forked from bartvdbraak/blender
a2366a3a2e
sc->T and sc->data2 were behind __HAIR__ ifdef, now they are not anymore, so we can always assign the correct value.
256 lines
8.7 KiB
C
256 lines
8.7 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.
|
|
*/
|
|
|
|
#ifndef __BSDF_HAIR_H__
|
|
#define __BSDF_HAIR_H__
|
|
|
|
CCL_NAMESPACE_BEGIN
|
|
|
|
|
|
ccl_device int bsdf_hair_reflection_setup(ShaderClosure *sc)
|
|
{
|
|
sc->type = CLOSURE_BSDF_HAIR_REFLECTION_ID;
|
|
sc->data0 = clamp(sc->data0, 0.001f, 1.0f);
|
|
sc->data1 = clamp(sc->data1, 0.001f, 1.0f);
|
|
return SD_BSDF|SD_BSDF_HAS_EVAL;
|
|
}
|
|
|
|
ccl_device int bsdf_hair_transmission_setup(ShaderClosure *sc)
|
|
{
|
|
sc->type = CLOSURE_BSDF_HAIR_TRANSMISSION_ID;
|
|
sc->data0 = clamp(sc->data0, 0.001f, 1.0f);
|
|
sc->data1 = clamp(sc->data1, 0.001f, 1.0f);
|
|
return SD_BSDF|SD_BSDF_HAS_EVAL;
|
|
}
|
|
|
|
ccl_device float3 bsdf_hair_reflection_eval_reflect(const ShaderClosure *sc, const float3 I, const float3 omega_in, float *pdf)
|
|
{
|
|
float offset = sc->data2;
|
|
float3 Tg = sc->T;
|
|
float roughness1 = sc->data0;
|
|
float roughness2 = sc->data1;
|
|
|
|
float Iz = dot(Tg, I);
|
|
float3 locy = normalize(I - Tg * Iz);
|
|
|
|
float theta_r = M_PI_2_F - fast_acosf(Iz);
|
|
|
|
float omega_in_z = dot(Tg, omega_in);
|
|
float3 omega_in_y = normalize(omega_in - Tg * omega_in_z);
|
|
|
|
float theta_i = M_PI_2_F - fast_acosf(omega_in_z);
|
|
float cosphi_i = dot(omega_in_y, locy);
|
|
|
|
if(M_PI_2_F - fabsf(theta_i) < 0.001f || cosphi_i < 0.0f) {
|
|
*pdf = 0.0f;
|
|
return make_float3(*pdf, *pdf, *pdf);
|
|
}
|
|
|
|
float roughness1_inv = 1.0f / roughness1;
|
|
float roughness2_inv = 1.0f / roughness2;
|
|
float phi_i = fast_acosf(cosphi_i) * roughness2_inv;
|
|
phi_i = fabsf(phi_i) < M_PI_F ? phi_i : M_PI_F;
|
|
float costheta_i = fast_cosf(theta_i);
|
|
|
|
float a_R = fast_atan2f(((M_PI_2_F + theta_r) * 0.5f - offset) * roughness1_inv, 1.0f);
|
|
float b_R = fast_atan2f(((-M_PI_2_F + theta_r) * 0.5f - offset) * roughness1_inv, 1.0f);
|
|
|
|
float theta_h = (theta_i + theta_r) * 0.5f;
|
|
float t = theta_h - offset;
|
|
|
|
float phi_pdf = fast_cosf(phi_i * 0.5f) * 0.25f * roughness2_inv;
|
|
float theta_pdf = roughness1 / (2 * (t*t + roughness1*roughness1) * (a_R - b_R)* costheta_i);
|
|
*pdf = phi_pdf * theta_pdf;
|
|
|
|
return make_float3(*pdf, *pdf, *pdf);
|
|
}
|
|
|
|
ccl_device float3 bsdf_hair_transmission_eval_reflect(const ShaderClosure *sc, const float3 I, const float3 omega_in, float *pdf)
|
|
{
|
|
return make_float3(0.0f, 0.0f, 0.0f);
|
|
}
|
|
|
|
|
|
ccl_device float3 bsdf_hair_reflection_eval_transmit(const ShaderClosure *sc, const float3 I, const float3 omega_in, float *pdf)
|
|
{
|
|
return make_float3(0.0f, 0.0f, 0.0f);
|
|
}
|
|
|
|
ccl_device float3 bsdf_hair_transmission_eval_transmit(const ShaderClosure *sc, const float3 I, const float3 omega_in, float *pdf)
|
|
{
|
|
float offset = sc->data2;
|
|
float3 Tg = sc->T;
|
|
float roughness1 = sc->data0;
|
|
float roughness2 = sc->data1;
|
|
float Iz = dot(Tg, I);
|
|
float3 locy = normalize(I - Tg * Iz);
|
|
|
|
float theta_r = M_PI_2_F - fast_acosf(Iz);
|
|
|
|
float omega_in_z = dot(Tg, omega_in);
|
|
float3 omega_in_y = normalize(omega_in - Tg * omega_in_z);
|
|
|
|
float theta_i = M_PI_2_F - fast_acosf(omega_in_z);
|
|
float phi_i = fast_acosf(dot(omega_in_y, locy));
|
|
|
|
if(M_PI_2_F - fabsf(theta_i) < 0.001f) {
|
|
*pdf = 0.0f;
|
|
return make_float3(*pdf, *pdf, *pdf);
|
|
}
|
|
|
|
float costheta_i = fast_cosf(theta_i);
|
|
|
|
float roughness1_inv = 1.0f / roughness1;
|
|
float a_TT = fast_atan2f(((M_PI_2_F + theta_r)/2 - offset) * roughness1_inv, 1.0f);
|
|
float b_TT = fast_atan2f(((-M_PI_2_F + theta_r)/2 - offset) * roughness1_inv, 1.0f);
|
|
float c_TT = 2 * fast_atan2f(M_PI_2_F / roughness2, 1.0f);
|
|
|
|
float theta_h = (theta_i + theta_r) / 2;
|
|
float t = theta_h - offset;
|
|
float phi = fabsf(phi_i);
|
|
|
|
float p = M_PI_F - phi;
|
|
float theta_pdf = roughness1 / (2 * (t*t + roughness1 * roughness1) * (a_TT - b_TT)*costheta_i);
|
|
float phi_pdf = roughness2 / (c_TT * (p * p + roughness2 * roughness2));
|
|
|
|
*pdf = phi_pdf * theta_pdf;
|
|
return make_float3(*pdf, *pdf, *pdf);
|
|
}
|
|
|
|
ccl_device int bsdf_hair_reflection_sample(const ShaderClosure *sc, float3 Ng, float3 I, float3 dIdx, float3 dIdy, float randu, float randv, float3 *eval, float3 *omega_in, float3 *domega_in_dx, float3 *domega_in_dy, float *pdf)
|
|
{
|
|
float offset = sc->data2;
|
|
float3 Tg = sc->T;
|
|
float roughness1 = sc->data0;
|
|
float roughness2 = sc->data1;
|
|
float Iz = dot(Tg, I);
|
|
float3 locy = normalize(I - Tg * Iz);
|
|
float3 locx = cross(locy, Tg);
|
|
float theta_r = M_PI_2_F - fast_acosf(Iz);
|
|
|
|
float roughness1_inv = 1.0f / roughness1;
|
|
float a_R = fast_atan2f(((M_PI_2_F + theta_r) * 0.5f - offset) * roughness1_inv, 1.0f);
|
|
float b_R = fast_atan2f(((-M_PI_2_F + theta_r) * 0.5f - offset) * roughness1_inv, 1.0f);
|
|
|
|
float t = roughness1 * tanf(randu * (a_R - b_R) + b_R);
|
|
|
|
float theta_h = t + offset;
|
|
float theta_i = 2 * theta_h - theta_r;
|
|
|
|
float costheta_i, sintheta_i;
|
|
fast_sincosf(theta_i, &sintheta_i, &costheta_i);
|
|
|
|
float phi = 2 * safe_asinf(1 - 2 * randv) * roughness2;
|
|
|
|
float phi_pdf = fast_cosf(phi * 0.5f) * 0.25f / roughness2;
|
|
|
|
float theta_pdf = roughness1 / (2 * (t*t + roughness1*roughness1) * (a_R - b_R)*costheta_i);
|
|
|
|
float sinphi, cosphi;
|
|
fast_sincosf(phi, &sinphi, &cosphi);
|
|
*omega_in =(cosphi * costheta_i) * locy -
|
|
(sinphi * costheta_i) * locx +
|
|
( sintheta_i) * Tg;
|
|
|
|
//differentials - TODO: find a better approximation for the reflective bounce
|
|
#ifdef __RAY_DIFFERENTIALS__
|
|
*domega_in_dx = 2 * dot(locy, dIdx) * locy - dIdx;
|
|
*domega_in_dy = 2 * dot(locy, dIdy) * locy - dIdy;
|
|
#endif
|
|
|
|
*pdf = fabsf(phi_pdf * theta_pdf);
|
|
if(M_PI_2_F - fabsf(theta_i) < 0.001f)
|
|
*pdf = 0.0f;
|
|
|
|
*eval = make_float3(*pdf, *pdf, *pdf);
|
|
|
|
return LABEL_REFLECT|LABEL_GLOSSY;
|
|
}
|
|
|
|
ccl_device int bsdf_hair_transmission_sample(const ShaderClosure *sc, float3 Ng, float3 I, float3 dIdx, float3 dIdy, float randu, float randv, float3 *eval, float3 *omega_in, float3 *domega_in_dx, float3 *domega_in_dy, float *pdf)
|
|
{
|
|
float offset = sc->data2;
|
|
float3 Tg = sc->T;
|
|
float roughness1 = sc->data0;
|
|
float roughness2 = sc->data1;
|
|
float Iz = dot(Tg, I);
|
|
float3 locy = normalize(I - Tg * Iz);
|
|
float3 locx = cross(locy, Tg);
|
|
float theta_r = M_PI_2_F - fast_acosf(Iz);
|
|
|
|
float roughness1_inv = 1.0f / roughness1;
|
|
float a_TT = fast_atan2f(((M_PI_2_F + theta_r)/2 - offset) * roughness1_inv, 1.0f);
|
|
float b_TT = fast_atan2f(((-M_PI_2_F + theta_r)/2 - offset) * roughness1_inv, 1.0f);
|
|
float c_TT = 2 * fast_atan2f(M_PI_2_F / roughness2, 1.0f);
|
|
|
|
float t = roughness1 * tanf(randu * (a_TT - b_TT) + b_TT);
|
|
|
|
float theta_h = t + offset;
|
|
float theta_i = 2 * theta_h - theta_r;
|
|
|
|
float costheta_i, sintheta_i;
|
|
fast_sincosf(theta_i, &sintheta_i, &costheta_i);
|
|
|
|
float p = roughness2 * tanf(c_TT * (randv - 0.5f));
|
|
float phi = p + M_PI_F;
|
|
float theta_pdf = roughness1 / (2 * (t*t + roughness1*roughness1) * (a_TT - b_TT) * costheta_i);
|
|
float phi_pdf = roughness2 / (c_TT * (p * p + roughness2 * roughness2));
|
|
|
|
float sinphi, cosphi;
|
|
fast_sincosf(phi, &sinphi, &cosphi);
|
|
*omega_in =(cosphi * costheta_i) * locy -
|
|
(sinphi * costheta_i) * locx +
|
|
( sintheta_i) * Tg;
|
|
|
|
//differentials - TODO: find a better approximation for the transmission bounce
|
|
#ifdef __RAY_DIFFERENTIALS__
|
|
*domega_in_dx = 2 * dot(locy, dIdx) * locy - dIdx;
|
|
*domega_in_dy = 2 * dot(locy, dIdy) * locy - dIdy;
|
|
#endif
|
|
|
|
*pdf = fabsf(phi_pdf * theta_pdf);
|
|
if(M_PI_2_F - fabsf(theta_i) < 0.001f) {
|
|
*pdf = 0.0f;
|
|
}
|
|
|
|
*eval = make_float3(*pdf, *pdf, *pdf);
|
|
|
|
kernel_assert(dot(locy, *omega_in) < 0.0f);
|
|
|
|
return LABEL_TRANSMIT|LABEL_GLOSSY;
|
|
}
|
|
|
|
CCL_NAMESPACE_END
|
|
|
|
#endif /* __BSDF_HAIR_H__ */
|
|
|