diff options
Diffstat (limited to 'intern/cycles/kernel/svm/bsdf_ashikhmin_velvet.h')
-rw-r--r-- | intern/cycles/kernel/svm/bsdf_ashikhmin_velvet.h | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/intern/cycles/kernel/svm/bsdf_ashikhmin_velvet.h b/intern/cycles/kernel/svm/bsdf_ashikhmin_velvet.h new file mode 100644 index 00000000000..40bae72a6c5 --- /dev/null +++ b/intern/cycles/kernel/svm/bsdf_ashikhmin_velvet.h @@ -0,0 +1,154 @@ +/* + * 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_ASHIKHMIN_VELVET_H__ +#define __BSDF_ASHIKHMIN_VELVET_H__ + +CCL_NAMESPACE_BEGIN + +typedef struct BsdfAshikhminVelvetClosure { + //float3 m_N; + float m_invsigma2; +} BsdfAshikhminVelvetClosure; + +__device void bsdf_ashikhmin_velvet_setup(ShaderData *sd, float3 N, float sigma) +{ + BsdfAshikhminVelvetClosure *self = (BsdfAshikhminVelvetClosure*)sd->svm_closure_data; + + sigma = fmaxf(sigma, 0.01f); + + //self->m_N = N; + self->m_invsigma2 = 1.0f/(sigma * sigma); + + sd->svm_closure = CLOSURE_BSDF_ASHIKHMIN_VELVET_ID; + sd->flag |= SD_BSDF_HAS_EVAL; +} + +__device void bsdf_ashikhmin_velvet_blur(ShaderData *sd, float roughness) +{ +} + +__device float3 bsdf_ashikhmin_velvet_eval_reflect(const ShaderData *sd, const float3 I, const float3 omega_in, float *pdf) +{ + const BsdfAshikhminVelvetClosure *self = (const BsdfAshikhminVelvetClosure*)sd->svm_closure_data; + float3 m_N = sd->N; + + float cosNO = dot(m_N, I); + float cosNI = dot(m_N, omega_in); + if(cosNO > 0 && cosNI > 0) { + float3 H = normalize(omega_in + I); + + float cosNH = dot(m_N, H); + float cosHO = fabsf(dot(I, H)); + + float cosNHdivHO = cosNH / cosHO; + cosNHdivHO = fmaxf(cosNHdivHO, 0.00001f); + + float fac1 = 2 * fabsf(cosNHdivHO * cosNO); + float fac2 = 2 * fabsf(cosNHdivHO * cosNI); + + float sinNH2 = 1 - cosNH * cosNH; + float sinNH4 = sinNH2 * sinNH2; + float cotangent2 = (cosNH * cosNH) / sinNH2; + + float D = expf(-cotangent2 * self->m_invsigma2) * self->m_invsigma2 * M_1_PI_F / sinNH4; + float G = min(1.0f, min(fac1, fac2)); // TODO: derive G from D analytically + + float out = 0.25f * (D * G) / cosNO; + + *pdf = 0.5f * M_1_PI_F; + return make_float3(out, out, out); + } + return make_float3(0, 0, 0); +} + +__device float3 bsdf_ashikhmin_velvet_eval_transmit(const ShaderData *sd, const float3 I, const float3 omega_in, float *pdf) +{ + return make_float3(0.0f, 0.0f, 0.0f); +} + +__device float bsdf_ashikhmin_velvet_albedo(const ShaderData *sd, const float3 I) +{ + return 1.0f; +} + +__device int bsdf_ashikhmin_velvet_sample(const ShaderData *sd, float randu, float randv, float3 *eval, float3 *omega_in, float3 *domega_in_dx, float3 *domega_in_dy, float *pdf) +{ + const BsdfAshikhminVelvetClosure *self = (const BsdfAshikhminVelvetClosure*)sd->svm_closure_data; + float3 m_N = sd->N; + + // we are viewing the surface from above - send a ray out with uniform + // distribution over the hemisphere + sample_uniform_hemisphere(m_N, randu, randv, omega_in, pdf); + + if(dot(sd->Ng, *omega_in) > 0) { + float3 H = normalize(*omega_in + sd->I); + + float cosNI = dot(m_N, *omega_in); + float cosNO = dot(m_N, sd->I); + float cosNH = dot(m_N, H); + float cosHO = fabsf(dot(sd->I, H)); + + float cosNHdivHO = cosNH / cosHO; + cosNHdivHO = fmaxf(cosNHdivHO, 0.00001f); + + float fac1 = 2 * fabsf(cosNHdivHO * cosNO); + float fac2 = 2 * fabsf(cosNHdivHO * cosNI); + + float sinNH2 = 1 - cosNH * cosNH; + float sinNH4 = sinNH2 * sinNH2; + float cotangent2 = (cosNH * cosNH) / sinNH2; + + float D = expf(-cotangent2 * self->m_invsigma2) * self->m_invsigma2 * M_1_PI_F / sinNH4; + float G = min(1.0f, min(fac1, fac2)); // TODO: derive G from D analytically + + float power = 0.25f * (D * G) / cosNO; + + *eval = make_float3(power, power, power); + +#ifdef __RAY_DIFFERENTIALS__ + // TODO: find a better approximation for the retroreflective bounce + *domega_in_dx = (2 * dot(m_N, sd->dI.dx)) * m_N - sd->dI.dx; + *domega_in_dy = (2 * dot(m_N, sd->dI.dy)) * m_N - sd->dI.dy; + *domega_in_dx *= 125; + *domega_in_dy *= 125; +#endif + } else + *pdf = 0.0f; + + return LABEL_REFLECT|LABEL_DIFFUSE; +} + +CCL_NAMESPACE_END + +#endif /* __BSDF_ASHIKHMIN_VELVET_H__ */ + |