webgl_geometry_colors_lookuptable.html 4.8 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. <!-- Import maps polyfill -->
  25. <!-- Remove this when import maps will be widely supported -->
  26. <script async src="https://unpkg.com/[email protected]/dist/es-module-shims.js"></script>
  27. <script type="importmap">
  28. {
  29. "imports": {
  30. "three": "../build/three.module.js",
  31. "three/addons/": "./jsm/"
  32. }
  33. }
  34. </script>
  35. <script type="module">
  36. import * as THREE from 'three';
  37. import { GUI } from 'three/addons/libs/lil-gui.module.min.js';
  38. import { OrbitControls } from 'three/addons/controls/OrbitControls.js';
  39. import { Lut } from 'three/addons/math/Lut.js';
  40. THREE.ColorManagement.enabled = false; // TODO: Confirm correct color management.
  41. let container;
  42. let perpCamera, orthoCamera, renderer, lut;
  43. let mesh, sprite;
  44. let scene, uiScene;
  45. let params;
  46. init();
  47. function init() {
  48. container = document.getElementById( 'container' );
  49. scene = new THREE.Scene();
  50. scene.background = new THREE.Color( 0xffffff );
  51. uiScene = new THREE.Scene();
  52. lut = new Lut();
  53. const width = window.innerWidth;
  54. const height = window.innerHeight;
  55. perpCamera = new THREE.PerspectiveCamera( 60, width / height, 1, 100 );
  56. perpCamera.position.set( 0, 0, 10 );
  57. scene.add( perpCamera );
  58. orthoCamera = new THREE.OrthographicCamera( - 1, 1, 1, - 1, 1, 2 );
  59. orthoCamera.position.set( 0.5, 0, 1 );
  60. sprite = new THREE.Sprite( new THREE.SpriteMaterial( {
  61. map: new THREE.CanvasTexture( lut.createCanvas() )
  62. } ) );
  63. sprite.scale.x = 0.125;
  64. uiScene.add( sprite );
  65. mesh = new THREE.Mesh( undefined, new THREE.MeshLambertMaterial( {
  66. side: THREE.DoubleSide,
  67. color: 0xF5F5F5,
  68. vertexColors: true
  69. } ) );
  70. scene.add( mesh );
  71. params = {
  72. colorMap: 'rainbow',
  73. };
  74. loadModel( );
  75. const pointLight = new THREE.PointLight( 0xffffff, 1 );
  76. perpCamera.add( pointLight );
  77. renderer = new THREE.WebGLRenderer( { antialias: true } );
  78. renderer.outputColorSpace = THREE.LinearSRGBColorSpace;
  79. renderer.autoClear = false;
  80. renderer.setPixelRatio( window.devicePixelRatio );
  81. renderer.setSize( width, height );
  82. container.appendChild( renderer.domElement );
  83. window.addEventListener( 'resize', onWindowResize );
  84. const controls = new OrbitControls( perpCamera, renderer.domElement );
  85. controls.addEventListener( 'change', render );
  86. const gui = new GUI();
  87. gui.add( params, 'colorMap', [ 'rainbow', 'cooltowarm', 'blackbody', 'grayscale' ] ).onChange( function () {
  88. updateColors();
  89. render();
  90. } );
  91. }
  92. function onWindowResize() {
  93. const width = window.innerWidth;
  94. const height = window.innerHeight;
  95. perpCamera.aspect = width / height;
  96. perpCamera.updateProjectionMatrix();
  97. renderer.setSize( width, height );
  98. render();
  99. }
  100. function render() {
  101. renderer.clear();
  102. renderer.render( scene, perpCamera );
  103. renderer.render( uiScene, orthoCamera );
  104. }
  105. function loadModel( ) {
  106. const loader = new THREE.BufferGeometryLoader();
  107. loader.load( 'models/json/pressure.json', function ( geometry ) {
  108. geometry.center();
  109. geometry.computeVertexNormals();
  110. // default color attribute
  111. const colors = [];
  112. for ( let i = 0, n = geometry.attributes.position.count; i < n; ++ i ) {
  113. colors.push( 1, 1, 1 );
  114. }
  115. geometry.setAttribute( 'color', new THREE.Float32BufferAttribute( colors, 3 ) );
  116. mesh.geometry = geometry;
  117. updateColors();
  118. render();
  119. } );
  120. }
  121. function updateColors() {
  122. lut.setColorMap( params.colorMap );
  123. lut.setMax( 2000 );
  124. lut.setMin( 0 );
  125. const geometry = mesh.geometry;
  126. const pressures = geometry.attributes.pressure;
  127. const colors = geometry.attributes.color;
  128. for ( let i = 0; i < pressures.array.length; i ++ ) {
  129. const colorValue = pressures.array[ i ];
  130. const color = lut.getColor( colorValue );
  131. if ( color === undefined ) {
  132. console.log( 'Unable to determine color for value:', colorValue );
  133. } else {
  134. colors.setXYZ( i, color.r, color.g, color.b );
  135. }
  136. }
  137. colors.needsUpdate = true;
  138. const map = sprite.material.map;
  139. lut.updateCanvas( map.image );
  140. map.needsUpdate = true;
  141. }
  142. </script>
  143. </body>
  144. </html>