffer( interleavedFloat32Buffer, 4 );
const interleavedBuffer8 = new THREE.InterleavedBuffer( interleavedUint8Buffer, 16 );
geometry.setAttribute( 'position', new THREE.InterleavedBufferAttribute( interleavedBuffer32, 3, 0, false ) );
geometry.setAttribute( 'color', new THREE.InterleavedBufferAttribute( interleavedBuffer8, 3, 12, true ) );
//
const material = new THREE.PointsMaterial( { size: 15, vertexColors: true } );
points = new THREE.Points( geometry, material );
scene.add( points );
//
renderer = new THREE.WebGLRenderer();
renderer.setPixelRatio( window.devicePixelRatio );
renderer.setSize( window.innerWidth, window.innerHeight );
container.appendChild( renderer.domElement );
//
stats = new Stats();
container.appendChild( stats.dom );
//
window.addEventListener( 'resize', onWindowResize );
}
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() {
const time = Date.now() * 0.001;
points.rotation.x = time * 0.25;
points.rotation.y = time * 0.5;
renderer.render( scene, camera );
}
</script>
</body>
</html>