diff options
Diffstat (limited to 'intern/cycles/kernel/closure/bsdf_util.h')
| -rw-r--r-- | intern/cycles/kernel/closure/bsdf_util.h | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/intern/cycles/kernel/closure/bsdf_util.h b/intern/cycles/kernel/closure/bsdf_util.h index b0c5280b6cb..3dc15d5791c 100644 --- a/intern/cycles/kernel/closure/bsdf_util.h +++ b/intern/cycles/kernel/closure/bsdf_util.h @@ -124,6 +124,13 @@ ccl_device float3 fresnel_conductor(float cosi, const float3 eta, const float3 k return(Rparl2 + Rperp2) * 0.5f; } +ccl_device float schlick_fresnel(float u) +{ + float m = clamp(1.0f - u, 0.0f, 1.0f); + float m2 = m * m; + return m2 * m2 * m; // pow(m, 5) +} + ccl_device float smooth_step(float edge0, float edge1, float x) { float result; @@ -136,6 +143,19 @@ ccl_device float smooth_step(float edge0, float edge1, float x) return result; } +/* Calculate the fresnel color which is a blend between white and the F0 color (cspec0) */ +ccl_device_forceinline float3 interpolate_fresnel_color(float3 L, float3 H, float ior, float F0, float3 cspec0) { + /* Calculate the fresnel interpolation factor + * The value from fresnel_dielectric_cos(...) has to be normalized because + * the cspec0 keeps the F0 color + */ + float F0_norm = 1.0f / (1.0f - F0); + float FH = (fresnel_dielectric_cos(dot(L, H), ior) - F0) * F0_norm; + + /* Blend between white and a specular color with respect to the fresnel */ + return cspec0 * (1.0f - FH) + make_float3(1.0f, 1.0f, 1.0f) * FH; +} + CCL_NAMESPACE_END #endif /* __BSDF_UTIL_H__ */ |