text: /**
   * @author alteredq / http://alteredqualia.com/
   *
   * Simple fake tilt-shift effect, modulating two pass Gaussian blur (see above) by vertical position
   *
   * - 9 samples per pass
   * - standard deviation 2.7
   * - h and v parameters should be set to 1 / width and 1 / height
   * - r parameter control where focused horizontal line lies
   */
  
  function VerticalTiltShiftShader() {
  
  	return {
  
  	uniforms: {
  
  		tDiffuse: { value: null },
  		v:        { value: 1.0 / 512.0 },
  		r:        { value: 0.35 }
  
  	},
  
  	vertexShader: `
  
  		varying vec2 vUv;
  
  		void main() {
  
  			vUv = uv;
  			gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );
  
  		}
  
  	`,
  
  	fragmentShader: `
  
  		uniform sampler2D tDiffuse;
  		uniform float v;
  		uniform float r;
  
  		varying vec2 vUv;
  
  		void main() {
  
  			vec4 sum = vec4( 0.0 );
  
  			float vv = v * abs( r - vUv.y );
  
  			sum += texture2D( tDiffuse, vec2( vUv.x, vUv.y - 4.0 * vv ) ) * 0.051;
  			sum += texture2D( tDiffuse, vec2( vUv.x, vUv.y - 3.0 * vv ) ) * 0.0918;
  			sum += texture2D( tDiffuse, vec2( vUv.x, vUv.y - 2.0 * vv ) ) * 0.12245;
  			sum += texture2D( tDiffuse, vec2( vUv.x, vUv.y - 1.0 * vv ) ) * 0.1531;
  			sum += texture2D( tDiffuse, vec2( vUv.x, vUv.y ) ) * 0.1633;
  			sum += texture2D( tDiffuse, vec2( vUv.x, vUv.y + 1.0 * vv ) ) * 0.1531;
  			sum += texture2D( tDiffuse, vec2( vUv.x, vUv.y + 2.0 * vv ) ) * 0.12245;
  			sum += texture2D( tDiffuse, vec2( vUv.x, vUv.y + 3.0 * vv ) ) * 0.0918;
  			sum += texture2D( tDiffuse, vec2( vUv.x, vUv.y + 4.0 * vv ) ) * 0.051;
  
  			gl_FragColor = sum;
  
  		}
  
  	`
  	}
  
  };
  
  module.exports = VerticalTiltShiftShader;
  