webgl_buffergeometry.html 6.7 KB

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  1. <!DOCTYPE html>
  2. <html lang="en">
  3. <head>
  4. <title>three.js webgl - buffergeometry</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://github.com/mrdoob/three.js" target="_blank">three.js</a> webgl - buffergeometry</div>
  30. <script src="../build/three.min.js"></script>
  31. <script src="js/Detector.js"></script>
  32. <script src="js/Stats.js"></script>
  33. <script>
  34. if ( ! Detector.webgl ) Detector.addGetWebGLMessage();
  35. var container, stats;
  36. var camera, scene, renderer;
  37. var mesh;
  38. init();
  39. animate();
  40. function init() {
  41. container = document.getElementById( 'container' );
  42. //
  43. camera = new THREE.PerspectiveCamera( 27, window.innerWidth / window.innerHeight, 1, 3500 );
  44. camera.position.z = 2750;
  45. scene = new THREE.Scene();
  46. scene.fog = new THREE.Fog( 0x050505, 2000, 3500 );
  47. //
  48. scene.add( new THREE.AmbientLight( 0x444444 ) );
  49. var light1 = new THREE.DirectionalLight( 0xffffff, 0.5 );
  50. light1.position.set( 1, 1, 1 );
  51. scene.add( light1 );
  52. var light2 = new THREE.DirectionalLight( 0xffffff, 1.5 );
  53. light2.position.set( 0, -1, 0 );
  54. scene.add( light2 );
  55. //
  56. var triangles = 250000;
  57. var geometry = new THREE.BufferGeometry();
  58. geometry.attributes = {
  59. index: {
  60. itemSize: 1,
  61. array: new Int16Array( triangles * 3 ),
  62. numItems: triangles * 3
  63. },
  64. position: {
  65. itemSize: 3,
  66. array: new Float32Array( triangles * 3 * 3 ),
  67. numItems: triangles * 3 * 3
  68. },
  69. normal: {
  70. itemSize: 3,
  71. array: new Float32Array( triangles * 3 * 3 ),
  72. numItems: triangles * 3 * 3
  73. },
  74. color: {
  75. itemSize: 3,
  76. array: new Float32Array( triangles * 3 * 3 ),
  77. numItems: triangles * 3 * 3
  78. }
  79. }
  80. // break geometry into
  81. // chunks of 20,000 triangles (3 unique vertices per triangle)
  82. // for indices to fit into 16 bit integer number
  83. var chunkSize = 20000;
  84. var indices = geometry.attributes.index.array;
  85. for ( var i = 0; i < indices.length; i ++ ) {
  86. indices[ i ] = i % ( 3 * chunkSize );
  87. }
  88. var positions = geometry.attributes.position.array;
  89. var normals = geometry.attributes.normal.array;
  90. var colors = geometry.attributes.color.array;
  91. var color = new THREE.Color();
  92. var n = 800, n2 = n/2; // triangles spread in the cube
  93. var d = 12, d2 = d/2; // individual triangle size
  94. var pA = new THREE.Vector3();
  95. var pB = new THREE.Vector3();
  96. var pC = new THREE.Vector3();
  97. var cb = new THREE.Vector3();
  98. var ab = new THREE.Vector3();
  99. for ( var i = 0; i < positions.length; i += 9 ) {
  100. // positions
  101. var x = Math.random() * n - n2;
  102. var y = Math.random() * n - n2;
  103. var z = Math.random() * n - n2;
  104. var ax = x + Math.random() * d - d2;
  105. var ay = y + Math.random() * d - d2;
  106. var az = z + Math.random() * d - d2;
  107. var bx = x + Math.random() * d - d2;
  108. var by = y + Math.random() * d - d2;
  109. var bz = z + Math.random() * d - d2;
  110. var cx = x + Math.random() * d - d2;
  111. var cy = y + Math.random() * d - d2;
  112. var cz = z + Math.random() * d - d2;
  113. positions[ i ] = ax;
  114. positions[ i + 1 ] = ay;
  115. positions[ i + 2 ] = az;
  116. positions[ i + 3 ] = bx;
  117. positions[ i + 4 ] = by;
  118. positions[ i + 5 ] = bz;
  119. positions[ i + 6 ] = cx;
  120. positions[ i + 7 ] = cy;
  121. positions[ i + 8 ] = cz;
  122. // flat face normals
  123. pA.set( ax, ay, az );
  124. pB.set( bx, by, bz );
  125. pC.set( cx, cy, cz );
  126. cb.sub( pC, pB );
  127. ab.sub( pA, pB );
  128. cb.crossSelf( ab );
  129. cb.normalize();
  130. var nx = cb.x;
  131. var ny = cb.y;
  132. var nz = cb.z;
  133. normals[ i ] = nx;
  134. normals[ i + 1 ] = ny;
  135. normals[ i + 2 ] = nz;
  136. normals[ i + 3 ] = nx;
  137. normals[ i + 4 ] = ny;
  138. normals[ i + 5 ] = nz;
  139. normals[ i + 6 ] = nx;
  140. normals[ i + 7 ] = ny;
  141. normals[ i + 8 ] = nz;
  142. // colors
  143. var vx = ( x / n ) + 0.5;
  144. var vy = ( y / n ) + 0.5;
  145. var vz = ( z / n ) + 0.5;
  146. //color.setHSV( 0.5 + 0.5 * vx, 0.25 + 0.75 * vy, 0.25 + 0.75 * vz );
  147. color.setRGB( vx, vy, vz );
  148. colors[ i ] = color.r;
  149. colors[ i + 1 ] = color.g;
  150. colors[ i + 2 ] = color.b;
  151. colors[ i + 3 ] = color.r;
  152. colors[ i + 4 ] = color.g;
  153. colors[ i + 5 ] = color.b;
  154. colors[ i + 6 ] = color.r;
  155. colors[ i + 7 ] = color.g;
  156. colors[ i + 8 ] = color.b;
  157. }
  158. geometry.offsets = [];
  159. var start = 0;
  160. var index = 0;
  161. var left = triangles * 3;
  162. for ( ;; ) {
  163. var count = Math.min( chunkSize * 3, left );
  164. var chunk = { start: start, count: count, index: index };
  165. geometry.offsets.push( chunk );
  166. start += count;
  167. index += chunkSize * 3;
  168. left -= count;
  169. if ( left <= 0 ) break;
  170. }
  171. geometry.computeBoundingSphere();
  172. var material = new THREE.MeshPhongMaterial( { color: 0xaaaaaa, ambient: 0xaaaaaa, specular: 0xffffff, shininess: 250,
  173. side: THREE.DoubleSide, perPixel: true, vertexColors: THREE.VertexColors } );
  174. mesh = new THREE.Mesh( geometry, material );
  175. scene.add( mesh );
  176. //
  177. renderer = new THREE.WebGLRenderer( { antialias: false, clearColor: 0x333333, clearAlpha: 1, alpha: false } );
  178. renderer.setSize( window.innerWidth, window.innerHeight );
  179. renderer.setClearColor( scene.fog.color, 1 );
  180. renderer.gammaInput = true;
  181. renderer.gammaOutput = true;
  182. renderer.physicallyBasedShading = true;
  183. container.appendChild( renderer.domElement );
  184. //
  185. stats = new Stats();
  186. stats.domElement.style.position = 'absolute';
  187. stats.domElement.style.top = '0px';
  188. container.appendChild( stats.domElement );
  189. //
  190. window.addEventListener( 'resize', onWindowResize, false );
  191. }
  192. function onWindowResize() {
  193. windowHalfX = window.innerWidth / 2;
  194. windowHalfY = window.innerHeight / 2;
  195. camera.aspect = window.innerWidth / window.innerHeight;
  196. camera.updateProjectionMatrix();
  197. renderer.setSize( window.innerWidth, window.innerHeight );
  198. }
  199. //
  200. function animate() {
  201. requestAnimationFrame( animate );
  202. render();
  203. stats.update();
  204. }
  205. function render() {
  206. var time = Date.now() * 0.001;
  207. mesh.rotation.x = time * 0.25;
  208. mesh.rotation.y = time * 0.5;
  209. renderer.render( scene, camera );
  210. }
  211. </script>
  212. </body>
  213. </html>