webgl_buffergeometry_points_interleaved.html 3.9 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. <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 - particles</div>
  12. <script type="importmap">
  13. {
  14. "imports": {
  15. "three": "../build/three.module.js",
  16. "three/addons/": "./jsm/"
  17. }
  18. }
  19. </script>
  20. <script type="module">
  21. import * as THREE from 'three';
  22. import Stats from 'three/addons/libs/stats.module.js';
  23. let container, stats;
  24. let camera, scene, renderer;
  25. let points;
  26. init();
  27. animate();
  28. function init() {
  29. container = document.getElementById( 'container' );
  30. camera = new THREE.PerspectiveCamera( 27, window.innerWidth / window.innerHeight, 5, 3500 );
  31. camera.position.z = 2750;
  32. scene = new THREE.Scene();
  33. scene.background = new THREE.Color( 0x050505 );
  34. scene.fog = new THREE.Fog( 0x050505, 2000, 3500 );
  35. //
  36. const particles = 500000;
  37. const geometry = new THREE.BufferGeometry();
  38. // create a generic buffer of binary data (a single particle has 16 bytes of data)
  39. const arrayBuffer = new ArrayBuffer( particles * 16 );
  40. // the following typed arrays share the same buffer
  41. const interleavedFloat32Buffer = new Float32Array( arrayBuffer );
  42. const interleavedUint8Buffer = new Uint8Array( arrayBuffer );
  43. //
  44. const color = new THREE.Color();
  45. const n = 1000, n2 = n / 2; // particles spread in the cube
  46. for ( let i = 0; i < interleavedFloat32Buffer.length; i += 4 ) {
  47. // position (first 12 bytes)
  48. const x = Math.random() * n - n2;
  49. const y = Math.random() * n - n2;
  50. const z = Math.random() * n - n2;
  51. interleavedFloat32Buffer[ i + 0 ] = x;
  52. interleavedFloat32Buffer[ i + 1 ] = y;
  53. interleavedFloat32Buffer[ i + 2 ] = z;
  54. // color (last 4 bytes)
  55. const vx = ( x / n ) + 0.5;
  56. const vy = ( y / n ) + 0.5;
  57. const vz = ( z / n ) + 0.5;
  58. color.setRGB( vx, vy, vz, THREE.SRGBColorSpace );
  59. const j = ( i + 3 ) * 4;
  60. interleavedUint8Buffer[ j + 0 ] = color.r * 255;
  61. interleavedUint8Buffer[ j + 1 ] = color.g * 255;
  62. interleavedUint8Buffer[ j + 2 ] = color.b * 255;
  63. interleavedUint8Buffer[ j + 3 ] = 0; // not needed
  64. }
  65. const interleavedBuffer32 = new THREE.InterleavedBuffer( interleavedFloat32Buffer, 4 );
  66. const interleavedBuffer8 = new THREE.InterleavedBuffer( interleavedUint8Buffer, 16 );
  67. geometry.setAttribute( 'position', new THREE.InterleavedBufferAttribute( interleavedBuffer32, 3, 0, false ) );
  68. geometry.setAttribute( 'color', new THREE.InterleavedBufferAttribute( interleavedBuffer8, 3, 12, true ) );
  69. //
  70. const material = new THREE.PointsMaterial( { size: 15, vertexColors: true } );
  71. points = new THREE.Points( geometry, material );
  72. scene.add( points );
  73. //
  74. renderer = new THREE.WebGLRenderer();
  75. renderer.setPixelRatio( window.devicePixelRatio );
  76. renderer.setSize( window.innerWidth, window.innerHeight );
  77. container.appendChild( renderer.domElement );
  78. //
  79. stats = new Stats();
  80. container.appendChild( stats.dom );
  81. //
  82. window.addEventListener( 'resize', onWindowResize );
  83. }
  84. function onWindowResize() {
  85. camera.aspect = window.innerWidth / window.innerHeight;
  86. camera.updateProjectionMatrix();
  87. renderer.setSize( window.innerWidth, window.innerHeight );
  88. }
  89. //
  90. function animate() {
  91. requestAnimationFrame( animate );
  92. render();
  93. stats.update();
  94. }
  95. function render() {
  96. const time = Date.now() * 0.001;
  97. points.rotation.x = time * 0.25;
  98. points.rotation.y = time * 0.5;
  99. renderer.render( scene, camera );
  100. }
  101. </script>
  102. </body>
  103. </html>