View Full Version : Eccentricity maps don't render in MR

08 August 2010, 12:15 AM
So I've been using a technique for a little while now which is to create a map for Eccentricity on a blinn shader. This method allows me to give the illusion of fingerprints on glass, or scratches etc. This method is not a specular map since it doesn't define where things are shiny and where they are not, it simply defines where the highlight is expanded and where it it tight.. So in maya software renderer it works perfectly every time, and in the realtime viewport it also works perfectly (viewport 2.0) however, in mental ray it doesn't work at all.

So I'm left with trying to render the highlights alone in maya software and composite them after.. what I'm wondering is if someone smart might have an alternative way of doing this same thing that would work in mental ray..?

I tried with the mental ray Blinn shader but it doesn't have those properties open..

08 August 2010, 09:18 AM
Sounds like you could use the glossiness parameter of the mia_material.

Avoid mib_shaders. They are kept around for legacy reasons.

08 August 2010, 11:16 AM
Hi cowsmanaut,
try this in case you have not.In the file texture node where you have eccentricity mapped try putting on the Alpha is luminance switch.If it works with blinn in maya software it is possible that information is not being read in mental ray as it is looking for the alpha channel and we assume it will take the luminance value by default.
Hope it solves your issue.

08 August 2010, 12:26 AM
Snikt, works perfectly. Odd solution.. doesn't seem like it should affect it but it does. Thanks

08 August 2010, 03:23 AM
Hi cowsmanaut,
glad it worked for you.Recently had a similar issue but that was across maya 8.5 and maya 2010 at work.The solution though was same.

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08 August 2010, 03:23 AM
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