webgl_materials_cubemap_render_to_mipmaps.html 6.3 KB

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  1. <!DOCTYPE html>
  2. <html lang="en">
  3. <head>
  4. <title>three.js webgl - materials - cubemap mipmaps</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">
  12. <a href="https://threejs.org" target="_blank" rel="noopener">three.js</a> - rendering to cubemap mip levels demo.<br/>
  13. Left: original cubemap<br/>
  14. Right: generated cubemap<br/>
  15. </div>
  16. <!-- Import maps polyfill -->
  17. <!-- Remove this when import maps will be widely supported -->
  18. <script async src="https://unpkg.com/[email protected]/dist/es-module-shims.js"></script>
  19. <script type="importmap">
  20. {
  21. "imports": {
  22. "three": "../build/three.module.js",
  23. "three/addons/": "./jsm/"
  24. }
  25. }
  26. </script>
  27. <script type="module">
  28. import * as THREE from 'three';
  29. import { OrbitControls } from 'three/addons/controls/OrbitControls.js';
  30. let container;
  31. let camera, scene, renderer;
  32. const CubemapFilterShader = {
  33. uniforms: {
  34. cubeTexture: { value: null },
  35. mipIndex: { value: 0 },
  36. },
  37. vertexShader: /* glsl */ `
  38. varying vec3 vWorldDirection;
  39. #include <common>
  40. void main() {
  41. vWorldDirection = transformDirection(position, modelMatrix);
  42. #include <begin_vertex>
  43. #include <project_vertex>
  44. gl_Position.z = gl_Position.w; // set z to camera.far
  45. }
  46. `,
  47. fragmentShader: /* glsl */ `
  48. uniform samplerCube cubeTexture;
  49. varying vec3 vWorldDirection;
  50. uniform float mipIndex;
  51. #include <common>
  52. void main() {
  53. vec3 cubeCoordinates = normalize(vWorldDirection);
  54. // Colorize mip levels
  55. vec4 color = vec4(1.0, 0.0, 0.0, 1.0);
  56. if (mipIndex == 0.0) color.rgb = vec3(1.0, 1.0, 1.0);
  57. else if (mipIndex == 1.0) color.rgb = vec3(0.0, 0.0, 1.0);
  58. else if (mipIndex == 2.0) color.rgb = vec3(0.0, 1.0, 1.0);
  59. else if (mipIndex == 3.0) color.rgb = vec3(0.0, 1.0, 0.0);
  60. else if (mipIndex == 4.0) color.rgb = vec3(1.0, 1.0, 0.0);
  61. gl_FragColor = textureCube(cubeTexture, cubeCoordinates, 0.0) * color;
  62. }
  63. `,
  64. };
  65. init();
  66. animate();
  67. async function loadCubeTexture( urls ) {
  68. return new Promise( function ( resolve ) {
  69. new THREE.CubeTextureLoader().load( urls, function ( cubeTexture ) {
  70. resolve( cubeTexture );
  71. } );
  72. } );
  73. }
  74. function allocateCubemapRenderTarget( cubeMapSize ) {
  75. const params = {
  76. magFilter: THREE.LinearFilter,
  77. minFilter: THREE.LinearMipMapLinearFilter,
  78. generateMipmaps: false,
  79. type: THREE.HalfFloatType,
  80. format: THREE.RGBAFormat,
  81. colorSpace: THREE.LinearSRGBColorSpace,
  82. depthBuffer: false,
  83. };
  84. const rt = new THREE.WebGLCubeRenderTarget( cubeMapSize, params );
  85. const mipLevels = Math.log( cubeMapSize ) * Math.LOG2E + 1.0;
  86. for ( let i = 0; i < mipLevels; i ++ ) rt.texture.mipmaps.push( {} );
  87. rt.texture.mapping = THREE.CubeReflectionMapping;
  88. return rt;
  89. }
  90. function renderToCubeTexture( cubeMapRenderTarget, sourceCubeTexture ) {
  91. const geometry = new THREE.BoxGeometry( 5, 5, 5 );
  92. const material = new THREE.ShaderMaterial( {
  93. name: 'FilterCubemap',
  94. uniforms: THREE.UniformsUtils.clone( CubemapFilterShader.uniforms ),
  95. vertexShader: CubemapFilterShader.vertexShader,
  96. fragmentShader: CubemapFilterShader.fragmentShader,
  97. side: THREE.BackSide,
  98. blending: THREE.NoBlending,
  99. } );
  100. material.uniforms.cubeTexture.value = sourceCubeTexture;
  101. const mesh = new THREE.Mesh( geometry, material );
  102. const cubeCamera = new THREE.CubeCamera( 1, 10, cubeMapRenderTarget );
  103. const mipmapCount = Math.floor( Math.log2( Math.max( cubeMapRenderTarget.width, cubeMapRenderTarget.height ) ) );
  104. for ( let mipmap = 0; mipmap < mipmapCount; mipmap ++ ) {
  105. material.uniforms.mipIndex.value = mipmap;
  106. material.needsUpdate = true;
  107. cubeMapRenderTarget.viewport.set( 0, 0, cubeMapRenderTarget.width >> mipmap, cubeMapRenderTarget.height >> mipmap );
  108. cubeCamera.activeMipmapLevel = mipmap;
  109. cubeCamera.update( renderer, mesh );
  110. }
  111. mesh.geometry.dispose();
  112. mesh.material.dispose();
  113. }
  114. function init() {
  115. container = document.createElement( 'div' );
  116. document.body.appendChild( container );
  117. // Create renderer
  118. renderer = new THREE.WebGLRenderer( { antialias: true } );
  119. renderer.setPixelRatio( window.devicePixelRatio );
  120. renderer.setSize( window.innerWidth, window.innerHeight );
  121. container.appendChild( renderer.domElement );
  122. scene = new THREE.Scene();
  123. camera = new THREE.PerspectiveCamera( 50, window.innerWidth / window.innerHeight, 1, 10000 );
  124. camera.position.z = 500;
  125. // Create controls
  126. const controls = new OrbitControls( camera, renderer.domElement );
  127. controls.minPolarAngle = Math.PI / 4;
  128. controls.maxPolarAngle = Math.PI / 1.5;
  129. window.addEventListener( 'resize', onWindowResize );
  130. // Load a cube texture
  131. const r = 'textures/cube/Park3Med/';
  132. const urls = [
  133. r + 'px.jpg', r + 'nx.jpg',
  134. r + 'py.jpg', r + 'ny.jpg',
  135. r + 'pz.jpg', r + 'nz.jpg'
  136. ];
  137. loadCubeTexture( urls ).then( ( cubeTexture ) => {
  138. // Allocate a cube map render target
  139. const cubeMapRenderTarget = allocateCubemapRenderTarget( 512 );
  140. // Render to all the mip levels of cubeMapRenderTarget
  141. renderToCubeTexture( cubeMapRenderTarget, cubeTexture );
  142. // Create geometry
  143. const sphere = new THREE.SphereGeometry( 100, 128, 128 );
  144. let material = new THREE.MeshBasicMaterial( { color: 0xffffff, envMap: cubeTexture } );
  145. let mesh = new THREE.Mesh( sphere, material );
  146. mesh.position.set( - 100, 0, 0 );
  147. scene.add( mesh );
  148. material = material.clone();
  149. material.envMap = cubeMapRenderTarget.texture;
  150. mesh = new THREE.Mesh( sphere, material );
  151. mesh.position.set( 100, 0, 0 );
  152. scene.add( mesh );
  153. } );
  154. }
  155. function onWindowResize() {
  156. camera.aspect = window.innerWidth / window.innerHeight;
  157. camera.updateProjectionMatrix();
  158. renderer.setSize( window.innerWidth, window.innerHeight );
  159. }
  160. function animate() {
  161. requestAnimationFrame( animate );
  162. renderer.render( scene, camera );
  163. }
  164. </script>
  165. </body>
  166. </html>