webgpu_multiple_rendertargets_readback.html 6.5 KB

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  1. <html lang="en">
  2. <head>
  3. <title>three.js webgpu - mrt readback</title>
  4. <meta charset="utf-8">
  5. <link rel="shortcut icon" href="#">
  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="info">
  11. <a href="https://threejs.org" target="_blank" rel="noopener">three.js</a> webgpu - mrt readback
  12. </div>
  13. <script type="importmap">
  14. {
  15. "imports": {
  16. "three": "../build/three.module.js",
  17. "three/addons/": "./jsm/",
  18. "three/nodes": "./jsm/nodes/Nodes.js"
  19. }
  20. }
  21. </script>
  22. <script type="module">
  23. import * as THREE from 'three';
  24. import { OrbitControls } from 'three/addons/controls/OrbitControls.js';
  25. import { GUI } from 'three/addons/libs/lil-gui.module.min.js';
  26. import { MeshBasicNodeMaterial, NodeMaterial, mix, modelNormalMatrix, normalGeometry, normalize, outputStruct, step, texture, uniform, uv, varying, vec2, vec4 } from 'three/nodes';
  27. import WebGPU from 'three/addons/capabilities/WebGPU.js';
  28. import WebGL from 'three/addons/capabilities/WebGL.js';
  29. import WebGPURenderer from 'three/addons/renderers/webgpu/WebGPURenderer.js';
  30. import QuadMesh from 'three/addons/objects/QuadMesh.js';
  31. let camera, scene, renderer, torus;
  32. let quadMesh, renderTarget, readbackTarget, material, readbackMaterial, pixelBuffer, pixelBufferTexture;
  33. const gui = new GUI();
  34. const options = {
  35. selection: 'mrt',
  36. };
  37. gui.add( options, 'selection', [ 'mrt', 'diffuse', 'normal' ] );
  38. class WriteGBufferMaterial extends NodeMaterial {
  39. constructor( diffuseTexture ) {
  40. super();
  41. this.lights = false;
  42. this.fog = false;
  43. this.colorSpaced = false;
  44. this.diffuseTexture = diffuseTexture;
  45. const vUv = varying( uv() );
  46. const transformedNormal = modelNormalMatrix.mul( normalGeometry );
  47. const vNormal = varying( normalize( transformedNormal ) );
  48. const repeat = uniform( vec2( 5, 0.5 ) );
  49. const gColor = texture( this.diffuseTexture, vUv.mul( repeat ) );
  50. const gNormal = vec4( normalize( vNormal ), 1.0 );
  51. this.fragmentNode = outputStruct( gColor, gNormal );
  52. }
  53. }
  54. class ReadGBufferMaterial extends NodeMaterial {
  55. constructor( tDiffuse, tNormal ) {
  56. super();
  57. this.lights = false;
  58. this.fog = false;
  59. const vUv = varying( uv() );
  60. const diffuse = texture( tDiffuse, vUv );
  61. const normal = texture( tNormal, vUv );
  62. this.fragmentNode = mix( diffuse, normal, step( 0.5, vUv.x ) );
  63. }
  64. }
  65. init();
  66. function init() {
  67. if ( WebGPU.isAvailable() === false && WebGL.isWebGL2Available() === false ) {
  68. document.body.appendChild( WebGPU.getErrorMessage() );
  69. throw new Error( 'No WebGPU or WebGL2 support' );
  70. }
  71. renderer = new WebGPURenderer( { antialias: true } );
  72. renderer.setPixelRatio( window.devicePixelRatio );
  73. renderer.setSize( window.innerWidth, window.innerHeight );
  74. renderer.setAnimationLoop( render );
  75. document.body.appendChild( renderer.domElement );
  76. // Create a multi render target with Float buffers
  77. renderTarget = new THREE.RenderTarget(
  78. window.innerWidth * window.devicePixelRatio,
  79. window.innerHeight * window.devicePixelRatio,
  80. { count: 2, minFilter: THREE.NearestFilter, magFilter: THREE.NearestFilter }
  81. );
  82. // Name our G-Buffer attachments for debugging
  83. renderTarget.textures[ 0 ].name = 'diffuse';
  84. renderTarget.textures[ 1 ].name = 'normal';
  85. // Init readback render target, readback data texture, readback material
  86. // Be careful with the size! 512 is already big. Reading data back from the GPU is computationally intensive
  87. const size = 512;
  88. readbackTarget = new THREE.RenderTarget( size, size, { count: 2 } );
  89. pixelBuffer = new Uint8Array( size ** 2 * 4 ).fill( 0 );
  90. pixelBufferTexture = new THREE.DataTexture( pixelBuffer, size, size );
  91. pixelBufferTexture.type = THREE.UnsignedByteType;
  92. pixelBufferTexture.format = THREE.RGBAFormat;
  93. readbackMaterial = new MeshBasicNodeMaterial();
  94. readbackMaterial.colorNode = texture( pixelBufferTexture );
  95. // Scene setup
  96. scene = new THREE.Scene();
  97. scene.background = new THREE.Color( 0x222222 );
  98. camera = new THREE.PerspectiveCamera( 70, window.innerWidth / window.innerHeight, 0.1, 50 );
  99. camera.position.z = 4;
  100. const loader = new THREE.TextureLoader();
  101. const diffuse = loader.load( 'textures/hardwood2_diffuse.jpg' );
  102. diffuse.colorSpace = THREE.SRGBColorSpace;
  103. diffuse.wrapS = THREE.RepeatWrapping;
  104. diffuse.wrapT = THREE.RepeatWrapping;
  105. torus = new THREE.Mesh(
  106. new THREE.TorusKnotGeometry( 1, 0.3, 128, 32 ),
  107. new WriteGBufferMaterial( diffuse )
  108. );
  109. scene.add( torus );
  110. material = new ReadGBufferMaterial( renderTarget.textures[ 0 ], renderTarget.textures[ 1 ] );
  111. quadMesh = new QuadMesh( material );
  112. // Controls
  113. new OrbitControls( camera, renderer.domElement );
  114. window.addEventListener( 'resize', onWindowResize );
  115. }
  116. function onWindowResize() {
  117. camera.aspect = window.innerWidth / window.innerHeight;
  118. camera.updateProjectionMatrix();
  119. renderer.setSize( window.innerWidth, window.innerHeight );
  120. const dpr = renderer.getPixelRatio();
  121. renderTarget.setSize( window.innerWidth * dpr, window.innerHeight * dpr );
  122. }
  123. async function render( time ) {
  124. const selection = options.selection;
  125. torus.rotation.y = ( time / 1000 ) * .4;
  126. // render scene into target
  127. renderer.setRenderTarget( selection === 'mrt' ? renderTarget : readbackTarget );
  128. renderer.render( scene, camera );
  129. // render post FX
  130. renderer.setRenderTarget( null );
  131. if ( selection === 'mrt' ) {
  132. quadMesh.material = material;
  133. } else {
  134. quadMesh.material = readbackMaterial;
  135. await readback();
  136. }
  137. quadMesh.render( renderer );
  138. }
  139. async function readback() {
  140. const width = readbackTarget.width;
  141. const height = readbackTarget.height;
  142. const selection = options.selection;
  143. if ( selection === 'diffuse' ) {
  144. pixelBuffer = await renderer.readRenderTargetPixelsAsync( readbackTarget, 0, 0, width, height, 0 ); // zero is optional
  145. pixelBufferTexture.image.data = pixelBuffer;
  146. pixelBufferTexture.needsUpdate = true;
  147. } else if ( selection === 'normal' ) {
  148. pixelBuffer = await renderer.readRenderTargetPixelsAsync( readbackTarget, 0, 0, width, height, 1 );
  149. pixelBufferTexture.image.data = pixelBuffer;
  150. pixelBufferTexture.needsUpdate = true;
  151. }
  152. }
  153. </script>
  154. </body>
  155. </html>