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- <!DOCTYPE html>
- <html lang="en">
- <head>
- <title>three.js webgl - buffergeometry - custom VBOs</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 - custom VBOs</div>
- <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;
- const particles = 300000;
- let drawCount = 10000;
- init();
- animate();
- function init() {
- container = document.getElementById( 'container' );
- //
- renderer = new THREE.WebGLRenderer();
- renderer.setPixelRatio( window.devicePixelRatio );
- renderer.setSize( window.innerWidth, window.innerHeight );
- renderer.setAnimationLoop( animate );
- container.appendChild( renderer.domElement );
- //
- 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 geometry = new THREE.BufferGeometry();
- const positions = [];
- const positions2 = [];
- const colors = [];
- const color = new THREE.Color();
- const n = 1000, n2 = n / 2; // particles spread in the cube
- for ( let i = 0; i < particles; i ++ ) {
- // positions
- const x = Math.random() * n - n2;
- const y = Math.random() * n - n2;
- const z = Math.random() * n - n2;
- positions.push( x, y, z );
- positions2.push( z * 0.3, x * 0.3, y * 0.3 );
- // colors
- const vx = ( x / n ) + 0.5;
- const vy = ( y / n ) + 0.5;
- const vz = ( z / n ) + 0.5;
- color.setRGB( vx, vy, vz, THREE.SRGBColorSpace );
- colors.push( color.r, color.g, color.b );
- }
- const gl = renderer.getContext();
- const pos = gl.createBuffer();
- gl.bindBuffer( gl.ARRAY_BUFFER, pos );
- gl.bufferData( gl.ARRAY_BUFFER, new Float32Array( positions ), gl.STATIC_DRAW );
- const pos2 = gl.createBuffer();
- gl.bindBuffer( gl.ARRAY_BUFFER, pos2 );
- gl.bufferData( gl.ARRAY_BUFFER, new Float32Array( positions2 ), gl.STATIC_DRAW );
- const rgb = gl.createBuffer();
- gl.bindBuffer( gl.ARRAY_BUFFER, rgb );
- gl.bufferData( gl.ARRAY_BUFFER, new Float32Array( colors ), gl.STATIC_DRAW );
- const posAttr1 = new THREE.GLBufferAttribute( pos, gl.FLOAT, 3, 4, particles );
- const posAttr2 = new THREE.GLBufferAttribute( pos2, gl.FLOAT, 3, 4, particles );
- geometry.setAttribute( 'position', posAttr1 );
- setInterval( function () {
- const attr = geometry.getAttribute( 'position' );
- geometry.setAttribute( 'position', ( attr === posAttr1 ) ? posAttr2 : posAttr1 );
- }, 2000 );
- geometry.setAttribute( 'color', new THREE.GLBufferAttribute( rgb, gl.FLOAT, 3, 4, particles ) );
- //
- const material = new THREE.PointsMaterial( { size: 15, vertexColors: true } );
- points = new THREE.Points( geometry, material );
- geometry.boundingSphere = new THREE.Sphere().set( new THREE.Vector3(), 500 );
- scene.add( points );
- //
- 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() {
- drawCount = ( Math.max( 5000, drawCount ) + Math.floor( 500 * Math.random() ) ) % particles;
- points.geometry.setDrawRange( 0, drawCount );
- const time = Date.now() * 0.001;
- points.rotation.x = time * 0.1;
- points.rotation.y = time * 0.2;
- renderer.render( scene, camera );
- stats.update();
- }
- </script>
- </body>
- </html>
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