webgl_buffergeometry_points_dynamicbufferattribute.html 4.0 KB

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  1. <!DOCTYPE html>
  2. <html lang="en">
  3. <head>
  4. <title>three.js webgl - buffergeometry [particles]</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. <style>
  8. body {
  9. color: #cccccc;
  10. font-family:Monospace;
  11. font-size:13px;
  12. text-align:center;
  13. background-color: #050505;
  14. margin: 0px;
  15. overflow: hidden;
  16. }
  17. #info {
  18. position: absolute;
  19. top: 0px; width: 100%;
  20. padding: 5px;
  21. }
  22. a {
  23. color: #0080ff;
  24. }
  25. </style>
  26. </head>
  27. <body>
  28. <div id="container"></div>
  29. <div id="info"><a href="http://threejs.org" target="_blank" rel="noopener">three.js</a> webgl - buffergeometry - particles</div>
  30. <script src="../build/three.js"></script>
  31. <script src="js/Detector.js"></script>
  32. <script src="js/libs/stats.min.js"></script>
  33. <script>
  34. if ( ! Detector.webgl ) Detector.addGetWebGLMessage();
  35. var container, stats;
  36. var camera, scene, renderer;
  37. var points;
  38. init();
  39. animate();
  40. function init() {
  41. container = document.getElementById( 'container' );
  42. //
  43. renderer = new THREE.WebGLRenderer( { antialias: false } );
  44. renderer.setPixelRatio( window.devicePixelRatio );
  45. renderer.setSize( window.innerWidth, window.innerHeight );
  46. container.appendChild( renderer.domElement );
  47. //
  48. camera = new THREE.PerspectiveCamera( 27, window.innerWidth / window.innerHeight, 5, 3500 );
  49. camera.position.z = 2750;
  50. scene = new THREE.Scene();
  51. scene.background = new THREE.Color( 0x050505 );
  52. scene.fog = new THREE.Fog( 0x050505, 2000, 3500 );
  53. //
  54. var particles = 500000;
  55. var geometry = new THREE.BufferGeometry();
  56. var positions = [];
  57. var positions2 = [];
  58. var colors = [];
  59. var color = new THREE.Color();
  60. var n = 1000, n2 = n / 2; // particles spread in the cube
  61. for ( var i = 0; i < particles; i ++ ) {
  62. // positions
  63. var x = Math.random() * n - n2;
  64. var y = Math.random() * n - n2;
  65. var z = Math.random() * n - n2;
  66. positions.push( x, y, z );
  67. positions2.push( z, x, y );
  68. // colors
  69. var vx = ( x / n ) + 0.5;
  70. var vy = ( y / n ) + 0.5;
  71. var vz = ( z / n ) + 0.5;
  72. color.setRGB( vx, vy, vz );
  73. colors.push( color.r, color.g, color.b );
  74. }
  75. var gl = renderer.context;
  76. var pos = gl.createBuffer();
  77. gl.bindBuffer(gl.ARRAY_BUFFER, pos);
  78. gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(positions), gl.STATIC_DRAW);
  79. var pos2 = gl.createBuffer();
  80. gl.bindBuffer(gl.ARRAY_BUFFER, pos2);
  81. gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(positions2), gl.STATIC_DRAW);
  82. var rgb = gl.createBuffer();
  83. gl.bindBuffer(gl.ARRAY_BUFFER, rgb);
  84. gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(colors), gl.STATIC_DRAW);
  85. var posAttr = new THREE.DynamicBufferAttribute( gl, pos, gl.FLOAT, 3, particles );
  86. geometry.addAttribute( 'position', posAttr );
  87. setInterval(function () {
  88. posAttr.buffer = (posAttr.buffer === pos) ? pos2 : pos;
  89. posAttr.needsUpdate = true;
  90. }, 2000);
  91. geometry.addAttribute( 'color', new THREE.DynamicBufferAttribute( gl, rgb, gl.FLOAT, 3, particles ) );
  92. geometry.computeBoundingSphere();
  93. //
  94. var material = new THREE.PointsMaterial( { size: 15, vertexColors: THREE.VertexColors } );
  95. points = new THREE.Points( geometry, material );
  96. scene.add( points );
  97. //
  98. stats = new Stats();
  99. container.appendChild( stats.dom );
  100. //
  101. window.addEventListener( 'resize', onWindowResize, false );
  102. }
  103. function onWindowResize() {
  104. camera.aspect = window.innerWidth / window.innerHeight;
  105. camera.updateProjectionMatrix();
  106. renderer.setSize( window.innerWidth, window.innerHeight );
  107. }
  108. //
  109. function animate() {
  110. requestAnimationFrame( animate );
  111. render();
  112. stats.update();
  113. }
  114. function render() {
  115. var time = Date.now() * 0.001;
  116. points.rotation.x = time * 0.25;
  117. points.rotation.y = time * 0.5;
  118. renderer.render( scene, camera );
  119. }
  120. </script>
  121. </body>
  122. </html>