webgl_materials_cubemap_render_to_mipmaps.html 6.1 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. <script type="importmap">
  17. {
  18. "imports": {
  19. "three": "../build/three.module.js",
  20. "three/addons/": "./jsm/"
  21. }
  22. }
  23. </script>
  24. <script type="module">
  25. import * as THREE from 'three';
  26. import { OrbitControls } from 'three/addons/controls/OrbitControls.js';
  27. let container;
  28. let camera, scene, renderer;
  29. const CubemapFilterShader = {
  30. name: 'CubemapFilterShader',
  31. uniforms: {
  32. cubeTexture: { value: null },
  33. mipIndex: { value: 0 },
  34. },
  35. vertexShader: /* glsl */ `
  36. varying vec3 vWorldDirection;
  37. #include <common>
  38. void main() {
  39. vWorldDirection = transformDirection(position, modelMatrix);
  40. #include <begin_vertex>
  41. #include <project_vertex>
  42. gl_Position.z = gl_Position.w; // set z to camera.far
  43. }
  44. `,
  45. fragmentShader: /* glsl */ `
  46. uniform samplerCube cubeTexture;
  47. varying vec3 vWorldDirection;
  48. uniform float mipIndex;
  49. #include <common>
  50. void main() {
  51. vec3 cubeCoordinates = normalize(vWorldDirection);
  52. // Colorize mip levels
  53. vec4 color = vec4(1.0, 0.0, 0.0, 1.0);
  54. if (mipIndex == 0.0) color.rgb = vec3(1.0, 1.0, 1.0);
  55. else if (mipIndex == 1.0) color.rgb = vec3(0.0, 0.0, 1.0);
  56. else if (mipIndex == 2.0) color.rgb = vec3(0.0, 1.0, 1.0);
  57. else if (mipIndex == 3.0) color.rgb = vec3(0.0, 1.0, 0.0);
  58. else if (mipIndex == 4.0) color.rgb = vec3(1.0, 1.0, 0.0);
  59. gl_FragColor = textureCube(cubeTexture, cubeCoordinates, 0.0) * color;
  60. }
  61. `,
  62. };
  63. init();
  64. async function loadCubeTexture( urls ) {
  65. return new Promise( function ( resolve ) {
  66. new THREE.CubeTextureLoader().load( urls, function ( cubeTexture ) {
  67. resolve( cubeTexture );
  68. } );
  69. } );
  70. }
  71. function allocateCubemapRenderTarget( cubeMapSize ) {
  72. const params = {
  73. magFilter: THREE.LinearFilter,
  74. minFilter: THREE.LinearMipMapLinearFilter,
  75. generateMipmaps: false,
  76. type: THREE.HalfFloatType,
  77. format: THREE.RGBAFormat,
  78. colorSpace: THREE.LinearSRGBColorSpace,
  79. depthBuffer: false,
  80. };
  81. const rt = new THREE.WebGLCubeRenderTarget( cubeMapSize, params );
  82. const mipLevels = Math.log( cubeMapSize ) * Math.LOG2E + 1.0;
  83. for ( let i = 0; i < mipLevels; i ++ ) rt.texture.mipmaps.push( {} );
  84. rt.texture.mapping = THREE.CubeReflectionMapping;
  85. return rt;
  86. }
  87. function renderToCubeTexture( cubeMapRenderTarget, sourceCubeTexture ) {
  88. const geometry = new THREE.BoxGeometry( 5, 5, 5 );
  89. const material = new THREE.ShaderMaterial( {
  90. name: CubemapFilterShader.name,
  91. uniforms: THREE.UniformsUtils.clone( CubemapFilterShader.uniforms ),
  92. vertexShader: CubemapFilterShader.vertexShader,
  93. fragmentShader: CubemapFilterShader.fragmentShader,
  94. side: THREE.BackSide,
  95. blending: THREE.NoBlending,
  96. } );
  97. material.uniforms.cubeTexture.value = sourceCubeTexture;
  98. const mesh = new THREE.Mesh( geometry, material );
  99. const cubeCamera = new THREE.CubeCamera( 1, 10, cubeMapRenderTarget );
  100. const mipmapCount = Math.floor( Math.log2( Math.max( cubeMapRenderTarget.width, cubeMapRenderTarget.height ) ) );
  101. for ( let mipmap = 0; mipmap < mipmapCount; mipmap ++ ) {
  102. material.uniforms.mipIndex.value = mipmap;
  103. material.needsUpdate = true;
  104. cubeMapRenderTarget.viewport.set( 0, 0, cubeMapRenderTarget.width >> mipmap, cubeMapRenderTarget.height >> mipmap );
  105. cubeCamera.activeMipmapLevel = mipmap;
  106. cubeCamera.update( renderer, mesh );
  107. }
  108. mesh.geometry.dispose();
  109. mesh.material.dispose();
  110. }
  111. function init() {
  112. container = document.createElement( 'div' );
  113. document.body.appendChild( container );
  114. // Create renderer
  115. renderer = new THREE.WebGLRenderer( { antialias: true } );
  116. renderer.setPixelRatio( window.devicePixelRatio );
  117. renderer.setSize( window.innerWidth, window.innerHeight );
  118. renderer.setAnimationLoop( animate );
  119. container.appendChild( renderer.domElement );
  120. scene = new THREE.Scene();
  121. camera = new THREE.PerspectiveCamera( 50, window.innerWidth / window.innerHeight, 1, 10000 );
  122. camera.position.z = 500;
  123. // Create controls
  124. const controls = new OrbitControls( camera, renderer.domElement );
  125. controls.minPolarAngle = Math.PI / 4;
  126. controls.maxPolarAngle = Math.PI / 1.5;
  127. window.addEventListener( 'resize', onWindowResize );
  128. // Load a cube texture
  129. const r = 'textures/cube/Park3Med/';
  130. const urls = [
  131. r + 'px.jpg', r + 'nx.jpg',
  132. r + 'py.jpg', r + 'ny.jpg',
  133. r + 'pz.jpg', r + 'nz.jpg'
  134. ];
  135. loadCubeTexture( urls ).then( ( cubeTexture ) => {
  136. // Allocate a cube map render target
  137. const cubeMapRenderTarget = allocateCubemapRenderTarget( 512 );
  138. // Render to all the mip levels of cubeMapRenderTarget
  139. renderToCubeTexture( cubeMapRenderTarget, cubeTexture );
  140. // Create geometry
  141. const sphere = new THREE.SphereGeometry( 100, 128, 128 );
  142. let material = new THREE.MeshBasicMaterial( { color: 0xffffff, envMap: cubeTexture } );
  143. let mesh = new THREE.Mesh( sphere, material );
  144. mesh.position.set( - 100, 0, 0 );
  145. scene.add( mesh );
  146. material = material.clone();
  147. material.envMap = cubeMapRenderTarget.texture;
  148. mesh = new THREE.Mesh( sphere, material );
  149. mesh.position.set( 100, 0, 0 );
  150. scene.add( mesh );
  151. } );
  152. }
  153. function onWindowResize() {
  154. camera.aspect = window.innerWidth / window.innerHeight;
  155. camera.updateProjectionMatrix();
  156. renderer.setSize( window.innerWidth, window.innerHeight );
  157. }
  158. function animate() {
  159. renderer.render( scene, camera );
  160. }
  161. </script>
  162. </body>
  163. </html>