|
|
|
|
|
|
|
#define SSS_PASS 1 |
|
|
|
#define SSS_BILATERAL 1 |
|
|
|
#define SSS_DEBUG 0 |
|
|
|
#define SSS_USE_TANGENT_PLANE 0 |
|
|
|
#define MILLIMETERS_PER_METER 1000 |
|
|
|
#ifdef SSS_MODEL_BASIC |
|
|
|
#define CENTIMETERS_PER_METER 100 |
|
|
|
|
|
|
|
//------------------------------------------------------------------------------------- |
|
|
|
// Inputs & outputs |
|
|
|
//------------------------------------------------------------------------------------- |
|
|
|
|
|
|
|
float4x4 _ViewMatrix, _ProjMatrix; // TEMP: make these global |
|
|
|
|
|
|
|
float _WorldScales[SSS_N_PROFILES]; // Size of the world unit in meters |
|
|
|
#ifdef SSS_MODEL_DISNEY |
|
|
|
|
|
|
|
float maxDistance = _FilterKernelsBasic[profileID][SSS_BASIC_N_SAMPLES - 1].a; |
|
|
|
#endif |
|
|
|
|
|
|
|
// Take the first (central) sample. |
|
|
|
// TODO: copy its neighborhood into LDS. |
|
|
|
float2 centerPosition = posInput.unPositionSS; |
|
|
|
float3 centerIrradiance = LOAD_TEXTURE2D(_IrradianceSource, centerPosition).rgb; |
|
|
|
|
|
|
|
float centerDepth = LOAD_TEXTURE2D(_MainDepthTexture, posInput.unPositionSS).r; |
|
|
|
float centerDepth = LOAD_TEXTURE2D(_MainDepthTexture, centerPosition).r; |
|
|
|
// Compute the view-space dimensions of the pixel as a quad projected onto geometry. |
|
|
|
float2 unitsPerPixel = 2 * abs(cornerPosVS.xy - centerPosVS.xy); |
|
|
|
float2 pixelsPerMm = rcp(millimPerUnit * unitsPerPixel); |
|
|
|
#if SSS_USE_TANGENT_PLANE |
|
|
|
[branch] |
|
|
|
if (distScale == 0) |
|
|
|
{ |
|
|
|
#if SSS_DEBUG |
|
|
|
return float4(0, 0, 1, 1); |
|
|
|
#else |
|
|
|
return float4(bsdfData.diffuseColor * centerIrradiance, 1); |
|
|
|
#endif |
|
|
|
} |
|
|
|
// Take the first (central) sample. |
|
|
|
// TODO: copy its neighborhood into LDS. |
|
|
|
float2 centerPosition = posInput.unPositionSS; |
|
|
|
float3 centerIrradiance = LOAD_TEXTURE2D(_IrradianceSource, centerPosition).rgb; |
|
|
|
UpdatePositionInput(centerDepth, _InvViewProjMatrix, _ViewProjMatrix, posInput); |
|
|
|
// Compute the disk tangential to the surface. |
|
|
|
float3 normalVS = mul((float3x3)_ViewMatrix, bsdfData.normalWS); |
|
|
|
float3x3 basisVS = GetLocalFrame(normalVS); |
|
|
|
float3 tangentX = basisVS[0] * rcp(millimPerUnit); |
|
|
|
float3 tangentY = basisVS[1] * rcp(millimPerUnit); |
|
|
|
|
|
|
|
// Accumulate filtered irradiance and bilateral weights (for renormalization). |
|
|
|
float3 totalIrradiance, totalWeight; |
|
|
|
|
|
|
|
{ |
|
|
|
float centerRcpPdf = _FilterKernelsNearField[profileID][0][1]; |
|
|
|
float3 centerWeight = KernelValCircle(0, shapeParam) * centerRcpPdf; |
|
|
|
|
|
|
|
totalIrradiance = centerWeight * centerIrradiance; |
|
|
|
totalWeight = centerWeight; |
|
|
|
|
|
|
|
[unroll] |
|
|
|
for (uint i = 1; i < SSS_N_SAMPLES_NEAR_FIELD; i++) |
|
|
|
{ |
|
|
|
float r = _FilterKernelsNearField[profileID][i][0]; |
|
|
|
/* The relative sample position is known at compile time. */ |
|
|
|
float phi = TWO_PI * Fibonacci2d(i, SSS_N_SAMPLES_NEAR_FIELD).y; |
|
|
|
float2 vec = r * float2(cos(phi), sin(phi)); |
|
|
|
|
|
|
|
float3 relPosVS = vec.x * tangentX + vec.y * tangentY; |
|
|
|
float3 positionVS = centerPosVS + relPosVS; |
|
|
|
float4 positionCS = mul(_ProjMatrix, float4(positionVS, 1)); |
|
|
|
float2 positionSS = positionCS.xy * (rcp(positionCS.w) * 0.5) + 0.5; |
|
|
|
float2 positionXY = positionSS * _ScreenSize.xy; |
|
|
|
float3 irradiance = LOAD_TEXTURE2D(_IrradianceSource, positionXY).rgb; |
|
|
|
|
|
|
|
/* TODO: see if making this a [branch] improves performance. */ |
|
|
|
[flatten] |
|
|
|
if (any(irradiance)) |
|
|
|
{ |
|
|
|
/* Apply bilateral weighting. */ |
|
|
|
float z = LOAD_TEXTURE2D(_MainDepthTexture, positionXY).r; |
|
|
|
float d = LinearEyeDepth(z, _ZBufferParams); |
|
|
|
float t = d - positionVS.z; |
|
|
|
|
|
|
|
float3 x = millimPerUnit * length(relPosVS + float3(0, 0, t)); |
|
|
|
float p = _FilterKernelsNearField[profileID][i][1]; |
|
|
|
#if SSS_BILATERAL |
|
|
|
float3 w = KernelValCircle(x, shapeParam) * p; |
|
|
|
#else |
|
|
|
float3 w = KernelValCircle(r, shapeParam) * p; |
|
|
|
#endif |
|
|
|
|
|
|
|
totalIrradiance += w * irradiance; |
|
|
|
totalWeight += w; |
|
|
|
} |
|
|
|
else |
|
|
|
{ |
|
|
|
/*************************************************************************/ |
|
|
|
/* The irradiance is 0. This could happen for 3 reasons. */ |
|
|
|
/* Most likely, the surface fragment does not have an SSS material. */ |
|
|
|
/* Alternatively, our sample comes from a region without any geometry. */ |
|
|
|
/* Finally, the surface fragment could be completely shadowed. */ |
|
|
|
/* Our blur is energy-preserving, so 'centerWeight' should be set to 0. */ |
|
|
|
/* We do not terminate the loop since we want to gather the contribution */ |
|
|
|
/* of the remaining samples (e.g. in case of hair covering skin). */ |
|
|
|
/* Note: See comment in the output of deferred.shader */ |
|
|
|
/*************************************************************************/ |
|
|
|
} |
|
|
|
} |
|
|
|
} |
|
|
|
|
|
|
|
#else |
|
|
|
// Compute the view-space dimensions of the pixel as a quad projected onto geometry. |
|
|
|
float2 unitsPerPixel = 2 * abs(cornerPosVS.xy - centerPosVS.xy); |
|
|
|
float2 pixelsPerMm = rcp(millimPerUnit * unitsPerPixel); |
|
|
|
|
|
|
|
// We perform point sampling. Therefore, we can avoid the cost |
|
|
|
// of filtering if we stay within the bounds of the current pixel. |
|
|
|
|
|
|
|
millimPerUnit, pixelsPerMm, totalIrradiance, totalWeight) |
|
|
|
#endif |
|
|
|
} |
|
|
|
#endif |
|
|
|
// Compute the view-space dimensions of the pixel as a quad projected onto geometry. |
|
|
|
float2 unitsPerPixel = 2 * abs(cornerPosVS.xy - centerPosVS.xy); |
|
|
|
float2 pixelsPerCm = rcp(centimPerUnit * unitsPerPixel); |
|
|
|
|
|
|
|
// Compute the filtering direction. |
|
|
|
|
Evgenii Golubev
8 年前