b9ce231060
More information in this post: http://code.blender.org/ Thanks to all contributes for giving their permission!
96 lines
2.6 KiB
C
96 lines
2.6 KiB
C
/*
|
|
* Copyright 2011-2013 Blender Foundation
|
|
*
|
|
* Licensed under the Apache License, Version 2.0 (the "License");
|
|
* you may not use this file except in compliance with the License.
|
|
* You may obtain a copy of the License at
|
|
*
|
|
* http://www.apache.org/licenses/LICENSE-2.0
|
|
*
|
|
* Unless required by applicable law or agreed to in writing, software
|
|
* distributed under the License is distributed on an "AS IS" BASIS,
|
|
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
* See the License for the specific language governing permissions and
|
|
* limitations under the License
|
|
*/
|
|
|
|
#ifndef __BSDF_OREN_NAYAR_H__
|
|
#define __BSDF_OREN_NAYAR_H__
|
|
|
|
CCL_NAMESPACE_BEGIN
|
|
|
|
__device float3 bsdf_oren_nayar_get_intensity(const ShaderClosure *sc, float3 n, float3 v, float3 l)
|
|
{
|
|
float nl = max(dot(n, l), 0.0f);
|
|
float nv = max(dot(n, v), 0.0f);
|
|
float t = dot(l, v) - nl * nv;
|
|
|
|
if (t > 0.0f)
|
|
t /= max(nl, nv) + FLT_MIN;
|
|
float is = nl * (sc->data0 + sc->data1 * t);
|
|
return make_float3(is, is, is);
|
|
}
|
|
|
|
__device int bsdf_oren_nayar_setup(ShaderClosure *sc)
|
|
{
|
|
float sigma = sc->data0;
|
|
|
|
sc->type = CLOSURE_BSDF_OREN_NAYAR_ID;
|
|
|
|
sigma = clamp(sigma, 0.0f, 1.0f);
|
|
|
|
float div = 1.0f / (M_PI_F + ((3.0f * M_PI_F - 4.0f) / 6.0f) * sigma);
|
|
|
|
sc->data0 = 1.0f * div;
|
|
sc->data1 = sigma * div;
|
|
|
|
return SD_BSDF | SD_BSDF_HAS_EVAL;
|
|
}
|
|
|
|
__device void bsdf_oren_nayar_blur(ShaderClosure *sc, float roughness)
|
|
{
|
|
}
|
|
|
|
__device float3 bsdf_oren_nayar_eval_reflect(const ShaderClosure *sc, const float3 I, const float3 omega_in, float *pdf)
|
|
{
|
|
if (dot(sc->N, omega_in) > 0.0f) {
|
|
*pdf = 0.5f * M_1_PI_F;
|
|
return bsdf_oren_nayar_get_intensity(sc, sc->N, I, omega_in);
|
|
}
|
|
else {
|
|
*pdf = 0.0f;
|
|
return make_float3(0.0f, 0.0f, 0.0f);
|
|
}
|
|
}
|
|
|
|
__device float3 bsdf_oren_nayar_eval_transmit(const ShaderClosure *sc, const float3 I, const float3 omega_in, float *pdf)
|
|
{
|
|
return make_float3(0.0f, 0.0f, 0.0f);
|
|
}
|
|
|
|
__device int bsdf_oren_nayar_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)
|
|
{
|
|
sample_uniform_hemisphere(sc->N, randu, randv, omega_in, pdf);
|
|
|
|
if (dot(Ng, *omega_in) > 0.0f) {
|
|
*eval = bsdf_oren_nayar_get_intensity(sc, sc->N, I, *omega_in);
|
|
|
|
#ifdef __RAY_DIFFERENTIALS__
|
|
// TODO: find a better approximation for the bounce
|
|
*domega_in_dx = (2.0f * dot(sc->N, dIdx)) * sc->N - dIdx;
|
|
*domega_in_dy = (2.0f * dot(sc->N, dIdy)) * sc->N - dIdy;
|
|
#endif
|
|
}
|
|
else {
|
|
*pdf = 0.0f;
|
|
*eval = make_float3(0.0f, 0.0f, 0.0f);
|
|
}
|
|
|
|
return LABEL_REFLECT | LABEL_DIFFUSE;
|
|
}
|
|
|
|
|
|
CCL_NAMESPACE_END
|
|
|
|
#endif /* __BSDF_OREN_NAYAR_H__ */
|