17f2cdd104
This is an implementation of thin film iridescence in the Principled BSDF based on "A Practical Extension to Microfacet Theory for the Modeling of Varying Iridescence". There are still several open topics that are left for future work: - Currently, the thin film only affects dielectric Fresnel, not metallic. Properly specifying thin films on metals requires a proper conductive Fresnel term with complex IOR inputs, any attempt of trying to hack it into the F82 model we currently use for the Principled BSDF is fundamentally flawed. In the future, we'll add a node for proper conductive Fresnel, including thin films. - The F0/F90 control is not very elegantly implemented right now. It fundamentally works, but enabling thin film while using a Specular Tint causes a jump in appearance since the models integrate it differently. Then again, thin film interference is a physical effect, so of course a non-physical tweak doesn't play nicely with it. - The white point handling is currently quite crude. In short: The code computes XYZ values of the reflectance spectrum, but we'd need the XYZ values of the product of the reflectance spectrum and the neutral illuminant of the working color space. Currently, this is addressed by just dividing by the XYZ values of the illuminant, but it would be better to do a proper chromatic adaptation transform or to use the proper reference curves for the working space instead of the XYZ curves from the paper. Pull Request: https://projects.blender.org/blender/blender/pulls/118477
640 lines
22 KiB
C
640 lines
22 KiB
C
/* SPDX-FileCopyrightText: 2011-2022 Blender Foundation
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*
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* SPDX-License-Identifier: Apache-2.0 */
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#pragma once
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// clang-format off
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#include "kernel/closure/bsdf_ashikhmin_velvet.h"
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#include "kernel/closure/bsdf_diffuse.h"
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#include "kernel/closure/bsdf_oren_nayar.h"
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#include "kernel/closure/bsdf_phong_ramp.h"
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#include "kernel/closure/bsdf_diffuse_ramp.h"
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#include "kernel/closure/bsdf_microfacet.h"
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#include "kernel/closure/bsdf_sheen.h"
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#include "kernel/closure/bsdf_transparent.h"
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#include "kernel/closure/bsdf_ray_portal.h"
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#include "kernel/closure/bsdf_ashikhmin_shirley.h"
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#include "kernel/closure/bsdf_toon.h"
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#include "kernel/closure/bsdf_hair.h"
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#include "kernel/closure/bsdf_principled_hair_chiang.h"
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#include "kernel/closure/bsdf_principled_hair_huang.h"
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#include "kernel/closure/bssrdf.h"
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#include "kernel/closure/volume.h"
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// clang-format on
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CCL_NAMESPACE_BEGIN
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/* Returns the square of the roughness of the closure if it has roughness,
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* 0 for singular closures and 1 otherwise. */
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ccl_device_inline float bsdf_get_specular_roughness_squared(ccl_private const ShaderClosure *sc)
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{
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if (CLOSURE_IS_BSDF_SINGULAR(sc->type)) {
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return 0.0f;
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}
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if (CLOSURE_IS_BSDF_MICROFACET(sc->type)) {
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ccl_private MicrofacetBsdf *bsdf = (ccl_private MicrofacetBsdf *)sc;
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return bsdf->alpha_x * bsdf->alpha_y;
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}
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return 1.0f;
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}
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ccl_device_inline float bsdf_get_roughness_pass_squared(ccl_private const ShaderClosure *sc)
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{
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if (sc->type == CLOSURE_BSDF_OREN_NAYAR_ID) {
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ccl_private OrenNayarBsdf *bsdf = (ccl_private OrenNayarBsdf *)sc;
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return sqr(sqr(bsdf->roughness));
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}
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/* For the Principled BSDF, we want the Roughness pass to return the value that
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* was set in the node. However, this value doesn't affect all closures (e.g.
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* diffuse), so skip those that don't really have a concept of roughness. */
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if (CLOSURE_IS_BSDF_DIFFUSE(sc->type)) {
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return -1.0f;
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}
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return bsdf_get_specular_roughness_squared(sc);
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}
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/* An additional term to smooth illumination on grazing angles when using bump mapping.
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* Based on "Taming the Shadow Terminator" by Matt Jen-Yuan Chiang,
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* Yining Karl Li and Brent Burley. */
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ccl_device_inline float bump_shadowing_term(int shader_flag, float3 Ng, float3 N, float3 I)
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{
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const float cosNI = dot(N, I);
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if (cosNI < 0.0f) {
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Ng = -Ng;
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}
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float g = safe_divide(dot(Ng, I), cosNI * dot(Ng, N));
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/* If the incoming light is on the unshadowed side, return full brightness. */
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if (g >= 1.0f) {
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return 1.0f;
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}
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/* If the incoming light points away from the surface, return black. */
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if (g < 0.0f) {
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return 0.0f;
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}
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/* When bump map correction is not used do skip the smoothing. */
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if ((shader_flag & SD_USE_BUMP_MAP_CORRECTION) == 0) {
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return 1.0f;
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}
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/* Return smoothed value to avoid discontinuity at perpendicular angle. */
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float g2 = sqr(g);
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return -g2 * g + g2 + g;
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}
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ccl_device_inline float shift_cos_in(float cos_in, const float frequency_multiplier)
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{
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/* Shadow terminator workaround, taken from Appleseed.
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* SPDX-License-Identifier: MIT
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* Copyright (c) 2019 Francois Beaune, The appleseedhq Organization */
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cos_in = min(cos_in, 1.0f);
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const float angle = fast_acosf(cos_in);
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const float val = max(cosf(angle * frequency_multiplier), 0.0f) / cos_in;
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return val;
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}
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ccl_device_inline bool bsdf_is_transmission(ccl_private const ShaderClosure *sc, const float3 wo)
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{
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return dot(sc->N, wo) < 0.0f;
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}
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ccl_device_inline int bsdf_sample(KernelGlobals kg,
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ccl_private ShaderData *sd,
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ccl_private const ShaderClosure *sc,
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const int path_flag,
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const float3 rand,
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ccl_private Spectrum *eval,
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ccl_private float3 *wo,
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ccl_private float *pdf,
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ccl_private float2 *sampled_roughness,
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ccl_private float *eta)
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{
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/* For curves use the smooth normal, particularly for ribbons the geometric
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* normal gives too much darkening otherwise. */
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*eval = zero_spectrum();
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*pdf = 0.f;
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int label = LABEL_NONE;
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const float3 Ng = (sd->type & PRIMITIVE_CURVE) ? sc->N : sd->Ng;
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const float2 rand_xy = float3_to_float2(rand);
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switch (sc->type) {
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case CLOSURE_BSDF_DIFFUSE_ID:
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label = bsdf_diffuse_sample(sc, Ng, sd->wi, rand_xy, eval, wo, pdf);
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*sampled_roughness = one_float2();
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*eta = 1.0f;
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break;
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#if defined(__SVM__) || defined(__OSL__)
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case CLOSURE_BSDF_OREN_NAYAR_ID:
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label = bsdf_oren_nayar_sample(sc, Ng, sd->wi, rand_xy, eval, wo, pdf);
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*sampled_roughness = one_float2();
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*eta = 1.0f;
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break;
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# ifdef __OSL__
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case CLOSURE_BSDF_PHONG_RAMP_ID:
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label = bsdf_phong_ramp_sample(sc, Ng, sd->wi, rand_xy, eval, wo, pdf, sampled_roughness);
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*eta = 1.0f;
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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, Ng, sd->wi, rand_xy, eval, wo, pdf);
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*sampled_roughness = one_float2();
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*eta = 1.0f;
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break;
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# endif
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case CLOSURE_BSDF_TRANSLUCENT_ID:
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label = bsdf_translucent_sample(sc, Ng, sd->wi, rand_xy, eval, wo, pdf);
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*sampled_roughness = one_float2();
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*eta = 1.0f;
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break;
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case CLOSURE_BSDF_TRANSPARENT_ID:
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label = bsdf_transparent_sample(sc, Ng, sd->wi, eval, wo, pdf);
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*sampled_roughness = zero_float2();
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*eta = 1.0f;
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break;
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case CLOSURE_BSDF_RAY_PORTAL_ID:
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/* ray portals are not handled by the BSDF code, we should never get here */
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kernel_assert(false);
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break;
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case CLOSURE_BSDF_MICROFACET_GGX_ID:
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case CLOSURE_BSDF_MICROFACET_GGX_REFRACTION_ID:
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case CLOSURE_BSDF_MICROFACET_GGX_GLASS_ID:
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label = bsdf_microfacet_ggx_sample(
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kg, sc, Ng, sd->wi, rand, eval, wo, pdf, sampled_roughness, eta);
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break;
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case CLOSURE_BSDF_MICROFACET_BECKMANN_ID:
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case CLOSURE_BSDF_MICROFACET_BECKMANN_REFRACTION_ID:
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case CLOSURE_BSDF_MICROFACET_BECKMANN_GLASS_ID:
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label = bsdf_microfacet_beckmann_sample(
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kg, sc, Ng, sd->wi, rand, eval, wo, pdf, sampled_roughness, eta);
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break;
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case CLOSURE_BSDF_ASHIKHMIN_SHIRLEY_ID:
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label = bsdf_ashikhmin_shirley_sample(
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sc, Ng, sd->wi, rand_xy, eval, wo, pdf, sampled_roughness);
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*eta = 1.0f;
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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, Ng, sd->wi, rand_xy, eval, wo, pdf);
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*sampled_roughness = one_float2();
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*eta = 1.0f;
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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, Ng, sd->wi, rand_xy, eval, wo, pdf);
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*sampled_roughness = one_float2();
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*eta = 1.0f;
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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, Ng, sd->wi, rand_xy, eval, wo, pdf);
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// double check if this is valid
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*sampled_roughness = one_float2();
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*eta = 1.0f;
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break;
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case CLOSURE_BSDF_HAIR_REFLECTION_ID:
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label = bsdf_hair_reflection_sample(
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sc, Ng, sd->wi, rand_xy, eval, wo, pdf, sampled_roughness);
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*eta = 1.0f;
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break;
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case CLOSURE_BSDF_HAIR_TRANSMISSION_ID:
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label = bsdf_hair_transmission_sample(
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sc, Ng, sd->wi, rand_xy, eval, wo, pdf, sampled_roughness);
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*eta = 1.0f;
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break;
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# ifdef __PRINCIPLED_HAIR__
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case CLOSURE_BSDF_HAIR_CHIANG_ID:
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label = bsdf_hair_chiang_sample(kg, sc, sd, rand, eval, wo, pdf, sampled_roughness);
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*eta = 1.0f;
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break;
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case CLOSURE_BSDF_HAIR_HUANG_ID:
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label = bsdf_hair_huang_sample(kg, sc, sd, rand, eval, wo, pdf, sampled_roughness);
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*eta = 1.0f;
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break;
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# endif
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case CLOSURE_BSDF_SHEEN_ID:
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label = bsdf_sheen_sample(sc, Ng, sd->wi, rand_xy, eval, wo, pdf);
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*sampled_roughness = one_float2();
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*eta = 1.0f;
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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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/* Test if BSDF sample should be treated as transparent for background. */
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if (label & LABEL_TRANSMIT) {
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float threshold_squared = kernel_data.background.transparent_roughness_squared_threshold;
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if (threshold_squared >= 0.0f && !(label & LABEL_DIFFUSE)) {
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if (bsdf_get_specular_roughness_squared(sc) <= threshold_squared) {
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label |= LABEL_TRANSMIT_TRANSPARENT;
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}
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}
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}
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else {
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/* Shadow terminator offset. */
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const float frequency_multiplier =
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kernel_data_fetch(objects, sd->object).shadow_terminator_shading_offset;
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if (frequency_multiplier > 1.0f) {
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const float cosNO = dot(*wo, sc->N);
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*eval *= shift_cos_in(cosNO, frequency_multiplier);
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}
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if (label & LABEL_DIFFUSE) {
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if (!isequal(sc->N, sd->N)) {
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*eval *= bump_shadowing_term(sd->flag, sd->N, sc->N, *wo);
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}
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}
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}
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#ifdef WITH_CYCLES_DEBUG
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kernel_assert(*pdf >= 0.0f);
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kernel_assert(eval->x >= 0.0f && eval->y >= 0.0f && eval->z >= 0.0f);
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#endif
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return label;
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}
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ccl_device_inline void bsdf_roughness_eta(const KernelGlobals kg,
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ccl_private const ShaderClosure *sc,
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const float3 wo,
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ccl_private float2 *roughness,
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ccl_private float *eta)
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{
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#ifdef __SVM__
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float alpha = 1.0f;
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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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*roughness = one_float2();
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*eta = 1.0f;
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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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*roughness = one_float2();
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*eta = 1.0f;
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break;
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# ifdef __OSL__
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case CLOSURE_BSDF_PHONG_RAMP_ID:
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alpha = phong_ramp_exponent_to_roughness(((ccl_private const PhongRampBsdf *)sc)->exponent);
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*roughness = make_float2(alpha, alpha);
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*eta = 1.0f;
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break;
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case CLOSURE_BSDF_DIFFUSE_RAMP_ID:
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*roughness = one_float2();
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*eta = 1.0f;
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break;
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# endif
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case CLOSURE_BSDF_TRANSLUCENT_ID:
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*roughness = one_float2();
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*eta = 1.0f;
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break;
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case CLOSURE_BSDF_TRANSPARENT_ID:
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case CLOSURE_BSDF_RAY_PORTAL_ID:
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*roughness = zero_float2();
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*eta = 1.0f;
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break;
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case CLOSURE_BSDF_MICROFACET_GGX_ID:
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case CLOSURE_BSDF_MICROFACET_GGX_REFRACTION_ID:
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case CLOSURE_BSDF_MICROFACET_GGX_GLASS_ID:
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case CLOSURE_BSDF_MICROFACET_BECKMANN_ID:
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case CLOSURE_BSDF_MICROFACET_BECKMANN_REFRACTION_ID:
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case CLOSURE_BSDF_MICROFACET_BECKMANN_GLASS_ID: {
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ccl_private const MicrofacetBsdf *bsdf = (ccl_private const MicrofacetBsdf *)sc;
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*roughness = make_float2(bsdf->alpha_x, bsdf->alpha_y);
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*eta = (bsdf_is_transmission(sc, wo)) ? bsdf->ior : 1.0f;
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break;
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}
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case CLOSURE_BSDF_ASHIKHMIN_SHIRLEY_ID: {
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ccl_private const MicrofacetBsdf *bsdf = (ccl_private const MicrofacetBsdf *)sc;
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*roughness = make_float2(bsdf->alpha_x, bsdf->alpha_y);
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*eta = 1.0f;
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break;
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}
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case CLOSURE_BSDF_ASHIKHMIN_VELVET_ID:
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*roughness = one_float2();
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*eta = 1.0f;
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break;
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case CLOSURE_BSDF_DIFFUSE_TOON_ID:
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*roughness = one_float2();
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*eta = 1.0f;
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break;
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case CLOSURE_BSDF_GLOSSY_TOON_ID:
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// double check if this is valid
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*roughness = one_float2();
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*eta = 1.0f;
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break;
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case CLOSURE_BSDF_HAIR_REFLECTION_ID:
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*roughness = make_float2(((ccl_private HairBsdf *)sc)->roughness1,
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((ccl_private HairBsdf *)sc)->roughness2);
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*eta = 1.0f;
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break;
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case CLOSURE_BSDF_HAIR_TRANSMISSION_ID:
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*roughness = make_float2(((ccl_private HairBsdf *)sc)->roughness1,
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((ccl_private HairBsdf *)sc)->roughness2);
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*eta = 1.0f;
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break;
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# ifdef __PRINCIPLED_HAIR__
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case CLOSURE_BSDF_HAIR_CHIANG_ID:
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alpha = ((ccl_private ChiangHairBSDF *)sc)->m0_roughness;
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*roughness = make_float2(alpha, alpha);
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*eta = 1.0f;
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break;
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case CLOSURE_BSDF_HAIR_HUANG_ID:
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alpha = ((ccl_private HuangHairBSDF *)sc)->roughness;
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*roughness = make_float2(alpha, alpha);
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*eta = 1.0f;
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break;
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# endif
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case CLOSURE_BSDF_SHEEN_ID:
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alpha = ((ccl_private SheenBsdf *)sc)->roughness;
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*roughness = make_float2(alpha, alpha);
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*eta = 1.0f;
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break;
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#endif
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default:
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*roughness = one_float2();
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*eta = 1.0f;
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break;
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}
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}
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ccl_device_inline int bsdf_label(const KernelGlobals kg,
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ccl_private const ShaderClosure *sc,
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const float3 wo)
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{
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/* For curves use the smooth normal, particularly for ribbons the geometric
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* normal gives too much darkening otherwise. */
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int label;
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switch (sc->type) {
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case CLOSURE_BSDF_DIFFUSE_ID:
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case CLOSURE_BSSRDF_BURLEY_ID:
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case CLOSURE_BSSRDF_RANDOM_WALK_ID:
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case CLOSURE_BSSRDF_RANDOM_WALK_SKIN_ID:
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label = LABEL_REFLECT | LABEL_DIFFUSE;
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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 = LABEL_REFLECT | LABEL_DIFFUSE;
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break;
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# ifdef __OSL__
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case CLOSURE_BSDF_PHONG_RAMP_ID:
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label = LABEL_REFLECT | LABEL_GLOSSY;
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break;
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case CLOSURE_BSDF_DIFFUSE_RAMP_ID:
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label = LABEL_REFLECT | LABEL_DIFFUSE;
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break;
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# endif
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case CLOSURE_BSDF_TRANSLUCENT_ID:
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label = LABEL_TRANSMIT | LABEL_DIFFUSE;
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break;
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case CLOSURE_BSDF_TRANSPARENT_ID:
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label = LABEL_TRANSMIT | LABEL_TRANSPARENT;
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break;
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case CLOSURE_BSDF_RAY_PORTAL_ID:
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label = LABEL_TRANSMIT | LABEL_RAY_PORTAL;
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break;
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case CLOSURE_BSDF_MICROFACET_GGX_ID:
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case CLOSURE_BSDF_MICROFACET_BECKMANN_ID:
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case CLOSURE_BSDF_MICROFACET_GGX_REFRACTION_ID:
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case CLOSURE_BSDF_MICROFACET_BECKMANN_REFRACTION_ID:
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case CLOSURE_BSDF_MICROFACET_GGX_GLASS_ID:
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case CLOSURE_BSDF_MICROFACET_BECKMANN_GLASS_ID: {
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ccl_private const MicrofacetBsdf *bsdf = (ccl_private const MicrofacetBsdf *)sc;
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label = ((bsdf_is_transmission(sc, wo)) ? LABEL_TRANSMIT : LABEL_REFLECT) |
|
|
((bsdf_microfacet_eval_flag(bsdf)) ? LABEL_GLOSSY : LABEL_SINGULAR);
|
|
break;
|
|
}
|
|
case CLOSURE_BSDF_ASHIKHMIN_SHIRLEY_ID:
|
|
label = LABEL_REFLECT | LABEL_GLOSSY;
|
|
break;
|
|
case CLOSURE_BSDF_ASHIKHMIN_VELVET_ID:
|
|
label = LABEL_REFLECT | LABEL_DIFFUSE;
|
|
break;
|
|
case CLOSURE_BSDF_DIFFUSE_TOON_ID:
|
|
label = LABEL_REFLECT | LABEL_DIFFUSE;
|
|
break;
|
|
case CLOSURE_BSDF_GLOSSY_TOON_ID:
|
|
label = LABEL_REFLECT | LABEL_GLOSSY;
|
|
break;
|
|
case CLOSURE_BSDF_HAIR_REFLECTION_ID:
|
|
label = LABEL_REFLECT | LABEL_GLOSSY;
|
|
break;
|
|
case CLOSURE_BSDF_HAIR_TRANSMISSION_ID:
|
|
label = LABEL_TRANSMIT | LABEL_GLOSSY;
|
|
break;
|
|
# ifdef __PRINCIPLED_HAIR__
|
|
case CLOSURE_BSDF_HAIR_CHIANG_ID:
|
|
if (bsdf_is_transmission(sc, wo))
|
|
label = LABEL_TRANSMIT | LABEL_GLOSSY;
|
|
else
|
|
label = LABEL_REFLECT | LABEL_GLOSSY;
|
|
break;
|
|
case CLOSURE_BSDF_HAIR_HUANG_ID:
|
|
label = LABEL_REFLECT | LABEL_GLOSSY;
|
|
break;
|
|
# endif
|
|
case CLOSURE_BSDF_SHEEN_ID:
|
|
label = LABEL_REFLECT | LABEL_DIFFUSE;
|
|
break;
|
|
#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) {
|
|
if (bsdf_get_specular_roughness_squared(sc) <= threshold_squared) {
|
|
label |= LABEL_TRANSMIT_TRANSPARENT;
|
|
}
|
|
}
|
|
}
|
|
return label;
|
|
}
|
|
|
|
#ifndef __KERNEL_CUDA__
|
|
ccl_device
|
|
#else
|
|
ccl_device_inline
|
|
#endif
|
|
Spectrum
|
|
bsdf_eval(KernelGlobals kg,
|
|
ccl_private ShaderData *sd,
|
|
ccl_private const ShaderClosure *sc,
|
|
const float3 wo,
|
|
ccl_private float *pdf)
|
|
{
|
|
Spectrum eval = zero_spectrum();
|
|
*pdf = 0.f;
|
|
|
|
switch (sc->type) {
|
|
case CLOSURE_BSDF_DIFFUSE_ID:
|
|
eval = bsdf_diffuse_eval(sc, sd->wi, wo, pdf);
|
|
break;
|
|
#if defined(__SVM__) || defined(__OSL__)
|
|
case CLOSURE_BSDF_OREN_NAYAR_ID:
|
|
eval = bsdf_oren_nayar_eval(sc, sd->wi, wo, pdf);
|
|
break;
|
|
# ifdef __OSL__
|
|
case CLOSURE_BSDF_PHONG_RAMP_ID:
|
|
eval = bsdf_phong_ramp_eval(sc, sd->wi, wo, pdf);
|
|
break;
|
|
case CLOSURE_BSDF_DIFFUSE_RAMP_ID:
|
|
eval = bsdf_diffuse_ramp_eval(sc, sd->wi, wo, pdf);
|
|
break;
|
|
# endif
|
|
case CLOSURE_BSDF_TRANSLUCENT_ID:
|
|
eval = bsdf_translucent_eval(sc, sd->wi, wo, pdf);
|
|
break;
|
|
case CLOSURE_BSDF_TRANSPARENT_ID:
|
|
eval = bsdf_transparent_eval(sc, sd->wi, wo, pdf);
|
|
break;
|
|
case CLOSURE_BSDF_RAY_PORTAL_ID:
|
|
eval = bsdf_ray_portal_eval(sc, sd->wi, wo, pdf);
|
|
break;
|
|
case CLOSURE_BSDF_MICROFACET_GGX_ID:
|
|
case CLOSURE_BSDF_MICROFACET_GGX_REFRACTION_ID:
|
|
case CLOSURE_BSDF_MICROFACET_GGX_GLASS_ID:
|
|
/* For consistency with eval() this should be using sd->Ng, but that causes
|
|
* artifacts (see shadow_terminator_metal test). Needs deeper investigation
|
|
* for how to solve this. */
|
|
eval = bsdf_microfacet_ggx_eval(kg, sc, sd->N, sd->wi, wo, pdf);
|
|
break;
|
|
case CLOSURE_BSDF_MICROFACET_BECKMANN_ID:
|
|
case CLOSURE_BSDF_MICROFACET_BECKMANN_REFRACTION_ID:
|
|
case CLOSURE_BSDF_MICROFACET_BECKMANN_GLASS_ID:
|
|
eval = bsdf_microfacet_beckmann_eval(kg, sc, sd->N, sd->wi, wo, pdf);
|
|
break;
|
|
case CLOSURE_BSDF_ASHIKHMIN_SHIRLEY_ID:
|
|
eval = bsdf_ashikhmin_shirley_eval(sc, sd->N, sd->wi, wo, pdf);
|
|
break;
|
|
case CLOSURE_BSDF_ASHIKHMIN_VELVET_ID:
|
|
eval = bsdf_ashikhmin_velvet_eval(sc, sd->wi, wo, pdf);
|
|
break;
|
|
case CLOSURE_BSDF_DIFFUSE_TOON_ID:
|
|
eval = bsdf_diffuse_toon_eval(sc, sd->wi, wo, pdf);
|
|
break;
|
|
case CLOSURE_BSDF_GLOSSY_TOON_ID:
|
|
eval = bsdf_glossy_toon_eval(sc, sd->wi, wo, pdf);
|
|
break;
|
|
# ifdef __PRINCIPLED_HAIR__
|
|
case CLOSURE_BSDF_HAIR_CHIANG_ID:
|
|
eval = bsdf_hair_chiang_eval(kg, sd, sc, wo, pdf);
|
|
break;
|
|
case CLOSURE_BSDF_HAIR_HUANG_ID:
|
|
eval = bsdf_hair_huang_eval(kg, sd, sc, wo, pdf);
|
|
break;
|
|
# endif
|
|
case CLOSURE_BSDF_HAIR_REFLECTION_ID:
|
|
eval = bsdf_hair_reflection_eval(sc, sd->wi, wo, pdf);
|
|
break;
|
|
case CLOSURE_BSDF_HAIR_TRANSMISSION_ID:
|
|
eval = bsdf_hair_transmission_eval(sc, sd->wi, wo, pdf);
|
|
break;
|
|
case CLOSURE_BSDF_SHEEN_ID:
|
|
eval = bsdf_sheen_eval(sc, sd->wi, wo, pdf);
|
|
break;
|
|
#endif
|
|
default:
|
|
break;
|
|
}
|
|
|
|
if (CLOSURE_IS_BSDF_DIFFUSE(sc->type)) {
|
|
if (!isequal(sc->N, sd->N)) {
|
|
eval *= bump_shadowing_term(sd->flag, sd->N, sc->N, wo);
|
|
}
|
|
}
|
|
|
|
/* Shadow terminator offset. */
|
|
const float frequency_multiplier =
|
|
kernel_data_fetch(objects, sd->object).shadow_terminator_shading_offset;
|
|
if (frequency_multiplier > 1.0f) {
|
|
const float cosNO = dot(wo, sc->N);
|
|
if (cosNO >= 0.0f) {
|
|
eval *= shift_cos_in(cosNO, frequency_multiplier);
|
|
}
|
|
}
|
|
|
|
#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? */
|
|
#if defined(__SVM__) || defined(__OSL__)
|
|
switch (sc->type) {
|
|
case CLOSURE_BSDF_MICROFACET_GGX_ID:
|
|
case CLOSURE_BSDF_MICROFACET_GGX_REFRACTION_ID:
|
|
case CLOSURE_BSDF_MICROFACET_GGX_GLASS_ID:
|
|
case CLOSURE_BSDF_MICROFACET_BECKMANN_ID:
|
|
case CLOSURE_BSDF_MICROFACET_BECKMANN_REFRACTION_ID:
|
|
case CLOSURE_BSDF_MICROFACET_BECKMANN_GLASS_ID:
|
|
/* TODO: Recompute energy preservation after blur? */
|
|
bsdf_microfacet_blur(sc, roughness);
|
|
break;
|
|
case CLOSURE_BSDF_ASHIKHMIN_SHIRLEY_ID:
|
|
bsdf_ashikhmin_shirley_blur(sc, roughness);
|
|
break;
|
|
# ifdef __PRINCIPLED_HAIR__
|
|
case CLOSURE_BSDF_HAIR_CHIANG_ID:
|
|
bsdf_hair_chiang_blur(sc, roughness);
|
|
break;
|
|
case CLOSURE_BSDF_HAIR_HUANG_ID:
|
|
bsdf_hair_huang_blur(sc, roughness);
|
|
break;
|
|
# endif
|
|
default:
|
|
break;
|
|
}
|
|
#endif
|
|
}
|
|
|
|
ccl_device_inline Spectrum bsdf_albedo(KernelGlobals kg,
|
|
ccl_private const ShaderData *sd,
|
|
ccl_private const ShaderClosure *sc,
|
|
const bool reflection,
|
|
const bool transmission)
|
|
{
|
|
Spectrum albedo = sc->weight;
|
|
/* Some closures include additional components such as Fresnel terms that cause their albedo to
|
|
* be below 1. The point of this function is to return a best-effort estimation of their albedo,
|
|
* meaning the amount of reflected/refracted light that would be expected when illuminated by a
|
|
* uniform white background.
|
|
* This is used for the denoising albedo pass and diffuse/glossy/transmission color passes.
|
|
* NOTE: This should always match the sample_weight of the closure - as in, if there's an albedo
|
|
* adjustment in here, the sample_weight should also be reduced accordingly.
|
|
* TODO(lukas): Consider calling this function to determine the sample_weight? Would be a bit of
|
|
* extra overhead though. */
|
|
#if defined(__SVM__) || defined(__OSL__)
|
|
if (CLOSURE_IS_BSDF_MICROFACET(sc->type)) {
|
|
albedo *= bsdf_microfacet_estimate_albedo(
|
|
kg, sd, (ccl_private const MicrofacetBsdf *)sc, reflection, transmission);
|
|
}
|
|
# ifdef __PRINCIPLED_HAIR__
|
|
else if (sc->type == CLOSURE_BSDF_HAIR_CHIANG_ID) {
|
|
/* TODO(lukas): Principled Hair could also be split into a glossy and a transmission component,
|
|
* similar to Glass BSDFs. */
|
|
albedo *= bsdf_hair_chiang_albedo(sd, sc);
|
|
}
|
|
else if (sc->type == CLOSURE_BSDF_HAIR_HUANG_ID) {
|
|
albedo *= bsdf_hair_huang_albedo(sd, sc);
|
|
}
|
|
# endif
|
|
#endif
|
|
return albedo;
|
|
}
|
|
|
|
CCL_NAMESPACE_END
|