{
	parms {
#ifdef PS3
		projectionMatrixZ.z		projectionMatrixZ.z * 0.5 - 0.5
#endif
	}
	state {
		depthfunc	GL_ALWAYS
		depthmask
		alphamask
		twosided
	}
	hlsl_vp {
		result.position = vertex.position;
	}
	hlsl_fp {
		float2 tc = screenPosToTexcoord( fragment.position.xy, $positionToViewTexture );

		const float MAX_FLAT_DEPTH = 10.0;		// maximum depth for two adjacent pixels to be considered in the same plane
		const float MIN_CRACK_DEPTH = 100.0;	// a pixel is considered a crack if it's depth increases this much between two adjacent pixels
		const float MAX_CRACK_DISTANCE = 500.0;	// don't look for cracks beyond this point because small far away adjacent geometry will appear as cracks

		float3 foundCrack = _float3( 0.0 );
		for ( float x = -4.0; x <= 4.0; x += 1.0 ) {
			for ( float y = -4.0; y <= 4.0; y += 1.0 ) {
				float2 localTC = tc + float2( x, y ) * $positionToViewTexture.zw;

				float centerDepth = tex2Ddepth( $spare1Map, localTC );
				float4 surroundingDepth;
				surroundingDepth.x = tex2Ddepth( $spare1Map, localTC + float2( +1, 0 ) * $positionToViewTexture.zw );
				surroundingDepth.y = tex2Ddepth( $spare1Map, localTC + float2( 0, +1 ) * $positionToViewTexture.zw );
				surroundingDepth.z = tex2Ddepth( $spare1Map, localTC + float2( -1, 0 ) * $positionToViewTexture.zw );
				surroundingDepth.w = tex2Ddepth( $spare1Map, localTC + float2( 0, -1 ) * $positionToViewTexture.zw );

#if defined( PS3 )
				float centerClipZ = ( centerDepth - 0.5 ) * $projectionMatrixZ.w / ( centerDepth + $projectionMatrixZ.z );
				float4 surroundingClipZ = ( surroundingDepth - 0.5 ) * $projectionMatrixZ.w / ( surroundingDepth + $projectionMatrixZ.z );
#elif defined( XBOX )
				float centerClipZ = -( $projectionMatrixZ.w / ( -centerDepth - $projectionMatrixZ.z ) ) * centerDepth;
				float4 surroundingClipZ = -( $projectionMatrixZ.w / ( -surroundingDepth - $projectionMatrixZ.z ) ) * surroundingDepth;
#else
				centerDepth = centerDepth * 2.0 - 1.0;
				surroundingDepth = surroundingDepth * 2.0 - 1.0;
				float centerClipZ = -( $projectionMatrixZ.w / ( -centerDepth - $projectionMatrixZ.z ) ) * centerDepth;
				float4 surroundingClipZ = -( $projectionMatrixZ.w / ( -surroundingDepth - $projectionMatrixZ.z ) ) * surroundingDepth;
#endif

				float minClipX = min( surroundingClipZ.x, surroundingClipZ.z );
				float minClipY = min( surroundingClipZ.y, surroundingClipZ.w );
				float minClipZ = min( minClipX, minClipY );

				float2 averageSurroundingClipZ = ( surroundingClipZ.xy + surroundingClipZ.zw ) * 0.5;

				if ( abs( averageSurroundingClipZ.x - surroundingClipZ.x ) < MAX_FLAT_DEPTH &&
						centerClipZ - averageSurroundingClipZ.x > MIN_CRACK_DEPTH && averageSurroundingClipZ.x < MAX_CRACK_DISTANCE ) {
					foundCrack = float3( localTC.x, localTC.y, minClipZ );
				}
				if ( abs( averageSurroundingClipZ.y - surroundingClipZ.y ) < MAX_FLAT_DEPTH &&
							centerClipZ - averageSurroundingClipZ.y > MIN_CRACK_DEPTH && averageSurroundingClipZ.y < MAX_CRACK_DISTANCE ) {
					foundCrack = float3( localTC.x, localTC.y, minClipZ );
				}
			}
		}

		if ( foundCrack.z != 0.0 ) {
			for ( float x = -16.0; x <= 16.0; x += 4.0 ) {
				for ( float y = -16.0; y <= 16.0; y += 4.0 ) {
					float2 localTC = foundCrack.xy + float2( x, y ) * $positionToViewTexture.zw;
					float centerDepth = tex2Ddepth( $spare1Map, localTC );
					float4 surroundingDepth;
					surroundingDepth.x = tex2Ddepth( $spare1Map, localTC + float2( +1, 0 ) * $positionToViewTexture.zw );
					surroundingDepth.y = tex2Ddepth( $spare1Map, localTC + float2( 0, +1 ) * $positionToViewTexture.zw );
					surroundingDepth.z = tex2Ddepth( $spare1Map, localTC + float2( -1, 0 ) * $positionToViewTexture.zw );
					surroundingDepth.w = tex2Ddepth( $spare1Map, localTC + float2( 0, -1 ) * $positionToViewTexture.zw );

#if defined( PS3 )
					float centerClipZ = ( centerDepth - 0.5 ) * $projectionMatrixZ.w / ( centerDepth + $projectionMatrixZ.z );
					float4 surroundingClipZ = ( surroundingDepth - 0.5 ) * $projectionMatrixZ.w / ( surroundingDepth + $projectionMatrixZ.z );
#elif defined( XBOX )
					float centerClipZ = -( $projectionMatrixZ.w / ( -centerDepth - $projectionMatrixZ.z ) ) * centerDepth;
					float4 surroundingClipZ = -( $projectionMatrixZ.w / ( -surroundingDepth - $projectionMatrixZ.z ) ) * surroundingDepth;
#else
					centerDepth = centerDepth * 2.0 - 1.0;
					surroundingDepth = surroundingDepth * 2.0 - 1.0;
					float centerClipZ = -( $projectionMatrixZ.w / ( -centerDepth - $projectionMatrixZ.z ) ) * centerDepth;
					float4 surroundingClipZ = -( $projectionMatrixZ.w / ( -surroundingDepth - $projectionMatrixZ.z ) ) * surroundingDepth;
#endif

					float2 averageSurroundingClipZ = ( surroundingClipZ.xy + surroundingClipZ.zw ) * 0.5;

					if ( abs( averageSurroundingClipZ.x - surroundingClipZ.x ) < MAX_FLAT_DEPTH &&
							centerClipZ - averageSurroundingClipZ.x > MIN_CRACK_DEPTH && averageSurroundingClipZ.x < MAX_CRACK_DISTANCE ) {
					} else if ( abs( averageSurroundingClipZ.y - surroundingClipZ.y ) < MAX_FLAT_DEPTH &&
								centerClipZ - averageSurroundingClipZ.y > MIN_CRACK_DEPTH && averageSurroundingClipZ.y < MAX_CRACK_DISTANCE ) {
					} else if ( centerClipZ > foundCrack.z + MIN_CRACK_DEPTH ) {
						foundCrack.z = 0.0;
					}
				}
			}
		}

		if ( foundCrack.z != 0.0 ) {
			result.color = float4( 1.0, 0.25, 0.25, 1.0 );
		} else {
			float centerDepth = tex2Ddepth( $spare1Map, tc );
#if defined( PS3 )
			float centerClipZ = ( centerDepth - 0.5 ) * $projectionMatrixZ.w / ( centerDepth + $projectionMatrixZ.z );
#elif defined( XBOX )
			float centerClipZ = -( $projectionMatrixZ.w / ( -centerDepth - $projectionMatrixZ.z ) ) * centerDepth;
#else
			centerDepth = centerDepth * 2.0 - 1.0;
			float centerClipZ = -( $projectionMatrixZ.w / ( -centerDepth - $projectionMatrixZ.z ) ) * centerDepth;
#endif
			result.color = _float4( centerClipZ / 1000 );
		}
	}
}