feat: vanilla fresnel

features/Grass Lighting/Shaders/Features/GrassLighting.ini

@@ -1,2 +1,2 @@
 [Info]
-Version = 2-0-3
+Version = 2-1-0

features/Grass Lighting/Shaders/GrassLighting/GrassLighting.hlsli

@@ -1,10 +1,27 @@
+#include "Common/BRDF.hlsli"
+#include "Common/Color.hlsli"
+
 namespace GrassLighting
 {
-	float3 GetLightSpecularInput(float3 L, float3 V, float3 N, float3 lightColor, float shininess)
+	float3 GetLightSpecularInput(float3 L, float3 V, float3 N, float3 lightColor, float roughness, float3 F0)
 	{
 		float3 H = normalize(V + L);
-		float HdotN = saturate(dot(H, N));
+#if defined(VANILLA_FRESNEL)
+		if (SharedData::vanillaFresnelSettings.Enable && SharedData::vanillaFresnelSettings.EnableGGXOnGrass) {
+			float NdotL = saturate(dot(N, L));
+			float NdotV = saturate(dot(N, V));
+			float NdotH = saturate(dot(N, H));
+			float VdotH = saturate(dot(V, H));
 
+			float D = BRDF::D_GGX(roughness, NdotH);
+			float G = BRDF::Vis_SmithJointApprox(roughness, NdotL, NdotV);
+			float3 F = BRDF::F_Schlick(F0, VdotH);
+			float3 specular = D * G * F;
+			return specular * lightColor * NdotL * Color::PBRLightingCompensation;
+		}
+#endif
+		float shininess = (1.0 - roughness) * 100.f;
+		float HdotN = saturate(dot(H, N));
 		float lightColorMultiplier = exp2(shininess * log2(HdotN));
 		return lightColor * lightColorMultiplier.xxx;
 	}

features/Vanilla Fresnel/Shaders/Features/VanillaFresnel.ini

@@ -0,0 +1,2 @@
+[Info]
+Version = 1-0-0

package/Shaders/Common/LightingEval.hlsli

@@ -95,6 +95,25 @@ float3 VanillaSpecular(DirectContext context, float shininess, float2 uv, float2
 	return lightColorMultiplier;
 }
 
+float3 MicrofacetSpecular(DirectContext context, float3 F0, float roughness)
+{
+	const float3 N = context.worldNormal;
+	const float3 V = context.viewDir;
+	const float3 L = context.lightDir;
+	const float3 H = context.halfVector;
+
+	float NdotL = clamp(dot(N, L), EPSILON_DOT_CLAMP, 1);
+	float NdotV = saturate(abs(dot(N, V)) + EPSILON_DOT_CLAMP);
+	float NdotH = saturate(dot(N, H));
+	float VdotH = saturate(dot(V, H));
+
+	float D = BRDF::D_GGX(roughness, NdotH);
+	float G = BRDF::Vis_SmithJointApprox(roughness, NdotV, NdotL);
+	float3 F = BRDF::F_Schlick(F0, VdotH);
+
+	return D * G * F * NdotL;
+}
+
 void EvaluateLighting(DirectContext context, MaterialProperties material, float3x3 tbnTr, float2 uv, float2 uv_ddx, float2 uv_ddy, out DirectLightingOutput lightingOutput)
 {
 	lightingOutput = (DirectLightingOutput)0;
@@ -145,6 +164,17 @@ void EvaluateLighting(DirectContext context, MaterialProperties material, float3
 #	if defined(BACK_LIGHTING)
 	lightingOutput.diffuse += softLightColor * saturate(-NdotL) * material.backLightColor * Color::VanillaNormalization();
 #	endif
+
+#	if defined(VANILLA_FRESNEL)
+	if (SharedData::vanillaFresnelSettings.Enable && SharedData::vanillaFresnelSettings.EnableGGX) {
+		lightingOutput.specular = diffuseLightColor * MicrofacetSpecular(context, material.F0, material.Roughness) * Color::PBRLightingCompensation * Color::PBRLightingScale;
+
+		float2 specularBRDF = BRDF::EnvBRDF(material.Roughness, saturate(dot(context.worldNormal, context.viewDir)));
+		lightingOutput.specular *= 1 + material.F0 * (1 / (specularBRDF.x + specularBRDF.y) - 1);
+		return;
+	}
+#	endif
+
 	lightingOutput.specular = VanillaSpecular(context, material.Shininess, uv, uv_ddx, uv_ddy) * material.SpecularColor * material.Glossiness * diffuseLightColor * Color::VanillaNormalization();
 #endif
 }

package/Shaders/Common/Permutation.hlsli

@@ -75,6 +75,7 @@ namespace Permutation
 		static const uint GrassSphereNormal = (1 << 3);
 		static const uint IsSun = (1 << 4);
 		static const uint SuppressExternalEmittance = (1 << 5);
+		static const uint IsEye = (1 << 6);
 	}
 
 	namespace ExtraFeatureFlags

package/Shaders/Common/SharedData.hlsli

@@ -310,6 +310,22 @@ namespace SharedData
 		float4 wetParams;
 	};
 
+	struct VanillaFresnelSettings
+	{
+		uint Enable;
+		uint EnableGGX;
+		uint EnableGGXOnGrass;
+		uint EnableDynamicCubemapsConversion;
+		uint EnableEyeSpecialHandling;
+		float RoughnessMultiplier;
+		float SpecularRoughnessBlend;
+		float BaseF0Multiplier;
+		float MinF0;
+		float CubemapToF0Multiplier;
+		float ComplexMaterialF0Multiplier;
+		float pad;
+	};
+
 	cbuffer FeatureData : register(b6)
 	{
 		GrassLightingSettings grassLightingSettings;
@@ -330,6 +346,7 @@ namespace SharedData
 		ExponentialHeightFogSettings exponentialHeightFogSettings;
 		TruePBRSettings truePBRSettings;
 		SkinData skinData;
+		VanillaFresnelSettings vanillaFresnelSettings;
 	};
 
 	Texture2D<float4> DepthTexture : register(t17);

package/Shaders/Lighting.hlsl

@@ -1870,6 +1870,9 @@ PS_OUTPUT main(PS_INPUT input, bool frontFace : SV_IsFrontFace)
 	shininess = lerp(shininess, shininess * complexMaterialColor.y, complexMaterial);
 	if (complexMaterial) {
 		complexSpecular = lerp(1.0, baseColor.xyz, complexMaterialColor.z);
+#		if defined(VANILLA_FRESNEL)
+		complexSpecular = saturate(complexSpecular * (SharedData::vanillaFresnelSettings.Enable ? SharedData::vanillaFresnelSettings.ComplexMaterialF0Multiplier : 1.0));
+#		endif
 		baseColor.xyz = lerp(baseColor.xyz, 0.0, complexMaterialColor.z);
 	}
 #	endif  // defined (EMAT) && defined(ENVMAP)
@@ -2120,7 +2123,7 @@ PS_OUTPUT main(PS_INPUT input, bool frontFace : SV_IsFrontFace)
 #			endif  // SPECULAR
 #		endif      // SPARKLE
 
-#	endif      // SNOW
+#	endif  // SNOW
 
 #	if defined(WORLD_MAP)
 	baseColor.xyz = GetWorldMapBaseColor(rawBaseColor.xyz, baseColor.xyz, projWeight);
@@ -2277,7 +2280,27 @@ PS_OUTPUT main(PS_INPUT input, bool frontFace : SV_IsFrontFace)
 #		if defined(BACK_LIGHTING)
 	material.backLightColor = backLightColor.xyz;
 #		endif
-#	endif  // TRUE_PBR
+
+#		if defined(VANILLA_FRESNEL)
+	const bool enableVanillaFresnel = SharedData::vanillaFresnelSettings.Enable;
+	const bool isEyeMaterial = (Permutation::ExtraShaderDescriptor & Permutation::ExtraFlags::IsEye) != 0;
+	material.F0 = enableVanillaFresnel ? SharedData::vanillaFresnelSettings.MinF0 : 0.0;
+#			if defined(SPECULAR)
+	if (enableVanillaFresnel && !isEyeMaterial) {
+		material.F0 = saturate(glossiness * SpecularColor.xyz / Math::PI);
+		float roughnessFromSpecular = (1.0 - glossiness) * (1.0 - glossiness);
+		float roughnessFromShininess = ShininessToRoughness(material.Shininess);
+		material.Roughness = lerp(roughnessFromShininess, roughnessFromSpecular, SharedData::vanillaFresnelSettings.SpecularRoughnessBlend * (1.0 - glossiness));
+	}
+#			endif
+	if (enableVanillaFresnel && isEyeMaterial && SharedData::vanillaFresnelSettings.EnableEyeSpecialHandling) {
+		material.F0 = 0.027;
+		material.Roughness = 0.1;
+	}
+	material.F0 = max((enableVanillaFresnel ? SharedData::vanillaFresnelSettings.MinF0 : 0.0), material.F0 * SharedData::vanillaFresnelSettings.BaseF0Multiplier);
+	const float3 baseF0 = material.F0;
+#		endif  // VANILLA_FRESNEL
+#	endif      // TRUE_PBR
 
 #	if defined(SKIN) && defined(CS_SKIN)
 	const float ExtraRoughness = BRDF::F_Schlick(0.04, saturate(dot(worldNormal.xyz, viewDirection))) * SharedData::skinData.fuzzParams.w;
@@ -2346,10 +2369,16 @@ PS_OUTPUT main(PS_INPUT input, bool frontFace : SV_IsFrontFace)
 		uint2 envSize;
 		TexEnvSampler.GetDimensions(envSize.x, envSize.y);
 
-#			if defined(EMAT)
+#			if defined(EMAT) && !defined(VANILLA_FRESNEL)
 		if (envSize.x == 1 && envSize.y == 1 || complexMaterial) {
+#			elif defined(VANILLA_FRESNEL)
+		bool vfStartDynamicCubemapTest = (enableVanillaFresnel && SharedData::vanillaFresnelSettings.EnableDynamicCubemapsConversion);
+#				if defined(EMAT)
+		vfStartDynamicCubemapTest = complexMaterial || vfStartDynamicCubemapTest;
+#				endif
+		if (vfStartDynamicCubemapTest || (envSize.x == 1 && envSize.y == 1)) {
 #			else
-		if (envSize.x == 1 && envSize.y == 1) {
+	if (envSize.x == 1 && envSize.y == 1) {
 #			endif
 
 			dynamicCubemap = true;
@@ -2369,15 +2398,26 @@ PS_OUTPUT main(PS_INPUT input, bool frontFace : SV_IsFrontFace)
 			}
 #			endif
 
+#			if defined(VANILLA_FRESNEL)
+			dynamicCubemap = dynamicCubemap || (SharedData::vanillaFresnelSettings.EnableDynamicCubemapsConversion && enableVanillaFresnel);
+			const float originRoughness = material.Roughness;
+#			endif
+
 			if (dynamicCubemap) {
 				float4 envColorBase = TexEnvSampler.SampleLevel(SampEnvSampler, float3(1.0, 0.0, 0.0), 15);
+				bool usingDynamicCubemap = envColorBase.a < 1.0;
 
-				if (envColorBase.a < 1.0) {
+				if (usingDynamicCubemap) {
 					material.F0 = Color::SkyrimGammaToLinear(envColorBase.rgb);
 					material.Roughness = envColorBase.a;
 				} else {
+#			if defined(VANILLA_FRESNEL)
+					material.F0 = saturate(Color::SkyrimGammaToLinear(envColorBase.rgb) * Math::PI * SharedData::vanillaFresnelSettings.CubemapToF0Multiplier);
+					material.Roughness = material.Roughness;
+#			else
 					material.F0 = 1.0;
 					material.Roughness = 1.0 / 7.0;
+#			endif
 				}
 
 #			if defined(CREATOR)
@@ -2392,10 +2432,42 @@ PS_OUTPUT main(PS_INPUT input, bool frontFace : SV_IsFrontFace)
 				material.Roughness = lerp(material.Roughness, complexMaterialRoughness, complexMaterial);
 				material.F0 = lerp(material.F0, complexSpecular, complexMaterial);
 #			endif
+
+				envMask = saturate(envMask);
+#			if defined(VANILLA_FRESNEL)
+				if (enableVanillaFresnel) {
+#				if defined(SPECULAR)
+					material.F0 = max(lerp(baseF0, material.F0, envMask), SharedData::vanillaFresnelSettings.MinF0);
+#				else
+					material.F0 = max(lerp(0, material.F0, envMask), SharedData::vanillaFresnelSettings.MinF0);
+#				endif
+#				if defined(EMAT)
+					if (!complexMaterial) {
+#				endif
+						material.Roughness = lerp(originRoughness, material.Roughness, envMask);
+						if (!isEyeMaterial && !usingDynamicCubemap) {
+							material.F0 = saturate(material.F0 + envMask * material.BaseColor);
+							material.BaseColor = lerp(material.BaseColor, 0, envMask);
+						}
+#				if defined(EMAT)
+					}
+#				endif
+				}
+#			endif
 			}
 		}
 #		endif
 
+#		if defined(VANILLA_FRESNEL) && !defined(TRUE_PBR)
+		if (enableVanillaFresnel) {
+			if (isEyeMaterial && SharedData::vanillaFresnelSettings.EnableEyeSpecialHandling) {
+				material.F0 = 0.027;
+				material.Roughness = 0.1;
+			}
+			material.Roughness = clamp(material.Roughness * SharedData::vanillaFresnelSettings.RoughnessMultiplier, 0.04, 1.0);
+		}
+#		endif
+
 		if (!dynamicCubemap) {
 			float3 envColorBase = Color::SkyrimGammaToLinear(TexEnvSampler.Sample(SampEnvSampler, envSamplingPoint).xyz);
 			envColor = envColorBase.xyz * envMask;
@@ -3029,7 +3101,10 @@ PS_OUTPUT main(PS_INPUT input, bool frontFace : SV_IsFrontFace)
 #		endif
 #	endif
 #	if defined(ENVMAP) || defined(MULTI_LAYER_PARALLAX) || defined(EYE)
-	indirectLobeWeights.specular *= envMask;
+#		if defined(VANILLA_FRESNEL)
+	if (!enableVanillaFresnel)
+#		endif
+		indirectLobeWeights.specular *= envMask;
 #	endif
 
 #	if defined(SPECULAR) && !defined(TRUE_PBR)
@@ -3093,12 +3168,18 @@ PS_OUTPUT main(PS_INPUT input, bool frontFace : SV_IsFrontFace)
 #		if defined(DYNAMIC_CUBEMAPS)
 	if (!dynamicCubemap)
 #		endif
-		specularColor += envColor * Color::IrradianceToLinear(diffuseColor);
+#		if defined(VANILLA_FRESNEL)
+		if (!(enableVanillaFresnel && SharedData::vanillaFresnelSettings.EnableDynamicCubemapsConversion))
+#		endif
+			specularColor += envColor * Color::IrradianceToLinear(diffuseColor);
 	indirectLobeWeights.diffuse += envColor;
 #	endif
 
 #	if defined(EMAT_ENVMAP)
-	specularColor *= complexSpecular;
+#		if defined(VANILLA_FRESNEL)
+	if (!(enableVanillaFresnel && SharedData::vanillaFresnelSettings.EnableGGX))
+#		endif
+		specularColor *= complexSpecular;
 #	endif  // defined (EMAT) && defined(ENVMAP)
 
 #	if defined(LOD_LAND_BLEND) && defined(TRUE_PBR)

package/Shaders/RunGrass.hlsl

@@ -279,12 +279,10 @@ struct PS_OUTPUT
 	float4 NormalGlossiness: SV_Target2;
 	float4 Albedo: SV_Target3;
 	float4 Specular: SV_Target4;
-#		if defined(TRUE_PBR)
 	float4 Reflectance: SV_Target5;
-#		endif  // TRUE_PBR
 	float4 Masks: SV_Target6;
 	float4 Masks2: SV_Target7;
-#	endif      // RENDER_DEPTH
+#	endif  // RENDER_DEPTH
 };
 #else
 struct PS_OUTPUT
@@ -476,6 +474,14 @@ PS_OUTPUT main(PS_INPUT input, bool frontFace : SV_IsFrontFace)
 		baseColor.xyz *= SharedData::grassLightingSettings.BasicGrassBrightness;
 #			endif  // !TRUE_PBR
 
+#			if defined(VANILLA_FRESNEL)
+	const bool enableVanillaFresnel = SharedData::vanillaFresnelSettings.Enable;
+	float3 F0 = enableVanillaFresnel ? max(SharedData::vanillaFresnelSettings.MinF0, saturate(specColor.w * SharedData::grassLightingSettings.SpecularStrength * SharedData::vanillaFresnelSettings.BaseF0Multiplier / Math::PI)) : 0.0;
+#			else
+	float3 F0 = 0.0;
+#			endif
+	float roughness = saturate(1.0 - SharedData::grassLightingSettings.Glossiness * 0.01);
+
 #			if defined(TRUE_PBR)
 	float4 rawRMAOS = TexRMAOSSampler.SampleBias(SampRMAOSSampler, input.TexCoord.xy, SharedData::MipBias) * float4(PBRParams1.x, 1, 1, PBRParams1.y);
 
@@ -567,7 +573,7 @@ PS_OUTPUT main(PS_INPUT input, bool frontFace : SV_IsFrontFace)
 	float3 subsurfaceColor = dirLightColor * dirDetailedShadow * (GetSoftLightMultiplier(dirLightAngle, softLightRolloff)) * Color::VanillaNormalization();
 
 	if (complex)
-		lightsSpecularColor += dirDetailedShadow * GrassLighting::GetLightSpecularInput(SharedData::DirLightDirection.xyz, viewDirection, normal, dirLightColor, SharedData::grassLightingSettings.Glossiness) * Color::VanillaNormalization();
+		lightsSpecularColor += dirDetailedShadow * GrassLighting::GetLightSpecularInput(SharedData::DirLightDirection.xyz, viewDirection, normal, dirLightColor, roughness, F0) * Color::VanillaNormalization();
 #			endif
 
 #			if defined(LIGHT_LIMIT_FIX)
@@ -633,7 +639,7 @@ PS_OUTPUT main(PS_INPUT input, bool frontFace : SV_IsFrontFace)
 				lightsDiffuseColor += lightDiffuseColor * Color::VanillaNormalization();
 
 				if (complex)
-					lightsSpecularColor += GrassLighting::GetLightSpecularInput(normalizedLightDirection, viewDirection, normal, lightColor, SharedData::grassLightingSettings.Glossiness) * Color::VanillaNormalization();
+					lightsSpecularColor += GrassLighting::GetLightSpecularInput(normalizedLightDirection, viewDirection, normal, lightColor, roughness, F0) * Color::VanillaNormalization();
 #				endif
 			}
 		}
@@ -680,7 +686,10 @@ PS_OUTPUT main(PS_INPUT input, bool frontFace : SV_IsFrontFace)
 #				endif
 
 	specularColor += lightsSpecularColor;
-	specularColor *= specColor.w * SharedData::grassLightingSettings.SpecularStrength;
+#				if defined(VANILLA_FRESNEL)
+	if (!(SharedData::vanillaFresnelSettings.Enable && SharedData::vanillaFresnelSettings.EnableGGXOnGrass))
+#				endif
+		specularColor *= specColor.w * SharedData::grassLightingSettings.SpecularStrength;
 #			endif
 
 #			if defined(LIGHT_LIMIT_FIX) && defined(LLFDEBUG)
@@ -705,8 +714,22 @@ PS_OUTPUT main(PS_INPUT input, bool frontFace : SV_IsFrontFace)
 	psout.NormalGlossiness = float4(GBuffer::EncodeNormal(normalVS), 1 - pbrSurfaceProperties.Roughness, 1);
 	psout.Reflectance = float4(indirectSpecularLobeWeight, 1);
 #			else
+
+	float3 reflectance = 0;
+#				if defined(DYNAMIC_CUBEMAPS) && (defined(VANILLA_FRESNEL) || defined(TRUE_PBR))
+#					if defined(VANILLA_FRESNEL)
+	if (SharedData::vanillaFresnelSettings.Enable) {
+#					endif
+		float2 specularBDRF = BRDF::EnvBRDF(roughness, saturate(dot(viewDirection, normal)));
+		reflectance = F0 * specularBDRF.x + specularBDRF.y;
+#					if defined(VANILLA_FRESNEL)
+	}
+#					endif
+#				endif
+
+	psout.Reflectance = float4(reflectance, 1);
 	psout.Albedo = float4(albedo, 1);
-	psout.NormalGlossiness = float4(GBuffer::EncodeNormal(normalVS), specColor.w, 1);
+	psout.NormalGlossiness = float4(GBuffer::EncodeNormal(normalVS), 1.0 - roughness, 1);
 #			endif
 
 	psout.Specular = float4(specularColor, 1);

src/Feature.cpp

@@ -33,6 +33,7 @@
 #include "Features/TerrainVariation.h"
 #include "Features/UnifiedWater.h"
 #include "Features/Upscaling.h"
+#include "Features/VanillaFresnel.h"
 #include "Features/VolumetricLighting.h"
 #include "Features/VolumetricShadows.h"
 #include "Features/WaterEffects.h"
@@ -231,6 +232,7 @@ const std::vector<Feature*>& Feature::GetFeatureList()
 		&globals::features::skySync,
 		&globals::features::terrainBlending,
 		&globals::features::terrainHelper,
+		&globals::features::vanillaFresnel,
 		&globals::features::volumetricLighting,
 		&globals::features::lodBlending,
 		&globals::features::inverseSquareLighting,