three.js/examples/js/shaders/SepiaShader.js

( function () {

	/**
 * Sepia tone shader
 * based on glfx.js sepia shader
 * https://github.com/evanw/glfx.js
 */
	var SepiaShader = {
		uniforms: {
			'tDiffuse': {
				value: null
			},
			'amount': {
				value: 1.0
			}
		},
		vertexShader: [ 'varying vec2 vUv;', 'void main() {', '	vUv = uv;', '	gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );', '}' ].join( '\n' ),
		fragmentShader: [ 'uniform float amount;', 'uniform sampler2D tDiffuse;', 'varying vec2 vUv;', 'void main() {', '	vec4 color = texture2D( tDiffuse, vUv );', '	vec3 c = color.rgb;', '	color.r = dot( c, vec3( 1.0 - 0.607 * amount, 0.769 * amount, 0.189 * amount ) );', '	color.g = dot( c, vec3( 0.349 * amount, 1.0 - 0.314 * amount, 0.168 * amount ) );', '	color.b = dot( c, vec3( 0.272 * amount, 0.534 * amount, 1.0 - 0.869 * amount ) );', '	gl_FragColor = vec4( min( vec3( 1.0 ), color.rgb ), color.a );', '}' ].join( '\n' )
	};

	THREE.SepiaShader = SepiaShader;

} )();