webgl_materials_texture_hdr.html

<!DOCTYPE html>
<html lang="en">
	<head>
		<title>three.js webgl - materials - HDR texture loader</title>
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		<meta name="viewport" content="width=device-width, user-scalable=no, minimum-scale=1.0, maximum-scale=1.0">
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			body {
				color: #fff;
				font-family:Monospace;
				font-size:13px;
				text-align:center;
				font-weight: bold;

				background-color: #000;
				margin: 0px;
				overflow: hidden;
			}

			#info {
				color:#fff;
				position: absolute;
				top: 0px; width: 100%;
				padding: 5px;

			}

			a { color: red; }

		</style>
	</head>
	<body>

		<div id="container"></div>
		<div id="info">
			<a href="http://threejs.org" target="_blank">three.js</a> - webgl HDR texture loader example -
			based on <a href="http://spidergl.org/example.php?id=13" target="_blank">SpiderGL</a>
		</div>

		<script src="../build/three.js"></script>
		<script src="js/loaders/RGBELoader.js"></script>

		<script src="js/Detector.js"></script>
		<script src="js/libs/stats.min.js"></script>

		<!-- HDR fragment shader -->

		<script id="fs-hdr" type="x-shader/x-fragment">

			uniform sampler2D   tDiffuse;
			uniform float       exposure;
			uniform float       brightMax;

			varying vec2  vUv;

			vec3 decode_pnghdr( const in vec4 color ) {

				vec4 rgbcolor = vec4( 0.0, 0.0, 0.0, 0.0 );

				if ( color.w > 0.0 ) {
					float f = pow(2.0, 127.0*(color.w-0.5));
					rgbcolor.xyz = color.xyz * f;
				}
				return rgbcolor.xyz;

				/*
				// remove gamma correction
				vec4 res = color * color;

				// decoded RI
				float ri = pow( 2.0, res.w * 32.0 - 16.0 );

				// decoded HDR pixel
				res.xyz = res.xyz * ri;
				return res.xyz;
				*/
			}

			void main()	{

				vec4 color = texture2D( tDiffuse, vUv );
				color.xyz  = decode_pnghdr( color );

				// apply gamma correction and exposure
				//gl_FragColor = vec4( pow( exposure * color.xyz, vec3( 0.474 ) ), 1.0 );

				// Perform tone-mapping
				float Y = dot(vec4(0.30, 0.59, 0.11, 0.0), color);
				float YD = exposure * (exposure/brightMax + 1.0) / (exposure + 1.0);
				color *= YD;

				gl_FragColor = vec4( color.xyz, 1.0 );

			}

		</script>

		<!-- HDR vertex shader -->

		<script id="vs-hdr" type="x-shader/x-vertex">

			varying vec2 vUv;

			void main()	{

				vUv  = uv;
				gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );

			}

		</script>


		<script>

			if ( ! Detector.webgl ) Detector.addGetWebGLMessage();

			var container, stats;

			var camera, scene, renderer;
			var materialHDR, quad, gamma, exposure;

			var sign = 1, rate = 1;

			var clock = new THREE.Clock();

			init();

			function init() {

				container = document.getElementById( 'container' );

				camera = new THREE.PerspectiveCamera( 50, window.innerWidth / window.innerHeight, 1, 10000 );
				camera.position.z = 900;

				scene = new THREE.Scene();

				var loader = new THREE.RGBELoader();

				var texture = loader.load( "textures/miranda_uncropped.hdr", function( texture, textureData ){
					console.log( textureData.header ); // header string
					console.log( [textureData.width, textureData.height] ); // dimensions
					materialHDR = new THREE.ShaderMaterial( {

						uniforms: {
							tDiffuse:  { value: texture },
							exposure:  { value: textureData.exposure },
							brightMax: { value: textureData.gamma }
							},
						vertexShader: getText( 'vs-hdr' ),
						fragmentShader: getText( 'fs-hdr' )

					} );
					quad = new THREE.Mesh( new THREE.PlaneBufferGeometry( textureData.width, textureData.height ), materialHDR );
					quad.position.z = -100;
					scene.add( quad );
					animate();
				} );
				texture.minFilter = THREE.LinearFilter;
				texture.magFilter = THREE.NearestFilter;


				renderer = new THREE.WebGLRenderer();
				renderer.setPixelRatio( window.devicePixelRatio );
				renderer.setSize( window.innerWidth, window.innerHeight );
				container.appendChild( renderer.domElement );

				stats = new Stats();
				container.appendChild( stats.dom );

				//

				window.addEventListener( 'resize', onWindowResize, false );

			}


			function onWindowResize() {

				camera.aspect = window.innerWidth / window.innerHeight;
				camera.updateProjectionMatrix();

				renderer.setSize( window.innerWidth, window.innerHeight );

			}

			function getText( id ) {

				return document.getElementById( id ).textContent;

			}

			//

			function animate() {

				requestAnimationFrame( animate );

				render();
				stats.update();

			}

			function render() {

				delta = clock.getDelta() * 5;

				if ( materialHDR.uniforms.exposure.value > 0 || materialHDR.uniforms.exposure.value < 1 ) {

					rate = 0.25;

				} else {

					rate = 1;

				}

				if ( materialHDR.uniforms.exposure.value > 5 || materialHDR.uniforms.exposure.value <= 0 ) {

					sign *= -1;

				}

				materialHDR.uniforms.exposure.value += sign * rate * delta;

				renderer.render( scene, camera );

			}

		</script>
	</body>
</html>