webgl_geometry_colors_lookuptable.html 4.5 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="importmap">
  25. {
  26. "imports": {
  27. "three": "../build/three.module.js",
  28. "three/addons/": "./jsm/"
  29. }
  30. }
  31. </script>
  32. <script type="module">
  33. import * as THREE from 'three';
  34. import { GUI } from 'three/addons/libs/lil-gui.module.min.js';
  35. import { OrbitControls } from 'three/addons/controls/OrbitControls.js';
  36. import { Lut } from 'three/addons/math/Lut.js';
  37. let container;
  38. let perpCamera, orthoCamera, renderer, lut;
  39. let mesh, sprite;
  40. let scene, uiScene;
  41. let params;
  42. init();
  43. function init() {
  44. container = document.getElementById( 'container' );
  45. scene = new THREE.Scene();
  46. scene.background = new THREE.Color( 0xffffff );
  47. uiScene = new THREE.Scene();
  48. lut = new Lut();
  49. const width = window.innerWidth;
  50. const height = window.innerHeight;
  51. perpCamera = new THREE.PerspectiveCamera( 60, width / height, 1, 100 );
  52. perpCamera.position.set( 0, 0, 10 );
  53. scene.add( perpCamera );
  54. orthoCamera = new THREE.OrthographicCamera( - 1, 1, 1, - 1, 1, 2 );
  55. orthoCamera.position.set( 0.5, 0, 1 );
  56. sprite = new THREE.Sprite( new THREE.SpriteMaterial( {
  57. map: new THREE.CanvasTexture( lut.createCanvas() )
  58. } ) );
  59. sprite.material.map.colorSpace = THREE.SRGBColorSpace;
  60. sprite.scale.x = 0.125;
  61. uiScene.add( sprite );
  62. mesh = new THREE.Mesh( undefined, new THREE.MeshLambertMaterial( {
  63. side: THREE.DoubleSide,
  64. color: 0xF5F5F5,
  65. vertexColors: true
  66. } ) );
  67. scene.add( mesh );
  68. params = {
  69. colorMap: 'rainbow',
  70. };
  71. loadModel( );
  72. const pointLight = new THREE.PointLight( 0xffffff, 3, 0, 0 );
  73. perpCamera.add( pointLight );
  74. renderer = new THREE.WebGLRenderer( { antialias: true } );
  75. renderer.autoClear = false;
  76. renderer.setPixelRatio( window.devicePixelRatio );
  77. renderer.setSize( width, height );
  78. container.appendChild( renderer.domElement );
  79. window.addEventListener( 'resize', onWindowResize );
  80. const controls = new OrbitControls( perpCamera, renderer.domElement );
  81. controls.addEventListener( 'change', render );
  82. const gui = new GUI();
  83. gui.add( params, 'colorMap', [ 'rainbow', 'cooltowarm', 'blackbody', 'grayscale' ] ).onChange( function () {
  84. updateColors();
  85. render();
  86. } );
  87. }
  88. function onWindowResize() {
  89. const width = window.innerWidth;
  90. const height = window.innerHeight;
  91. perpCamera.aspect = width / height;
  92. perpCamera.updateProjectionMatrix();
  93. renderer.setSize( width, height );
  94. render();
  95. }
  96. function render() {
  97. renderer.clear();
  98. renderer.render( scene, perpCamera );
  99. renderer.render( uiScene, orthoCamera );
  100. }
  101. function loadModel( ) {
  102. const loader = new THREE.BufferGeometryLoader();
  103. loader.load( 'models/json/pressure.json', function ( geometry ) {
  104. geometry.center();
  105. geometry.computeVertexNormals();
  106. // default color attribute
  107. const colors = [];
  108. for ( let i = 0, n = geometry.attributes.position.count; i < n; ++ i ) {
  109. colors.push( 1, 1, 1 );
  110. }
  111. geometry.setAttribute( 'color', new THREE.Float32BufferAttribute( colors, 3 ) );
  112. mesh.geometry = geometry;
  113. updateColors();
  114. render();
  115. } );
  116. }
  117. function updateColors() {
  118. lut.setColorMap( params.colorMap );
  119. lut.setMax( 2000 );
  120. lut.setMin( 0 );
  121. const geometry = mesh.geometry;
  122. const pressures = geometry.attributes.pressure;
  123. const colors = geometry.attributes.color;
  124. const color = new THREE.Color();
  125. for ( let i = 0; i < pressures.array.length; i ++ ) {
  126. const colorValue = pressures.array[ i ];
  127. color.copy( lut.getColor( colorValue ) ).convertSRGBToLinear();
  128. colors.setXYZ( i, color.r, color.g, color.b );
  129. }
  130. colors.needsUpdate = true;
  131. const map = sprite.material.map;
  132. lut.updateCanvas( map.image );
  133. map.needsUpdate = true;
  134. }
  135. </script>
  136. </body>
  137. </html>