forked from bartvdbraak/blender
23c276832b
This commit adds a new distribution to the Glossy, Anisotropic and Glass BSDFs that implements the multiple-scattering microfacet model described in the paper "Multiple-Scattering Microfacet BSDFs with the Smith Model". Essentially, the improvement is that unlike classical GGX, which only models single scattering and assumes the contribution of multiple bounces to be zero, this new model performs a random walk on the microsurface until the ray leaves it again, which ensures perfect energy conservation. In practise, this means that the "darkening problem" - GGX materials becoming darker with increasing roughness - is solved in a physically correct and efficient way. The downside of this model is that it has no (known) analytic expression for evalation. However, it can be evaluated stochastically, and although the correct PDF isn't known either, the properties of MIS and the balance heuristic guarantee an unbiased result at the cost of slightly higher noise. Reviewers: dingto, #cycles, brecht Reviewed By: dingto, #cycles, brecht Subscribers: bliblubli, ace_dragon, gregzaal, brecht, harvester, dingto, marcog, swerner, jtheninja, Blendify, nutel Differential Revision: https://developer.blender.org/D2002
336 lines
14 KiB
C
336 lines
14 KiB
C
/*
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* Copyright 2011-2013 Blender Foundation
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#include "../closure/bsdf_ashikhmin_velvet.h"
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#include "../closure/bsdf_diffuse.h"
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#include "../closure/bsdf_oren_nayar.h"
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#include "../closure/bsdf_phong_ramp.h"
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#include "../closure/bsdf_diffuse_ramp.h"
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#include "../closure/bsdf_microfacet.h"
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#include "../closure/bsdf_microfacet_multi.h"
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#include "../closure/bsdf_reflection.h"
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#include "../closure/bsdf_refraction.h"
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#include "../closure/bsdf_transparent.h"
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#include "../closure/bsdf_ashikhmin_shirley.h"
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#include "../closure/bsdf_toon.h"
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#include "../closure/bsdf_hair.h"
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#ifdef __SUBSURFACE__
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# include "../closure/bssrdf.h"
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#endif
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#ifdef __VOLUME__
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# include "../closure/volume.h"
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#endif
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CCL_NAMESPACE_BEGIN
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ccl_device int bsdf_sample(KernelGlobals *kg, ShaderData *sd, const ShaderClosure *sc, float randu, float randv, float3 *eval, float3 *omega_in, differential3 *domega_in, float *pdf)
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{
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int label;
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#ifdef __OSL__
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if(kg->osl && sc->prim)
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return OSLShader::bsdf_sample(sd, sc, randu, randv, *eval, *omega_in, *domega_in, *pdf);
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#endif
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switch(sc->type) {
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case CLOSURE_BSDF_DIFFUSE_ID:
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case CLOSURE_BSDF_BSSRDF_ID:
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label = bsdf_diffuse_sample(sc, ccl_fetch(sd, Ng), ccl_fetch(sd, I), ccl_fetch(sd, dI).dx, ccl_fetch(sd, dI).dy, randu, randv,
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eval, omega_in, &domega_in->dx, &domega_in->dy, pdf);
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break;
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#ifdef __SVM__
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case CLOSURE_BSDF_OREN_NAYAR_ID:
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label = bsdf_oren_nayar_sample(sc, ccl_fetch(sd, Ng), ccl_fetch(sd, I), ccl_fetch(sd, dI).dx, ccl_fetch(sd, dI).dy, randu, randv,
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eval, omega_in, &domega_in->dx, &domega_in->dy, pdf);
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break;
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/*case CLOSURE_BSDF_PHONG_RAMP_ID:
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label = bsdf_phong_ramp_sample(sc, ccl_fetch(sd, Ng), ccl_fetch(sd, I), ccl_fetch(sd, dI).dx, ccl_fetch(sd, dI).dy, randu, randv,
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eval, omega_in, &domega_in->dx, &domega_in->dy, pdf);
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break;
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case CLOSURE_BSDF_DIFFUSE_RAMP_ID:
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label = bsdf_diffuse_ramp_sample(sc, ccl_fetch(sd, Ng), ccl_fetch(sd, I), ccl_fetch(sd, dI).dx, ccl_fetch(sd, dI).dy, randu, randv,
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eval, omega_in, &domega_in->dx, &domega_in->dy, pdf);
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break;*/
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case CLOSURE_BSDF_TRANSLUCENT_ID:
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label = bsdf_translucent_sample(sc, ccl_fetch(sd, Ng), ccl_fetch(sd, I), ccl_fetch(sd, dI).dx, ccl_fetch(sd, dI).dy, randu, randv,
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eval, omega_in, &domega_in->dx, &domega_in->dy, pdf);
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break;
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case CLOSURE_BSDF_REFLECTION_ID:
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label = bsdf_reflection_sample(sc, ccl_fetch(sd, Ng), ccl_fetch(sd, I), ccl_fetch(sd, dI).dx, ccl_fetch(sd, dI).dy, randu, randv,
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eval, omega_in, &domega_in->dx, &domega_in->dy, pdf);
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break;
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case CLOSURE_BSDF_REFRACTION_ID:
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label = bsdf_refraction_sample(sc, ccl_fetch(sd, Ng), ccl_fetch(sd, I), ccl_fetch(sd, dI).dx, ccl_fetch(sd, dI).dy, randu, randv,
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eval, omega_in, &domega_in->dx, &domega_in->dy, pdf);
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break;
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case CLOSURE_BSDF_TRANSPARENT_ID:
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label = bsdf_transparent_sample(sc, ccl_fetch(sd, Ng), ccl_fetch(sd, I), ccl_fetch(sd, dI).dx, ccl_fetch(sd, dI).dy, randu, randv,
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eval, omega_in, &domega_in->dx, &domega_in->dy, pdf);
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break;
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case CLOSURE_BSDF_MICROFACET_GGX_ID:
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case CLOSURE_BSDF_MICROFACET_GGX_ANISO_ID:
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case CLOSURE_BSDF_MICROFACET_GGX_REFRACTION_ID:
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label = bsdf_microfacet_ggx_sample(kg, sc, ccl_fetch(sd, Ng), ccl_fetch(sd, I), ccl_fetch(sd, dI).dx, ccl_fetch(sd, dI).dy, randu, randv,
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eval, omega_in, &domega_in->dx, &domega_in->dy, pdf);
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break;
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case CLOSURE_BSDF_MICROFACET_MULTI_GGX_ID:
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label = bsdf_microfacet_multi_ggx_sample(kg, sc, ccl_fetch(sd, Ng), ccl_fetch(sd, I), ccl_fetch(sd, dI).dx, ccl_fetch(sd, dI).dy, randu, randv,
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eval, omega_in, &domega_in->dx, &domega_in->dy, pdf, &ccl_fetch(sd, lcg_state));
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break;
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case CLOSURE_BSDF_MICROFACET_MULTI_GGX_GLASS_ID:
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label = bsdf_microfacet_multi_ggx_glass_sample(kg, sc, ccl_fetch(sd, Ng), ccl_fetch(sd, I), ccl_fetch(sd, dI).dx, ccl_fetch(sd, dI).dy, randu, randv,
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eval, omega_in, &domega_in->dx, &domega_in->dy, pdf, &ccl_fetch(sd, lcg_state));
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break;
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case CLOSURE_BSDF_MICROFACET_BECKMANN_ID:
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case CLOSURE_BSDF_MICROFACET_BECKMANN_ANISO_ID:
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case CLOSURE_BSDF_MICROFACET_BECKMANN_REFRACTION_ID:
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label = bsdf_microfacet_beckmann_sample(kg, sc, ccl_fetch(sd, Ng), ccl_fetch(sd, I), ccl_fetch(sd, dI).dx, ccl_fetch(sd, dI).dy, randu, randv,
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eval, omega_in, &domega_in->dx, &domega_in->dy, pdf);
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break;
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case CLOSURE_BSDF_ASHIKHMIN_SHIRLEY_ID:
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case CLOSURE_BSDF_ASHIKHMIN_SHIRLEY_ANISO_ID:
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label = bsdf_ashikhmin_shirley_sample(sc, ccl_fetch(sd, Ng), ccl_fetch(sd, I), ccl_fetch(sd, dI).dx, ccl_fetch(sd, dI).dy, randu, randv,
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eval, omega_in, &domega_in->dx, &domega_in->dy, pdf);
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break;
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case CLOSURE_BSDF_ASHIKHMIN_VELVET_ID:
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label = bsdf_ashikhmin_velvet_sample(sc, ccl_fetch(sd, Ng), ccl_fetch(sd, I), ccl_fetch(sd, dI).dx, ccl_fetch(sd, dI).dy, randu, randv,
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eval, omega_in, &domega_in->dx, &domega_in->dy, pdf);
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break;
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case CLOSURE_BSDF_DIFFUSE_TOON_ID:
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label = bsdf_diffuse_toon_sample(sc, ccl_fetch(sd, Ng), ccl_fetch(sd, I), ccl_fetch(sd, dI).dx, ccl_fetch(sd, dI).dy, randu, randv,
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eval, omega_in, &domega_in->dx, &domega_in->dy, pdf);
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break;
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case CLOSURE_BSDF_GLOSSY_TOON_ID:
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label = bsdf_glossy_toon_sample(sc, ccl_fetch(sd, Ng), ccl_fetch(sd, I), ccl_fetch(sd, dI).dx, ccl_fetch(sd, dI).dy, randu, randv,
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eval, omega_in, &domega_in->dx, &domega_in->dy, pdf);
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break;
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case CLOSURE_BSDF_HAIR_REFLECTION_ID:
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label = bsdf_hair_reflection_sample(sc, ccl_fetch(sd, Ng), ccl_fetch(sd, I), ccl_fetch(sd, dI).dx, ccl_fetch(sd, dI).dy, randu, randv,
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eval, omega_in, &domega_in->dx, &domega_in->dy, pdf);
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break;
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case CLOSURE_BSDF_HAIR_TRANSMISSION_ID:
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label = bsdf_hair_transmission_sample(sc, ccl_fetch(sd, Ng), ccl_fetch(sd, I), ccl_fetch(sd, dI).dx, ccl_fetch(sd, dI).dy, randu, randv,
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eval, omega_in, &domega_in->dx, &domega_in->dy, pdf);
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break;
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#endif
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#ifdef __VOLUME__
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case CLOSURE_VOLUME_HENYEY_GREENSTEIN_ID:
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label = volume_henyey_greenstein_sample(sc, ccl_fetch(sd, I), ccl_fetch(sd, dI).dx, ccl_fetch(sd, dI).dy, randu, randv, eval, omega_in, &domega_in->dx, &domega_in->dy, pdf);
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break;
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#endif
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default:
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label = LABEL_NONE;
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break;
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}
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return label;
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}
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ccl_device float3 bsdf_eval(KernelGlobals *kg, ShaderData *sd, const ShaderClosure *sc, const float3 omega_in, float *pdf)
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{
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float3 eval;
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#ifdef __OSL__
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if(kg->osl && sc->prim)
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return OSLShader::bsdf_eval(sd, sc, omega_in, *pdf);
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#endif
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if(dot(ccl_fetch(sd, Ng), omega_in) >= 0.0f) {
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switch(sc->type) {
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case CLOSURE_BSDF_DIFFUSE_ID:
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case CLOSURE_BSDF_BSSRDF_ID:
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eval = bsdf_diffuse_eval_reflect(sc, ccl_fetch(sd, I), omega_in, pdf);
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break;
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#ifdef __SVM__
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case CLOSURE_BSDF_OREN_NAYAR_ID:
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eval = bsdf_oren_nayar_eval_reflect(sc, ccl_fetch(sd, I), omega_in, pdf);
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break;
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/*case CLOSURE_BSDF_PHONG_RAMP_ID:
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eval = bsdf_phong_ramp_eval_reflect(sc, ccl_fetch(sd, I), omega_in, pdf);
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break;
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case CLOSURE_BSDF_DIFFUSE_RAMP_ID:
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eval = bsdf_diffuse_ramp_eval_reflect(sc, ccl_fetch(sd, I), omega_in, pdf);
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break;*/
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case CLOSURE_BSDF_TRANSLUCENT_ID:
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eval = bsdf_translucent_eval_reflect(sc, ccl_fetch(sd, I), omega_in, pdf);
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break;
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case CLOSURE_BSDF_REFLECTION_ID:
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eval = bsdf_reflection_eval_reflect(sc, ccl_fetch(sd, I), omega_in, pdf);
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break;
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case CLOSURE_BSDF_REFRACTION_ID:
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eval = bsdf_refraction_eval_reflect(sc, ccl_fetch(sd, I), omega_in, pdf);
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break;
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case CLOSURE_BSDF_TRANSPARENT_ID:
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eval = bsdf_transparent_eval_reflect(sc, ccl_fetch(sd, I), omega_in, pdf);
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break;
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case CLOSURE_BSDF_MICROFACET_GGX_ID:
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case CLOSURE_BSDF_MICROFACET_GGX_ANISO_ID:
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case CLOSURE_BSDF_MICROFACET_GGX_REFRACTION_ID:
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eval = bsdf_microfacet_ggx_eval_reflect(sc, ccl_fetch(sd, I), omega_in, pdf);
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break;
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case CLOSURE_BSDF_MICROFACET_MULTI_GGX_ID:
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eval = bsdf_microfacet_multi_ggx_eval_reflect(sc, ccl_fetch(sd, I), omega_in, pdf, &ccl_fetch(sd, lcg_state));
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break;
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case CLOSURE_BSDF_MICROFACET_MULTI_GGX_GLASS_ID:
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eval = bsdf_microfacet_multi_ggx_glass_eval_reflect(sc, ccl_fetch(sd, I), omega_in, pdf, &ccl_fetch(sd, lcg_state));
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break;
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case CLOSURE_BSDF_MICROFACET_BECKMANN_ID:
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case CLOSURE_BSDF_MICROFACET_BECKMANN_ANISO_ID:
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case CLOSURE_BSDF_MICROFACET_BECKMANN_REFRACTION_ID:
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eval = bsdf_microfacet_beckmann_eval_reflect(sc, ccl_fetch(sd, I), omega_in, pdf);
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break;
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case CLOSURE_BSDF_ASHIKHMIN_SHIRLEY_ID:
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case CLOSURE_BSDF_ASHIKHMIN_SHIRLEY_ANISO_ID:
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eval = bsdf_ashikhmin_shirley_eval_reflect(sc, ccl_fetch(sd, I), omega_in, pdf);
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break;
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case CLOSURE_BSDF_ASHIKHMIN_VELVET_ID:
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eval = bsdf_ashikhmin_velvet_eval_reflect(sc, ccl_fetch(sd, I), omega_in, pdf);
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break;
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case CLOSURE_BSDF_DIFFUSE_TOON_ID:
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eval = bsdf_diffuse_toon_eval_reflect(sc, ccl_fetch(sd, I), omega_in, pdf);
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break;
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case CLOSURE_BSDF_GLOSSY_TOON_ID:
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eval = bsdf_glossy_toon_eval_reflect(sc, ccl_fetch(sd, I), omega_in, pdf);
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break;
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case CLOSURE_BSDF_HAIR_REFLECTION_ID:
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eval = bsdf_hair_reflection_eval_reflect(sc, ccl_fetch(sd, I), omega_in, pdf);
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break;
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case CLOSURE_BSDF_HAIR_TRANSMISSION_ID:
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eval = bsdf_hair_transmission_eval_reflect(sc, ccl_fetch(sd, I), omega_in, pdf);
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break;
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#endif
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#ifdef __VOLUME__
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case CLOSURE_VOLUME_HENYEY_GREENSTEIN_ID:
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eval = volume_henyey_greenstein_eval_phase(sc, ccl_fetch(sd, I), omega_in, pdf);
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break;
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#endif
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default:
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eval = make_float3(0.0f, 0.0f, 0.0f);
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break;
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}
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}
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else {
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switch(sc->type) {
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case CLOSURE_BSDF_DIFFUSE_ID:
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case CLOSURE_BSDF_BSSRDF_ID:
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eval = bsdf_diffuse_eval_transmit(sc, ccl_fetch(sd, I), omega_in, pdf);
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break;
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#ifdef __SVM__
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case CLOSURE_BSDF_OREN_NAYAR_ID:
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eval = bsdf_oren_nayar_eval_transmit(sc, ccl_fetch(sd, I), omega_in, pdf);
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break;
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case CLOSURE_BSDF_TRANSLUCENT_ID:
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eval = bsdf_translucent_eval_transmit(sc, ccl_fetch(sd, I), omega_in, pdf);
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break;
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case CLOSURE_BSDF_REFLECTION_ID:
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eval = bsdf_reflection_eval_transmit(sc, ccl_fetch(sd, I), omega_in, pdf);
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break;
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case CLOSURE_BSDF_REFRACTION_ID:
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eval = bsdf_refraction_eval_transmit(sc, ccl_fetch(sd, I), omega_in, pdf);
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break;
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case CLOSURE_BSDF_TRANSPARENT_ID:
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eval = bsdf_transparent_eval_transmit(sc, ccl_fetch(sd, I), omega_in, pdf);
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break;
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case CLOSURE_BSDF_MICROFACET_GGX_ID:
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case CLOSURE_BSDF_MICROFACET_GGX_ANISO_ID:
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case CLOSURE_BSDF_MICROFACET_GGX_REFRACTION_ID:
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eval = bsdf_microfacet_ggx_eval_transmit(sc, ccl_fetch(sd, I), omega_in, pdf);
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break;
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case CLOSURE_BSDF_MICROFACET_MULTI_GGX_ID:
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eval = bsdf_microfacet_multi_ggx_eval_transmit(sc, ccl_fetch(sd, I), omega_in, pdf, &ccl_fetch(sd, lcg_state));
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break;
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case CLOSURE_BSDF_MICROFACET_MULTI_GGX_GLASS_ID:
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eval = bsdf_microfacet_multi_ggx_glass_eval_transmit(sc, ccl_fetch(sd, I), omega_in, pdf, &ccl_fetch(sd, lcg_state));
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break;
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case CLOSURE_BSDF_MICROFACET_BECKMANN_ID:
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case CLOSURE_BSDF_MICROFACET_BECKMANN_ANISO_ID:
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case CLOSURE_BSDF_MICROFACET_BECKMANN_REFRACTION_ID:
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eval = bsdf_microfacet_beckmann_eval_transmit(sc, ccl_fetch(sd, I), omega_in, pdf);
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break;
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case CLOSURE_BSDF_ASHIKHMIN_SHIRLEY_ID:
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case CLOSURE_BSDF_ASHIKHMIN_SHIRLEY_ANISO_ID:
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eval = bsdf_ashikhmin_shirley_eval_transmit(sc, ccl_fetch(sd, I), omega_in, pdf);
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break;
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case CLOSURE_BSDF_ASHIKHMIN_VELVET_ID:
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eval = bsdf_ashikhmin_velvet_eval_transmit(sc, ccl_fetch(sd, I), omega_in, pdf);
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break;
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case CLOSURE_BSDF_DIFFUSE_TOON_ID:
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eval = bsdf_diffuse_toon_eval_transmit(sc, ccl_fetch(sd, I), omega_in, pdf);
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break;
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case CLOSURE_BSDF_GLOSSY_TOON_ID:
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eval = bsdf_glossy_toon_eval_transmit(sc, ccl_fetch(sd, I), omega_in, pdf);
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break;
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case CLOSURE_BSDF_HAIR_REFLECTION_ID:
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eval = bsdf_hair_reflection_eval_transmit(sc, ccl_fetch(sd, I), omega_in, pdf);
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break;
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case CLOSURE_BSDF_HAIR_TRANSMISSION_ID:
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eval = bsdf_hair_transmission_eval_transmit(sc, ccl_fetch(sd, I), omega_in, pdf);
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break;
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#endif
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#ifdef __VOLUME__
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case CLOSURE_VOLUME_HENYEY_GREENSTEIN_ID:
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eval = volume_henyey_greenstein_eval_phase(sc, ccl_fetch(sd, I), omega_in, pdf);
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break;
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#endif
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default:
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eval = make_float3(0.0f, 0.0f, 0.0f);
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break;
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}
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}
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return eval;
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}
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ccl_device void bsdf_blur(KernelGlobals *kg, ShaderClosure *sc, float roughness)
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{
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/* ToDo: do we want to blur volume closures? */
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#ifdef __OSL__
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if(kg->osl && sc->prim) {
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OSLShader::bsdf_blur(sc, roughness);
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return;
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}
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#endif
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#ifdef __SVM__
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switch(sc->type) {
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case CLOSURE_BSDF_MICROFACET_MULTI_GGX_ID:
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case CLOSURE_BSDF_MICROFACET_MULTI_GGX_GLASS_ID:
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bsdf_microfacet_multi_ggx_blur(sc, roughness);
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break;
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case CLOSURE_BSDF_MICROFACET_GGX_ID:
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case CLOSURE_BSDF_MICROFACET_GGX_ANISO_ID:
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case CLOSURE_BSDF_MICROFACET_GGX_REFRACTION_ID:
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bsdf_microfacet_ggx_blur(sc, roughness);
|
|
break;
|
|
case CLOSURE_BSDF_MICROFACET_BECKMANN_ID:
|
|
case CLOSURE_BSDF_MICROFACET_BECKMANN_ANISO_ID:
|
|
case CLOSURE_BSDF_MICROFACET_BECKMANN_REFRACTION_ID:
|
|
bsdf_microfacet_beckmann_blur(sc, roughness);
|
|
break;
|
|
case CLOSURE_BSDF_ASHIKHMIN_SHIRLEY_ID:
|
|
case CLOSURE_BSDF_ASHIKHMIN_SHIRLEY_ANISO_ID:
|
|
bsdf_ashikhmin_shirley_blur(sc, roughness);
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
#endif
|
|
}
|
|
|
|
CCL_NAMESPACE_END
|
|
|