webgl_geometry_colors_lookuptable.html 4.3 KB

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  1. <!DOCTYPE html>
  2. <html lang="en">
  3. <head>
  4. <title>three.js webgl - lookup table</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. <style>
  9. body {
  10. background-color: #fff;
  11. color: #444;
  12. }
  13. a {
  14. color: red;
  15. }
  16. </style>
  17. </head>
  18. <body>
  19. <div id="info">
  20. <a href="https://threejs.org" target="_blank" rel="noopener">three.js</a> webgl - lookup table<br/>
  21. vertex color values from a range of data values
  22. </div>
  23. <div id="container"></div>
  24. <script type="module">
  25. import * as THREE from '../build/three.module.js';
  26. import { GUI } from './jsm/libs/dat.gui.module.js';
  27. import { OrbitControls } from './jsm/controls/OrbitControls.js';
  28. import { Lut } from './jsm/math/Lut.js';
  29. let container;
  30. let perpCamera, orthoCamera, renderer, lut;
  31. let mesh, sprite;
  32. let scene, uiScene;
  33. let params;
  34. init();
  35. function init() {
  36. container = document.getElementById( 'container' );
  37. scene = new THREE.Scene();
  38. scene.background = new THREE.Color( 0xffffff );
  39. uiScene = new THREE.Scene();
  40. lut = new Lut();
  41. const width = window.innerWidth;
  42. const height = window.innerHeight;
  43. perpCamera = new THREE.PerspectiveCamera( 60, width / height, 1, 100 );
  44. perpCamera.position.set( 0, 0, 10 );
  45. scene.add( perpCamera );
  46. orthoCamera = new THREE.OrthographicCamera( - 1, 1, 1, - 1, 1, 2 );
  47. orthoCamera.position.set( 0.5, 0, 1 );
  48. sprite = new THREE.Sprite( new THREE.SpriteMaterial( {
  49. map: new THREE.CanvasTexture( lut.createCanvas() )
  50. } ) );
  51. sprite.scale.x = 0.125;
  52. uiScene.add( sprite );
  53. mesh = new THREE.Mesh( undefined, new THREE.MeshLambertMaterial( {
  54. side: THREE.DoubleSide,
  55. color: 0xF5F5F5,
  56. vertexColors: true
  57. } ) );
  58. scene.add( mesh );
  59. params = {
  60. colorMap: 'rainbow',
  61. };
  62. loadModel( );
  63. const pointLight = new THREE.PointLight( 0xffffff, 1 );
  64. perpCamera.add( pointLight );
  65. renderer = new THREE.WebGLRenderer( { antialias: true } );
  66. renderer.autoClear = false;
  67. renderer.setPixelRatio( window.devicePixelRatio );
  68. renderer.setSize( width, height );
  69. container.appendChild( renderer.domElement );
  70. window.addEventListener( 'resize', onWindowResize );
  71. const controls = new OrbitControls( perpCamera, renderer.domElement );
  72. controls.addEventListener( 'change', render );
  73. const gui = new GUI();
  74. gui.add( params, 'colorMap', [ 'rainbow', 'cooltowarm', 'blackbody', 'grayscale' ] ).onChange( function () {
  75. updateColors();
  76. render();
  77. } );
  78. }
  79. function onWindowResize() {
  80. const width = window.innerWidth;
  81. const height = window.innerHeight;
  82. perpCamera.aspect = width / height;
  83. perpCamera.updateProjectionMatrix();
  84. renderer.setSize( width, height );
  85. render();
  86. }
  87. function render() {
  88. renderer.clear();
  89. renderer.render( scene, perpCamera );
  90. renderer.render( uiScene, orthoCamera );
  91. }
  92. function loadModel( ) {
  93. const loader = new THREE.BufferGeometryLoader();
  94. loader.load( 'models/json/pressure.json', function ( geometry ) {
  95. geometry.center();
  96. geometry.computeVertexNormals();
  97. // default color attribute
  98. const colors = [];
  99. for ( let i = 0, n = geometry.attributes.position.count; i < n; ++ i ) {
  100. colors.push( 1, 1, 1 );
  101. }
  102. geometry.setAttribute( 'color', new THREE.Float32BufferAttribute( colors, 3 ) );
  103. mesh.geometry = geometry;
  104. updateColors();
  105. render();
  106. } );
  107. }
  108. function updateColors() {
  109. lut.setColorMap( params.colorMap );
  110. lut.setMax( 2000 );
  111. lut.setMin( 0 );
  112. const geometry = mesh.geometry;
  113. const pressures = geometry.attributes.pressure;
  114. const colors = geometry.attributes.color;
  115. for ( let i = 0; i < pressures.array.length; i ++ ) {
  116. const colorValue = pressures.array[ i ];
  117. const color = lut.getColor( colorValue );
  118. if ( color === undefined ) {
  119. console.log( 'Unable to determine color for value:', colorValue );
  120. } else {
  121. colors.setXYZ( i, color.r, color.g, color.b );
  122. }
  123. }
  124. colors.needsUpdate = true;
  125. const map = sprite.material.map;
  126. lut.updateCanvas( map.image );
  127. map.needsUpdate = true;
  128. }
  129. </script>
  130. </body>
  131. </html>