webgl_geometry_colors_lookuptable.html 4.7 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. let container;
  41. let perpCamera, orthoCamera, renderer, lut;
  42. let mesh, sprite;
  43. let scene, uiScene;
  44. let params;
  45. init();
  46. function init() {
  47. container = document.getElementById( 'container' );
  48. scene = new THREE.Scene();
  49. scene.background = new THREE.Color( 0xffffff );
  50. uiScene = new THREE.Scene();
  51. lut = new Lut();
  52. const width = window.innerWidth;
  53. const height = window.innerHeight;
  54. perpCamera = new THREE.PerspectiveCamera( 60, width / height, 1, 100 );
  55. perpCamera.position.set( 0, 0, 10 );
  56. scene.add( perpCamera );
  57. orthoCamera = new THREE.OrthographicCamera( - 1, 1, 1, - 1, 1, 2 );
  58. orthoCamera.position.set( 0.5, 0, 1 );
  59. sprite = new THREE.Sprite( new THREE.SpriteMaterial( {
  60. map: new THREE.CanvasTexture( lut.createCanvas() )
  61. } ) );
  62. sprite.scale.x = 0.125;
  63. uiScene.add( sprite );
  64. mesh = new THREE.Mesh( undefined, new THREE.MeshLambertMaterial( {
  65. side: THREE.DoubleSide,
  66. color: 0xF5F5F5,
  67. vertexColors: true
  68. } ) );
  69. scene.add( mesh );
  70. params = {
  71. colorMap: 'rainbow',
  72. };
  73. loadModel( );
  74. const pointLight = new THREE.PointLight( 0xffffff, 1 );
  75. perpCamera.add( pointLight );
  76. renderer = new THREE.WebGLRenderer( { antialias: true } );
  77. renderer.autoClear = false;
  78. renderer.setPixelRatio( window.devicePixelRatio );
  79. renderer.setSize( width, height );
  80. container.appendChild( renderer.domElement );
  81. window.addEventListener( 'resize', onWindowResize );
  82. const controls = new OrbitControls( perpCamera, renderer.domElement );
  83. controls.addEventListener( 'change', render );
  84. const gui = new GUI();
  85. gui.add( params, 'colorMap', [ 'rainbow', 'cooltowarm', 'blackbody', 'grayscale' ] ).onChange( function () {
  86. updateColors();
  87. render();
  88. } );
  89. }
  90. function onWindowResize() {
  91. const width = window.innerWidth;
  92. const height = window.innerHeight;
  93. perpCamera.aspect = width / height;
  94. perpCamera.updateProjectionMatrix();
  95. renderer.setSize( width, height );
  96. render();
  97. }
  98. function render() {
  99. renderer.clear();
  100. renderer.render( scene, perpCamera );
  101. renderer.render( uiScene, orthoCamera );
  102. }
  103. function loadModel( ) {
  104. const loader = new THREE.BufferGeometryLoader();
  105. loader.load( 'models/json/pressure.json', function ( geometry ) {
  106. geometry.center();
  107. geometry.computeVertexNormals();
  108. // default color attribute
  109. const colors = [];
  110. for ( let i = 0, n = geometry.attributes.position.count; i < n; ++ i ) {
  111. colors.push( 1, 1, 1 );
  112. }
  113. geometry.setAttribute( 'color', new THREE.Float32BufferAttribute( colors, 3 ) );
  114. mesh.geometry = geometry;
  115. updateColors();
  116. render();
  117. } );
  118. }
  119. function updateColors() {
  120. lut.setColorMap( params.colorMap );
  121. lut.setMax( 2000 );
  122. lut.setMin( 0 );
  123. const geometry = mesh.geometry;
  124. const pressures = geometry.attributes.pressure;
  125. const colors = geometry.attributes.color;
  126. for ( let i = 0; i < pressures.array.length; i ++ ) {
  127. const colorValue = pressures.array[ i ];
  128. const color = lut.getColor( colorValue );
  129. if ( color === undefined ) {
  130. console.log( 'Unable to determine color for value:', colorValue );
  131. } else {
  132. colors.setXYZ( i, color.r, color.g, color.b );
  133. }
  134. }
  135. colors.needsUpdate = true;
  136. const map = sprite.material.map;
  137. lut.updateCanvas( map.image );
  138. map.needsUpdate = true;
  139. }
  140. </script>
  141. </body>
  142. </html>