[Yafray-devel] Fresnel effect too dominant for IOR=1.5

[lynx . abraxas]

Hello!



First of all thanks for the great free raytracer. I started with blender/yafray 
a few weeks ago and am very impressed  what can be done with it.
But when trying to get a realistic wine glas with yafray and caustics I got 
stuck reducing the fresnel effect. In the net I found a statement that it would 
be implicit linked to IOR. Comparing it with the blender internal raytracer and 
physical values (5 and 1.25, 
http://www-nw.uni-regensburg.de/~.grr06742.back.physik.uni-regensburg.de/BLENDER/GLAS_B~1.PNG)
 it is obviously too dominant (freoff= 1.25: 
http://www-nw.uni-regensburg.de/~.grr06742.back.physik.uni-regensburg.de/BLENDER/GLAS_B~2.PNG)
 in yafray pics even if the fresnel offset is set to the maximum of 5 (freoff= 
5.00: 
http://www-nw.uni-regensburg.de/~.grr06742.back.physik.uni-regensburg.de/BLENDER/GLAS_B~3.PNG).
I would like to know where the strength of the fresnel effect is set in the 
code of yafray or how to influence it in the xml code (I couldn't find any docs 
on that and changing the fresnel offset to negativ values in the xml file 
didn't help).

By the way: When disableing RayMirror in the Blender yafray settings the 
fresnel effect does not disappear. It just seems to influence the shading ad 
the sides of the glas.
I'm using yafray 0.9 and blender 2.45.

Any help or hints apreciated
Lynx