[hdesbois]

Hi,
I'm not sure about this angle thing. ior are commonly measured for different polarization angles (0 and 90). You can mix two iors to simulate birefringence, but that's not physically correct since Maxwell does not use polarization anyway. If you want a material that changes color with viewing angle, maybe a regular mxm is better. Mixing ior is tricky and unpredictible.
Regards,
HD
PS: for r2 files, see:
http://www.maxwellrender.com/forum/view ... hp?t=15114