/* SPDX-License-Identifier: Apache-2.0 * Copyright 2011-2022 Blender Foundation */ #pragma once // clang-format off #include "kernel/closure/bsdf_ashikhmin_velvet.h" #include "kernel/closure/bsdf_diffuse.h" #include "kernel/closure/bsdf_oren_nayar.h" #include "kernel/closure/bsdf_phong_ramp.h" #include "kernel/closure/bsdf_diffuse_ramp.h" #include "kernel/closure/bsdf_microfacet.h" #include "kernel/closure/bsdf_microfacet_multi.h" #include "kernel/closure/bsdf_reflection.h" #include "kernel/closure/bsdf_refraction.h" #include "kernel/closure/bsdf_transparent.h" #include "kernel/closure/bsdf_ashikhmin_shirley.h" #include "kernel/closure/bsdf_toon.h" #include "kernel/closure/bsdf_hair.h" #include "kernel/closure/bsdf_hair_principled.h" #include "kernel/closure/bsdf_principled_diffuse.h" #include "kernel/closure/bsdf_principled_sheen.h" #include "kernel/closure/bssrdf.h" #include "kernel/closure/volume.h" // clang-format on CCL_NAMESPACE_BEGIN /* Returns the square of the roughness of the closure if it has roughness, * 0 for singular closures and 1 otherwise. */ ccl_device_inline float bsdf_get_specular_roughness_squared(ccl_private const ShaderClosure *sc) { if (CLOSURE_IS_BSDF_SINGULAR(sc->type)) { return 0.0f; } if (CLOSURE_IS_BSDF_MICROFACET(sc->type)) { ccl_private MicrofacetBsdf *bsdf = (ccl_private MicrofacetBsdf *)sc; return bsdf->alpha_x * bsdf->alpha_y; } return 1.0f; } ccl_device_inline float bsdf_get_roughness_squared(ccl_private const ShaderClosure *sc) { /* This version includes diffuse, mainly for baking Principled BSDF * where specular and metallic zero otherwise does not bake the * specified roughness parameter. */ if (sc->type == CLOSURE_BSDF_OREN_NAYAR_ID) { ccl_private OrenNayarBsdf *bsdf = (ccl_private OrenNayarBsdf *)sc; return sqr(sqr(bsdf->roughness)); } if (sc->type == CLOSURE_BSDF_PRINCIPLED_DIFFUSE_ID) { ccl_private PrincipledDiffuseBsdf *bsdf = (ccl_private PrincipledDiffuseBsdf *)sc; return sqr(sqr(bsdf->roughness)); } if (CLOSURE_IS_BSDF_DIFFUSE(sc->type)) { return 0.0f; } return bsdf_get_specular_roughness_squared(sc); } /* An additional term to smooth illumination on grazing angles when using bump mapping. * Based on "Taming the Shadow Terminator" by Matt Jen-Yuan Chiang, * Yining Karl Li and Brent Burley. */ ccl_device_inline float bump_shadowing_term(float3 Ng, float3 N, float3 I) { float g = safe_divide(dot(Ng, I), dot(N, I) * dot(Ng, N)); /* If the incoming light is on the unshadowed side, return full brightness. */ if (g >= 1.0f) { return 1.0f; } /* If the incoming light points away from the surface, return black. */ if (g < 0.0f) { return 0.0f; } /* Return smoothed value to avoid discontinuity at perpendicular angle. */ float g2 = sqr(g); return -g2 * g + g2 + g; } ccl_device_inline float shift_cos_in(float cos_in, const float frequency_multiplier) { /* Shadow terminator workaround, taken from Appleseed. * SPDX-License-Identifier: MIT * Copyright (c) 2019 Francois Beaune, The appleseedhq Organization */ cos_in = min(cos_in, 1.0f); const float angle = fast_acosf(cos_in); const float val = max(cosf(angle * frequency_multiplier), 0.0f) / cos_in; return val; } ccl_device_inline int bsdf_sample(KernelGlobals kg, ccl_private ShaderData *sd, ccl_private const ShaderClosure *sc, float randu, float randv, ccl_private float3 *eval, ccl_private float3 *omega_in, ccl_private differential3 *domega_in, ccl_private float *pdf) { /* For curves use the smooth normal, particularly for ribbons the geometric * normal gives too much darkening otherwise. */ int label; const float3 Ng = (sd->type & PRIMITIVE_CURVE) ? sc->N : sd->Ng; switch (sc->type) { case CLOSURE_BSDF_DIFFUSE_ID: label = bsdf_diffuse_sample(sc, Ng, sd->I, sd->dI.dx, sd->dI.dy, randu, randv, eval, omega_in, &domega_in->dx, &domega_in->dy, pdf); break; #ifdef __SVM__ case CLOSURE_BSDF_OREN_NAYAR_ID: label = bsdf_oren_nayar_sample(sc, Ng, sd->I, sd->dI.dx, sd->dI.dy, randu, randv, eval, omega_in, &domega_in->dx, &domega_in->dy, pdf); break; # ifdef __OSL__ case CLOSURE_BSDF_PHONG_RAMP_ID: label = bsdf_phong_ramp_sample(sc, Ng, sd->I, sd->dI.dx, sd->dI.dy, randu, randv, eval, omega_in, &domega_in->dx, &domega_in->dy, pdf); break; case CLOSURE_BSDF_DIFFUSE_RAMP_ID: label = bsdf_diffuse_ramp_sample(sc, Ng, sd->I, sd->dI.dx, sd->dI.dy, randu, randv, eval, omega_in, &domega_in->dx, &domega_in->dy, pdf); break; # endif case CLOSURE_BSDF_TRANSLUCENT_ID: label = bsdf_translucent_sample(sc, Ng, sd->I, sd->dI.dx, sd->dI.dy, randu, randv, eval, omega_in, &domega_in->dx, &domega_in->dy, pdf); break; case CLOSURE_BSDF_REFLECTION_ID: label = bsdf_reflection_sample(sc, Ng, sd->I, sd->dI.dx, sd->dI.dy, randu, randv, eval, omega_in, &domega_in->dx, &domega_in->dy, pdf); break; case CLOSURE_BSDF_REFRACTION_ID: label = bsdf_refraction_sample(sc, Ng, sd->I, sd->dI.dx, sd->dI.dy, randu, randv, eval, omega_in, &domega_in->dx, &domega_in->dy, pdf); break; case CLOSURE_BSDF_TRANSPARENT_ID: label = bsdf_transparent_sample(sc, Ng, sd->I, sd->dI.dx, sd->dI.dy, randu, randv, eval, omega_in, &domega_in->dx, &domega_in->dy, pdf); break; case CLOSURE_BSDF_MICROFACET_GGX_ID: case CLOSURE_BSDF_MICROFACET_GGX_FRESNEL_ID: case CLOSURE_BSDF_MICROFACET_GGX_CLEARCOAT_ID: case CLOSURE_BSDF_MICROFACET_GGX_REFRACTION_ID: label = bsdf_microfacet_ggx_sample(kg, sc, Ng, sd->I, sd->dI.dx, sd->dI.dy, randu, randv, eval, omega_in, &domega_in->dx, &domega_in->dy, pdf); break; case CLOSURE_BSDF_MICROFACET_MULTI_GGX_ID: case CLOSURE_BSDF_MICROFACET_MULTI_GGX_FRESNEL_ID: label = bsdf_microfacet_multi_ggx_sample(kg, sc, Ng, sd->I, sd->dI.dx, sd->dI.dy, randu, randv, eval, omega_in, &domega_in->dx, &domega_in->dy, pdf, &sd->lcg_state); break; case CLOSURE_BSDF_MICROFACET_MULTI_GGX_GLASS_ID: case CLOSURE_BSDF_MICROFACET_MULTI_GGX_GLASS_FRESNEL_ID: label = bsdf_microfacet_multi_ggx_glass_sample(kg, sc, Ng, sd->I, sd->dI.dx, sd->dI.dy, randu, randv, eval, omega_in, &domega_in->dx, &domega_in->dy, pdf, &sd->lcg_state); break; case CLOSURE_BSDF_MICROFACET_BECKMANN_ID: case CLOSURE_BSDF_MICROFACET_BECKMANN_REFRACTION_ID: label = bsdf_microfacet_beckmann_sample(kg, sc, Ng, sd->I, sd->dI.dx, sd->dI.dy, randu, randv, eval, omega_in, &domega_in->dx, &domega_in->dy, pdf); break; case CLOSURE_BSDF_ASHIKHMIN_SHIRLEY_ID: label = bsdf_ashikhmin_shirley_sample(sc, Ng, sd->I, sd->dI.dx, sd->dI.dy, randu, randv, eval, omega_in, &domega_in->dx, &domega_in->dy, pdf); break; case CLOSURE_BSDF_ASHIKHMIN_VELVET_ID: label = bsdf_ashikhmin_velvet_sample(sc, Ng, sd->I, sd->dI.dx, sd->dI.dy, randu, randv, eval, omega_in, &domega_in->dx, &domega_in->dy, pdf); break; case CLOSURE_BSDF_DIFFUSE_TOON_ID: label = bsdf_diffuse_toon_sample(sc, Ng, sd->I, sd->dI.dx, sd->dI.dy, randu, randv, eval, omega_in, &domega_in->dx, &domega_in->dy, pdf); break; case CLOSURE_BSDF_GLOSSY_TOON_ID: label = bsdf_glossy_toon_sample(sc, Ng, sd->I, sd->dI.dx, sd->dI.dy, randu, randv, eval, omega_in, &domega_in->dx, &domega_in->dy, pdf); break; case CLOSURE_BSDF_HAIR_REFLECTION_ID: label = bsdf_hair_reflection_sample(sc, Ng, sd->I, sd->dI.dx, sd->dI.dy, randu, randv, eval, omega_in, &domega_in->dx, &domega_in->dy, pdf); break; case CLOSURE_BSDF_HAIR_TRANSMISSION_ID: label = bsdf_hair_transmission_sample(sc, Ng, sd->I, sd->dI.dx, sd->dI.dy, randu, randv, eval, omega_in, &domega_in->dx, &domega_in->dy, pdf); break; case CLOSURE_BSDF_HAIR_PRINCIPLED_ID: label = bsdf_principled_hair_sample( kg, sc, sd, randu, randv, eval, omega_in, &domega_in->dx, &domega_in->dy, pdf); break; # ifdef __PRINCIPLED__ case CLOSURE_BSDF_PRINCIPLED_DIFFUSE_ID: label = bsdf_principled_diffuse_sample(sc, Ng, sd->I, sd->dI.dx, sd->dI.dy, randu, randv, eval, omega_in, &domega_in->dx, &domega_in->dy, pdf); break; case CLOSURE_BSDF_PRINCIPLED_SHEEN_ID: label = bsdf_principled_sheen_sample(sc, Ng, sd->I, sd->dI.dx, sd->dI.dy, randu, randv, eval, omega_in, &domega_in->dx, &domega_in->dy, pdf); break; # endif /* __PRINCIPLED__ */ #endif default: label = LABEL_NONE; break; } /* Test if BSDF sample should be treated as transparent for background. */ if (label & LABEL_TRANSMIT) { float threshold_squared = kernel_data.background.transparent_roughness_squared_threshold; if (threshold_squared >= 0.0f && !(label & LABEL_DIFFUSE)) { if (bsdf_get_specular_roughness_squared(sc) <= threshold_squared) { label |= LABEL_TRANSMIT_TRANSPARENT; } } } else { /* Shadow terminator offset. */ const float frequency_multiplier = kernel_tex_fetch(__objects, sd->object).shadow_terminator_shading_offset; if (frequency_multiplier > 1.0f) { *eval *= shift_cos_in(dot(*omega_in, sc->N), frequency_multiplier); } if (label & LABEL_DIFFUSE) { if (!isequal_float3(sc->N, sd->N)) { *eval *= bump_shadowing_term((label & LABEL_TRANSMIT) ? -sd->N : sd->N, sc->N, *omega_in); } } } #ifdef WITH_CYCLES_DEBUG kernel_assert(*pdf >= 0.0f); kernel_assert(eval->x >= 0.0f && eval->y >= 0.0f && eval->z >= 0.0f); #endif return label; } #ifndef __KERNEL_CUDA__ ccl_device #else ccl_device_inline #endif float3 bsdf_eval(KernelGlobals kg, ccl_private ShaderData *sd, ccl_private const ShaderClosure *sc, const float3 omega_in, const bool is_transmission, ccl_private float *pdf) { float3 eval = zero_float3(); if (!is_transmission) { switch (sc->type) { case CLOSURE_BSDF_DIFFUSE_ID: eval = bsdf_diffuse_eval_reflect(sc, sd->I, omega_in, pdf); break; #ifdef __SVM__ case CLOSURE_BSDF_OREN_NAYAR_ID: eval = bsdf_oren_nayar_eval_reflect(sc, sd->I, omega_in, pdf); break; # ifdef __OSL__ case CLOSURE_BSDF_PHONG_RAMP_ID: eval = bsdf_phong_ramp_eval_reflect(sc, sd->I, omega_in, pdf); break; case CLOSURE_BSDF_DIFFUSE_RAMP_ID: eval = bsdf_diffuse_ramp_eval_reflect(sc, sd->I, omega_in, pdf); break; # endif case CLOSURE_BSDF_TRANSLUCENT_ID: eval = bsdf_translucent_eval_reflect(sc, sd->I, omega_in, pdf); break; case CLOSURE_BSDF_REFLECTION_ID: eval = bsdf_reflection_eval_reflect(sc, sd->I, omega_in, pdf); break; case CLOSURE_BSDF_REFRACTION_ID: eval = bsdf_refraction_eval_reflect(sc, sd->I, omega_in, pdf); break; case CLOSURE_BSDF_TRANSPARENT_ID: eval = bsdf_transparent_eval_reflect(sc, sd->I, omega_in, pdf); break; case CLOSURE_BSDF_MICROFACET_GGX_ID: case CLOSURE_BSDF_MICROFACET_GGX_FRESNEL_ID: case CLOSURE_BSDF_MICROFACET_GGX_CLEARCOAT_ID: case CLOSURE_BSDF_MICROFACET_GGX_REFRACTION_ID: eval = bsdf_microfacet_ggx_eval_reflect(sc, sd->I, omega_in, pdf); break; case CLOSURE_BSDF_MICROFACET_MULTI_GGX_ID: case CLOSURE_BSDF_MICROFACET_MULTI_GGX_FRESNEL_ID: eval = bsdf_microfacet_multi_ggx_eval_reflect(sc, sd->I, omega_in, pdf, &sd->lcg_state); break; case CLOSURE_BSDF_MICROFACET_MULTI_GGX_GLASS_ID: case CLOSURE_BSDF_MICROFACET_MULTI_GGX_GLASS_FRESNEL_ID: eval = bsdf_microfacet_multi_ggx_glass_eval_reflect( sc, sd->I, omega_in, pdf, &sd->lcg_state); break; case CLOSURE_BSDF_MICROFACET_BECKMANN_ID: case CLOSURE_BSDF_MICROFACET_BECKMANN_REFRACTION_ID: eval = bsdf_microfacet_beckmann_eval_reflect(sc, sd->I, omega_in, pdf); break; case CLOSURE_BSDF_ASHIKHMIN_SHIRLEY_ID: eval = bsdf_ashikhmin_shirley_eval_reflect(sc, sd->I, omega_in, pdf); break; case CLOSURE_BSDF_ASHIKHMIN_VELVET_ID: eval = bsdf_ashikhmin_velvet_eval_reflect(sc, sd->I, omega_in, pdf); break; case CLOSURE_BSDF_DIFFUSE_TOON_ID: eval = bsdf_diffuse_toon_eval_reflect(sc, sd->I, omega_in, pdf); break; case CLOSURE_BSDF_GLOSSY_TOON_ID: eval = bsdf_glossy_toon_eval_reflect(sc, sd->I, omega_in, pdf); break; case CLOSURE_BSDF_HAIR_PRINCIPLED_ID: eval = bsdf_principled_hair_eval(kg, sd, sc, omega_in, pdf); break; case CLOSURE_BSDF_HAIR_REFLECTION_ID: eval = bsdf_hair_reflection_eval_reflect(sc, sd->I, omega_in, pdf); break; case CLOSURE_BSDF_HAIR_TRANSMISSION_ID: eval = bsdf_hair_transmission_eval_reflect(sc, sd->I, omega_in, pdf); break; # ifdef __PRINCIPLED__ case CLOSURE_BSDF_PRINCIPLED_DIFFUSE_ID: eval = bsdf_principled_diffuse_eval_reflect(sc, sd->I, omega_in, pdf); break; case CLOSURE_BSDF_PRINCIPLED_SHEEN_ID: eval = bsdf_principled_sheen_eval_reflect(sc, sd->I, omega_in, pdf); break; # endif /* __PRINCIPLED__ */ #endif default: break; } if (CLOSURE_IS_BSDF_DIFFUSE(sc->type)) { if (!isequal_float3(sc->N, sd->N)) { eval *= bump_shadowing_term(sd->N, sc->N, omega_in); } } /* Shadow terminator offset. */ const float frequency_multiplier = kernel_tex_fetch(__objects, sd->object).shadow_terminator_shading_offset; if (frequency_multiplier > 1.0f) { eval *= shift_cos_in(dot(omega_in, sc->N), frequency_multiplier); } } else { switch (sc->type) { case CLOSURE_BSDF_DIFFUSE_ID: eval = bsdf_diffuse_eval_transmit(sc, sd->I, omega_in, pdf); break; #ifdef __SVM__ case CLOSURE_BSDF_OREN_NAYAR_ID: eval = bsdf_oren_nayar_eval_transmit(sc, sd->I, omega_in, pdf); break; case CLOSURE_BSDF_TRANSLUCENT_ID: eval = bsdf_translucent_eval_transmit(sc, sd->I, omega_in, pdf); break; case CLOSURE_BSDF_REFLECTION_ID: eval = bsdf_reflection_eval_transmit(sc, sd->I, omega_in, pdf); break; case CLOSURE_BSDF_REFRACTION_ID: eval = bsdf_refraction_eval_transmit(sc, sd->I, omega_in, pdf); break; case CLOSURE_BSDF_TRANSPARENT_ID: eval = bsdf_transparent_eval_transmit(sc, sd->I, omega_in, pdf); break; case CLOSURE_BSDF_MICROFACET_GGX_ID: case CLOSURE_BSDF_MICROFACET_GGX_FRESNEL_ID: case CLOSURE_BSDF_MICROFACET_GGX_CLEARCOAT_ID: case CLOSURE_BSDF_MICROFACET_GGX_REFRACTION_ID: eval = bsdf_microfacet_ggx_eval_transmit(sc, sd->I, omega_in, pdf); break; case CLOSURE_BSDF_MICROFACET_MULTI_GGX_ID: case CLOSURE_BSDF_MICROFACET_MULTI_GGX_FRESNEL_ID: eval = bsdf_microfacet_multi_ggx_eval_transmit(sc, sd->I, omega_in, pdf, &sd->lcg_state); break; case CLOSURE_BSDF_MICROFACET_MULTI_GGX_GLASS_ID: case CLOSURE_BSDF_MICROFACET_MULTI_GGX_GLASS_FRESNEL_ID: eval = bsdf_microfacet_multi_ggx_glass_eval_transmit( sc, sd->I, omega_in, pdf, &sd->lcg_state); break; case CLOSURE_BSDF_MICROFACET_BECKMANN_ID: case CLOSURE_BSDF_MICROFACET_BECKMANN_REFRACTION_ID: eval = bsdf_microfacet_beckmann_eval_transmit(sc, sd->I, omega_in, pdf); break; case CLOSURE_BSDF_ASHIKHMIN_SHIRLEY_ID: eval = bsdf_ashikhmin_shirley_eval_transmit(sc, sd->I, omega_in, pdf); break; case CLOSURE_BSDF_ASHIKHMIN_VELVET_ID: eval = bsdf_ashikhmin_velvet_eval_transmit(sc, sd->I, omega_in, pdf); break; case CLOSURE_BSDF_DIFFUSE_TOON_ID: eval = bsdf_diffuse_toon_eval_transmit(sc, sd->I, omega_in, pdf); break; case CLOSURE_BSDF_GLOSSY_TOON_ID: eval = bsdf_glossy_toon_eval_transmit(sc, sd->I, omega_in, pdf); break; case CLOSURE_BSDF_HAIR_PRINCIPLED_ID: eval = bsdf_principled_hair_eval(kg, sd, sc, omega_in, pdf); break; case CLOSURE_BSDF_HAIR_REFLECTION_ID: eval = bsdf_hair_reflection_eval_transmit(sc, sd->I, omega_in, pdf); break; case CLOSURE_BSDF_HAIR_TRANSMISSION_ID: eval = bsdf_hair_transmission_eval_transmit(sc, sd->I, omega_in, pdf); break; # ifdef __PRINCIPLED__ case CLOSURE_BSDF_PRINCIPLED_DIFFUSE_ID: eval = bsdf_principled_diffuse_eval_transmit(sc, sd->I, omega_in, pdf); break; case CLOSURE_BSDF_PRINCIPLED_SHEEN_ID: eval = bsdf_principled_sheen_eval_transmit(sc, sd->I, omega_in, pdf); break; # endif /* __PRINCIPLED__ */ #endif default: break; } if (CLOSURE_IS_BSDF_DIFFUSE(sc->type)) { if (!isequal_float3(sc->N, sd->N)) { eval *= bump_shadowing_term(-sd->N, sc->N, omega_in); } } } #ifdef WITH_CYCLES_DEBUG kernel_assert(*pdf >= 0.0f); kernel_assert(eval.x >= 0.0f && eval.y >= 0.0f && eval.z >= 0.0f); #endif return eval; } ccl_device void bsdf_blur(KernelGlobals kg, ccl_private ShaderClosure *sc, float roughness) { /* TODO: do we want to blur volume closures? */ #ifdef __SVM__ switch (sc->type) { case CLOSURE_BSDF_MICROFACET_MULTI_GGX_ID: case CLOSURE_BSDF_MICROFACET_MULTI_GGX_FRESNEL_ID: case CLOSURE_BSDF_MICROFACET_MULTI_GGX_GLASS_ID: case CLOSURE_BSDF_MICROFACET_MULTI_GGX_GLASS_FRESNEL_ID: bsdf_microfacet_multi_ggx_blur(sc, roughness); break; case CLOSURE_BSDF_MICROFACET_GGX_ID: case CLOSURE_BSDF_MICROFACET_GGX_FRESNEL_ID: case CLOSURE_BSDF_MICROFACET_GGX_CLEARCOAT_ID: case CLOSURE_BSDF_MICROFACET_GGX_REFRACTION_ID: bsdf_microfacet_ggx_blur(sc, roughness); break; case CLOSURE_BSDF_MICROFACET_BECKMANN_ID: case CLOSURE_BSDF_MICROFACET_BECKMANN_REFRACTION_ID: bsdf_microfacet_beckmann_blur(sc, roughness); break; case CLOSURE_BSDF_ASHIKHMIN_SHIRLEY_ID: bsdf_ashikhmin_shirley_blur(sc, roughness); break; case CLOSURE_BSDF_HAIR_PRINCIPLED_ID: bsdf_principled_hair_blur(sc, roughness); break; default: break; } #endif } CCL_NAMESPACE_END