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Diffstat (limited to 'intern/cycles/kernel/osl/bsdf_westin.cpp')
| -rw-r--r-- | intern/cycles/kernel/osl/bsdf_westin.cpp | 239 |
1 files changed, 239 insertions, 0 deletions
diff --git a/intern/cycles/kernel/osl/bsdf_westin.cpp b/intern/cycles/kernel/osl/bsdf_westin.cpp new file mode 100644 index 00000000000..d322f6a7f7e --- /dev/null +++ b/intern/cycles/kernel/osl/bsdf_westin.cpp @@ -0,0 +1,239 @@ +/* + * Adapted from Open Shading Language with this license: + * + * Copyright (c) 2009-2010 Sony Pictures Imageworks Inc., et al. + * All Rights Reserved. + * + * Modifications Copyright 2011, Blender Foundation. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * * Neither the name of Sony Pictures Imageworks nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#include <OpenImageIO/fmath.h> + +#include <OSL/genclosure.h> + +#include "osl_closures.h" + +#include "util_math.h" + +CCL_NAMESPACE_BEGIN + +using namespace OSL; + +class WestinBackscatterClosure : public BSDFClosure { +public: + Vec3 m_N; + float m_roughness; + float m_invroughness; + WestinBackscatterClosure() : BSDFClosure(Labels::GLOSSY) { } + + void setup() + { + m_roughness = clamp(m_roughness, 1e-5f, 1.0f); + m_invroughness = m_roughness > 0 ? 1 / m_roughness : 0; + } + + bool mergeable (const ClosurePrimitive *other) const { + const WestinBackscatterClosure *comp = (const WestinBackscatterClosure *)other; + return m_N == comp->m_N && m_roughness == comp->m_roughness && + BSDFClosure::mergeable(other); + } + + size_t memsize () const { return sizeof(*this); } + + const char *name () const { return "westin_backscatter"; } + + void print_on (std::ostream &out) const + { + out << name() << " ("; + out << "(" << m_N[0] << ", " << m_N[1] << ", " << m_N[2] << "), "; + out << m_roughness; + out << ")"; + } + + float albedo (const Vec3 &omega_out) const + { + return 1.0f; + } + + Color3 eval_reflect (const Vec3 &omega_out, const Vec3 &omega_in, float &pdf) const + { + // pdf is implicitly 0 (no indirect sampling) + float cosNO = m_N.dot(omega_out); + float cosNI = m_N.dot(omega_in); + if (cosNO > 0 && cosNI > 0) { + float cosine = omega_out.dot(omega_in); + pdf = cosine > 0 ? (m_invroughness + 1) * powf(cosine, m_invroughness) : 0; + pdf *= 0.5f * float(M_1_PI); + return Color3 (pdf, pdf, pdf); + } + return Color3 (0, 0, 0); + } + + Color3 eval_transmit (const Vec3 &omega_out, const Vec3 &omega_in, float &pdf) const + { + return Color3 (0, 0, 0); + } + + ustring sample (const Vec3 &Ng, + const Vec3 &omega_out, const Vec3 &domega_out_dx, const Vec3 &domega_out_dy, + float randu, float randv, + Vec3 &omega_in, Vec3 &domega_in_dx, Vec3 &domega_in_dy, + float &pdf, Color3 &eval) const + { + float cosNO = m_N.dot(omega_out); + if (cosNO > 0) { + domega_in_dx = domega_out_dx; + domega_in_dy = domega_out_dy; + Vec3 T, B; + make_orthonormals (omega_out, T, B); + float phi = 2 * (float) M_PI * randu; + float cosTheta = powf(randv, 1 / (m_invroughness + 1)); + float sinTheta2 = 1 - cosTheta * cosTheta; + float sinTheta = sinTheta2 > 0 ? sqrtf(sinTheta2) : 0; + omega_in = (cosf(phi) * sinTheta) * T + + (sinf(phi) * sinTheta) * B + + ( cosTheta) * omega_out; + if (Ng.dot(omega_in) > 0) + { + // common terms for pdf and eval + float cosNI = m_N.dot(omega_in); + // make sure the direction we chose is still in the right hemisphere + if (cosNI > 0) + { + pdf = 0.5f * (float) M_1_PI * powf(cosTheta, m_invroughness); + pdf = (m_invroughness + 1) * pdf; + eval.setValue(pdf, pdf, pdf); + // Since there is some blur to this reflection, make the + // derivatives a bit bigger. In theory this varies with the + // exponent but the exact relationship is complex and + // requires more ops than are practical. + domega_in_dx *= 10; + domega_in_dy *= 10; + } + } + } + return Labels::REFLECT; + } + +}; + + +class WestinSheenClosure : public BSDFClosure { +public: + Vec3 m_N; + float m_edginess; +// float m_normalization; + WestinSheenClosure() : BSDFClosure(Labels::DIFFUSE) { } + + void setup() {}; + + bool mergeable (const ClosurePrimitive *other) const { + const WestinSheenClosure *comp = (const WestinSheenClosure *)other; + return m_N == comp->m_N && m_edginess == comp->m_edginess && + BSDFClosure::mergeable(other); + } + + size_t memsize () const { return sizeof(*this); } + + const char *name () const { return "westin_sheen"; } + + void print_on (std::ostream &out) const + { + out << name() << " ("; + out << "(" << m_N[0] << ", " << m_N[1] << ", " << m_N[2] << "), "; + out << m_edginess; + out << ")"; + } + + float albedo (const Vec3 &omega_out) const + { + return 1.0f; + } + + Color3 eval_reflect (const Vec3 &omega_out, const Vec3 &omega_in, float &pdf) const + { + // pdf is implicitly 0 (no indirect sampling) + float cosNO = m_N.dot(omega_out); + float cosNI = m_N.dot(omega_in); + if (cosNO > 0 && cosNI > 0) { + float sinNO2 = 1 - cosNO * cosNO; + pdf = cosNI * float(M_1_PI); + float westin = sinNO2 > 0 ? powf(sinNO2, 0.5f * m_edginess) * pdf : 0; + return Color3 (westin, westin, westin); + } + return Color3 (0, 0, 0); + } + + Color3 eval_transmit (const Vec3 &omega_out, const Vec3 &omega_in, float &pdf) const + { + return Color3 (0, 0, 0); + } + + ustring sample (const Vec3 &Ng, + const Vec3 &omega_out, const Vec3 &domega_out_dx, const Vec3 &domega_out_dy, + float randu, float randv, + Vec3 &omega_in, Vec3 &domega_in_dx, Vec3 &domega_in_dy, + float &pdf, Color3 &eval) const + { + // we are viewing the surface from the right side - send a ray out with cosine + // distribution over the hemisphere + sample_cos_hemisphere (m_N, omega_out, randu, randv, omega_in, pdf); + if (Ng.dot(omega_in) > 0) { + // TODO: account for sheen when sampling + float cosNO = m_N.dot(omega_out); + float sinNO2 = 1 - cosNO * cosNO; + float westin = sinNO2 > 0 ? powf(sinNO2, 0.5f * m_edginess) * pdf : 0; + eval.setValue(westin, westin, westin); + // TODO: find a better approximation for the diffuse bounce + domega_in_dx = (2 * m_N.dot(domega_out_dx)) * m_N - domega_out_dx; + domega_in_dy = (2 * m_N.dot(domega_out_dy)) * m_N - domega_out_dy; + domega_in_dx *= 125; + domega_in_dy *= 125; + } else + pdf = 0; + return Labels::REFLECT; + } +}; + + + +ClosureParam bsdf_westin_backscatter_params[] = { + CLOSURE_VECTOR_PARAM(WestinBackscatterClosure, m_N), + CLOSURE_FLOAT_PARAM (WestinBackscatterClosure, m_roughness), + CLOSURE_STRING_KEYPARAM("label"), + CLOSURE_FINISH_PARAM(WestinBackscatterClosure) }; + +ClosureParam bsdf_westin_sheen_params[] = { + CLOSURE_VECTOR_PARAM(WestinSheenClosure, m_N), + CLOSURE_FLOAT_PARAM (WestinSheenClosure, m_edginess), + CLOSURE_STRING_KEYPARAM("label"), + CLOSURE_FINISH_PARAM(WestinSheenClosure) }; + +CLOSURE_PREPARE(bsdf_westin_backscatter_prepare, WestinBackscatterClosure) +CLOSURE_PREPARE(bsdf_westin_sheen_prepare, WestinSheenClosure) + +CCL_NAMESPACE_END + |