[blueplanetdesign]

Perhaps this will assist you.
I parphrase from an earlier post by Tom;

For clipping, you need to use several maps.

Reflectance map has to be black in invisible parts,

transmittance map has to be white in invisible parts and completely black in visible parts,

rougness map has to be black in invisible parts.

With a little patience and some inventiveness you will get
the result you want.

Post your progress and we will help if we can.

[blueplanetdesign]

Try an ordinary Maxwell metal material with some roughness applied.

[tokiop]

Coatings are very specific, if you have no use of their rainbow proprieties (I guess it's not the physicians vocab ) simply use another traditional material layer on top of the first one to control specularity.. but anyway, only one metal layer should work for what your after!

[jdp]

something like this?
I can share the material if you want.

[jonathan löwe]

hmmm nice
if you like to share, i'd take it!


best regards
jonathan

[jdp]

sure , here we are:

micropierced aluminium

and this is how it is done, nothing very special:



hope you enjoy...

[jdp]

I've started a topic in the main forum and results are even better (not mine):

http://www.maxwellrender.com/forum/view ... highlight=