Bxdf fixes cook torrance #930

devshgraphicsprogramming · 2025-09-16T14:03:10Z

Description

Continues #899 , #916 and #919

Testing

TODO list:

…eturn quants

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

include/nbl/builtin/hlsl/math/functions.hlsl

include/nbl/builtin/hlsl/cpp_compat/vector.hlsl

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

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

…ent_and_pdf

…back into OrientedEta struct

devshgraphicsprogramming · 2025-10-08T08:36:43Z

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

+        retval.iso_cache.VdotL = hlsl::mix(scalar_type(2.0) * retval.iso_cache.VdotH * retval.iso_cache.VdotH - scalar_type(1.0),
+                                VdotH * (LdotH - rcpOrientedEta.value[0] + VdotH * rcpOrientedEta.value[0]), transmitted);


there's a more graceful way to compute this via mix, see my other comment

devshgraphicsprogramming · 2025-10-08T08:39:13Z

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

    }

-    OrientedEtas<T> getRefractionOrientedEta() NBL_CONST_MEMBER_FUNC { return orientedEta; }
+    scalar_type getRefractionOrientedEta() NBL_CONST_MEMBER_FUNC { return orientedEta.value[0]; }   // expect T to be monochrome?


its a bit of a complicated topic, its possible to have RGB fresnel without dispersion by fixing the refraction Eta to be something else than the etas used to compute RGB reflectance or some sort of interpolation of them.

This is a good default cause the Etas wont differ that much anyway

devshgraphicsprogramming · 2025-10-08T08:42:54Z

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

+        fresnel::OrientedEtas<vector_type> orientedEta = fresnel::OrientedEtas<vector_type>::create(typename F::scalar_type(1.0), hlsl::promote<vector_type>(fresnel.getRefractionOrientedEta()));
+        return cache.isValid(orientedEta);


why are you promoting to a vector!? Cache.isValid MUST take the Eta as a scalar!!!!

devshgraphicsprogramming · 2025-10-08T08:48:21Z

include/nbl/builtin/hlsl/bxdf/ndf/ggx.hlsl

+    template<class Interaction, class MicrofacetCache, typename C=bool_constant<!IsAnisotropic> NBL_FUNC_REQUIRES(RequiredInteraction<Interaction> && RequiredMicrofacetCache<MicrofacetCache>)
+    enable_if_t<C::value && !IsAnisotropic, dg1_query_type> createDG1Query(NBL_CONST_REF_ARG(Interaction) interaction, NBL_CONST_REF_ARG(MicrofacetCache) cache)
+    {
+        dg1_query_type dg1_query;
+        dg1_query.ndf = __ndf_base.template D<MicrofacetCache>(cache);
+        scalar_type clampedNdotV = interaction.getNdotV(_clamp);
+        dg1_query.G1_over_2NdotV = base_type::G1_wo_numerator_devsh_part(clampedNdotV, __ndf_base.devsh_part(interaction.getNdotV2()));
+        return dg1_query;
+    }
+    template<class LS, class Interaction, typename C=bool_constant<!IsAnisotropic> NBL_FUNC_REQUIRES(LightSample<LS> && RequiredInteraction<Interaction>)
+    enable_if_t<C::value && !IsAnisotropic, g2g1_query_type> createG2G1Query(NBL_CONST_REF_ARG(LS) _sample, NBL_CONST_REF_ARG(Interaction) interaction)
+    {
+        g2g1_query_type g2_query;
+        g2_query.devsh_l = __ndf_base.devsh_part(_sample.getNdotL2());
+        g2_query.devsh_v = __ndf_base.devsh_part(interaction.getNdotV2());
+        return g2_query;
+    }
+    template<class Interaction, class MicrofacetCache, typename C=bool_constant<IsAnisotropic> NBL_FUNC_REQUIRES(RequiredInteraction<Interaction> && RequiredMicrofacetCache<MicrofacetCache>)
+    enable_if_t<C::value && IsAnisotropic, dg1_query_type> createDG1Query(NBL_CONST_REF_ARG(Interaction) interaction, NBL_CONST_REF_ARG(MicrofacetCache) cache)
+    {
+        dg1_query_type dg1_query;
+        dg1_query.ndf = __ndf_base.template D<MicrofacetCache>(cache);
+        scalar_type clampedNdotV = interaction.getNdotV(_clamp);
+        dg1_query.G1_over_2NdotV = base_type::G1_wo_numerator_devsh_part(clampedNdotV, __ndf_base.devsh_part(interaction.getTdotV2(), interaction.getBdotV2(), interaction.getNdotV2()));
+        return dg1_query;
+    }


if you made createDG1Query use createG2G1Query and grab the devsh_v from the return value you could get away with only having one createDG1Query method I think

include/nbl/builtin/hlsl/bxdf/ndf/ggx.hlsl

devshgraphicsprogramming · 2025-10-08T08:52:21Z

include/nbl/builtin/hlsl/bxdf/ndf/ggx.hlsl

+        dmq.microfacetMeasure = d;
+        dmq.projectedLightMeasure = d * _sample.getNdotL(BxDFClampMode::BCM_MAX);


this is wrong, the projectedLightMeasure needs a full transform same as beckmann

because its the PDF of V getting reflected through H which has a PDF of microfacetmeasure

devshgraphicsprogramming · 2025-10-08T09:09:16Z

include/nbl/builtin/hlsl/bxdf/ndf/ggx.hlsl

+    {
+        scalar_type d = __ndf_base.template D<MicrofacetCache>(cache);
+        quant_type dmq;
+        dmq.microfacetMeasure = d;  // note: microfacetMeasure/2NdotV


huh? then the method shouldn't be called D but D_over_2NdotV

but the comment is wrong, cause your __ndf_base.D is actually the NDF, not anythingelse

devshgraphicsprogramming · 2025-10-08T09:11:24Z

include/nbl/builtin/hlsl/bxdf/ndf/ggx.hlsl

+        scalar_type NdotL_over_denominator = _sample.getNdotL(BxDFClampMode::BCM_ABS);
+        if (transmitted)
+                NdotL_over_denominator *= -scalar_type(4.0) * VdotHLdotH / (VdotH_etaLdotH * VdotH_etaLdotH);
+        dmq.projectedLightMeasure = d * NdotL_over_denominator;


wrong the denominator is 4 NdotV NdotL, so NdotL over denominator must be 0.25 / NdotV(ABS)

for the transmission case its - VdotHLdotH / (VdotH_etaLdotH*VdotH_etaLdotH*NdotV(abs))

So its NdotL_over_denominator = mix(0.25,VdotHLdotH*neg_rcp2_VdotH_etaLdotH,transmitted)/NdotV(ABS);

devshgraphicsprogramming · 2025-10-08T10:00:47Z

include/nbl/builtin/hlsl/bxdf/ndf/ggx.hlsl

+        dmq.microfacetMeasure = d;  // note: microfacetMeasure/2NdotV
+
+        const scalar_type VdotHLdotH = quant_query.getVdotHLdotH();
+        const scalar_type VdotH_etaLdotH = quant_query.getVdotH_etaLdotH();


should already take this a neg_rcp2_VdotH_etaLdotH // -(VdotH+eta*LdotH)^(-2)

devshgraphicsprogramming · 2025-10-08T10:07:43Z

include/nbl/builtin/hlsl/bxdf/ndf.hlsl

+// help avoid preprocessor splitting template declarations by comma
+#define SINGLE_ARG(...) __VA_ARGS__


if you want a global macro, make it NDF prefixed.

Also all macros need NBL_HLSL prefix

devshgraphicsprogramming · 2025-10-08T10:19:36Z

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

+    template<typename C=bool_constant<!IsAnisotropic>, typename T=conditional_t<IsBSDF, vector3_type, vector2_type> >
+    enable_if_t<C::value && !IsAnisotropic, sample_type> generate(NBL_CONST_REF_ARG(isotropic_interaction_type) interaction, const T u, NBL_REF_ARG(isocache_type) cache)


you can use conditional_t directly in a function signature, there's no need to add another template parameter T

P.S. also try to use NBL_FUNC_REQUIRES instead of the enable_if_t

devshgraphicsprogramming · 2025-10-08T10:21:35Z

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

+        fresnel_type _f = fresnel;
+        NBL_IF_CONSTEXPR(IsBSDF)
+            _f = impl::getOrientedFresnel<fresnel_type, IsBSDF>::__call(fresnel, interaction.getNdotV());


either don't passIsBSDF to impl::getOrientedFresnel or skip the NBL_IF_CONSTEXPR

devshgraphicsprogramming · 2025-10-08T10:23:25Z

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

-        spectral_type quo = hlsl::promote<spectral_type>(0.0);
        const bool notTIR = impl::check_TIR_helper<fresnel_type, IsBSDF>::template __call<MicrofacetCache>(_f, cache);
-        if (notTIR)
+        assert(notTIR);


add a comment why

devshgraphicsprogramming · 2025-10-08T10:30:27Z

include/nbl/builtin/hlsl/bxdf/ndf/beckmann.hlsl

-    template<class MicrofacetCache>
-    NBL_CONSTEXPR_STATIC_INLINE bool RequiredMicrofacetCache = IsAnisotropic ? AnisotropicMicrofacetCache<MicrofacetCache> : ReadableIsotropicMicrofacetCache<MicrofacetCache>;
+    NDF_CONSTEXPR_DECLS(_IsAnisotropic,reflect_refract);
+    NDF_TYPE_ALIASES(SINGLE_ARG(Beckmann<T,IsAnisotropic,SupportedPaths>), SINGLE_ARG(impl::BeckmannCommon<T,IsAnisotropic>), impl::SBeckmannDG1Query<scalar_type>, impl::SBeckmannG2overG1Query<scalar_type>, DualMeasureQuantQuery<scalar_type>);


You could structure the macro to take a BOOST_PP tuple

NDF_TYPE_ALIASES((Beckmann<T,IsAnisotropic,SupportedPaths>)(impl::BeckmannCommon<T,IsAnisotropic>)(impl::SBeckmannDG1Query<scalar_type>)(impl::SBeckmannG2overG1Query<scalar_type>)(DualMeasureQuantQuery<scalar_type>))

and then get the args via BOOST_PP_TUPLE_ELEM

devshgraphicsprogramming · 2025-10-08T10:32:17Z

include/nbl/builtin/hlsl/bxdf/ndf/beckmann.hlsl

+        quant_query_type quant_query;   // only has members for refraction
+        if (SupportsTransmission)
+        {
+            quant_query.VdotHLdotH = cache.getVdotHLdotH();


add a comment that even though in PBRT its abs(VdotH)*abs(LdotH) we leverage that under transmission the sign must always be negattive and rest of the code accounts for that.

or where the getVdotHLdotH concept check is defined

devshgraphicsprogramming · 2025-10-08T10:35:37Z

include/nbl/builtin/hlsl/bxdf/ndf/microfacet_to_light_transform.hlsl

+    scalar_type getVdotH_etaLdotH() NBL_CONST_MEMBER_FUNC { return VdotH_etaLdotH; }
+
+    scalar_type VdotHLdotH;
+    scalar_type VdotH_etaLdotH;


the VdotH_etaLdotH needs to change (name and what they store) as per #930 (comment)

and a comment needs to be left here or in the concept #930 (comment)

devshgraphicsprogramming · 2025-10-08T10:44:05Z

include/nbl/builtin/hlsl/bxdf/ndf/microfacet_to_light_transform.hlsl

+      retval.projectedLightMeasure = microfacetMeasure*mix<scalar_type>(scalar_type(0.25),VdotHLdotH,transmitted);
+      scalar_type denominator = clampedNdotV;
+      if (transmitted) // VdotHLdotH is negative under transmission, so thats denominator is negative
            denominator *= -VdotH_etaLdotH * VdotH_etaLdotH;
-        }
-        return pdf * (transmitted ? VdotHLdotH : scalar_type(0.25)) / denominator;
-    }
-
-    scalar_type pdf;
-    scalar_type absNdotV;
-    bool transmitted;
-    scalar_type VdotH;
-    scalar_type LdotH;
-    scalar_type VdotHLdotH;
-    scalar_type orientedEta;
+      retval.projectedLightMeasure /= denominator;


this is correct, unlike #930 (comment)

although you may want to reformulate it same way into mix(0.25,VdotHLdotH*neg_rcp2_VdotH_etaLdotH,transmitted)/NdotV(ABS);

devshgraphicsprogramming · 2025-10-08T10:55:24Z

include/nbl/builtin/hlsl/bxdf/ndf/ggx.hlsl

+        dmq.microfacetMeasure = dg1;
+        dmq.projectedLightMeasure = dg1;// TODO: figure this out * _sample.getNdotL(BxDFClampMode::BCM_MAX);
+        return dmq;
+    }
+    template<class LS, class Interaction, typename C=bool_constant<IsBSDF> NBL_FUNC_REQUIRES(LightSample<LS> && RequiredInteraction<Interaction>)
+    enable_if_t<C::value && IsBSDF, quant_type> DG1(NBL_CONST_REF_ARG(dg1_query_type) query, NBL_CONST_REF_ARG(quant_query_type) quant_query, NBL_CONST_REF_ARG(LS) _sample, NBL_CONST_REF_ARG(Interaction) interaction)
+    {
+        scalar_type dg1 = base_type::template DG1<dg1_query_type>(query);
+        quant_type dmq;
+        dmq.microfacetMeasure = dg1;  // note: microfacetMeasure/2NdotV


if your base DG1 returns something else than actual DG1 like DG1_over_4NdotV, then it should be called DG1_over_4NdotV

then you assign straight to projectedLightMeasure in the reflective case and properly multiply the 4*NdotV back in for the microfacetMeasure

ideally you should really just return DG1_over_2NdotV cause extra 0.5 mul is kinda pointless inside

devshgraphicsprogramming · 2025-10-08T11:00:41Z

include/nbl/builtin/hlsl/bxdf/ndf/ggx.hlsl

+        const scalar_type VdotHLdotH = quant_query.getVdotHLdotH();
+        const scalar_type VdotH_etaLdotH = quant_query.getVdotH_etaLdotH();
+        const bool transmitted = reflect_refract==MTT_REFRACT || (reflect_refract!=MTT_REFLECT && VdotHLdotH < scalar_type(0.0));
+        scalar_type NdotL_over_denominator = _sample.getNdotL(BxDFClampMode::BCM_ABS);
+        if (transmitted)
+                NdotL_over_denominator *= -scalar_type(4.0) * VdotHLdotH / (VdotH_etaLdotH * VdotH_etaLdotH);
+        dmq.projectedLightMeasure = dg1;// TODO: figure this out * NdotL_over_denominator;


for the projectedLightMeasure transmittance you'd just do mix(0.5,2.0,transmitted)*DG1_over_2NdotV and then

if (transmitted) dmq.projectedLightMeasure *= VdotHLdotH*neg_rcp2_VdotH_etaLdotH; dmq.microfacetMeasure *= 2.0*clampedNdotV;

devshgraphicsprogramming · 2025-10-08T11:01:57Z

include/nbl/builtin/hlsl/bxdf/ndf/ggx.hlsl

+    template<class LS, class Interaction, class MicrofacetCache, typename C=bool_constant<!IsBSDF> NBL_FUNC_REQUIRES(LightSample<LS> && RequiredInteraction<Interaction> && RequiredMicrofacetCache<MicrofacetCache>)
+    enable_if_t<C::value && !IsBSDF, quant_type> D(NBL_CONST_REF_ARG(quant_query_type) quant_query, NBL_CONST_REF_ARG(LS) _sample, NBL_CONST_REF_ARG(Interaction) interaction, NBL_CONST_REF_ARG(MicrofacetCache) cache)
+    {
+        scalar_type d = __ndf_base.template D<MicrofacetCache>(cache);
+        quant_type dmq;
+        dmq.microfacetMeasure = d;
+        dmq.projectedLightMeasure = d * _sample.getNdotL(BxDFClampMode::BCM_MAX);
+        return dmq;
+    }
+    template<class LS, class Interaction, class MicrofacetCache, typename C=bool_constant<IsBSDF> NBL_FUNC_REQUIRES(LightSample<LS> && RequiredInteraction<Interaction> && RequiredMicrofacetCache<MicrofacetCache>)
+    enable_if_t<C::value && IsBSDF, quant_type> D(NBL_CONST_REF_ARG(quant_query_type) quant_query, NBL_CONST_REF_ARG(LS) _sample, NBL_CONST_REF_ARG(Interaction) interaction, NBL_CONST_REF_ARG(MicrofacetCache) cache)
+    {
+        scalar_type d = __ndf_base.template D<MicrofacetCache>(cache);
+        quant_type dmq;
+        dmq.microfacetMeasure = d;  // note: microfacetMeasure/2NdotV
+
+        const scalar_type VdotHLdotH = quant_query.getVdotHLdotH();
+        const scalar_type VdotH_etaLdotH = quant_query.getVdotH_etaLdotH();
+        const bool transmitted = reflect_refract==MTT_REFRACT || (reflect_refract!=MTT_REFLECT && VdotHLdotH < scalar_type(0.0));
+        scalar_type NdotL_over_denominator = _sample.getNdotL(BxDFClampMode::BCM_ABS);
+        if (transmitted)
+                NdotL_over_denominator *= -scalar_type(4.0) * VdotHLdotH / (VdotH_etaLdotH * VdotH_etaLdotH);
+        dmq.projectedLightMeasure = d * NdotL_over_denominator;
+        return dmq;
+    }
+
+    template<class LS, class Interaction, typename C=bool_constant<!IsBSDF> NBL_FUNC_REQUIRES(LightSample<LS> && RequiredInteraction<Interaction>)
+    enable_if_t<C::value && !IsBSDF, quant_type> DG1(NBL_CONST_REF_ARG(dg1_query_type) query, NBL_CONST_REF_ARG(quant_query_type) quant_query, NBL_CONST_REF_ARG(LS) _sample, NBL_CONST_REF_ARG(Interaction) interaction)
+    {
+        scalar_type dg1 = base_type::template DG1<dg1_query_type>(query);
+        quant_type dmq;
+        dmq.microfacetMeasure = dg1;
+        dmq.projectedLightMeasure = dg1;// TODO: figure this out * _sample.getNdotL(BxDFClampMode::BCM_MAX);
+        return dmq;
+    }
+    template<class LS, class Interaction, typename C=bool_constant<IsBSDF> NBL_FUNC_REQUIRES(LightSample<LS> && RequiredInteraction<Interaction>)
+    enable_if_t<C::value && IsBSDF, quant_type> DG1(NBL_CONST_REF_ARG(dg1_query_type) query, NBL_CONST_REF_ARG(quant_query_type) quant_query, NBL_CONST_REF_ARG(LS) _sample, NBL_CONST_REF_ARG(Interaction) interaction)
+    {
+        scalar_type dg1 = base_type::template DG1<dg1_query_type>(query);
+        quant_type dmq;
+        dmq.microfacetMeasure = dg1;  // note: microfacetMeasure/2NdotV
+
+        const scalar_type VdotHLdotH = quant_query.getVdotHLdotH();
+        const scalar_type VdotH_etaLdotH = quant_query.getVdotH_etaLdotH();
+        const bool transmitted = reflect_refract==MTT_REFRACT || (reflect_refract!=MTT_REFLECT && VdotHLdotH < scalar_type(0.0));
+        scalar_type NdotL_over_denominator = _sample.getNdotL(BxDFClampMode::BCM_ABS);
+        if (transmitted)
+                NdotL_over_denominator *= -scalar_type(4.0) * VdotHLdotH / (VdotH_etaLdotH * VdotH_etaLdotH);
+        dmq.projectedLightMeasure = dg1;// TODO: figure this out * NdotL_over_denominator;
+        return dmq;
+    }


This stuff maybe we can rethink, I'd be tempted to allow an NDF "skip" providing D and correlated if it has both the DG1 and Dcorrelated methods (so the cook torrance can leverage that and skip multiplying D with correlated by itself for eval)

devshgraphicsprogramming · 2025-10-08T11:03:19Z

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

    NBL_CONSTEXPR_STATIC_INLINE bool IsBSDF = ndf_type::NDFSurfaceType != ndf::MTT_REFLECT;

+    template<class Interaction, class MicrofacetCache>
+    static bool __checkValid(NBL_CONST_REF_ARG(fresnel_type) f, NBL_CONST_REF_ARG(sample_type) _sample, NBL_CONST_REF_ARG(Interaction) interaction, NBL_CONST_REF_ARG(MicrofacetCache) cache)


why make static and pass the f if its your member?

is it because the fresnel is already properly oriented? then give f a clear name like reorientedFresnel

and since its static you may as well make the __checkValid into a standalone struct functor with a partial spec on IsBSDF, that way you don't call impl::check_TIR_helper but you can call cache.isValid(reorientedFresnel.getRefractionOrientedEta()) directly

actually if you use impl::checkValid<IsBSDF>::template __call() here

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

Lines 350 to 351 in dcc2464

const bool notTIR = impl::check_TIR_helper<fresnel_type, IsBSDF>::template __call<MicrofacetCache>(_f, cache);

assert(notTIR);

then there's no need to have an impl::check_TIR_helper at all

devshgraphicsprogramming · 2025-10-09T08:17:15Z

include/nbl/builtin/hlsl/bxdf/ndf.hlsl


 // help avoid preprocessor splitting template declarations by comma
-#define SINGLE_ARG(...) __VA_ARGS__
+#define NDF_SINGLE_ARG(...) __VA_ARGS__


imho you wont need it if you rework NDF_TYPE_ALIASES into taking a boost PP Tuple

devshgraphicsprogramming · 2025-10-09T09:08:25Z

include/nbl/builtin/hlsl/bxdf/ndf/ggx.hlsl

+        else
+            dmq.projectedLightMeasure = d * _sample.getNdotL(BxDFClampMode::BCM_MAX);


btw you can always use ABS, because it should be the callee's job to not call you on backfacing BRDF if it chooses to

this is just the NDF

…cache with defaults

keptsecret added 23 commits September 4, 2025 10:46

changes to dual measure quant, old stuff commented out for now

5218545

create query structs in beckmann ndf, removed query concepts, funcs r…

f7525af

…eturn quants

did the same for ggx ndf, some fixes to beckmann

c50db68

Merge branch 'master' into bxdf_fixes_cook_torrance

c49bedb

fixes to ndf concept

319c954

moved eval, quotient/pdf into cook torrance base

4eeacf1

moved generate H into ndfs, generate impl in cook torrance base

e7bc784

use new cook torrance base in microfacet bxdfs

72226bb

Merge branch 'master' into bxdf_fixes_cook_torrance

f34b348

numerous typo bug fixes

ad13044

fixes to ggx ndf

d8d2116

fixed conductor fresnel naming ior as eta

238b08e

minor fixes to beckmann ndf, removed obsolete comments

8bc707f

added luminosity contribution hint to cook torrance bsdfs

9fb28cf

added aniso overloads to isotropic bxdf methods

4cb8a0a

checks for invalid generate sample

392dc31

removed obsolete commented out stuff

02de86e

added cartesian-polar conversions from unit tests

4a7f532

Merge branch 'fix_rotation_mat' into bxdf_fixes_cook_torrance

80c4f67

Merge branch 'master' into bxdf_fixes_cook_torrance

6233bd1

vector hashes

ce5fbac

Merge branch 'fix_rotation_mat' into bxdf_fixes_cook_torrance

47e814b

Merge branch 'master' into bxdf_fixes_cook_torrance

c983975

devshgraphicsprogramming commented Sep 16, 2025

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keptsecret added 2 commits September 17, 2025 15:26

fix fresnel usage in bxdf pdf

0f2ee0b

fix F calc in generate

b5f02e6

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keptsecret added 2 commits October 8, 2025 14:06

moved cook torrance checks into private func, changed checks in quoti…

22c4918

…ent_and_pdf

getRefractionOrientedEta returns a scalar, but now I have to turn it …

dcc2464

…back into OrientedEta struct

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keptsecret added 2 commits October 8, 2025 16:32

moved ndf type defs and constexpr declaration into macro

7aa071b

moved out quant query, adjusted ndf macro usage

97e5ce3

devshgraphicsprogramming commented Oct 8, 2025

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reduced duplicate code in beckmann, ggx ndfs

6272281

devshgraphicsprogramming commented Oct 9, 2025

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keptsecret added 2 commits October 9, 2025 16:19

fix calculations in cook torrance eval, generate

b55bdef

removed passthrough funcs, template directly on required interaction/…

444b656

…cache with defaults

		retval.iso_cache.VdotL = hlsl::mix(scalar_type(2.0) * retval.iso_cache.VdotH * retval.iso_cache.VdotH - scalar_type(1.0),
		VdotH * (LdotH - rcpOrientedEta.value[0] + VdotH * rcpOrientedEta.value[0]), transmitted);

		fresnel::OrientedEtas<vector_type> orientedEta = fresnel::OrientedEtas<vector_type>::create(typename F::scalar_type(1.0), hlsl::promote<vector_type>(fresnel.getRefractionOrientedEta()));
		return cache.isValid(orientedEta);

		dmq.microfacetMeasure = d;
		dmq.projectedLightMeasure = d * _sample.getNdotL(BxDFClampMode::BCM_MAX);

		// help avoid preprocessor splitting template declarations by comma
		#define SINGLE_ARG(...) __VA_ARGS__

		template<typename C=bool_constant<!IsAnisotropic>, typename T=conditional_t<IsBSDF, vector3_type, vector2_type> >
		enable_if_t<C::value && !IsAnisotropic, sample_type> generate(NBL_CONST_REF_ARG(isotropic_interaction_type) interaction, const T u, NBL_REF_ARG(isocache_type) cache)

	const bool notTIR = impl::check_TIR_helper<fresnel_type, IsBSDF>::template __call<MicrofacetCache>(_f, cache);
	assert(notTIR);

		else
		dmq.projectedLightMeasure = d * _sample.getNdotL(BxDFClampMode::BCM_MAX);

Bxdf fixes cook torrance #930

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Bxdf fixes cook torrance #930

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devshgraphicsprogramming commented Sep 16, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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Description

Testing

TODO list:

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devshgraphicsprogramming Oct 8, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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devshgraphicsprogramming Oct 8, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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devshgraphicsprogramming Oct 8, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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devshgraphicsprogramming commented Sep 16, 2025 •

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devshgraphicsprogramming Oct 8, 2025 •

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devshgraphicsprogramming Oct 8, 2025 •

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devshgraphicsprogramming Oct 8, 2025 •

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