three.js/examples/js/shaders/FilmShader.js

( function () {

	/**
 * Film grain & scanlines shader
 *
 * - ported from HLSL to WebGL / GLSL
 * http://www.truevision3d.com/forums/showcase/staticnoise_colorblackwhite_scanline_shaders-t18698.0.html
 *
 * Screen Space Static Postprocessor
 *
 * Produces an analogue noise overlay similar to a film grain / TV static
 *
 * Original implementation and noise algorithm
 * Pat 'Hawthorne' Shearon
 *
 * Optimized scanlines + noise version with intensity scaling
 * Georg 'Leviathan' Steinrohder
 *
 * This version is provided under a Creative Commons Attribution 3.0 License
 * http://creativecommons.org/licenses/by/3.0/
 */
	var FilmShader = {
		uniforms: {
			'tDiffuse': {
				value: null
			},
			'time': {
				value: 0.0
			},
			'nIntensity': {
				value: 0.5
			},
			'sIntensity': {
				value: 0.05
			},
			'sCount': {
				value: 4096
			},
			'grayscale': {
				value: 1
			}
		},
		vertexShader: [ 'varying vec2 vUv;', 'void main() {', '	vUv = uv;', '	gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );', '}' ].join( '\n' ),
		fragmentShader: [ '#include <common>', // control parameter
			'uniform float time;', 'uniform bool grayscale;', // noise effect intensity value (0 = no effect, 1 = full effect)
			'uniform float nIntensity;', // scanlines effect intensity value (0 = no effect, 1 = full effect)
			'uniform float sIntensity;', // scanlines effect count value (0 = no effect, 4096 = full effect)
			'uniform float sCount;', 'uniform sampler2D tDiffuse;', 'varying vec2 vUv;', 'void main() {', // sample the source
			'	vec4 cTextureScreen = texture2D( tDiffuse, vUv );', // make some noise
			'	float dx = rand( vUv + time );', // add noise
			'	vec3 cResult = cTextureScreen.rgb + cTextureScreen.rgb * clamp( 0.1 + dx, 0.0, 1.0 );', // get us a sine and cosine
			'	vec2 sc = vec2( sin( vUv.y * sCount ), cos( vUv.y * sCount ) );', // add scanlines
			'	cResult += cTextureScreen.rgb * vec3( sc.x, sc.y, sc.x ) * sIntensity;', // interpolate between source and result by intensity
			'	cResult = cTextureScreen.rgb + clamp( nIntensity, 0.0,1.0 ) * ( cResult - cTextureScreen.rgb );', // convert to grayscale if desired
			'	if( grayscale ) {', '		cResult = vec3( cResult.r * 0.3 + cResult.g * 0.59 + cResult.b * 0.11 );', '	}', '	gl_FragColor =	vec4( cResult, cTextureScreen.a );', '}' ].join( '\n' )
	};

	THREE.FilmShader = FilmShader;

} )();