webgl_buffergeometry_points_glbufferattribute.html 4.0 KB

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  1. <!DOCTYPE html>
  2. <html lang="en">
  3. <head>
  4. <title>three.js webgl - buffergeometry - custom VBOs</title>
  5. <meta charset="utf-8">
  6. <meta name="viewport" content="width=device-width, user-scalable=no, minimum-scale=1.0, maximum-scale=1.0">
  7. <link type="text/css" rel="stylesheet" href="main.css">
  8. </head>
  9. <body>
  10. <div id="container"></div>
  11. <div id="info"><a href="https://threejs.org" target="_blank" rel="noopener">three.js</a> webgl - buffergeometry - custom VBOs</div>
  12. <script type="module">
  13. import * as THREE from '../build/three.module.js';
  14. import Stats from './jsm/libs/stats.module.js';
  15. var container, stats;
  16. var camera, scene, renderer;
  17. var points;
  18. var particles = 300000;
  19. init();
  20. animate();
  21. function init() {
  22. container = document.getElementById( 'container' );
  23. //
  24. renderer = new THREE.WebGLRenderer( { antialias: false } );
  25. renderer.setPixelRatio( window.devicePixelRatio );
  26. renderer.setSize( window.innerWidth, window.innerHeight );
  27. container.appendChild( renderer.domElement );
  28. //
  29. camera = new THREE.PerspectiveCamera( 27, window.innerWidth / window.innerHeight, 5, 3500 );
  30. camera.position.z = 2750;
  31. scene = new THREE.Scene();
  32. scene.background = new THREE.Color( 0x050505 );
  33. scene.fog = new THREE.Fog( 0x050505, 2000, 3500 );
  34. //
  35. var geometry = new THREE.BufferGeometry();
  36. var positions = [];
  37. var positions2 = [];
  38. var colors = [];
  39. var color = new THREE.Color();
  40. var n = 1000, n2 = n / 2; // particles spread in the cube
  41. for ( var i = 0; i < particles; i ++ ) {
  42. // positions
  43. var x = Math.random() * n - n2;
  44. var y = Math.random() * n - n2;
  45. var z = Math.random() * n - n2;
  46. positions.push( x, y, z );
  47. positions2.push( z * 0.3, x * 0.3, y * 0.3 );
  48. // colors
  49. var vx = ( x / n ) + 0.5;
  50. var vy = ( y / n ) + 0.5;
  51. var vz = ( z / n ) + 0.5;
  52. color.setRGB( vx, vy, vz );
  53. colors.push( color.r, color.g, color.b );
  54. }
  55. var gl = renderer.getContext();
  56. var pos = gl.createBuffer();
  57. gl.bindBuffer( gl.ARRAY_BUFFER, pos );
  58. gl.bufferData( gl.ARRAY_BUFFER, new Float32Array( positions ), gl.STATIC_DRAW );
  59. var pos2 = gl.createBuffer();
  60. gl.bindBuffer( gl.ARRAY_BUFFER, pos2 );
  61. gl.bufferData( gl.ARRAY_BUFFER, new Float32Array( positions2 ), gl.STATIC_DRAW );
  62. var rgb = gl.createBuffer();
  63. gl.bindBuffer( gl.ARRAY_BUFFER, rgb );
  64. gl.bufferData( gl.ARRAY_BUFFER, new Float32Array( colors ), gl.STATIC_DRAW );
  65. var posAttr = new THREE.GLBufferAttribute( pos, gl.FLOAT, 3, 4, particles );
  66. geometry.setAttribute( 'position', posAttr );
  67. setInterval( function () {
  68. posAttr.buffer = ( posAttr.buffer === pos ) ? pos2 : pos;
  69. posAttr.needsUpdate = true;
  70. }, 2000 );
  71. geometry.setAttribute( 'color', new THREE.GLBufferAttribute( rgb, gl.FLOAT, 3, 4, particles ) );
  72. //
  73. var material = new THREE.PointsMaterial( { size: 15, vertexColors: THREE.VertexColors } );
  74. points = new THREE.Points( geometry, material );
  75. // Choose one:
  76. // geometry.boundingSphere = ( new THREE.Sphere() ).set( new THREE.Vector3(), Infinity );
  77. points.frustumCulled = false;
  78. scene.add( points );
  79. //
  80. stats = new Stats();
  81. container.appendChild( stats.dom );
  82. //
  83. window.addEventListener( 'resize', onWindowResize, false );
  84. }
  85. function onWindowResize() {
  86. camera.aspect = window.innerWidth / window.innerHeight;
  87. camera.updateProjectionMatrix();
  88. renderer.setSize( window.innerWidth, window.innerHeight );
  89. }
  90. //
  91. function animate() {
  92. requestAnimationFrame( animate );
  93. render();
  94. stats.update();
  95. }
  96. var drawCount = 10000;
  97. function render() {
  98. drawCount = ( Math.max( 5000, drawCount ) + Math.floor( 500 * Math.random() ) ) % particles;
  99. points.geometry.setDrawRange( 0, drawCount );
  100. var time = Date.now() * 0.001;
  101. points.rotation.x = time * 0.1;
  102. points.rotation.y = time * 0.2;
  103. renderer.render( scene, camera );
  104. }
  105. </script>
  106. </body>
  107. </html>