Iridescent bxdf tests

66_HLSLBxDFTests/app_resources/test_compile.comp.hlsl

@@ -8,14 +8,14 @@
 
 using namespace nbl::hlsl;
 
+using spectral_t = vector<float, 3>;
 using ray_dir_info_t = bxdf::ray_dir_info::SBasic<float>;
-using iso_interaction = bxdf::surface_interactions::SIsotropic<ray_dir_info_t>;
+using iso_interaction = bxdf::surface_interactions::SIsotropic<ray_dir_info_t, spectral_t>;
 using aniso_interaction = bxdf::surface_interactions::SAnisotropic<iso_interaction>;
 using sample_t = bxdf::SLightSample<ray_dir_info_t>;
 using iso_cache = bxdf::SIsotropicMicrofacetCache<float>;
 using aniso_cache = bxdf::SAnisotropicMicrofacetCache<iso_cache>;
 using quotient_pdf_t = sampling::quotient_and_pdf<float32_t3, float>;
-using spectral_t = vector<float, 3>;
 
 using iso_config_t = bxdf::SConfiguration<sample_t, iso_interaction, spectral_t>;
 using aniso_config_t = bxdf::SConfiguration<sample_t, aniso_interaction, spectral_t>;
@@ -32,6 +32,7 @@ void main(uint32_t3 ID : SV_DispatchThreadID)
     bxdf::reflection::SBeckmannAnisotropic<aniso_microfacet_config_t> beckmannAnisoBRDF;
     bxdf::reflection::SGGXIsotropic<iso_microfacet_config_t> ggxIsoBRDF;
     bxdf::reflection::SGGXAnisotropic<aniso_microfacet_config_t> ggxAnisoBRDF;
+    bxdf::reflection::SIridescent<iso_microfacet_config_t> iridBRDF;
 
     bxdf::transmission::SLambertian<iso_config_t> lambertianBSDF;
     bxdf::transmission::SOrenNayar<iso_config_t> orenNayarBSDF;
@@ -42,6 +43,7 @@ void main(uint32_t3 ID : SV_DispatchThreadID)
     bxdf::transmission::SBeckmannDielectricAnisotropic<aniso_microfacet_config_t> beckmannAnisoBSDF;
     bxdf::transmission::SGGXDielectricIsotropic<iso_microfacet_config_t> ggxIsoBSDF;
     bxdf::transmission::SGGXDielectricAnisotropic<aniso_microfacet_config_t> ggxAnisoBSDF;
+    // bxdf::transmission::SIridescent<iso_microfacet_config_t> iridBSDF;
 
 
     // do some nonsense calculations, but call all the relevant functions
@@ -76,6 +78,9 @@ void main(uint32_t3 ID : SV_DispatchThreadID)
     s = ggxAnisoBRDF.generate(anisointer, u.xy, cache);
     L += s.L.direction;
 
+    qp = iridBRDF.quotient_and_pdf(s, anisointer, cache);
+    L -= qp.quotient;
+
     qp = ggxAnisoBRDF.quotient_and_pdf(s, anisointer, cache);
     L -= qp.quotient;
 

66_HLSLBxDFTests/app_resources/test_components.hlsl

@@ -90,7 +90,7 @@ struct TestNDF : TestBxDF<BxDF>
         NBL_IF_CONSTEXPR(aniso)
         {
             dg1_query_type dq = base_t::bxdf.ndf.template createDG1Query<aniso_interaction, aniso_cache>(base_t::anisointer, cache);
-            fresnel_type _f = bxdf::impl::getOrientedFresnel<fresnel_type, base_t::bxdf_t::IsBSDF>::__call(base_t::bxdf.fresnel, base_t::anisointer.getNdotV());
+            fresnel_type _f = base_t::bxdf_t::getOrientedFresnel(base_t::bxdf.fresnel, base_t::anisointer.getNdotV());
             quant_query_type qq = bxdf::impl::quant_query_helper<ndf_type, fresnel_type, base_t::bxdf_t::IsBSDF>::template __call<aniso_cache>(base_t::bxdf.ndf, _f, cache);
             quant_type DG1 = base_t::bxdf.ndf.template DG1<sample_t, aniso_interaction>(dq, qq, s, base_t::anisointer);
             dg1 = DG1.microfacetMeasure * hlsl::abs(cache.getVdotH() / base_t::anisointer.getNdotV());
@@ -101,7 +101,7 @@ struct TestNDF : TestBxDF<BxDF>
         else
         {
             dg1_query_type dq = base_t::bxdf.ndf.template createDG1Query<iso_interaction, iso_cache>(base_t::isointer, isocache);
-            fresnel_type _f = bxdf::impl::getOrientedFresnel<fresnel_type, base_t::bxdf_t::IsBSDF>::__call(base_t::bxdf.fresnel, base_t::isointer.getNdotV());
+            fresnel_type _f = base_t::bxdf_t::getOrientedFresnel(base_t::bxdf.fresnel, base_t::isointer.getNdotV());
             quant_query_type qq = bxdf::impl::quant_query_helper<ndf_type, fresnel_type, base_t::bxdf_t::IsBSDF>::template __call<iso_cache>(base_t::bxdf.ndf, _f, isocache);
             quant_type DG1 = base_t::bxdf.ndf.template DG1<sample_t, iso_interaction>(dq, qq, s, base_t::isointer);
             dg1 = DG1.microfacetMeasure * hlsl::abs(isocache.getVdotH() / base_t::isointer.getNdotV());

66_HLSLBxDFTests/app_resources/tests.hlsl

@@ -264,6 +264,7 @@ struct TestReciprocity : TestBxDF<BxDF>
         rec_s = sample_t::createFromTangentSpace(rec_localL, anisointer.getFromTangentSpace());
 
         rec_isointer = iso_interaction_t::create(rec_V, base_t::rc.N);
+        rec_isointer.luminosityContributionHint = isointer.luminosityContributionHint;
         rec_anisointer = aniso_interaction_t::create(rec_isointer, base_t::rc.T, base_t::rc.B);
         rec_cache = cache;
         rec_cache.iso_cache.VdotH = cache.iso_cache.getLdotH();

66_HLSLBxDFTests/app_resources/tests_common.hlsl

@@ -46,14 +46,14 @@ namespace nbl
 namespace hlsl
 {
 
+using spectral_t = vector<float, 3>;
 using ray_dir_info_t = bxdf::ray_dir_info::SBasic<float>;
-using iso_interaction = bxdf::surface_interactions::SIsotropic<ray_dir_info_t>;
+using iso_interaction = bxdf::surface_interactions::SIsotropic<ray_dir_info_t, spectral_t>;
 using aniso_interaction = bxdf::surface_interactions::SAnisotropic<iso_interaction>;
 using sample_t = bxdf::SLightSample<ray_dir_info_t>;
 using iso_cache = bxdf::SIsotropicMicrofacetCache<float>;
 using aniso_cache = bxdf::SAnisotropicMicrofacetCache<iso_cache>;
 using quotient_pdf_t = sampling::quotient_and_pdf<float32_t3, float>;
-using spectral_t = vector<float, 3>;
 
 using iso_config_t = bxdf::SConfiguration<sample_t, iso_interaction, spectral_t>;
 using aniso_config_t = bxdf::SConfiguration<sample_t, aniso_interaction, spectral_t>;
@@ -81,6 +81,14 @@ bool checkEq(T a, T b, float32_t eps)
     return nbl::hlsl::all<vector<bool, vector_traits<T>::Dimension> >(nbl::hlsl::max<T>(_a / _b, _b / _a) <= hlsl::promote<T>(1 + eps));
 }
 
+template<>
+bool checkEq<float32_t>(float32_t a, float32_t b, float32_t eps)
+{
+    float32_t _a = hlsl::abs(a);
+    float32_t _b = hlsl::abs(b);
+    return nbl::hlsl::max<float32_t>(_a / _b, _b / _a) <= float32_t(1 + eps);
+}
+
 template<typename T>
 bool checkLt(T a, T b)
 {
@@ -131,6 +139,9 @@ struct SBxDFTestResources
         retval.alpha.y = ConvertToFloat01<uint32_t>::__call(retval.rng());
         retval.eta = ConvertToFloat01<uint32_t2>::__call(rng_vec2()) * hlsl::promote<float32_t2>(1.5) + hlsl::promote<float32_t2>(1.1); // range [1.1,2.6], also only do eta = eta/1.0 (air)
         retval.luma_coeff = float32_t3(0.2126, 0.7152, 0.0722); // luma coefficients for Rec. 709
+
+        retval.Dinc = ConvertToFloat01<uint32_t>::__call(retval.rng()) * 2400.0f + 100.0f;
+        retval.etaThinFilm = ConvertToFloat01<uint32_t>::__call(retval.rng()) * 0.5 + 1.1f; // range [1.1,1.6]
         return retval;
     }
 
@@ -147,6 +158,10 @@ struct SBxDFTestResources
     float32_t2 alpha;
     float32_t2 eta; // (eta, etak)
     float32_t3 luma_coeff;
+
+    // thin film stuff;
+    float Dinc; // in nm [100, 2500]
+    float etaThinFilm;
 };
 
 struct STestInitParams
@@ -184,6 +199,7 @@ struct TestBase
         rc = SBxDFTestResources::create(seed);
 
         isointer = iso_interaction::create(rc.V, rc.N);
+        isointer.luminosityContributionHint = rc.luma_coeff;
         anisointer = aniso_interaction::create(isointer, rc.T, rc.B);
     }
 
@@ -315,6 +331,21 @@ struct TestBxDF<bxdf::reflection::SGGXAnisotropic<aniso_microfacet_config_t>> :
     }
 };
 
+template<>
+struct TestBxDF<bxdf::reflection::SIridescent<iso_microfacet_config_t>> : TestBxDFBase<bxdf::reflection::SIridescent<iso_microfacet_config_t>>
+{
+    using base_t = TestBxDFBase<bxdf::reflection::SIridescent<iso_microfacet_config_t>>;
+
+    void initBxDF(SBxDFTestResources _rc)
+    {
+        base_t::bxdf.ndf = base_t::bxdf_t::ndf_type::create(_rc.alpha.x);
+        base_t::bxdf.fresnel = base_t::bxdf_t::fresnel_type::create(_rc.Dinc,hlsl::promote<float32_t3>(1.0),hlsl::promote<float32_t3>(_rc.etaThinFilm),hlsl::promote<float32_t3>(_rc.eta.x),hlsl::promote<float32_t3>(_rc.eta.y));
+#ifndef __HLSL_VERSION
+        base_t::name = "Iridescent BRDF";
+#endif
+    }
+};
+
 template<>
 struct TestBxDF<bxdf::transmission::SOrenNayar<iso_config_t>> : TestBxDFBase<bxdf::transmission::SOrenNayar<iso_config_t>>
 {
@@ -354,7 +385,6 @@ struct TestBxDF<bxdf::transmission::SThinSmoothDielectric<iso_config_t>> : TestB
     {
         using spectral_type = typename base_t::bxdf_t::spectral_type;
         base_t::bxdf.fresnel = bxdf::fresnel::Dielectric<spectral_type>::create(bxdf::fresnel::OrientedEtas<spectral_type>::create(base_t::isointer.getNdotV(bxdf::BxDFClampMode::BCM_ABS), hlsl::promote<spectral_type>(_rc.eta.x)));
-        base_t::bxdf.luminosityContributionHint = _rc.luma_coeff;
 #ifndef __HLSL_VERSION
         base_t::name = "Thin smooth dielectric BSDF";
 #endif
@@ -438,37 +468,58 @@ struct TestBxDF<bxdf::transmission::SGGXDielectricAnisotropic<Config>> : TestBxD
     }
 };
 
+template<class Config>
+struct TestBxDF<bxdf::transmission::SIridescent<Config>> : TestBxDFBase<bxdf::transmission::SIridescent<Config>>
+{
+    using base_t = TestBxDFBase<bxdf::transmission::SIridescent<Config>>;
+
+    void initBxDF(SBxDFTestResources _rc)
+    {
+        base_t::bxdf.ndf = base_t::bxdf_t::ndf_type::create(_rc.alpha.x);
+        base_t::bxdf.fresnel = base_t::bxdf_t::fresnel_type::create(_rc.Dinc,hlsl::promote<float32_t3>(1.0),hlsl::promote<float32_t3>(_rc.etaThinFilm),hlsl::promote<float32_t3>(_rc.eta.x));
+#ifndef __HLSL_VERSION
+        base_t::name = "Iridescent BSDF";
+#endif
+    }
+};
+
 
 namespace reciprocity_test_impl
 {
-template<class RayDirInfo NBL_PRIMARY_REQUIRES(bxdf::ray_dir_info::Basic<RayDirInfo>)
+template<class RayDirInfo, class Spectrum NBL_PRIMARY_REQUIRES(bxdf::ray_dir_info::Basic<RayDirInfo> && concepts::FloatingPointLikeVectorial<Spectrum>)
 struct SIsotropic
 {
+    using this_t = SIsotropic<RayDirInfo, Spectrum>;
     using ray_dir_info_type = RayDirInfo;
     using scalar_type = typename RayDirInfo::scalar_type;
     using vector3_type = typename RayDirInfo::vector3_type;
+    using spectral_type = Spectrum;
 
     // WARNING: Changed since GLSL, now arguments need to be normalized!
-    static SIsotropic<RayDirInfo> create(NBL_CONST_REF_ARG(RayDirInfo) normalizedV, const vector3_type normalizedN)
+    static this_t create(NBL_CONST_REF_ARG(RayDirInfo) normalizedV, const vector3_type normalizedN)
     {
-        SIsotropic<RayDirInfo> retval;
+        this_t retval;
         retval.V = normalizedV;
         retval.N = normalizedN;
         retval.NdotV = nbl::hlsl::dot<vector3_type>(retval.N, retval.V.getDirection());
         retval.NdotV2 = retval.NdotV * retval.NdotV;
+        retval.luminosityContributionHint = hlsl::promote<spectral_type>(1.0);
+        retval.throughputWeights = hlsl::promote<spectral_type>(1.0);
 
         return retval;
     }
 
     template<typename I NBL_FUNC_REQUIRES(bxdf::surface_interactions::Isotropic<I>)
-    static SIsotropic<RayDirInfo> copy(NBL_CONST_REF_ARG(I) other)
+    static this_t copy(NBL_CONST_REF_ARG(I) other)
     {
-        SIsotropic<RayDirInfo> retval;
+        this_t retval;
         retval.V = other.getV();
         retval.N = other.getN();
         retval.NdotV = other.getNdotV();
         retval.NdotV2 = other.getNdotV2();
         retval.pathOrigin = bxdf::PathOrigin::PO_SENSOR;
+        retval.luminosityContributionHint = other.luminosityContributionHint;
+        retval.throughputWeights = other.throughputWeights;
         return retval;
     }
 
@@ -481,12 +532,20 @@ struct SIsotropic
     scalar_type getNdotV2() NBL_CONST_MEMBER_FUNC { return NdotV2; }
 
     bxdf::PathOrigin getPathOrigin() NBL_CONST_MEMBER_FUNC { return pathOrigin; }
+    spectral_type getLuminosityContributionHint() NBL_CONST_MEMBER_FUNC { return luminosityContributionHint; }
+    spectral_type getPrefixThroughputWeights() NBL_CONST_MEMBER_FUNC
+    {
+        spectral_type prefixThroughputWeights = luminosityContributionHint * throughputWeights;
+        return prefixThroughputWeights / math::lpNorm<spectral_type,1>(prefixThroughputWeights);
+    }
 
     RayDirInfo V;
     vector3_type N;
     scalar_type NdotV;
     scalar_type NdotV2;
     bxdf::PathOrigin pathOrigin;
+    spectral_type luminosityContributionHint;
+    spectral_type throughputWeights;    // product of all quotients so far
 };
 
 template<class IsotropicInteraction NBL_PRIMARY_REQUIRES(bxdf::surface_interactions::Isotropic<IsotropicInteraction>)
@@ -498,6 +557,7 @@ struct SAnisotropic
     using scalar_type = typename ray_dir_info_type::scalar_type;
     using vector3_type = typename ray_dir_info_type::vector3_type;
     using matrix3x3_type = matrix<scalar_type, 3, 3>;
+    using spectral_type = typename isotropic_interaction_type::spectral_type;
 
     // WARNING: Changed since GLSL, now arguments need to be normalized!
     static this_t create(
@@ -551,6 +611,8 @@ struct SAnisotropic
     scalar_type getNdotV(bxdf::BxDFClampMode _clamp = bxdf::BxDFClampMode::BCM_NONE) NBL_CONST_MEMBER_FUNC { return isotropic.getNdotV(_clamp); }
     scalar_type getNdotV2() NBL_CONST_MEMBER_FUNC { return isotropic.getNdotV2(); }
     bxdf::PathOrigin getPathOrigin() NBL_CONST_MEMBER_FUNC { return isotropic.getPathOrigin(); }
+    spectral_type getLuminosityContributionHint() NBL_CONST_MEMBER_FUNC { return isotropic.getLuminosityContributionHint(); }
+    spectral_type getPrefixThroughputWeights() NBL_CONST_MEMBER_FUNC { return isotropic.getPrefixThroughputWeights(); }
 
     vector3_type getT() NBL_CONST_MEMBER_FUNC { return T; }
     vector3_type getB() NBL_CONST_MEMBER_FUNC { return B; }
@@ -599,7 +661,7 @@ struct CustomIsoMicrofacetConfiguration<LS,Interaction,MicrofacetCache,Spectrum
 };
 }
 
-using rectest_iso_interaction = reciprocity_test_impl::SIsotropic<ray_dir_info_t>;
+using rectest_iso_interaction = reciprocity_test_impl::SIsotropic<ray_dir_info_t, spectral_t>;
 using rectest_aniso_interaction = reciprocity_test_impl::SAnisotropic<rectest_iso_interaction>;
 using rectest_iso_microfacet_config_t = reciprocity_test_impl::CustomIsoMicrofacetConfiguration<sample_t, rectest_iso_interaction, iso_cache, spectral_t>;
 using rectest_aniso_microfacet_config_t = bxdf::SMicrofacetConfiguration<sample_t, rectest_aniso_interaction, aniso_cache, spectral_t>;