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- MSM_Substrate - MCT_Substrate - FStrataMaterialInput #rb charles.derousiers [CL 27563163 by marc audy in ue5-main branch]
51 lines
1.8 KiB
Plaintext
51 lines
1.8 KiB
Plaintext
// Copyright Epic Games, Inc. All Rights Reserved.
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#pragma once
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#ifndef SUBSTRATE_ENABLED
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#error "This header should only be included when Substrate is enabled."
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#endif
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#include "../PathTracingCommon.ush"
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#define SUBSTRATE_FRESNEL_F82 0
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#define SUBSTRATE_PATH_TRACING_GLINTS (SUBSTRATE_COMPLEXSPECIALPATH && PLATFORM_ENABLES_SUBSTRATE_GLINTS)
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#if SUBSTRATE_PATH_TRACING_GLINTS
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#include "/Engine/Private/Substrate/Glint/GlintThirdParty.ush"
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#endif
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float3 SubstrateLobeWeight(FPathTracingPayload Payload, float SatNoL)
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{
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// See reference in LuminanceWeight
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const float DistanceL = rcp(max(SatNoL, 0.001f));
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const float3 TransmittanceAboveAlongL = select(Payload.TransmittanceN < 1.f, pow(max(Payload.TransmittanceN, 0.0001f), DistanceL), Payload.TransmittanceN);
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return Payload.BSDFOpacity * Payload.WeightV * lerp(1.0f, TransmittanceAboveAlongL, Payload.CoverageAboveAlongN);
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}
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float3 SubstrateSpecularTint(FPathTracingPayload Payload, float NoV, float NoL, float VoH, float NoH)
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{
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float3 Out = 1.f;
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BRANCH
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if (Payload.SpecularProfileId != 0)
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{
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Out = EvaluateSpecularProfile(Payload.SpecularProfileId, NoV, NoL, VoH, NoH);
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}
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return Out;
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}
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void SubstrateGlint(FPathTracingPayload Payload, float3 InTangentV, float3 InTangentL, float2 InAlphaXY, in float InPdf, inout float OutWeight)
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{
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// For now use the GGX lobe sampling. This will be changed with glint importance sampling later on.
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#if SUBSTRATE_PATH_TRACING_GLINTS
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BRANCH
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if (Payload.GlintValue > 0)
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{
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const float2 GGXRoughnessXY = float2(sqrtFast(InAlphaXY.x), sqrtFast(InAlphaXY.y));
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FBeckmannDesc Beckmann = GGXToBeckmann(GGXRoughnessXY);
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const float Fs = f_P(InTangentV, InTangentL, float3(Beckmann.Sigma, Beckmann.Rho), Payload.GlintValue, Payload.GlintUV, Payload.GlintUVdx, Payload.GlintUVdy, true /*bIncludeGeometryTerm*/);
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OutWeight = Fs / max(0.0001f, InPdf);
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}
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#endif
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} |