webgl_read_float_buffer.html 7.1 KB

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  1. <!DOCTYPE html>
  2. <html lang="en">
  3. <head>
  4. <title>three.js webgl - read float pixels</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. <style>
  8. body {
  9. color: #ffffff;
  10. font-family:Monospace;
  11. font-size:13px;
  12. text-align:center;
  13. font-weight: bold;
  14. background-color: #000000;
  15. margin: 0px;
  16. overflow: hidden;
  17. }
  18. #info {
  19. position: absolute;
  20. top: 0px; width: 100%;
  21. padding: 5px;
  22. }
  23. a {
  24. color: #ffffff;
  25. }
  26. </style>
  27. </head>
  28. <body>
  29. <div id="container"></div>
  30. <div id="info"><a href="http://threejs.org" target="_blank">three.js</a> read float pixels webgl example</div>
  31. <script src="../build/three.min.js"></script>
  32. <script src="js/Detector.js"></script>
  33. <script src="js/libs/stats.min.js"></script>
  34. <script id="fragment_shader_screen" type="x-shader/x-fragment">
  35. varying vec2 vUv;
  36. uniform sampler2D tDiffuse;
  37. void main() {
  38. gl_FragColor = texture2D( tDiffuse, vUv );
  39. }
  40. </script>
  41. <script id="fragment_shader_pass_1" type="x-shader/x-fragment">
  42. varying vec2 vUv;
  43. uniform float time;
  44. void main() {
  45. float r = vUv.x;
  46. if( vUv.y < 0.5 ) r = 0.0;
  47. float g = vUv.y;
  48. if( vUv.x < 0.5 ) g = 0.0;
  49. gl_FragColor = vec4( r, g, time, 1.0 );
  50. }
  51. </script>
  52. <script id="vertexShader" type="x-shader/x-vertex">
  53. varying vec2 vUv;
  54. void main() {
  55. vUv = uv;
  56. gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );
  57. }
  58. </script>
  59. <script>
  60. if ( ! Detector.webgl ) Detector.addGetWebGLMessage();
  61. var container, stats;
  62. var cameraRTT, camera, sceneRTT, sceneScreen, scene, renderer, zmesh1, zmesh2;
  63. var mouseX = 0, mouseY = 0;
  64. var windowHalfX = window.innerWidth / 2;
  65. var windowHalfY = window.innerHeight / 2;
  66. var rtTexture, material, quad;
  67. var delta = 0.01;
  68. var valueNode;
  69. init();
  70. animate();
  71. function init() {
  72. container = document.getElementById( 'container' );
  73. camera = new THREE.PerspectiveCamera( 30, window.innerWidth / window.innerHeight, 1, 10000 );
  74. camera.position.z = 100;
  75. cameraRTT = new THREE.OrthographicCamera( window.innerWidth / - 2, window.innerWidth / 2, window.innerHeight / 2, window.innerHeight / - 2, -10000, 10000 );
  76. cameraRTT.position.z = 100;
  77. //
  78. scene = new THREE.Scene();
  79. sceneRTT = new THREE.Scene();
  80. sceneScreen = new THREE.Scene();
  81. var light = new THREE.DirectionalLight( 0xffffff );
  82. light.position.set( 0, 0, 1 ).normalize();
  83. sceneRTT.add( light );
  84. light = new THREE.DirectionalLight( 0xffaaaa, 1.5 );
  85. light.position.set( 0, 0, -1 ).normalize();
  86. sceneRTT.add( light );
  87. rtTexture = new THREE.WebGLRenderTarget( window.innerWidth, window.innerHeight, { minFilter: THREE.LinearFilter, magFilter: THREE.NearestFilter, format: THREE.RGBAFormat, type:THREE.FloatType } );
  88. material = new THREE.ShaderMaterial( {
  89. uniforms: { time: { type: "f", value: 0.0 } },
  90. vertexShader: document.getElementById( 'vertexShader' ).textContent,
  91. fragmentShader: document.getElementById( 'fragment_shader_pass_1' ).textContent
  92. } );
  93. var materialScreen = new THREE.ShaderMaterial( {
  94. uniforms: { tDiffuse: { type: "t", value: rtTexture } },
  95. vertexShader: document.getElementById( 'vertexShader' ).textContent,
  96. fragmentShader: document.getElementById( 'fragment_shader_screen' ).textContent,
  97. depthWrite: false
  98. } );
  99. var plane = new THREE.PlaneBufferGeometry( window.innerWidth, window.innerHeight );
  100. quad = new THREE.Mesh( plane, material );
  101. quad.position.z = -100;
  102. sceneRTT.add( quad );
  103. var geometry = new THREE.TorusGeometry( 100, 25, 15, 30 );
  104. var mat1 = new THREE.MeshPhongMaterial( { color: 0x555555, specular: 0xffaa00, shininess: 5 } );
  105. var mat2 = new THREE.MeshPhongMaterial( { color: 0x550000, specular: 0xff2200, shininess: 5 } );
  106. zmesh1 = new THREE.Mesh( geometry, mat1 );
  107. zmesh1.position.set( 0, 0, 100 );
  108. zmesh1.scale.set( 1.5, 1.5, 1.5 );
  109. sceneRTT.add( zmesh1 );
  110. zmesh2 = new THREE.Mesh( geometry, mat2 );
  111. zmesh2.position.set( 0, 150, 100 );
  112. zmesh2.scale.set( 0.75, 0.75, 0.75 );
  113. sceneRTT.add( zmesh2 );
  114. quad = new THREE.Mesh( plane, materialScreen );
  115. quad.position.z = -100;
  116. sceneScreen.add( quad );
  117. var n = 5,
  118. geometry = new THREE.SphereGeometry( 10, 64, 32 ),
  119. material2 = new THREE.MeshBasicMaterial( { color: 0xffffff, map: rtTexture } );
  120. for( var j = 0; j < n; j ++ ) {
  121. for( var i = 0; i < n; i ++ ) {
  122. mesh = new THREE.Mesh( geometry, material2 );
  123. mesh.position.x = ( i - ( n - 1 ) / 2 ) * 20;
  124. mesh.position.y = ( j - ( n - 1 ) / 2 ) * 20;
  125. mesh.position.z = 0;
  126. mesh.rotation.y = - Math.PI / 2;
  127. scene.add( mesh );
  128. }
  129. }
  130. renderer = new THREE.WebGLRenderer();
  131. renderer.setPixelRatio( window.devicePixelRatio );
  132. renderer.setSize( window.innerWidth, window.innerHeight );
  133. renderer.autoClear = false;
  134. container.appendChild( renderer.domElement );
  135. stats = new Stats();
  136. stats.domElement.style.position = 'absolute';
  137. stats.domElement.style.top = '0px';
  138. container.appendChild( stats.domElement );
  139. var valueDiv = document.createElement('div');
  140. valueDiv.style.position = 'absolute';
  141. valueDiv.style.top = '0px';
  142. valueDiv.style.right = '0px';
  143. valueDiv.style.width = '500px';
  144. valueDiv.style.height = '300px';
  145. valueDiv.style.fontSize = '60px';
  146. container.appendChild( valueDiv );
  147. valueNode = document.createTextNode('');
  148. valueDiv.appendChild(valueNode);
  149. document.addEventListener( 'mousemove', onDocumentMouseMove, false );
  150. }
  151. function onDocumentMouseMove( event ) {
  152. mouseX = ( event.clientX - windowHalfX );
  153. mouseY = ( event.clientY - windowHalfY );
  154. }
  155. //
  156. function animate() {
  157. requestAnimationFrame( animate );
  158. render();
  159. stats.update();
  160. }
  161. function render() {
  162. var time = Date.now() * 0.0015;
  163. camera.position.x += ( mouseX - camera.position.x ) * .05;
  164. camera.position.y += ( - mouseY - camera.position.y ) * .05;
  165. camera.lookAt( scene.position );
  166. if ( zmesh1 && zmesh2 ) {
  167. zmesh1.rotation.y = - time;
  168. zmesh2.rotation.y = - time + Math.PI / 2;
  169. }
  170. if ( material.uniforms.time.value > 1 || material.uniforms.time.value < 0 ) {
  171. delta *= -1;
  172. }
  173. material.uniforms.time.value += delta;
  174. renderer.clear();
  175. // Render first scene into texture
  176. renderer.render( sceneRTT, cameraRTT, rtTexture, true );
  177. // Render full screen quad with generated texture
  178. renderer.render( sceneScreen, cameraRTT );
  179. // Render second scene to screen
  180. // (using first scene as regular texture)
  181. renderer.render( scene, camera );
  182. var read = new Float32Array(4);
  183. renderer.readRenderTargetPixels(rtTexture, windowHalfX + mouseX, windowHalfY - mouseY, 1, 1, read);
  184. valueNode.nodeValue ='r:' + read[0] +' g:' + read[1] + ' b:' + read[2];
  185. }
  186. </script>
  187. </body>
  188. </html>