Skip to content

Commit 79c80cd

Browse files
keptsecretkeptsecret
committed
fixes calculations to NdotL, restore quick dot products in bsdf generate
1 parent 36c1f4b commit 79c80cd

File tree

2 files changed

+28
-81
lines changed

2 files changed

+28
-81
lines changed

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

Lines changed: 27 additions & 80 deletions
Original file line numberDiff line numberDiff line change
@@ -242,7 +242,7 @@ struct SCookTorrance
242242
template<typename C=bool_constant<IsBSDF> >
243243
enable_if_t<C::value && IsBSDF, sample_type> generate(NBL_CONST_REF_ARG(anisotropic_interaction_type) interaction, const vector3_type u, NBL_REF_ARG(anisocache_type) cache)
244244
{
245-
const vector3_type localV = hlsl::normalize(interaction.getTangentSpaceV());
245+
const vector3_type localV = interaction.getTangentSpaceV();
246246
const scalar_type NdotV = localV.z;
247247

248248
fresnel_type _f = impl::getOrientedFresnel<fresnel_type, IsBSDF>::__call(fresnel, NdotV);
@@ -270,90 +270,37 @@ struct SCookTorrance
270270
bool transmitted = math::partitionRandVariable(reflectance, z, rcpChoiceProb);
271271

272272
ray_dir_info_type V = interaction.getV();
273-
const vector3_type H = hlsl::normalize(hlsl::mul(interaction.getFromTangentSpace(), localH));
274-
275-
// TODO: UNDER CONSTRUCTION, will uncomment when sure basic stuff passes tests
276-
// Refract<scalar_type> r = Refract<scalar_type>::create(V.getDirection(), H);
277-
// const scalar_type LdotH = hlsl::mix(VdotH, r.getNdotT(rcpEta.value2[0]), transmitted);
278-
279-
// // fail if samples have invalid paths
280-
// const scalar_type viewShortenFactor = hlsl::mix(scalar_type(1.0), rcpEta.value[0], transmitted);
281-
// const scalar_type NdotL = localH.z * (VdotH * viewShortenFactor + hlsl::abs(LdotH)) - NdotV * viewShortenFactor;
282-
// // VNDF sampling guarantees that `VdotH` has same sign as `NdotV`
283-
// // and `transmitted` controls the sign of `LdotH` relative to `VdotH` by construction (reflect -> same sign, or refract -> opposite sign)
284-
// if (ComputeMicrofacetNormal<scalar_type>::isTransmissionPath(NdotV, NdotL) != transmitted)
285-
// return sample_type::createInvalid(); // should check if sample direction is invalid
286-
287-
// cache = anisocache_type::createPartial(VdotH, LdotH, localH.z, transmitted, rcpEta);
288-
// assert(cache.isValid(_f.getRefractionOrientedEta()));
289-
290-
// struct reflect_refract_wrapper // so we don't recalculate LdotH
291-
// {
292-
// vector3_type operator()(const bool doRefract, const scalar_type rcpOrientedEta) NBL_CONST_MEMBER_FUNC
293-
// {
294-
// return rr(NdotTorR, rcpOrientedEta);
295-
// }
296-
// bxdf::ReflectRefract<scalar_type> rr;
297-
// scalar_type NdotTorR;
298-
// };
299-
// bxdf::ReflectRefract<scalar_type> rr; // rr.getNdotTorR() and calls to mix as well as a good part of the computations should CSE with our computation of NdotL above
300-
// rr.refract = r;
301-
// reflect_refract_wrapper rrw;
302-
// rrw.rr = rr;
303-
// rrw.NdotTorR = LdotH;
304-
// ray_dir_info_type L = V.template reflectRefract<reflect_refract_wrapper>(rrw, transmitted, rcpEta.value[0]);
305-
306-
ray_dir_info_type L;
307-
if (transmitted)
308-
{
309-
// scalar_type eta = rcpEta.value[0]; // refraction takes eta as ior_incoming/ior_transmitted due to snell's law
310-
// vector3_type orientedH = ieee754::flipSignIfRHSNegative<vector3_type>(H, hlsl::promote<vector3_type>(NdotV));
311-
// scalar_type cosThetaI = hlsl::dot(V.getDirection(), orientedH);
312-
// scalar_type sin2ThetaI = hlsl::max(scalar_type(0), scalar_type(1) - cosThetaI * cosThetaI);
313-
// scalar_type sin2ThetaT = eta * eta * sin2ThetaI;
314-
315-
// if (sin2ThetaT >= 1) return sample_type::createInvalid();
316-
// scalar_type cosThetaT = hlsl::sqrt(scalar_type(1) - sin2ThetaT);
317-
// L.direction = eta * -V.getDirection() + (eta * cosThetaI - cosThetaT) * orientedH;
318-
319-
320-
Refract<scalar_type> r = Refract<scalar_type>::create(V.getDirection(), H);
321-
bxdf::ReflectRefract<scalar_type> rr;
322-
rr.refract = r;
323-
L = V.reflectRefract(rr, transmitted, rcpEta.value[0]);
324-
L.direction = hlsl::normalize(L.direction);
325-
}
326-
else
327-
{
328-
bxdf::Reflect<scalar_type> r = bxdf::Reflect<scalar_type>::create(V.getDirection(), H);
329-
L = V.reflect(r);
330-
L.direction = hlsl::normalize(L.direction);
331-
}
332-
333-
vector3_type _N = hlsl::normalize(interaction.getN());
334-
scalar_type NdotL = hlsl::dot(_N, L.getDirection());
273+
const vector3_type H = hlsl::mul(interaction.getFromTangentSpace(), localH);
274+
assert(hlsl::abs(hlsl::length(H) - scalar_type(1.0)) < scalar_type(1e-4));
275+
Refract<scalar_type> r = Refract<scalar_type>::create(V.getDirection(), H);
276+
const scalar_type LdotH = hlsl::mix(VdotH, r.getNdotT(rcpEta.value2[0]), transmitted);
277+
278+
// fail if samples have invalid paths
279+
const scalar_type NdotL = hlsl::mix(scalar_type(2.0) * VdotH * localH.z - NdotV,
280+
localH.z * (VdotH * rcpEta.value[0] + LdotH) - NdotV * rcpEta.value[0], transmitted);
281+
// VNDF sampling guarantees that `VdotH` has same sign as `NdotV`
282+
// and `transmitted` controls the sign of `LdotH` relative to `VdotH` by construction (reflect -> same sign, or refract -> opposite sign)
335283
if (ComputeMicrofacetNormal<scalar_type>::isTransmissionPath(NdotV, NdotL) != transmitted)
336284
return sample_type::createInvalid(); // should check if sample direction is invalid
337285

338-
cache.iso_cache.VdotH = VdotH;
339-
cache.iso_cache.LdotH = hlsl::dot(L.getDirection(), H);
340-
// cache.iso_cache.VdotL = hlsl::dot(V.getDirection(), L.getDirection());
341-
cache.iso_cache.VdotL = hlsl::mix(scalar_type(2.0) * VdotH * VdotH - scalar_type(1.0),
342-
VdotH * (VdotH * rcpEta.value[0] + cache.iso_cache.LdotH) - rcpEta.value[0], transmitted);
343-
// const scalar_type viewShortenFactor = hlsl::mix(scalar_type(1.0), rcpEta.value[0], transmitted);
344-
// scalar_type _VdotL = VdotH * (VdotH * viewShortenFactor + cache.iso_cache.LdotH) - viewShortenFactor;
345-
// scalar_type VdotL = hlsl::dot(V.getDirection(), L.getDirection());
346-
// assert(hlsl::abs(VdotL - cache.iso_cache.VdotL) < 1e-4);
347-
assert(localH.z > scalar_type(0.0));
348-
cache.iso_cache.absNdotH = hlsl::abs(localH.z);
349-
cache.iso_cache.NdotH2 = localH.z * localH.z;
350-
286+
cache = anisocache_type::createPartial(VdotH, LdotH, localH.z, transmitted, rcpEta);
351287
assert(cache.isValid(_f.getRefractionOrientedEta()));
352288

353-
// const scalar_type _viewShortenFactor = hlsl::mix(scalar_type(1.0), rcpEta.value[0], transmitted);
354-
// const scalar_type _NdotL = localH.z * (VdotH * _viewShortenFactor + cache.iso_cache.LdotH) - NdotV * _viewShortenFactor;
355-
scalar_type _NdotL = hlsl::dot(_N, L.getDirection());
356-
assert(hlsl::abs(_NdotL - NdotL) < 1e-4);
289+
struct reflect_refract_wrapper // so we don't recalculate LdotH
290+
{
291+
vector3_type operator()(const bool doRefract, const scalar_type rcpOrientedEta) NBL_CONST_MEMBER_FUNC
292+
{
293+
return rr(NdotTorR, rcpOrientedEta);
294+
}
295+
bxdf::ReflectRefract<scalar_type> rr;
296+
scalar_type NdotTorR;
297+
};
298+
bxdf::ReflectRefract<scalar_type> rr; // rr.getNdotTorR() and calls to mix as well as a good part of the computations should CSE with our computation of NdotL above
299+
rr.refract = r;
300+
reflect_refract_wrapper rrw;
301+
rrw.rr = rr;
302+
rrw.NdotTorR = LdotH;
303+
ray_dir_info_type L = V.template reflectRefract<reflect_refract_wrapper>(rrw, transmitted, rcpEta.value[0]);
357304

358305
const vector3_type T = interaction.getT();
359306
const vector3_type B = interaction.getB();

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

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -48,7 +48,7 @@ NBL_CONCEPT_END(
4848
((NBL_CONCEPT_REQ_TYPE)(T::dg1_query_type))
4949
((NBL_CONCEPT_REQ_TYPE)(T::g2g1_query_type))
5050
((NBL_CONCEPT_REQ_TYPE)(T::quant_query_type))
51-
((NBL_CONCEPT_REQ_EXPR_RET_TYPE)((T::GuaranteedVNDF), ::nbl::hlsl::is_same_v, bool))
51+
// ((NBL_CONCEPT_REQ_EXPR_RET_TYPE)((T::GuaranteedVNDF), ::nbl::hlsl::is_same_v, bool))
5252
((NBL_CONCEPT_REQ_EXPR_RET_TYPE)((ndf.template D<dummy_impl::sample_t, dummy_impl::interaction_t, dummy_impl::cache_t>(quant_query, _sample, interaction, cache)), ::nbl::hlsl::is_same_v, typename T::quant_type))
5353
((NBL_CONCEPT_REQ_EXPR_RET_TYPE)((ndf.template DG1<dummy_impl::sample_t, dummy_impl::interaction_t>(dg1_query, quant_query, _sample, interaction)), ::nbl::hlsl::is_same_v, typename T::quant_type))
5454
((NBL_CONCEPT_REQ_EXPR_RET_TYPE)((ndf.template correlated<dummy_impl::sample_t, dummy_impl::interaction_t, dummy_impl::cache_t>(g2_query, _sample, interaction, cache)), ::nbl::hlsl::is_same_v, typename T::scalar_type))

0 commit comments

Comments
 (0)