webgl_materials_cubemap_render_to_mipmaps.html 6.5 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242
  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. <meta property="og:title" content="three.js webgl - materials - cubemap mipmaps">
  8. <meta property="og:type" content="website">
  9. <meta property="og:url" content="https://threejs.org/examples/webgl_materials_cubemap_render_to_mipmaps.html">
  10. <meta property="og:image" content="https://threejs.org/examples/screenshots/webgl_materials_cubemap_render_to_mipmaps.jpg">
  11. <link type="text/css" rel="stylesheet" href="main.css">
  12. </head>
  13. <body>
  14. <div id="container"></div>
  15. <div id="info">
  16. <a href="https://threejs.org" target="_blank" rel="noopener">three.js</a> - rendering to cubemap mip levels demo.<br/>
  17. Left: original cubemap<br/>
  18. Right: generated cubemap<br/>
  19. </div>
  20. <script type="importmap">
  21. {
  22. "imports": {
  23. "three": "../build/three.module.js",
  24. "three/addons/": "./jsm/"
  25. }
  26. }
  27. </script>
  28. <script type="module">
  29. import * as THREE from 'three';
  30. import { OrbitControls } from 'three/addons/controls/OrbitControls.js';
  31. let container;
  32. let camera, scene, renderer;
  33. const CubemapFilterShader = {
  34. name: 'CubemapFilterShader',
  35. uniforms: {
  36. cubeTexture: { value: null },
  37. mipIndex: { value: 0 },
  38. },
  39. vertexShader: /* glsl */ `
  40. varying vec3 vWorldDirection;
  41. #include <common>
  42. void main() {
  43. vWorldDirection = transformDirection(position, modelMatrix);
  44. #include <begin_vertex>
  45. #include <project_vertex>
  46. gl_Position.z = gl_Position.w; // set z to camera.far
  47. }
  48. `,
  49. fragmentShader: /* glsl */ `
  50. uniform samplerCube cubeTexture;
  51. varying vec3 vWorldDirection;
  52. uniform float mipIndex;
  53. #include <common>
  54. void main() {
  55. vec3 cubeCoordinates = normalize(vWorldDirection);
  56. // Colorize mip levels
  57. vec4 color = vec4(1.0, 0.0, 0.0, 1.0);
  58. if (mipIndex == 0.0) color.rgb = vec3(1.0, 1.0, 1.0);
  59. else if (mipIndex == 1.0) color.rgb = vec3(0.0, 0.0, 1.0);
  60. else if (mipIndex == 2.0) color.rgb = vec3(0.0, 1.0, 1.0);
  61. else if (mipIndex == 3.0) color.rgb = vec3(0.0, 1.0, 0.0);
  62. else if (mipIndex == 4.0) color.rgb = vec3(1.0, 1.0, 0.0);
  63. gl_FragColor = textureCube(cubeTexture, cubeCoordinates, 0.0) * color;
  64. }
  65. `,
  66. };
  67. init();
  68. async function loadCubeTexture( urls ) {
  69. return new Promise( function ( resolve ) {
  70. new THREE.CubeTextureLoader().load( urls, function ( cubeTexture ) {
  71. resolve( cubeTexture );
  72. } );
  73. } );
  74. }
  75. function allocateCubemapRenderTarget( cubeMapSize ) {
  76. const params = {
  77. magFilter: THREE.LinearFilter,
  78. minFilter: THREE.LinearMipMapLinearFilter,
  79. generateMipmaps: false,
  80. type: THREE.HalfFloatType,
  81. format: THREE.RGBAFormat,
  82. colorSpace: THREE.LinearSRGBColorSpace,
  83. depthBuffer: false,
  84. };
  85. const rt = new THREE.WebGLCubeRenderTarget( cubeMapSize, params );
  86. const mipLevels = Math.log( cubeMapSize ) * Math.LOG2E + 1.0;
  87. for ( let i = 0; i < mipLevels; i ++ ) rt.texture.mipmaps.push( {} );
  88. rt.texture.mapping = THREE.CubeReflectionMapping;
  89. return rt;
  90. }
  91. function renderToCubeTexture( cubeMapRenderTarget, sourceCubeTexture ) {
  92. const geometry = new THREE.BoxGeometry( 5, 5, 5 );
  93. const material = new THREE.ShaderMaterial( {
  94. name: CubemapFilterShader.name,
  95. uniforms: THREE.UniformsUtils.clone( CubemapFilterShader.uniforms ),
  96. vertexShader: CubemapFilterShader.vertexShader,
  97. fragmentShader: CubemapFilterShader.fragmentShader,
  98. side: THREE.BackSide,
  99. blending: THREE.NoBlending,
  100. } );
  101. material.uniforms.cubeTexture.value = sourceCubeTexture;
  102. const mesh = new THREE.Mesh( geometry, material );
  103. const cubeCamera = new THREE.CubeCamera( 1, 10, cubeMapRenderTarget );
  104. const mipmapCount = Math.floor( Math.log2( Math.max( cubeMapRenderTarget.width, cubeMapRenderTarget.height ) ) );
  105. for ( let mipmap = 0; mipmap < mipmapCount; mipmap ++ ) {
  106. material.uniforms.mipIndex.value = mipmap;
  107. material.needsUpdate = true;
  108. cubeMapRenderTarget.viewport.set( 0, 0, cubeMapRenderTarget.width >> mipmap, cubeMapRenderTarget.height >> mipmap );
  109. cubeCamera.activeMipmapLevel = mipmap;
  110. cubeCamera.update( renderer, mesh );
  111. }
  112. mesh.geometry.dispose();
  113. mesh.material.dispose();
  114. }
  115. function init() {
  116. container = document.createElement( 'div' );
  117. document.body.appendChild( container );
  118. // Create renderer
  119. renderer = new THREE.WebGLRenderer( { antialias: true } );
  120. renderer.setPixelRatio( window.devicePixelRatio );
  121. renderer.setSize( window.innerWidth, window.innerHeight );
  122. renderer.setAnimationLoop( animate );
  123. container.appendChild( renderer.domElement );
  124. scene = new THREE.Scene();
  125. camera = new THREE.PerspectiveCamera( 50, window.innerWidth / window.innerHeight, 1, 10000 );
  126. camera.position.z = 500;
  127. // Create controls
  128. const controls = new OrbitControls( camera, renderer.domElement );
  129. controls.minPolarAngle = Math.PI / 4;
  130. controls.maxPolarAngle = Math.PI / 1.5;
  131. window.addEventListener( 'resize', onWindowResize );
  132. // Load a cube texture
  133. const r = 'textures/cube/Park3Med/';
  134. const urls = [
  135. r + 'px.jpg', r + 'nx.jpg',
  136. r + 'py.jpg', r + 'ny.jpg',
  137. r + 'pz.jpg', r + 'nz.jpg'
  138. ];
  139. loadCubeTexture( urls ).then( ( cubeTexture ) => {
  140. // Allocate a cube map render target
  141. const cubeMapRenderTarget = allocateCubemapRenderTarget( 512 );
  142. // Render to all the mip levels of cubeMapRenderTarget
  143. renderToCubeTexture( cubeMapRenderTarget, cubeTexture );
  144. // Create geometry
  145. const sphere = new THREE.SphereGeometry( 100, 128, 128 );
  146. let material = new THREE.MeshBasicMaterial( { color: 0xffffff, envMap: cubeTexture } );
  147. let mesh = new THREE.Mesh( sphere, material );
  148. mesh.position.set( - 100, 0, 0 );
  149. scene.add( mesh );
  150. material = material.clone();
  151. material.envMap = cubeMapRenderTarget.texture;
  152. mesh = new THREE.Mesh( sphere, material );
  153. mesh.position.set( 100, 0, 0 );
  154. scene.add( mesh );
  155. } );
  156. }
  157. function onWindowResize() {
  158. camera.aspect = window.innerWidth / window.innerHeight;
  159. camera.updateProjectionMatrix();
  160. renderer.setSize( window.innerWidth, window.innerHeight );
  161. }
  162. function animate() {
  163. renderer.render( scene, camera );
  164. }
  165. </script>
  166. </body>
  167. </html>
粤ICP备19079148号