three.js/examples/js/shaders/VerticalBlurShader.js

( function () {

	/**
 * Two pass Gaussian blur filter (horizontal and vertical blur shaders)
 * - described in http://www.gamerendering.com/2008/10/11/gaussian-blur-filter-shader/
 *	 and used in http://www.cake23.de/traveling-wavefronts-lit-up.html
 *
 * - 9 samples per pass
 * - standard deviation 2.7
 * - "h" and "v" parameters should be set to "1 / width" and "1 / height"
 */
	var VerticalBlurShader = {
		uniforms: {
			'tDiffuse': {
				value: null
			},
			'v': {
				value: 1.0 / 512.0
			}
		},
		vertexShader: [ 'varying vec2 vUv;', 'void main() {', '	vUv = uv;', '	gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );', '}' ].join( '\n' ),
		fragmentShader: [ 'uniform sampler2D tDiffuse;', 'uniform float v;', 'varying vec2 vUv;', 'void main() {', '	vec4 sum = vec4( 0.0 );', '	sum += texture2D( tDiffuse, vec2( vUv.x, vUv.y - 4.0 * v ) ) * 0.051;', '	sum += texture2D( tDiffuse, vec2( vUv.x, vUv.y - 3.0 * v ) ) * 0.0918;', '	sum += texture2D( tDiffuse, vec2( vUv.x, vUv.y - 2.0 * v ) ) * 0.12245;', '	sum += texture2D( tDiffuse, vec2( vUv.x, vUv.y - 1.0 * v ) ) * 0.1531;', '	sum += texture2D( tDiffuse, vec2( vUv.x, vUv.y ) ) * 0.1633;', '	sum += texture2D( tDiffuse, vec2( vUv.x, vUv.y + 1.0 * v ) ) * 0.1531;', '	sum += texture2D( tDiffuse, vec2( vUv.x, vUv.y + 2.0 * v ) ) * 0.12245;', '	sum += texture2D( tDiffuse, vec2( vUv.x, vUv.y + 3.0 * v ) ) * 0.0918;', '	sum += texture2D( tDiffuse, vec2( vUv.x, vUv.y + 4.0 * v ) ) * 0.051;', '	gl_FragColor = sum;', '}' ].join( '\n' )
	};

	THREE.VerticalBlurShader = VerticalBlurShader;

} )();