cache.isValid func, schlick fresnel reorient

Author: keptsecret

include/nbl/builtin/hlsl/bxdf/base/cook_torrance_base.hlsl

@@ -87,7 +87,7 @@ struct check_TIR_helper<F, true>
     template<class MicrofacetCache>
     static bool __call(NBL_CONST_REF_ARG(F) fresnel, NBL_CONST_REF_ARG(MicrofacetCache) cache)
     {
-        return ComputeMicrofacetNormal<typename F::scalar_type>::isValidMicrofacet(cache.isTransmission(), cache.getVdotL(), cache.getAbsNdotH(), fresnel.getRefractionOrientedEta());
+        return cache.isValid(fresnel.getRefractionOrientedEta());
     }
 };
 

include/nbl/builtin/hlsl/bxdf/common.hlsl

@@ -468,8 +468,10 @@ struct SLightSample
 #define NBL_CONCEPT_TPLT_PRM_KINDS (typename)
 #define NBL_CONCEPT_TPLT_PRM_NAMES (T)
 #define NBL_CONCEPT_PARAM_0 (cache, T)
-NBL_CONCEPT_BEGIN(1)
+#define NBL_CONCEPT_PARAM_1 (eta, fresnel::OrientedEtas<vector<typename T::scalar_type,1> >)
+NBL_CONCEPT_BEGIN(2)
 #define cache NBL_CONCEPT_PARAM_T NBL_CONCEPT_PARAM_0
+#define eta NBL_CONCEPT_PARAM_T NBL_CONCEPT_PARAM_1
 NBL_CONCEPT_END(
     ((NBL_CONCEPT_REQ_TYPE)(T::scalar_type))
     ((NBL_CONCEPT_REQ_TYPE)(T::vector3_type))
@@ -480,7 +482,9 @@ NBL_CONCEPT_END(
     ((NBL_CONCEPT_REQ_EXPR_RET_TYPE)((cache.getAbsNdotH()), ::nbl::hlsl::is_same_v, typename T::scalar_type))
     ((NBL_CONCEPT_REQ_EXPR_RET_TYPE)((cache.getNdotH2()), ::nbl::hlsl::is_same_v, typename T::scalar_type))
     ((NBL_CONCEPT_REQ_EXPR_RET_TYPE)((cache.isTransmission()), ::nbl::hlsl::is_same_v, bool))
+    ((NBL_CONCEPT_REQ_EXPR_RET_TYPE)((cache.isValid(eta)), ::nbl::hlsl::is_same_v, bool))
 );
+#undef eta
 #undef cache
 #include <nbl/builtin/hlsl/concepts/__end.hlsl>
 
@@ -637,6 +641,11 @@ struct SIsotropicMicrofacetCache
     // similar with BSDF sampling, as fresnel can be high while reflection can be invalid, or low while refraction would be invalid too
     bool isTransmission() NBL_CONST_MEMBER_FUNC { return getVdotHLdotH() < scalar_type(0.0); }
 
+    bool isValid(NBL_CONST_REF_ARG(fresnel::OrientedEtas<monochrome_type>) orientedEta) NBL_CONST_MEMBER_FUNC
+    {
+        return ComputeMicrofacetNormal<scalar_type>::isValidMicrofacet(isTransmission(), VdotL, absNdotH, orientedEta);
+    }
+
     scalar_type getVdotL() NBL_CONST_MEMBER_FUNC { return VdotL; }
     scalar_type getVdotH() NBL_CONST_MEMBER_FUNC { return VdotH; }
     scalar_type getLdotH() NBL_CONST_MEMBER_FUNC { return LdotH; }
@@ -809,6 +818,11 @@ struct SAnisotropicMicrofacetCache
     scalar_type getNdotH2() NBL_CONST_MEMBER_FUNC { return iso_cache.getNdotH2(); }
     bool isTransmission() NBL_CONST_MEMBER_FUNC { return iso_cache.isTransmission(); }
 
+    bool isValid(NBL_CONST_REF_ARG(fresnel::OrientedEtas<monochrome_type>) orientedEta) NBL_CONST_MEMBER_FUNC
+    {
+        return iso_cache.isValid(orientedEta);
+    }
+
     scalar_type getTdotH() NBL_CONST_MEMBER_FUNC { return TdotH; }
     scalar_type getTdotH2() NBL_CONST_MEMBER_FUNC { const scalar_type t = getTdotH(); return t*t; }
     scalar_type getBdotH() NBL_CONST_MEMBER_FUNC { return BdotH; }

include/nbl/builtin/hlsl/bxdf/fresnel.hlsl

@@ -312,7 +312,6 @@ NBL_CONCEPT_END(
     ((NBL_CONCEPT_REQ_TYPE)(T::scalar_type))
     ((NBL_CONCEPT_REQ_TYPE)(T::vector_type))
     ((NBL_CONCEPT_REQ_EXPR_RET_TYPE)((fresnel(cosTheta)), ::nbl::hlsl::is_same_v, typename T::vector_type))
-    ((NBL_CONCEPT_REQ_EXPR_RET_TYPE)((fresnel.getRefractionOrientedEta()), ::nbl::hlsl::is_same_v, OrientedEtas<typename T::vector_type>))
     ((NBL_CONCEPT_REQ_EXPR_RET_TYPE)((fresnel.getOrientedEtaRcps()), ::nbl::hlsl::is_same_v, OrientedEtaRcps<typename T::vector_type>))
 );
 #undef cosTheta
@@ -329,6 +328,7 @@ NBL_CONCEPT_BEGIN(2)
 #define cosTheta NBL_CONCEPT_PARAM_T NBL_CONCEPT_PARAM_1
 NBL_CONCEPT_END(
     ((NBL_CONCEPT_REQ_TYPE_ALIAS_CONCEPT)(Fresnel, T))
+    ((NBL_CONCEPT_REQ_EXPR_RET_TYPE)((fresnel.getRefractionOrientedEta()), ::nbl::hlsl::is_same_v, OrientedEtas<typename T::vector_type>))
     ((NBL_CONCEPT_REQ_EXPR_RET_TYPE)((fresnel.getReorientedFresnel(cosTheta)), ::nbl::hlsl::is_same_v, T))
 );
 #undef cosTheta
@@ -374,6 +374,14 @@ struct Schlick
         return rcpEta;
     }
 
+    Schlick<T> getReorientedFresnel(const scalar_type NdotI) NBL_CONST_MEMBER_FUNC
+    {
+        // correct? but also sclick works best between eta 1.4-2.2
+        OrientedEtaRcps<T> rcpEta = getOrientedEtaRcps();
+        T sqrt_newF0 = (hlsl::promote<T>(1.0) - rcpEta.value) / (hlsl::promote<T>(1.0) + rcpEta.value);
+        return Schlick<T>::create(sqrt_newF0 * sqrt_newF0);
+    }
+
     T F0;
 };
 
@@ -418,14 +426,6 @@ struct Conductor
         return (rs2 + rp2) * 0.5f;
     }
 
-    OrientedEtas<T> getRefractionOrientedEta() NBL_CONST_MEMBER_FUNC
-    {
-        OrientedEtas<T> orientedEta;
-        orientedEta.value = eta;
-        orientedEta.rcp = hlsl::promote<T>(1.0) / eta;
-        return orientedEta;
-    }
-
     OrientedEtaRcps<T> getOrientedEtaRcps() NBL_CONST_MEMBER_FUNC
     {
         OrientedEtaRcps<T> rcpEta;