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Diffstat (limited to 'intern/cycles/kernel/closure/bsdf_hair.h')
| -rw-r--r-- | intern/cycles/kernel/closure/bsdf_hair.h | 279 |
1 files changed, 279 insertions, 0 deletions
diff --git a/intern/cycles/kernel/closure/bsdf_hair.h b/intern/cycles/kernel/closure/bsdf_hair.h new file mode 100644 index 00000000000..5791598459c --- /dev/null +++ b/intern/cycles/kernel/closure/bsdf_hair.h @@ -0,0 +1,279 @@ +/* + * 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 + + +__device void bsdf_hair_reflection_blur(ShaderClosure *sc, float roughness) +{ +} + +__device void bsdf_hair_transmission_blur(ShaderClosure *sc, float roughness) +{ +} + +__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|SD_BSDF_GLOSSY; +} + +__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|SD_BSDF_GLOSSY; +} + +__device float3 bsdf_hair_reflection_eval_reflect(const ShaderClosure *sc, const float3 I, const float3 omega_in, float *pdf) +{ +#ifdef __HAIR__ + float offset = sc->offset; + float3 Tg = sc->T; +#else + float offset = 0.0f; + float3 Tg = make_float3(1.0f,0.0f,0.0f); +#endif + 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 - safe_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 - safe_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 phi_i = safe_acosf(cosphi_i) / roughness2; + phi_i = fabsf(phi_i) < M_PI_F ? phi_i : M_PI_F; + float costheta_i = cosf(theta_i); + + float a_R = atan2f(((M_PI_2_F + theta_r) * 0.5f - offset) / roughness1, 1.0f); + float b_R = atan2f(((-M_PI_2_F + theta_r) * 0.5f - offset) / roughness1, 1.0f); + + float theta_h = (theta_i + theta_r) * 0.5f; + float t = theta_h - offset; + + float phi_pdf = cos(phi_i * 0.5f) * 0.25f / roughness2; + 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); +} + +__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); +} + + +__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); +} + +__device float3 bsdf_hair_transmission_eval_transmit(const ShaderClosure *sc, const float3 I, const float3 omega_in, float *pdf) +{ +#ifdef __HAIR__ + float offset = sc->offset; + float3 Tg = sc->T; +#else + float offset = 0.0f; + float3 Tg = make_float3(1.0f,0.0f,0.0f); +#endif + 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 - safe_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 - safe_acosf(omega_in_z); + float phi_i = safe_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 = cosf(theta_i); + + float a_TT = atan2f(((M_PI_2_F + theta_r)/2 - offset) / roughness1, 1.0f); + float b_TT = atan2f(((-M_PI_2_F + theta_r)/2 - offset) / roughness1, 1.0f); + float c_TT = 2 * 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); +} + +__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) +{ +#ifdef __HAIR__ + float offset = sc->offset; + float3 Tg = sc->T; +#else + float offset = 0.0f; + float3 Tg = make_float3(1.0f,0.0f,0.0f); +#endif + 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 - safe_acosf(Iz); + + float a_R = atan2f(((M_PI_2_F + theta_r) * 0.5f - offset) / roughness1, 1.0f); + float b_R = atan2f(((-M_PI_2_F + theta_r) * 0.5f - offset) / roughness1, 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 = cosf(theta_i); + float sintheta_i = sinf(theta_i); + + float phi = 2 * safe_asinf(1 - 2 * randv) * roughness2; + + float phi_pdf = cos(phi * 0.5f) * 0.25f / roughness2; + + float theta_pdf = roughness1 / (2 * (t*t + roughness1*roughness1) * (a_R - b_R)*costheta_i); + + *omega_in =(cosf(phi) * costheta_i) * locy - + (sinf(phi) * 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); + + if(dot(locy, *omega_in) < 0.0f) { + return LABEL_REFLECT|LABEL_TRANSMIT|LABEL_GLOSSY; + } + + return LABEL_REFLECT|LABEL_GLOSSY; +} + +__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) +{ +#ifdef __HAIR__ + float offset = sc->offset; + float3 Tg = sc->T; +#else + float offset = 0.0f; + float3 Tg = make_float3(1.0f,0.0f,0.0f); +#endif + 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 - safe_acosf(Iz); + + float a_TT = atan2f(((M_PI_2_F + theta_r)/2 - offset) / roughness1, 1.0f); + float b_TT = atan2f(((-M_PI_2_F + theta_r)/2 - offset) / roughness1, 1.0f); + float c_TT = 2 * 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 = cosf(theta_i); + float sintheta_i = sinf(theta_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)); + + *omega_in =(cosf(phi) * costheta_i) * locy - + (sinf(phi) * 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); + + if(dot(locy, *omega_in) < 0.0f) + return LABEL_TRANSMIT|LABEL_GLOSSY; + + return LABEL_GLOSSY; +} + +CCL_NAMESPACE_END + +#endif /* __BSDF_HAIR_H__ */ + |