webgl_read_float_buffer.html 6.0 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.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, sceneRTT, sceneScreen, 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. cameraRTT = new THREE.OrthographicCamera( window.innerWidth / - 2, window.innerWidth / 2, window.innerHeight / 2, window.innerHeight / - 2, - 10000, 10000 );
  74. cameraRTT.position.z = 100;
  75. //
  76. sceneRTT = new THREE.Scene();
  77. sceneScreen = new THREE.Scene();
  78. var light = new THREE.DirectionalLight( 0xffffff );
  79. light.position.set( 0, 0, 1 ).normalize();
  80. sceneRTT.add( light );
  81. light = new THREE.DirectionalLight( 0xffaaaa, 1.5 );
  82. light.position.set( 0, 0, - 1 ).normalize();
  83. sceneRTT.add( light );
  84. rtTexture = new THREE.WebGLRenderTarget( window.innerWidth, window.innerHeight, { minFilter: THREE.LinearFilter, magFilter: THREE.NearestFilter, format: THREE.RGBAFormat, type: THREE.FloatType } );
  85. material = new THREE.ShaderMaterial( {
  86. uniforms: { time: { value: 0.0 } },
  87. vertexShader: document.getElementById( 'vertexShader' ).textContent,
  88. fragmentShader: document.getElementById( 'fragment_shader_pass_1' ).textContent
  89. } );
  90. var materialScreen = new THREE.ShaderMaterial( {
  91. uniforms: { tDiffuse: { value: rtTexture.texture } },
  92. vertexShader: document.getElementById( 'vertexShader' ).textContent,
  93. fragmentShader: document.getElementById( 'fragment_shader_screen' ).textContent,
  94. depthWrite: false
  95. } );
  96. var plane = new THREE.PlaneBufferGeometry( window.innerWidth, window.innerHeight );
  97. quad = new THREE.Mesh( plane, material );
  98. quad.position.z = - 100;
  99. sceneRTT.add( quad );
  100. var geometry = new THREE.TorusGeometry( 100, 25, 15, 30 );
  101. var mat1 = new THREE.MeshPhongMaterial( { color: 0x555555, specular: 0xffaa00, shininess: 5 } );
  102. var mat2 = new THREE.MeshPhongMaterial( { color: 0x550000, specular: 0xff2200, shininess: 5 } );
  103. zmesh1 = new THREE.Mesh( geometry, mat1 );
  104. zmesh1.position.set( 0, 0, 100 );
  105. zmesh1.scale.set( 1.5, 1.5, 1.5 );
  106. sceneRTT.add( zmesh1 );
  107. zmesh2 = new THREE.Mesh( geometry, mat2 );
  108. zmesh2.position.set( 0, 150, 100 );
  109. zmesh2.scale.set( 0.75, 0.75, 0.75 );
  110. sceneRTT.add( zmesh2 );
  111. quad = new THREE.Mesh( plane, materialScreen );
  112. quad.position.z = - 100;
  113. sceneScreen.add( quad );
  114. renderer = new THREE.WebGLRenderer();
  115. renderer.setPixelRatio( window.devicePixelRatio );
  116. renderer.setSize( window.innerWidth, window.innerHeight );
  117. renderer.autoClear = false;
  118. container.appendChild( renderer.domElement );
  119. stats = new Stats();
  120. container.appendChild( stats.dom );
  121. var valueDiv = document.createElement( 'div' );
  122. valueDiv.style.position = 'absolute';
  123. valueDiv.style.top = '0px';
  124. valueDiv.style.right = '0px';
  125. valueDiv.style.width = '500px';
  126. valueDiv.style.height = '300px';
  127. valueDiv.style.fontSize = '60px';
  128. container.appendChild( valueDiv );
  129. valueNode = document.createTextNode( '' );
  130. valueDiv.appendChild( valueNode );
  131. document.addEventListener( 'mousemove', onDocumentMouseMove, false );
  132. }
  133. function onDocumentMouseMove( event ) {
  134. mouseX = ( event.clientX - windowHalfX );
  135. mouseY = ( event.clientY - windowHalfY );
  136. }
  137. //
  138. function animate() {
  139. requestAnimationFrame( animate );
  140. render();
  141. stats.update();
  142. }
  143. function render() {
  144. var time = Date.now() * 0.0015;
  145. if ( zmesh1 && zmesh2 ) {
  146. zmesh1.rotation.y = - time;
  147. zmesh2.rotation.y = - time + Math.PI / 2;
  148. }
  149. if ( material.uniforms.time.value > 1 || material.uniforms.time.value < 0 ) {
  150. delta *= - 1;
  151. }
  152. material.uniforms.time.value += delta;
  153. renderer.clear();
  154. // Render first scene into texture
  155. renderer.render( sceneRTT, cameraRTT, rtTexture, true );
  156. // Render full screen quad with generated texture
  157. renderer.render( sceneScreen, cameraRTT );
  158. var read = new Float32Array( 4 );
  159. renderer.readRenderTargetPixels( rtTexture, windowHalfX + mouseX, windowHalfY - mouseY, 1, 1, read );
  160. valueNode.nodeValue = 'r:' + read[ 0 ] + ' g:' + read[ 1 ] + ' b:' + read[ 2 ];
  161. }
  162. </script>
  163. </body>
  164. </html>