diff options
Diffstat (limited to 'intern/cycles/kernel/osl/nodes/node_fresnel.h')
-rw-r--r-- | intern/cycles/kernel/osl/nodes/node_fresnel.h | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/intern/cycles/kernel/osl/nodes/node_fresnel.h b/intern/cycles/kernel/osl/nodes/node_fresnel.h new file mode 100644 index 00000000000..0c8a5276ede --- /dev/null +++ b/intern/cycles/kernel/osl/nodes/node_fresnel.h @@ -0,0 +1,21 @@ + +float fresnel_dielectric(vector Incoming, normal Normal, float eta) +{ + /* compute fresnel reflectance without explicitly computing + the refracted direction */ + float c = fabs(dot(Incoming, Normal)); + float g = eta * eta - 1 + c * c; + float result; + + if(g > 0) { + g = sqrt(g); + float A =(g - c)/(g + c); + float B =(c *(g + c)- 1)/(c *(g - c)+ 1); + result = 0.5 * A * A *(1 + B * B); + } + else + result = 1.0; /* TIR (no refracted component) */ + + return result; +} + |