// Cloth Method Definitions
BSDF *Cloth::GetBSDF(MemoryArena &arena, const SpectrumWavelengths &sw,
const Intersection &isect, const DifferentialGeometry &dgs) const
{
// Determine cloth coordinates and yarn at current point
Point uv;
float umax, scale = specularNormalization;
const Yarn *yarn = Pattern->GetYarn(dgs.u, dgs.v, &uv, &umax, &scale);
// Allocate _BSDF_
MultiBSDF<2> *bsdf = ARENA_ALLOC(arena, MultiBSDF<2>)(dgs, isect.dg.nn,
isect.exterior, isect.interior);
bsdf->Add(ARENA_ALLOC(arena, Lambertian)
(Kds.at(yarn->index)->Evaluate(sw, dgs).Clamp(0.f, 1.f)));
bsdf->Add(ARENA_ALLOC(arena, Irawan)
(Kss.at(yarn->index)->Evaluate(sw, dgs).Clamp(0.f, 1.f),
uv, umax, yarn, Pattern.get(), scale));
// Add ptr to CompositingParams structure
bsdf->SetCompositingParams(&compParams);
return bsdf;
}
// Glossy Method Definitions
BSDF *GlossyTranslucent::GetBSDF(MemoryArena &arena, const SpectrumWavelengths &sw,
const Intersection &isect, const DifferentialGeometry &dgs) const
{
// Allocate _BSDF_
// NOTE - lordcrc - changed clamping to 0..1 to avoid >1 reflection
SWCSpectrum d(Kd->Evaluate(sw, dgs).Clamp(0.f, 1.f));
SWCSpectrum t(Kt->Evaluate(sw, dgs).Clamp(0.f, 1.f));
SWCSpectrum s(Ks->Evaluate(sw, dgs));
float i = index->Evaluate(sw, dgs);
if (i > 0.f) {
const float ti = (i - 1.f) / (i + 1.f);
s *= ti * ti;
}
s = s.Clamp(0.f, 1.f);
SWCSpectrum a(Ka->Evaluate(sw, dgs).Clamp(0.f, 1.f));
float ld = depth->Evaluate(sw, dgs);
SWCSpectrum bs(Ks_bf->Evaluate(sw, dgs));
float bi = index_bf->Evaluate(sw, dgs);
if (bi > 0.f) {
const float bti = (bi - 1.f) / (bi + 1.f);
bs *= bti * bti;
}
bs = bs.Clamp(0.f, 1.f);
SWCSpectrum ba(Ka_bf->Evaluate(sw, dgs).Clamp(0.f, 1.f));
float bld = depth_bf->Evaluate(sw, dgs);
// Clamp roughness values to avoid artifacts with too small values
const float u = Clamp(nu->Evaluate(sw, dgs), 6e-3f, 1.f);
const float v = Clamp(nv->Evaluate(sw, dgs), 6e-3f, 1.f);
const float u2 = u * u;
const float v2 = v * v;
const float roughness = u * v;
const float anisotropy = u2 < v2 ? 1.f - u2 / v2 : v2 / u2 - 1.f;
// Clamp roughness values to avoid artifacts with too small values
const float bu = Clamp(nu_bf->Evaluate(sw, dgs), 6e-3f, 1.f);
const float bv = Clamp(nv_bf->Evaluate(sw, dgs), 6e-3f, 1.f);
const float bu2 = bu * bu;
const float bv2 = bv * bv;
const float broughness = bu * bv;
const float banisotropy = bu2 < bv2 ? 1.f - bu2 / bv2 : bv2 / bu2 - 1.f;
MultiBSDF<2> *bsdf = ARENA_ALLOC(arena, MultiBSDF<2>)(dgs, isect.dg.nn,
isect.exterior, isect.interior);
// add the BRDF
bsdf->Add(ARENA_ALLOC(arena, SchlickDoubleSidedBRDF)(d, s, bs, a, ba,
ld, bld, roughness, broughness, anisotropy, banisotropy,
multibounce, multibounce_bf));
// add the BTDF
bsdf->Add(ARENA_ALLOC(arena, SchlickTranslucentBTDF)(d, t, s, bs, a, ba,
ld, bld));
// Add ptr to CompositingParams structure
bsdf->SetCompositingParams(&compParams);
return bsdf;
}