blender/intern/cycles/kernel/osl/bsdf_westin.cpp
Campbell Barton 2d290040a1 style cleanup
2012-06-04 22:44:58 +00:00

244 lines
7.7 KiB
C++

/*
* 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