// Vlayer config options:
//#define VLAYERED_RECOMPUTE_PERLIGHT // TODO test more, make it a shader_features
#ifdef _VLAYERED_RECOMPUTE_PERLIGHT
#define VLAYERED_RECOMPUTE_PERLIGHT
// Now a shader_features
//#define VLAYERED_USE_REFRACTED_ANGLES_FOR_BASE
#endif
#ifdef _VLAYERED_USE_REFRACTED_ANGLES_FOR_BASE
#define VLAYERED_USE_REFRACTED_ANGLES_FOR_BASE
#endif
#define VLAYERED_DIFFUSE_ENERGY_HACKED_TERM
//#define VLAYERED_ANISOTROPY_IBL_DESTRETCH
// Mostly for struct array declarations, not really loops:
#ifdef _MATERIAL_FEATURE_COAT
#ifdef _MATERIAL_FEATURE_COAT_NORMALMAP
# define NB_NORMALS 2 // NB of interfaces with different normals (for additional clear coat normal map)
#else
# define NB_NORMALS 1
#endif
#if defined(VLAYERED_USE_REFRACTED_ANGLES_FOR_BASE)
# define NB_LV_DIR 2 // NB of interfaces with different L or V directions to consider (see BSDF( ) )
#else
# define NB_LV_DIR 1
#endif
#else
#else // ! _MATERIAL_FEATURE_COAT
# undef VLAYERED_USE_REFRACTED_ANGLES_FOR_BASE
# undef _MATERIAL_FEATURE_COAT_NORMALMAP // enforce a "coat enabled subfeature" condition on this shader_feature
# define NB_NORMALS 1
# define NB_LV_DIR 1
#endif
#endif // #ifdef _MATERIAL_FEATURE_COAT
// For NB_NORMALS arrays:
#define COAT_NORMAL_IDX 0
#define BASE_NORMAL_IDX (NB_NORMALS-1)
// For NB_LV_DIR arrays: make sure these indices match the above
#define TOP_DIR_IDX 0
#define BOTTOM_DIR_IDX (NB_LV_DIR-1)
// TODO: if dual lobe base
//#define BASE_NB_LOBES 1
return (HasFeatureFlag(bsdfData.materialFeatures, MATERIALFEATUREFLAGS_STACK_LIT_COAT));
}
bool IsCoatNormalMapEnabled(BSDFData bsdfData)
{
return (HasFeatureFlag(bsdfData.materialFeatures, MATERIALFEATUREFLAGS_STACK_LIT_COAT_NORMAL_MAP));
}
// Assume that bsdfData.diffusionProfile is init
void FillMaterialSSS(uint diffusionProfile, float subsurfaceMask, inout BSDFData bsdfData)
{
return sssData;
}
// Specular antialiasing
float NormalCurvatureToRoughness(float3 n)
{
float3 dNdx = ddx(n);
float3 dNdy = ddy(n);
float curvature = pow(max(dot(dNdx, dNdx), dot(dNdy, dNdy)), _NormalCurvatureToRoughnessExponent);
return saturate(curvature * _NormalCurvatureToRoughnessScale + _NormalCurvatureToRoughnessBias);
}
float FilterRoughness_TOKUYOSHI(float3 n, float r)
{
float3 deltaU = ddx(n);
float3 deltaV = ddy(n);
float variance = _SpecularAntiAliasingScreenSpaceVariance * (dot(deltaU, deltaU) + dot(deltaV, deltaV));
float squaredRoughness = saturate(r * r + min(2.0 * variance, _SpecularAntiAliasingThreshold));
return sqrt(squaredRoughness);
}
//-----------------------------------------------------------------------------
// conversion function for forward
//-----------------------------------------------------------------------------
// IMPORTANT: In our forward only case, all enable flags are statically know at compile time, so the compiler can do compile time optimization
bsdfData.materialFeatures = surfaceData.materialFeatures;
bsdfData.geomNormalWS = surfaceData.geomNormalWS; // We should always have this whether we enable coat normals or not.
// Specular AA: NormalCurvatureToRoughness
float normalCurvatureToRoughnessA = max(NormalCurvatureToRoughness(bsdfData.normalWS), bsdfData.perceptualRoughnessA);
float normalCurvatureToRoughnessB = max(NormalCurvatureToRoughness(bsdfData.normalWS), bsdfData.perceptualRoughnessB);
bsdfData.perceptualRoughnessA = lerp(bsdfData.perceptualRoughnessA, normalCurvatureToRoughnessA, _NormalCurvatureToRoughnessEnabled);
bsdfData.perceptualRoughnessB = lerp(bsdfData.perceptualRoughnessB, normalCurvatureToRoughnessB, _NormalCurvatureToRoughnessEnabled);
// Specular AA: Tokuyoshi Filtering.
float filterRoughnessA = FilterRoughness_TOKUYOSHI(bsdfData.normalWS, bsdfData.perceptualRoughnessA);
float filterRoughnessB = FilterRoughness_TOKUYOSHI(bsdfData.normalWS, bsdfData.perceptualRoughnessB);
bsdfData.perceptualRoughnessA = lerp(bsdfData.perceptualRoughnessA, filterRoughnessA, _SpecularAntiAliasingEnabled);
bsdfData.perceptualRoughnessB = lerp(bsdfData.perceptualRoughnessB, filterRoughnessB, _SpecularAntiAliasingEnabled);
bsdfData.lobeMix = surfaceData.lobeMix;
// There is no metallic with SSS and specular color mode
if (HasFeatureFlag(surfaceData.materialFeatures, MATERIALFEATUREFLAGS_STACK_LIT_COAT))
{
if (HasFeatureFlag(surfaceData.materialFeatures, MATERIALFEATUREFLAGS_STACK_LIT_COAT_NORMAL_MAP))
{
bsdfData.coatNormalWS = surfaceData.coatNormalWS;
}
FillMaterialCoatData(PerceptualSmoothnessToPerceptualRoughness(surfaceData.coatPerceptualSmoothness),
surfaceData.coatIor, surfaceData.coatThickness, surfaceData.coatExtinction, bsdfData);
// GetPreLightData prototype.
//-----------------------------------------------------------------------------
float NdotV; // Could be negative due to normal mapping, use ClampNdotV()
float NdotV[NB_NORMALS]; // Could be negative due to normal mapping, use ClampNdotV()
//float NdotV;
float bottomAngleFGD;
float TdotV; // Stored only when VLAYERED_RECOMPUTE_PERLIGHT
float BdotV;
return newAniso;
}
// Get the orthogonal component (or complement) of a vector V with regard to the vector N.
float3 GetOrthogonalComponent(float3 V, float3 N)
{
// V and N are supposed to be unit vectors
float VdotN = dot(V, N);
float3 VOrtho = V - VdotN * N;
float3 unitVOrtho = VOrtho * rsqrt(1.0 - Sq(VdotN));
return unitVOrtho;
}
float3 GetDirFromAngleAndOrthoFrame(float3 V, float3 N, float newVdotN)
{
float sintheta = sqrt(1.0 - Sq(newVdotN));
float3 newV = newVdotN * N + sintheta * V;
return newV;
}
void ComputeAdding_GetVOrthoGeomN(BSDFData bsdfData, float3 V, bool calledPerLight, out float3 vOrthoGeomN, out bool useGeomN)
{
vOrthoGeomN = (float3)0;
useGeomN = false;
if( !calledPerLight && IsCoatNormalMapEnabled(bsdfData) )
{
// In that case, since we have 2 normal maps we need to decide on a common orientation
// for our parallel interface model, otherwise the series expression doesn't make any
// sense. We will settle on using the geometric normal. It will be used for
// average mean propagation but all FGD or Fresnel terms will use the corresponding
// interface's normal map's normal for calculation. IBL fetches and lighting
// calculations (shading) for analytical lights should also use these.
// The rational for the later is that the resulting stats are still a local model, so
// all scattered rays should exit back up with the same normal as the ray that spawned
// them had on entry on top. So we assume bending is cancelled out.
//
// Also, since we are using a fake (and adjusted / lerped depending on roughness)
// refraction for the top (coat) interface, and this will be done, like stated,
// using the geometric normal, we will reconstruct a direction for the bottom
// interface using the "V and geomNormalWS" plane as a plane of incidence. So we
// calculate a pseudo-refracted angle in this plane, and with an orthogonal basis
// of it (2D basis embedded in 3D, ie basis formed by two 3D vectors)
// (using the orthogonal complement of V vs geomNormalWS), we will reconstruct
// the "V at the bottom interface". This V will then in turn be usable for further
// FGD / Fresnel calculations with the bottom interface normal (from the bottom
// normal map), which is not necessarily coplanar with V and geomNormalWS, hence
// this method.
//
// In all other cases: we either don't have a dual normal map, or we recompute the
// stats per light and in that case, the H vector serves as a common orientation
// and we calculate everything with it anyway (symmetric parametrization), so no
// normal map is involved.
vOrthoGeomN = GetOrthogonalComponent(V, bsdfData.geomNormalWS);
useGeomN = true;
}
}
//-----------------------------------------------------------------------------
// About layered BSDF statistical lobe data calculations:
// T12 should be multiplied by TIR.
// (more like p8, T21 <- T21*TIR, R21 <- R21 + (1-TIR)*T21 )
//
void ComputeStatistics(in float cti, in int i, in BSDFData bsdfData,
//ComputeStatistics(cti, V, vOrthoGeomN, useGeomN, i, bsdfData, preLightData, ctt, R12, T12, R21, T21, s_r12, s_t12, j12, s_r21, s_t21, j21);
void ComputeStatistics(in float cti, in float3 V, in float3 vOrthoGeomN, in bool useGeomN, in int i, in BSDFData bsdfData,
inout PreLightData preLightData,
out float ctt,
out float3 R12, out float3 T12, out float3 R21, out float3 T21,
out float s_r12, out float s_t12, out float j12,
n12 = GetCoatEta(bsdfData); //n2/n1;
R0 = FresnelUnpolarized(cti, n12, 1.0);
// At this point cti should be properly (coatNormalWS dot V) or NdotV or VdotH, see ComputeAdding.
// In the special case where we do have a coat normal, we will propagate a different angle than
// (coatNormalWS dot V) and vOrthoGeomN will be used.
// vOrthoGeomN is the orthogonal complement of V wrt geomNormalWS.
if (useGeomN)
{
cti = ClampNdotV(dot(bsdfData.geomNormalWS, V));
}
R12 = R0; // TODO: FGD
T12 = 1.0 - R12;
}
else
{
float ctiForFGD = cti;
// If we use the geometric normal propagation hack, we want to calculate FGD / Fresnel with
// an angle at the bottom interface between the average propagated direction and the normal from
// the bottom normal map. For that, we will recover a direction from the angle we propagated in
// the "V and geomNormalWS" plane of incidence. That direction will then serve to calculate an
// angle with the non-coplanar bottom normal from the normal map.
if (useGeomN)
{
float3 bottomDir = GetDirFromAngleAndOrthoFrame(vOrthoGeomN, bsdfData.geomNormalWS, cti);
ctiForFGD = ClampNdotV(dot(bsdfData.normalWS, bottomDir));
}
// We will also save this average bottom angle:
preLightData.bottomAngleFGD = ctiForFGD;
R12 = F_Schlick(bsdfData.fresnel0, cti);
R12 = F_Schlick(bsdfData.fresnel0, ctiForFGD);
T12 = 0.0;
#ifdef VLAYERED_DIFFUSE_ENERGY_HACKED_TERM
// Still should use FGD!
} //...ComputeStatistics()
void ComputeAdding(float _cti, in BSDFData bsdfData, inout PreLightData preLightData, bool calledPerLight = false)
void ComputeAdding(float _cti, float3 V, in BSDFData bsdfData, inout PreLightData preLightData, bool calledPerLight = false)
// _cti should be LdotH or VdotH if calledPerLight == true (symmetric parametrization), V is unused in this case.
// _cti should be NdotV if calledPerLight == false and no independent coat normal map is used (ie single normal map), V is unused in this case.
// _cti should be (coatNormalWS dot V) if calledPerLight == false and we have a coat normal map. V is used in this case
if( _DebugLobeMask.w == 0.0)
if( _DebugEnvLobeMask.w == 0.0)
{
preLightData.vLayerEnergyCoeff[COAT_LOBE_IDX] = 0.0 * F_Schlick(IorToFresnel0(bsdfData.coatIor), _cti);
preLightData.iblPerceptualRoughness[COAT_LOBE_IDX] = bsdfData.coatPerceptualRoughness;
#endif
// Global Variables
// Decide if we need the special path/hack for the coat normal map mode:
bool useGeomN;
float3 vOrthoGeomN; // only valid if useGeomN == true
ComputeAdding_GetVOrthoGeomN(bsdfData, V, calledPerLight, vOrthoGeomN, useGeomN);
float cti = _cti;
float3 R0i = float3(0.0, 0.0, 0.0), Ri0 = float3(0.0, 0.0, 0.0),
T0i = float3(1.0, 1.0, 1.0), Ti0 = float3(1.0, 1.0, 1.0);
float s_r21=0.0, s_t12=0.0, s_t21=0.0, j12=1.0, j21=1.0, ctt;
// Layer specific evaluation of the transmittance, reflectance, variance
ComputeStatistics(cti, i, bsdfData, ctt, R12, T12, R21, T21, s_r12, s_t12, j12, s_r21, s_t21, j21);
ComputeStatistics(cti, V, vOrthoGeomN, useGeomN, i, bsdfData, preLight Data, ctt, R12, T12, R21, T21, s_r12, s_t12, j12, s_r21, s_t21, j21);
// Multiple scattering forms
float3 denom = (float3(1.0, 1.0, 1.0) - Ri0*R12); //i = new layer, 0 = cumulative top (llab3.1 to 3.4)
// Then we need anisotropic roughness updates again for the 2
// bottom lobes, for analytical lights.
//
// TODO: VLAYERED_RECOMPUTE_PERLIGHT and calledPerLight bool
// First, to be less messy, immediately transfer vLayerPerceptualRoughness
// data into the iblPerceptualRoughness[] array
}
#endif
if( !perLightOption )
if( !perLightOption || calledPerLight )
{
ConvertAnisotropyToClampRoughness(preLightData.iblPerceptualRoughness[BASE_LOBEA_IDX], preLightData.iblAnisotropy[0],
preLightData.layeredRoughnessT[0], preLightData.layeredRoughnessB[0]);
// slnote dual map
float PreLightData_GetBaseNdotVForFGD(BSDFData bsdfData, PreLightData preLightData, float NdotV[NB_NORMALS])
{
float baseLayerNdotV;
if ( IsCoatNormalMapEnabled(bsdfData) )
{
baseLayerNdotV = preLightData.bottomAngleFGD;
}
else
{
//slnote: TODO TOTEST
//baseLayerNdotV = preLightData.bottomAngleFGD;
baseLayerNdotV = sqrt(1 + Sq(preLightData.coatIeta)*(Sq(NdotV[0]) - 1));
//TODO refactor with EvalIridescence, Lit::GetPreLightData
}
return baseLayerNdotV;
}
// slnote dual map
void PreLightData_SetupNormals(BSDFData bsdfData, inout PreLightData preLightData, float3 V, out float3 N[NB_NORMALS], out float NdotV[NB_NORMALS])
{
N[BASE_NORMAL_IDX] = bsdfData.normalWS;
preLightData.NdotV[BASE_NORMAL_IDX] = dot(N[BASE_NORMAL_IDX], V);
NdotV[BASE_NORMAL_IDX] = ClampNdotV(preLightData.NdotV[BASE_NORMAL_IDX]);
#ifdef _MATERIAL_FEATURE_COAT_NORMALMAP
if ( IsCoatNormalMapEnabled(bsdfData) )
{
N[COAT_NORMAL_IDX] = bsdfData.coatNormalWS;
preLightData.NdotV[COAT_NORMAL_IDX] = dot(N[COAT_NORMAL_IDX], V);
NdotV[COAT_NORMAL_IDX] = ClampNdotV(preLightData.NdotV[COAT_NORMAL_IDX]);
}
#endif
}
PreLightData GetPreLightData(float3 V, PositionInputs posInput, inout BSDFData bsdfData)
{
float3 N = bsdfData.normalWS;
preLightData.NdotV = dot(N, V);
float NdotV = ClampNdotV(preLightData.NdotV);
float3 N[NB_NORMALS];
float NdotV[NB_NORMALS];
PreLightData_SetupNormals(bsdfData, preLightData, V, N, NdotV);
preLightData.diffuseEnergy = float3(1.0, 1.0, 1.0);
// iblR (fetch direction compensated dominant spec)
// iblR (fetch direction in dominant spec direction / compensated for offspecular effect)
// energyCompensation (to a apply for each light sample since with multiple roughnesses, it becomes lobe specific)
// energyCompensation (to apply for each light sample since with multiple roughnesses, it becomes lobe specific)
//
// We also need for analytical lights:
//
float3 iblR[TOTAL_NB_LOBES];
float specularReflectivity[TOTAL_NB_LOBES];
float diffuseFGD[BASE_NB_LOBES];
float baseLayerNdotV = NdotV;
if( IsVLayeredEnabled(bsdfData) )
{
// --------------------------------------------------------------------
// A secondary coat normal map is possible here, NdotV[] and N[] are sized
// accordingly and are accessed by COAT|BASE_NORMAL_IDX
ComputeAdding(NdotV, bsdfData, preLightData, false);
ComputeAdding(NdotV[COAT_NORMAL_IDX], V, bsdfData, preLightData, false);
// After ComputeAdding, these are done for all lobes:
//
#ifndef VLAYERED_RECOMPUTE_PERLIGHT
// We can precalculate lambdaVs for all lights here since we're not doing ComputeAdding per light
preLightData.partLambdaV[COAT_LOBE_IDX] = GetSmithJointGGXPartLambdaV(NdotV, preLightData.layeredCoatRoughness);
preLightData.partLambdaV[BASE_LOBEA_IDX] = GetSmithJointGGXAnisoPartLambdaV(TdotV, BdotV, NdotV, preLightData.layeredRoughnessT[0], preLightData.layeredRoughnessB[0]);
preLightData.partLambdaV[BASE_LOBEB_IDX] = GetSmithJointGGXAnisoPartLambdaV(TdotV, BdotV, NdotV, preLightData.layeredRoughnessT[1], preLightData.layeredRoughnessB[1]);
preLightData.partLambdaV[COAT_LOBE_IDX] = GetSmithJointGGXPartLambdaV(NdotV[COAT_NORMAL_IDX], preLightData.layeredCoatRoughness);
preLightData.partLambdaV[BASE_LOBEA_IDX] = GetSmithJointGGXAnisoPartLambdaV(TdotV, BdotV, NdotV[BASE_NORMAL_IDX],
preLightData.layeredRoughnessT[0], preLightData.layeredRoughnessB[0]);
preLightData.partLambdaV[BASE_LOBEB_IDX] = GetSmithJointGGXAnisoPartLambdaV(TdotV, BdotV, NdotV[BASE_NORMAL_IDX],
preLightData.layeredRoughnessT[1], preLightData.layeredRoughnessB[1]);
#else
// Store those for eval analytical lights since we're going to
// recalculate lambdaV after each ComputeAdding for each light
stretch[0] = abs(preLightData.iblAnisotropy[0]) * saturate(5 * preLightData.iblPerceptualRoughness[BASE_LOBEA_IDX]);
stretch[1] = abs(preLightData.iblAnisotropy[1]) * saturate(5 * preLightData.iblPerceptualRoughness[BASE_LOBEB_IDX]);
iblN[COAT_LOBE_IDX] = N; // no anisotropy for coat.
iblN[BASE_LOBEA_IDX] = GetAnisotropicModifiedNormal(grainDirWS[0], N, V, stretch[0]);
iblN[BASE_LOBEB_IDX] = GetAnisotropicModifiedNormal(grainDirWS[1], N, V, stretch[1]);
iblN[COAT_LOBE_IDX] = N[COAT_NORMAL_IDX] ; // no anisotropy for coat.
iblN[BASE_LOBEA_IDX] = GetAnisotropicModifiedNormal(grainDirWS[0], N[BASE_NORMAL_IDX] , V, stretch[0]);
iblN[BASE_LOBEB_IDX] = GetAnisotropicModifiedNormal(grainDirWS[1], N[BASE_NORMAL_IDX] , V, stretch[1]);
}
else
// We can precalculate lambdaVs for all lights here since we're not doing ComputeAdding per light
preLightData.partLambdaV[COAT_LOBE_IDX] = GetSmithJointGGXPartLambdaV(NdotV, preLightData.layeredCoatRoughness);
preLightData.partLambdaV[BASE_LOBEA_IDX] = GetSmithJointGGXPartLambdaV(NdotV, preLightData.layeredRoughnessT[0]);
preLightData.partLambdaV[BASE_LOBEB_IDX] = GetSmithJointGGXPartLambdaV(NdotV, preLightData.layeredRoughnessT[1]);
preLightData.partLambdaV[COAT_LOBE_IDX] = GetSmithJointGGXPartLambdaV(NdotV[COAT_NORMAL_IDX], preLightData.layeredCoatRoughness);
preLightData.partLambdaV[BASE_LOBEA_IDX] = GetSmithJointGGXPartLambdaV(NdotV[BASE_NORMAL_IDX], preLightData.layeredRoughnessT[0]);
preLightData.partLambdaV[BASE_LOBEB_IDX] = GetSmithJointGGXPartLambdaV(NdotV[BASE_NORMAL_IDX], preLightData.layeredRoughnessT[1]);
iblN[0] = iblN[1] = iblN[2] = N;
iblN[COAT_LOBE_IDX] = N[COAT_NORMAL_IDX];
iblN[BASE_LOBEA_IDX] = iblN[BASE_LOBEB_IDX] = N[BASE_NORMAL_IDX];
} // anisotropy
// IBL
// because our ComputeAdding formulation is with "energy" coefficients calculated with a
// chain of Fresnel terms instead of a correct chain computed with the true FGD.
baseLayerNdotV = sqrt(1 + Sq(preLightData.coatIeta)*(Sq(NdotV) - 1) );
//TODO refactor with EvalIridescence, Lit::GetPreLightData
float baseLayerNdotV = PreLightData_GetBaseNdotVForFGD(bsdfData, preLightData, NdotV );
GetPreIntegratedFGDGGXAndDisneyDiffuse(NdotV,
GetPreIntegratedFGDGGXAndDisneyDiffuse(NdotV[COAT_NORMAL_IDX] ,
preLightData.iblPerceptualRoughness[COAT_LOBE_IDX],
preLightData.vLayerEnergyCoeff[TOP_VLAYER_IDX],
preLightData.specularFGD[COAT_LOBE_IDX],
// Notice again that the roughness and iblR properly use the output lobe statistics, but baseLayerNdotV
// is used for the offspecular correction because the true original offspecular tilt is parametrized by
// the angle at the base layer and the correction itself is influenced by that. See comments above.
preLightData.iblR[COAT_LOBE_IDX] = GetSpecularDominantDir(N, iblR[COAT_LOBE_IDX], preLightData.iblPerceptualRoughness[COAT_LOBE_IDX], NdotV);
preLightData.iblR[BASE_LOBEA_IDX] = GetSpecularDominantDir(N, iblR[BASE_LOBEA_IDX], preLightData.iblPerceptualRoughness[BASE_LOBEA_IDX], baseLayerNdotV);
preLightData.iblR[BASE_LOBEB_IDX] = GetSpecularDominantDir(N, iblR[BASE_LOBEB_IDX], preLightData.iblPerceptualRoughness[BASE_LOBEB_IDX], baseLayerNdotV);
preLightData.iblR[COAT_LOBE_IDX] = GetSpecularDominantDir(N[COAT_NORMAL_IDX] , iblR[COAT_LOBE_IDX], preLightData.iblPerceptualRoughness[COAT_LOBE_IDX], NdotV[COAT_NORMAL_IDX] );
preLightData.iblR[BASE_LOBEA_IDX] = GetSpecularDominantDir(N[BASE_NORMAL_IDX] , iblR[BASE_LOBEA_IDX], preLightData.iblPerceptualRoughness[BASE_LOBEA_IDX], baseLayerNdotV);
preLightData.iblR[BASE_LOBEB_IDX] = GetSpecularDominantDir(N[BASE_NORMAL_IDX] , iblR[BASE_LOBEB_IDX], preLightData.iblPerceptualRoughness[BASE_LOBEB_IDX], baseLayerNdotV);
#ifdef LIT_USE_GGX_ENERGY_COMPENSATION
// TODOENERGY:
// NO VLAYERING:
// --------------------------------------------------------------------
// Only a single normal map possible here, NdotV[] and N[] are sized to 1
// See ConvertSurfaceDataToBSDFData : The later are already clamped if
// vlayering is disabled, so could be used directly, but for later
// refactoring (instead of BSDFdata A and B values, we should really
float TdotV = dot(bsdfData.tangentWS, V);
float BdotV = dot(bsdfData.bitangentWS, V);
preLightData.partLambdaV[0] = GetSmithJointGGXAnisoPartLambdaV(TdotV, BdotV, NdotV, preLightData.layeredRoughnessT[0], preLightData.layeredRoughnessB[0]);
preLightData.partLambdaV[1] = GetSmithJointGGXAnisoPartLambdaV(TdotV, BdotV, NdotV, preLightData.layeredRoughnessT[1], preLightData.layeredRoughnessB[1]);
preLightData.partLambdaV[0] = GetSmithJointGGXAnisoPartLambdaV(TdotV, BdotV, NdotV[0] , preLightData.layeredRoughnessT[0], preLightData.layeredRoughnessB[0]);
preLightData.partLambdaV[1] = GetSmithJointGGXAnisoPartLambdaV(TdotV, BdotV, NdotV[0] , preLightData.layeredRoughnessT[1], preLightData.layeredRoughnessB[1]);
// For GGX aniso and IBL we have done an empirical (eye balled) approximation compare to the reference.
// We use a single fetch, and we stretch the normal to use based on various criteria.
float stretch[2];
stretch[0] = abs(bsdfData.anisotropy) * saturate(5 * preLightData.iblPerceptualRoughness[0]);
stretch[1] = abs(bsdfData.anisotropy) * saturate(5 * preLightData.iblPerceptualRoughness[1]);
iblN[0] = GetAnisotropicModifiedNormal(grainDirWS, N, V, stretch[0]);
iblN[1] = GetAnisotropicModifiedNormal(grainDirWS, N, V, stretch[1]);
iblN[0] = GetAnisotropicModifiedNormal(grainDirWS, N[0] , V, stretch[0]);
iblN[1] = GetAnisotropicModifiedNormal(grainDirWS, N[0] , V, stretch[1]);
preLightData.partLambdaV[0] = GetSmithJointGGXPartLambdaV(NdotV, preLightData.layeredRoughnessT[0]);
preLightData.partLambdaV[1] = GetSmithJointGGXPartLambdaV(NdotV, preLightData.layeredRoughnessT[1]);
iblN[0] = iblN[1] = N;
preLightData.partLambdaV[0] = GetSmithJointGGXPartLambdaV(NdotV[0] , preLightData.layeredRoughnessT[0]);
preLightData.partLambdaV[1] = GetSmithJointGGXPartLambdaV(NdotV[0] , preLightData.layeredRoughnessT[1]);
iblN[0] = iblN[1] = N[0] ;
} // ...no anisotropy
GetPreIntegratedFGDGGXAndDisneyDiffuse(baseLayerNdotV, // just NdotV here...
GetPreIntegratedFGDGGXAndDisneyDiffuse(NdotV[0],
preLightData.iblPerceptualRoughness[BASE_LOBEA_IDX],
bsdfData.fresnel0,
preLightData.specularFGD[BASE_LOBEA_IDX],
GetPreIntegratedFGDGGXAndDisneyDiffuse(baseLayerNdotV,
GetPreIntegratedFGDGGXAndDisneyDiffuse(NdotV[0],
preLightData.iblPerceptualRoughness[BASE_LOBEB_IDX],
bsdfData.fresnel0,
preLightData.specularFGD[BASE_LOBEB_IDX],
preLightData.iblPerceptualRoughness[0] *= fact;
preLightData.iblPerceptualRoughness[1] *= fact;
// Correction of reflected direction for better handling of rough material
preLightData.iblR[0] = GetSpecularDominantDir(N, iblR[0], preLightData.iblPerceptualRoughness[0], NdotV);
preLightData.iblR[1] = GetSpecularDominantDir(N, iblR[1], preLightData.iblPerceptualRoughness[1], NdotV);
preLightData.iblR[0] = GetSpecularDominantDir(N[0] , iblR[0], preLightData.iblPerceptualRoughness[0], NdotV[0] );
preLightData.iblR[1] = GetSpecularDominantDir(N[0] , iblR[1], preLightData.iblPerceptualRoughness[1], NdotV[0] );
#ifdef LIT_USE_GGX_ENERGY_COMPENSATION
// Here, since this compensation term is already an average applied to a sum
// BSDF share between directional light, punctual light and area light (reference)
//-----------------------------------------------------------------------------
// helpers
void CalculateAnisoAngles(BSDFData bsdfData, float3 L, float3 V, float invLenLV, out float TdotH, out float TdotL, out float BdotH, out float BdotL)
{
float3 H = (L + V) * invLenLV;
// BSDF helpers
// For anisotropy we must not saturate these values
TdotH = dot(bsdfData.tangentWS, H);
TdotL = dot(bsdfData.tangentWS, L);
BdotH = dot(bsdfData.bitangentWS, H);
BdotL = dot(bsdfData.bitangentWS, L);
}
//
// The following is to streamline the usage (in the BSDF evaluations) of NdotL[] and NdotV[]
// regardless of the reason why we need [2] sized arrays:
//
#if defined(VLAYERED_USE_REFRACTED_ANGLES_FOR_BASE) || defined(_MATERIAL_FEATURE_COAT_NORMALMAP)
#define DNLV_COAT_IDX 0
#define DNLV_BASE_IDX 1
#else
#define DNLV_COAT_IDX 0
#define DNLV_BASE_IDX 0
#endif
#if ((DNLV_BASE_IDX != BASE_NORMAL_IDX) && (DNLV_BASE_IDX != BOTTOM_DIR_IDX)) || ((DNLV_COAT_IDX != COAT_NORMAL_IDX) && (DNLV_BASE_IDX != COAT_DIR_IDX))
#error "DIR and NORMAL indices should match"
#endif
void CalculateAngles(float3 L, float3 V, float NdotL, float unclampedNdotV,
out float LdotV, out float invLenLV, out float NdotH, out float LdotH, out float NdotV)
#if defined(VLAYERED_USE_REFRACTED_ANGLES_FOR_BASE)
// static assert:
#if defined(_MATERIAL_FEATURE_COAT_NORMALMAP) && ((NB_LV_DIR != 2) || ( NB_NORMALS != 2) || (BASE_NORMAL_IDX != BOTTOM_DIR_IDX) || (COAT_NORMAL_IDX != TOP_DIR_IDX))
#error "Unexpected NB_NORMALS and/or NB_LV_DIR, should be 2 or unmatching indices between DIR_IDX vs NORMAL_IDX"
#endif
#define NDOTLV_SIZE NB_LV_DIR
#else
#define NDOTLV_SIZE NB_NORMALS
#endif //...defined(VLAYERED_USE_REFRACTED_ANGLES_FOR_BASE)
//BSDF_SetupNormalsAndAngles(bsdfData, preLightData, inNdotL,
// L, V, N, NdotL,
// H, NdotH, savedLdotH, NdotV);
void BSDF_SetupNormalsAndAngles(BSDFData bsdfData, inout PreLightData preLightData, float inNdotL,
inout float3 L[NB_LV_DIR], inout float3 V[NB_LV_DIR], out float3 N[NB_NORMALS], out float NdotL[NDOTLV_SIZE],
out float3 H, out float NdotH[NB_NORMALS], out float savedLdotH, out float NdotV[NDOTLV_SIZE])
// Optimized math. Ref: PBR Diffuse Lighting for GGX + Smith Microsurfaces (slide 114).
LdotV = dot(L, V);
invLenLV = rsqrt(max(2.0 * LdotV + 2.0, FLT_EPS)); // invLenLV = rcp(length(L + V)), clamp to avoid rsqrt(0) = NaN
NdotH = saturate((NdotL + unclampedNdotV) * invLenLV); // Do not clamp NdotV here
LdotH = saturate(invLenLV * LdotV + invLenLV);
NdotV = ClampNdotV(unclampedNdotV);
}
H = float3(0.0, 0.0, 0.0);
N[BASE_NORMAL_IDX] = bsdfData.normalWS;
#if defined(_MATERIAL_FEATURE_COAT_NORMALMAP)
if ( IsCoatNormalMapEnabled(bsdfData) )
{
N[COAT_NORMAL_IDX] = bsdfData.coatNormalWS;
}
#endif
// This function apply BSDF. Assumes that NdotL is positive.
void BSDF( float3 V, float3 L, float NdotL, float3 positionWS, PreLightData preLightData, BSDFData bsdfData,
out float3 diffuseLighting,
out float3 specularLighting)
{
float3 N = bsdfData.normalWS;
// preLightData.NdotV is sized with NB_NORMALS, not NDOTLV_SIZE, because the only useful
// precalculation that is not per light is NdotV with the coat normal (if it exists) and
// NdotV with the base normal (if coat normal exists), with the same V.
// But if VLAYERED_USE_REFRACTED_ANGLES_FOR_BASE is used, V is different at the bottom,
// and we will recalculate a refracted (along H) V here, per light, and the resulting base
// NdotV.
float unclampedNdotV[NB_NORMALS] = preLightData.NdotV;
float LdotV, invLenLV, NdotH, LdotH, NdotV;
// Optimized math. Ref: PBR Diffuse Lighting for GGX + Smith Microsurfaces (slide 114).
//float LdotV = dot(L, V);
//float invLenLV = rsqrt(max(2.0 * LdotV + 2.0, FLT_EPS)); // invLenLV = rcp(length(L + V)), clamp to avoid rsqrt(0) = NaN
//float NdotH = saturate((NdotL + preLightData.NdotV) * invLenLV); // Do not clamp NdotV here
//float LdotH = saturate(invLenLV * LdotV + invLenLV);
//float NdotV = ClampNdotV(preLightData.NdotV);
CalculateAngles(L, V, NdotL, preLightData.NdotV, LdotV, invLenLV, NdotH, LdotH, NdotV);
// static assert (to simplify code, COAT_NORMAL_IDX == BASE_NORMAL_IDX when no coat normal):
#if !defined(_MATERIAL_FEATURE_COAT_NORMALMAP) && (BASE_NORMAL_IDX != COAT_NORMAL_IDX)
#error "COAT_NORMAL_IDX shoud equal BASE_NORMAL_IDX when no coat normal map"
#endif
float3 DV[TOTAL_NB_LOBES];
// We will compute everything needed for top interface lighting, and this will alias to the
// (only) bottom interface when we're not vlayered (if we are and have a coat normal, we will
// use it as we transfered coatNormalWS above and if we don't, again, the only existing
// normal will be used)
// TODO: Proper Fresnel
float3 F = F_Schlick(bsdfData.fresnel0, LdotH);
// todo: inNdotL is with geometric N for now, so we don't use it.
NdotL[DNLV_COAT_IDX] = dot(N[COAT_NORMAL_IDX], L[TOP_DIR_IDX]);
// TODO: with iridescence, will be optionally per light sample
// Optimized math. Ref: PBR Diffuse Lighting for GGX + Smith Microsurfaces (slide 114).
float LdotV = dot(L[TOP_DIR_IDX], V[TOP_DIR_IDX]); // note: LdotV isn't reused elsewhere, just here.
float invLenLV = rsqrt(max(2.0 * LdotV + 2.0, FLT_EPS)); // invLenLV = rcp(length(L + V)), clamp to avoid rsqrt(0) = NaN
savedLdotH = saturate(invLenLV * LdotV + invLenLV);
NdotH[COAT_NORMAL_IDX] = saturate((NdotL[DNLV_COAT_IDX] + unclampedNdotV[COAT_NORMAL_IDX]) * invLenLV); // Do not clamp NdotV here
NdotV[DNLV_COAT_IDX] = ClampNdotV(unclampedNdotV[COAT_NORMAL_IDX]);
// --------------------------------------------------------------------
// VLAYERING:
// --------------------------------------------------------------------
// Save top angles in case VLAYERED_USE_REFRACTED_ANGLES_FOR_BASE option is used
float topLdotH = LdotH; // == VdotH)
float topNdotH = NdotH;
float topNdotL = NdotL;
float topNdotV = NdotV;
#if VLAYERED_USE_REFRACTED_ANGLES_FOR_BASE
// NdotH[] is size 2 only if we have two normal maps, but it doesn't change if we refract along
// H itself, so refracted angles considerations don't matter for it. Still we need to calculate
// it if we have two normal maps. Note we don't even test _MATERIAL_FEATURE_COAT_NORMALMAP, as
// BASE_NORMAL_IDX should alias COAT_NORMAL_IDX if there's no coat normalmap, and this line
// becomes a nop.
// We still reuse the top directions to be able to reuse computations above, regardless of
// refracted angle option since NdotH is invariant to it.
NdotH[BASE_NORMAL_IDX] = saturate((dot(N[BASE_NORMAL_IDX], L[TOP_DIR_IDX]) + unclampedNdotV[BASE_NORMAL_IDX]) * invLenLV); // Do not clamp NdotV here
#if defined(VLAYERED_USE_REFRACTED_ANGLES_FOR_BASE) || defined(_MATERIAL_FEATURE_ANISOTROPY)
// In both of these cases, we need H, so get this out of the way now:
H = (L[TOP_DIR_IDX] + V[TOP_DIR_IDX]) * invLenLV; // H stays the same so calculate it one time
#endif
#ifdef VLAYERED_RECOMPUTE_PERLIGHT
// TODOWIP
// Must call ComputeAdding and update partLambdaV
ComputeAdding(savedLdotH, V[TOP_DIR_IDX], bsdfData, preLightData, true);
// Notice the top LdotH as interface angle, symmetric model parametrization (see paper sec. 6 and comments
// on ComputeAdding)
// layered*Roughness* and vLayerEnergyCoeff are now updated for the proper light direction.
// !Updates to PartLambdaV are now needed, will be done later when we consider anisotropy.
// Note (see p9 eq(39)): if we don't recompute per light, we just reuse the IBL energy terms as the fresnel
// terms for our LdotH, too bad (similar to what we do with iridescence), along with the "wrongly" calculated
// energy.
// In any case, we should have used FGD terms (except for R12 at the start of the process) for the analytical
// light case, see comments at the top of ComputeAdding
#endif //...VLAYERED_RECOMPUTE_PERLIGHT
#ifdef VLAYERED_USE_REFRACTED_ANGLES_FOR_BASE
// Also, we will use the base normal map automatically if we have dual normal maps (coat normals)
// since we use generically N[BASE_NORMAL_IDX]
// TODOWIP
// Use the refracted angle at the bottom interface for BSDF calculations:
// an output lobe parametrization, but multiple-scattering is not accounted fully
// byt ComputeAdding (by deriving azimuth dependent covariance operators).
// by ComputeAdding (for anisotropy by deriving azimuth dependent covariance operators).
// In both cases we need to work around it, so just to test:
float3 H = (L + V) * invLenLV;
// H stays the same so calculate it one time
V = CoatRefract(V, H, preLightData.coatIeta);
L = reflect(-V, H);
NdotL = dot(N,L);
// In both cases we need to work around it.
//
// Using refracted angles for BSDF eval for the base in the case of analytical lights
// must be seen as a hack on top of the ComputeAdding method in which we consider that
// even though the output (energy coefficients) of the method are statistical averages
// over all incoming light directions and so to be used in the context of a split sum
// approximation, the analytical lights have all their energy in a specific ray direction
// and moreover, currently, the output coefficients of the method are formed from straight
// Fresnel terms, and not FGD terms.
//
V[BOTTOM_DIR_IDX] = CoatRefract(V[TOP_DIR_IDX], H, preLightData.coatIeta);
L[BOTTOM_DIR_IDX] = reflect(-V[BOTTOM_DIR_IDX], H);
NdotL[DNLV_BASE_IDX] = dot(N[BASE_NORMAL_IDX], L[BOTTOM_DIR_IDX]);
//LdotV = dot(L, V);
//invLenLV = rsqrt(max(2.0 * LdotV + 2.0, FLT_EPS)); // invLenLV = rcp(length(L + V)), clamp to avoid rsqrt(0) = NaN
//NdotH = saturate((NdotL + dot(N, V)) * invLenLV); // Do not clamp NdotV here
//LdotH = saturate(invLenLV * LdotV + invLenLV);
//NdotV = ClampNdotV(dot(N, V));
CalculateAngles(L, V, NdotL, dot(N, V), LdotV, invLenLV, NdotH, LdotH, NdotV);
float unclampedBaseNdotV = dot(N[BASE_NORMAL_IDX], V[BOTTOM_DIR_IDX]);
NdotV[DNLV_BASE_IDX] = ClampNdotV(unclampedBaseNdotV);
//NdotH[BASE_NORMAL_IDX] = already calculated, see above
#endif // #if VLAYERED_USE_REFRACTED_ANGLES_FOR_BASE
#else //, don't use refracted angles for bottom interface:
#ifdef VLAYERED_RECOMPUTE_PERLIGHT
// TODOWIP
// Must call ComputeAdding and update partLambdaV
ComputeAdding(topLdotH, bsdfData, preLightData, true);
// Notice topLdotH as interface angle, symmetric model parametrization (see sec. 6 and comments
// on ComputeAdding)
// layered*Roughness* and vLayerEnergyCoeff are now updated for the proper light direction.
preLightData.partLambdaV[COAT_LOBE_IDX] = GetSmithJointGGXPartLambdaV(topNdotV, preLightData.layeredCoatRoughness);
#if defined(_MATERIAL_FEATURE_COAT_NORMALMAP)
if ( IsCoatNormalMapEnabled(bsdfData) )
{
// Just to be clean we test the above, but since BASE_NORMAL_IDX should alias COAT_NORMAL_IDX
// if we don't have coat normals and no refracted angle to account, this is already computed
// and the compiler would remove this.
NdotL[DNLV_BASE_IDX] = dot(N[BASE_NORMAL_IDX], L[BOTTOM_DIR_IDX]);
//NdotH[BASE_NORMAL_IDX] = saturate((NdotL[DNLV_BASE_IDX] + unclampedNdotV[BASE_NORMAL_IDX]) * invLenLV); // Do not clamp NdotV here
NdotV[DNLV_BASE_IDX] = ClampNdotV(unclampedNdotV[BASE_NORMAL_IDX]);
}
// p9 eq(39): if we don't recompute per light, we just reuse the IBL energy terms as the fresnel terms
// for our LdotH, too bad (similar to what we do with iridescence), along with the "wrongly" calculated energy.
// Note that in any case, we should have used FGD terms (except for R12 at the start of the process)
// for the analytical light case, see comments at the top of ComputeAdding
#endif // #ifdef VLAYERED_USE_REFRACTED_ANGLES_FOR_BASE
// Finally, we will update the partLambdaV if we did ComputeAdding per light, having the proper
// angles wrt to refraction option and/or dual normal maps and considering anisotropy:
// we just changed V, update those:
preLightData.TdotV = dot(bsdfData.tangentWS, V);
preLightData.BdotV = dot(bsdfData.bitangentWS, V);
// we changed V, update those:
preLightData.TdotV = dot(bsdfData.tangentWS, V[BOTTOM_DIR_IDX]);
preLightData.BdotV = dot(bsdfData.bitangentWS, V[BOTTOM_DIR_IDX]);
preLightData.partLambdaV[BASE_LOBEA_IDX] = GetSmithJointGGXAnisoPartLambdaV(preLightData.TdotV, preLightData.BdotV, NdotV,
// we need to update partLambdaV as we recomputed the layering for this light (these depend on roughness):
preLightData.partLambdaV[COAT_LOBE_IDX] = GetSmithJointGGXPartLambdaV(NdotV[DNLV_COAT_IDX], preLightData.layeredCoatRoughness);
preLightData.partLambdaV[BASE_LOBEA_IDX] = GetSmithJointGGXAnisoPartLambdaV(preLightData.TdotV, preLightData.BdotV, NdotV[DNLV_BASE_IDX],
preLightData.partLambdaV[BASE_LOBEB_IDX] = GetSmithJointGGXAnisoPartLambdaV(preLightData.TdotV, preLightData.BdotV, NdotV,
preLightData.partLambdaV[BASE_LOBEB_IDX] = GetSmithJointGGXAnisoPartLambdaV(preLightData.TdotV, preLightData.BdotV, NdotV[DNLV_BASE_IDX],
} // anisotropy
else
{
#ifdef VLAYERED_RECOMPUTE_PERLIGHT
// we need to update partLambdaV as we recomputed the layering for this light (these depend on roughness):
preLightData.partLambdaV[COAT_LOBE_IDX] = GetSmithJointGGXPartLambdaV(NdotV[DNLV_COAT_IDX], preLightData.layeredCoatRoughness);
preLightData.partLambdaV[BASE_LOBEA_IDX] = GetSmithJointGGXPartLambdaV(NdotV[DNLV_BASE_IDX], preLightData.layeredRoughnessT[0]);
preLightData.partLambdaV[BASE_LOBEB_IDX] = GetSmithJointGGXPartLambdaV(NdotV[DNLV_BASE_IDX], preLightData.layeredRoughnessT[1]);
#endif
} //...no anisotropy
//float3 H = (L + V) * invLenLV;
#endif // _MATERIAL_FEATURE_COAT
}
else
{
// No vlayering, just check if we need H:
if (HasFeatureFlag(bsdfData.materialFeatures, MATERIALFEATUREFLAGS_STACK_LIT_ANISOTROPY))
{
H = (L[0] + V[0]) * invLenLV;
}
}
} //...BSDF_SetupNormalsAndAngles
void CalculateAnisoAngles(BSDFData bsdfData, float3 H, float3 L, float3 V, out float TdotH, out float TdotL, out float BdotH, out float BdotL)
{
// For anisotropy we must not saturate these values
TdotH = dot(bsdfData.tangentWS, H);
TdotL = dot(bsdfData.tangentWS, L);
BdotH = dot(bsdfData.bitangentWS, H);
BdotL = dot(bsdfData.bitangentWS, L);
}
// This function apply BSDF. Assumes that NdotL is positive.
void BSDF(float3 inV, float3 inL, float inNdotL, float3 positionWS, PreLightData preLightData, BSDFData bsdfData,
out float3 diffuseLighting,
out float3 specularLighting)
{
float NdotL[NDOTLV_SIZE];
float NdotV[NDOTLV_SIZE];
// IMPORTANT: use DNLV_COAT_IDX and DNLV_BASE_IDX to index NdotL and NdotV since they can be sized 2
// either if we have to deal with refraction or if we use dual normal maps: NB_LV_DIR is for L or V,
// while NB_NORMALS is for N, but in the cases of NdotL, NdotV, they will be sized
// max(NB_LV_DIR, NB_NORMALS)
float3 L[NB_LV_DIR], V[NB_LV_DIR];
float3 N[NB_NORMALS];
float savedLdotH;
// ...only one needed: when vlayered, only top needed for input to ComputeAdding and even then, only if we recompute per light,
// otherwise, no vlayered and base one is used for a standard Fresnel calculation.
float3 H = (float3)0; // might not be needed if no refracted_angles option and no anisotropy...
float NdotH[NB_NORMALS]; // NdotH[NB_LV_DIR] not needed since it stays the same wrt a refraction along H itself.
float3 DV[TOTAL_NB_LOBES]; // BSDF results per lobe
// Note that we're never missing an initialization for the following as the arrays are sized 1 in the cases
// we use only the "bottom" parts (which are the same as the top: ie in case we have dual normal maps but no
// refracted angles to account for).
L[TOP_DIR_IDX] = inL;
V[TOP_DIR_IDX] = inV;
BSDF_SetupNormalsAndAngles(bsdfData, preLightData, inNdotL, L, V, N, NdotL, H, NdotH, savedLdotH, NdotV);
// TODO: with iridescence, will be optionally per light sample
if( IsVLayeredEnabled(bsdfData) )
{
#ifdef _MATERIAL_FEATURE_COAT
// --------------------------------------------------------------------
// VLAYERING:
// --------------------------------------------------------------------
if (HasFeatureFlag(bsdfData.materialFeatures, MATERIALFEATUREFLAGS_STACK_LIT_ANISOTROPY))
{
CalculateAnisoAngles(bsdfData, L, V, invLenLV, TdotH, TdotL, BdotH, BdotL);
CalculateAnisoAngles(bsdfData, H, L[BOTTOM_DIR_IDX], V[BOTTOM_DIR_IDX], TdotH, TdotL, BdotH, BdotL);
DV[BASE_LOBEA_IDX] = DV_SmithJointGGXAniso(TdotH, BdotH, NdotH, NdotV, TdotL, BdotL, NdotL,
DV[BASE_LOBEA_IDX] = DV_SmithJointGGXAniso(TdotH, BdotH, NdotH[BASE_NORMAL_IDX], NdotV[DNLV_BASE_IDX], TdotL, BdotL, NdotL[DNLV_BASE_IDX],
DV[BASE_LOBEB_IDX] = DV_SmithJointGGXAniso(TdotH, BdotH, NdotH, NdotV, TdotL, BdotL, NdotL,
DV[BASE_LOBEB_IDX] = DV_SmithJointGGXAniso(TdotH, BdotH, NdotH[BASE_NORMAL_IDX], NdotV[DNLV_BASE_IDX], TdotL, BdotL, NdotL[DNLV_BASE_IDX],
DV[COAT_LOBE_IDX] = DV_SmithJointGGX(topNdotH, topNdotL, topNdotV, preLightData.layeredCoatRoughness, preLightData.partLambdaV[COAT_LOBE_IDX]);
DV[COAT_LOBE_IDX] = DV_SmithJointGGX(NdotH[COAT_NORMAL_IDX], NdotL[DNLV_COAT_IDX], NdotV[DNLV_COAT_IDX], preLightData.layeredCoatRoughness, preLightData.partLambdaV[COAT_LOBE_IDX]);
#ifdef VLAYERED_RECOMPUTE_PERLIGHT
preLightData.partLambdaV[BASE_LOBEA_IDX] = GetSmithJointGGXPartLambdaV(NdotV, preLightData.layeredRoughnessT[0]);
preLightData.partLambdaV[BASE_LOBEB_IDX] = GetSmithJointGGXPartLambdaV(NdotV, preLightData.layeredRoughnessT[1]);
#endif
DV[COAT_LOBE_IDX] = DV_SmithJointGGX(topNdotH, topNdotL, topNdotV, preLightData.layeredCoatRoughness, preLightData.partLambdaV[COAT_LOBE_IDX]);
DV[BASE_LOBEA_IDX] = DV_SmithJointGGX(NdotH, NdotL, NdotV, preLightData.layeredRoughnessT[0], preLightData.partLambdaV[BASE_LOBEA_IDX]);
DV[BASE_LOBEB_IDX] = DV_SmithJointGGX(NdotH, NdotL, NdotV, preLightData.layeredRoughnessT[1], preLightData.partLambdaV[BASE_LOBEB_IDX]);
DV[COAT_LOBE_IDX] = DV_SmithJointGGX(NdotH[COAT_NORMAL_IDX], NdotL[DNLV_COAT_IDX], NdotV[DNLV_COAT_IDX], preLightData.layeredCoatRoughness, preLightData.partLambdaV[COAT_LOBE_IDX]);
DV[BASE_LOBEA_IDX] = DV_SmithJointGGX(NdotH[BASE_NORMAL_IDX], NdotL[DNLV_BASE_IDX], NdotV[DNLV_BASE_IDX],
preLightData.layeredRoughnessT[0], preLightData.partLambdaV[BASE_LOBEA_IDX]);
DV[BASE_LOBEB_IDX] = DV_SmithJointGGX(NdotH[BASE_NORMAL_IDX], NdotL[DNLV_BASE_IDX], NdotV[DNLV_BASE_IDX],
preLightData.layeredRoughnessT[1], preLightData.partLambdaV[BASE_LOBEB_IDX]);
IF_DEBUG( if(_DebugLobeMask.x == 0.0) DV[COAT_LOBE_IDX] = (float3)0; )
IF_DEBUG( if(_DebugLobeMask.y == 0.0) DV[BASE_LOBEA_IDX] = (float3)0; )
IF_DEBUG( if(_DebugLobeMask.z == 0.0) DV[BASE_LOBEB_IDX] = (float3)0; )
specularLighting = preLightData.vLayerEnergyCoeff[BOTTOM_VLAYER_IDX]
* lerp(DV[BASE_LOBEA_IDX] * preLightData.energyCompensationFactor[BASE_LOBEA_IDX],
// --------------------------------------------------------------------
// NO VLAYERING:
// --------------------------------------------------------------------
// TODO: Proper Fresnel
float3 F = F_Schlick(bsdfData.fresnel0, savedLdotH);
float3 H = (L + V) * invLenLV;
CalculateAnisoAngles(bsdfData, L, V, invLenLV, TdotH, TdotL, BdotH, BdotL);
DV[0] = DV_SmithJointGGXAniso(TdotH, BdotH, NdotH, NdotV, TdotL, BdotL, NdotL,
CalculateAnisoAngles(bsdfData, H, L[0], V[0], TdotH, TdotL, BdotH, BdotL);
DV[0] = DV_SmithJointGGXAniso(TdotH, BdotH, NdotH[0], NdotV[0], TdotL, BdotL, NdotL[0],
DV[1] = DV_SmithJointGGXAniso(TdotH, BdotH, NdotH, NdotV, TdotL, BdotL, NdotL,
DV[1] = DV_SmithJointGGXAniso(TdotH, BdotH, NdotH[0], NdotV[0], TdotL, BdotL, NdotL[0],
DV[0] = DV_SmithJointGGX(NdotH, NdotL, NdotV, bsdfData.roughnessAT, preLightData.partLambdaV[0]);
DV[1] = DV_SmithJointGGX(NdotH, NdotL, NdotV, bsdfData.roughnessBT, preLightData.partLambdaV[1]);
DV[0] = DV_SmithJointGGX(NdotH[0], NdotL[0], NdotV[0], bsdfData.roughnessAT, preLightData.partLambdaV[0]);
DV[1] = DV_SmithJointGGX(NdotH[0], NdotL[0], NdotV[0], bsdfData.roughnessBT, preLightData.partLambdaV[1]);
IF_DEBUG( if(_DebugLobeMask.y == 0.0) DV[BASE_LOBEA_IDX] = (float3)0; )
IF_DEBUG( if(_DebugLobeMask.z == 0.0) DV[BASE_LOBEB_IDX] = (float3)0; )
specularLighting = F * lerp(DV[0]*preLightData.energyCompensationFactor[BASE_LOBEA_IDX],
DV[1]*preLightData.energyCompensationFactor[BASE_LOBEB_IDX],
bsdfData.lobeMix);
}//...BSDF
float3 EvaluateTransmission(BSDFData bsdfData, float3 transmittance, float NdotL, float NdotV, float LdotV, float attenuation)
{
// Apply wrapped lighting to better handle thin objects at grazing angles.
return intensity * transmittance;
}
void EvaluateBSDF_GetNormalUnclampedNdotV(BSDFData bsdfData, PreLightData preLightData, float3 V, out float3 N, out float unclampedNdotV)
{
#ifdef _MATERIAL_FEATURE_COAT_NORMALMAP
//TODOWIP for now just return geometric normal:
if ( IsCoatNormalMapEnabled(bsdfData) )
{
N = bsdfData.geomNormalWS;
unclampedNdotV = dot(N, V);
}
else
#endif
{
// TODOWIP, for now, preserve previous behavior
N = bsdfData.normalWS;
unclampedNdotV = preLightData.NdotV[BASE_NORMAL_IDX];
}
}
//-----------------------------------------------------------------------------
// EvaluateBSDF_Directional
//-----------------------------------------------------------------------------
DirectLighting lighting;
ZERO_INITIALIZE(DirectLighting, lighting);
float3 N = bsdfData.normalWS;
//slnote dual map
float3 N; float unclampedNdotV;
EvaluateBSDF_GetNormalUnclampedNdotV(bsdfData, preLightData, V, N, unclampedNdotV);
//float3 N = bsdfData.normalWS;
float NdotV = ClampNdotV(preLightData.NdotV);
//float NdotV = ClampNdotV(preLightData.NdotV);
float NdotV = ClampNdotV(unclampedNdotV);
float NdotL = dot(N, L);
float LdotV = dot(L, V);
distances.xyz = float3(dist, distSq, distRcp);
}
float3 N = bsdfData.normalWS;
float NdotV = ClampNdotV(preLightData.NdotV);
//slnote dual map
float3 N; float unclampedNdotV;
EvaluateBSDF_GetNormalUnclampedNdotV(bsdfData, preLightData, V, N, unclampedNdotV);
//float3 N = bsdfData.normalWS;
//float NdotV = ClampNdotV(preLightData.NdotV);
float NdotV = ClampNdotV(unclampedNdotV);
float NdotL = dot(N, L);
float LdotV = dot(L, V);
// Since the weights are influence blending weights, we can correctly
// use our lobe weight and mix them.
// -Fudge the sampling direction to dampen boundary artefacts.
// -Do early discard for planar reflections.
// -Fetch samples of preintegrated environment lighting
// (see preLD, first part of the split-sum approx.)
// -Use the BSDF preintegration terms we pre-fetched in preLightData
// Note: using influenceShapeType and projectionShapeType instead of (lightData|proxyData).shapeType allow to make compiler optimization in case the type is know (like for sky)
//slnote dual map
float3 influenceNormal; float unclampedNdotV;
EvaluateBSDF_GetNormalUnclampedNdotV(bsdfData, preLightData, V, influenceNormal, unclampedNdotV);
IF_FEATURE_COAT( if( (i == 0) && _DebugLobeMask.x == 0.0) continue; )
if( (i == (0 IF_FEATURE_COAT(+1))) && _DebugLobeMask.y == 0.0) continue;
if( (i == (1 IF_FEATURE_COAT(+1))) && _DebugLobeMask.z == 0.0) continue;
IF_FEATURE_COAT( if( (i == 0) && _DebugEnvLobeMask.x == 0.0) continue; )
if( (i == (0 IF_FEATURE_COAT(+1))) && _DebugEnvLobeMask.y == 0.0) continue;
if( (i == (1 IF_FEATURE_COAT(+1))) && _DebugEnvLobeMask.z == 0.0) continue;
EvaluateLight_EnvIntersection(positionWS, bsdfData.normalWS, lightData, influenceShapeType, R[i], tempWeight[i]);
//slnote dual map
//EvaluateLight_EnvIntersection(positionWS, bsdfData.normalWS, lightData, influenceShapeType, R[i], tempWeight[i]);
EvaluateLight_EnvIntersection(positionWS, influenceNormal, lightData, influenceShapeType, R[i], tempWeight[i]);
// When we are rough, we tend to see outward shifting of the reflection when at the boundary of the projection volume
// Also it appear like more sharp. To avoid these artifact and at the same time get better match to reference we lerp to original unmodified reflection.
{
float3 bakeDiffuseLighting = bakeLightingData.bakeDiffuseLighting;
float3 N; float unclampedNdotV;
EvaluateBSDF_GetNormalUnclampedNdotV(bsdfData, preLightData, V, N, unclampedNdotV);
GetScreenSpaceAmbientOcclusionMultibounce(posInput.positionSS, preLightData.NdotV, lerp(bsdfData.perceptualRoughnessA, bsdfData.perceptualRoughnessB, bsdfData.lobeMix), bsdfData.ambientOcclusion, 1.0, bsdfData.diffuseColor, bsdfData.fresnel0, aoFactor);
//GetScreenSpaceAmbientOcclusionMultibounce(posInput.positionSS, preLightData.NdotV, lerp(bsdfData.perceptualRoughnessA, bsdfData.perceptualRoughnessB, bsdfData.lobeMix), bsdfData.ambientOcclusion, 1.0, bsdfData.diffuseColor, bsdfData.fresnel0, aoFactor);
GetScreenSpaceAmbientOcclusionMultibounce(posInput.positionSS, unclampedNdotV, lerp(bsdfData.perceptualRoughnessA, bsdfData.perceptualRoughnessB, bsdfData.lobeMix), bsdfData.ambientOcclusion, 1.0, bsdfData.diffuseColor, bsdfData.fresnel0, aoFactor);
// Add indirect diffuse + emissive (if any) - Ambient occlusion is multiply by emissive which is wrong but not a big deal
bakeDiffuseLighting *= aoFactor.indirectAmbientOcclusion;
Evgenii Golubev
7 年前
