text: THREE.DepthLimitedBlurShader = {
  	defines: {
  		'KERNEL_RADIUS': 4,
  		'DEPTH_PACKING': 1,
  		'PERSPECTIVE_CAMERA': 1
  	},
  	uniforms: {
  		'tDiffuse': { value: null },
  		'size': { value: new THREE.Vector2( 512, 512 ) },
  		'sampleUvOffsets': { value: [ new THREE.Vector2( 0, 0 ) ] },
  		'sampleWeights': { value: [ 1.0 ] },
  		'tDepth': { value: null },
  		'cameraNear': { value: 10 },
  		'cameraFar': { value: 1000 },
  		'depthCutoff': { value: 10 },
  	},
  	vertexShader: [
  		"#include <common>",
  
  		"uniform vec2 size;",
  
  		"varying vec2 vUv;",
  		"varying vec2 vInvSize;",
  
  		"void main() {",
  		"	vUv = uv;",
  		"	vInvSize = 1.0 / size;",
  
  		"	gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );",
  		"}"
  
  	].join( "\n" ),
  	fragmentShader: [
  		"#include <common>",
  		"#include <packing>",
  
  		"uniform sampler2D tDiffuse;",
  		"uniform sampler2D tDepth;",
  
  		"uniform float cameraNear;",
  		"uniform float cameraFar;",
  		"uniform float depthCutoff;",
  
  		"uniform vec2 sampleUvOffsets[ KERNEL_RADIUS + 1 ];",
  		"uniform float sampleWeights[ KERNEL_RADIUS + 1 ];",
  
  		"varying vec2 vUv;",
  		"varying vec2 vInvSize;",
  
  		"float getDepth( const in vec2 screenPosition ) {",
  		"	#if DEPTH_PACKING == 1",
  		"	return unpackRGBAToDepth( texture2D( tDepth, screenPosition ) );",
  		"	#else",
  		"	return texture2D( tDepth, screenPosition ).x;",
  		"	#endif",
  		"}",
  
  		"float getViewZ( const in float depth ) {",
  		"	#if PERSPECTIVE_CAMERA == 1",
  		"	return perspectiveDepthToViewZ( depth, cameraNear, cameraFar );",
  		"	#else",
  		"	return orthographicDepthToViewZ( depth, cameraNear, cameraFar );",
  		"	#endif",
  		"}",
  
  		"void main() {",
  		"	float depth = getDepth( vUv );",
  		"	if( depth >= ( 1.0 - EPSILON ) ) {",
  		"		discard;",
  		"	}",
  
  		"	float centerViewZ = -getViewZ( depth );",
  		"	bool rBreak = false, lBreak = false;",
  
  		"	float weightSum = sampleWeights[0];",
  		"	vec4 diffuseSum = texture2D( tDiffuse, vUv ) * weightSum;",
  
  		"	for( int i = 1; i <= KERNEL_RADIUS; i ++ ) {",
  
  		"		float sampleWeight = sampleWeights[i];",
  		"		vec2 sampleUvOffset = sampleUvOffsets[i] * vInvSize;",
  
  		"		vec2 sampleUv = vUv + sampleUvOffset;",
  		"		float viewZ = -getViewZ( getDepth( sampleUv ) );",
  
  		"		if( abs( viewZ - centerViewZ ) > depthCutoff ) rBreak = true;",
  
  		"		if( ! rBreak ) {",
  		"			diffuseSum += texture2D( tDiffuse, sampleUv ) * sampleWeight;",
  		"			weightSum += sampleWeight;",
  		"		}",
  
  		"		sampleUv = vUv - sampleUvOffset;",
  		"		viewZ = -getViewZ( getDepth( sampleUv ) );",
  
  		"		if( abs( viewZ - centerViewZ ) > depthCutoff ) lBreak = true;",
  
  		"		if( ! lBreak ) {",
  		"			diffuseSum += texture2D( tDiffuse, sampleUv ) * sampleWeight;",
  		"			weightSum += sampleWeight;",
  		"		}",
  
  		"	}",
  
  		"	gl_FragColor = diffuseSum / weightSum;",
  		"}"
  	].join( "\n" )
  };
  
  THREE.BlurShaderUtils = {
  
  	createSampleWeights: function ( kernelRadius, stdDev ) {
  
  		var gaussian = function ( x, stdDev ) {
  
  			return Math.exp( - ( x * x ) / ( 2.0 * ( stdDev * stdDev ) ) ) / ( Math.sqrt( 2.0 * Math.PI ) * stdDev );
  
  		};
  
  		var weights = [];
  
  		for ( var i = 0; i <= kernelRadius; i ++ ) {
  
  			weights.push( gaussian( i, stdDev ) );
  
  		}
  
  		return weights;
  
  	},
  
  	createSampleOffsets: function ( kernelRadius, uvIncrement ) {
  
  		var offsets = [];
  
  		for ( var i = 0; i <= kernelRadius; i ++ ) {
  
  			offsets.push( uvIncrement.clone().multiplyScalar( i ) );
  
  		}
  
  		return offsets;
  
  	},
  
  	configure: function ( material, kernelRadius, stdDev, uvIncrement ) {
  
  		material.defines[ 'KERNEL_RADIUS' ] = kernelRadius;
  		material.uniforms[ 'sampleUvOffsets' ].value = THREE.BlurShaderUtils.createSampleOffsets( kernelRadius, uvIncrement );
  		material.uniforms[ 'sampleWeights' ].value = THREE.BlurShaderUtils.createSampleWeights( kernelRadius, stdDev );
  		material.needsUpdate = true;
  
  	}
  
  };
  