Author Topic: IOR Mapping, 1/IOR like in Corona Max and Vray  (Read 962 times)

2019-05-14, 21:05:56


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I would like to know how can I turn off and map the IOR in Cinema 4D/Corona, like in 3ds Max/Corona or Vray.
I want to connect a bitmap or any value with the 1/IOR method.

Thanks in advance.

2019-05-15, 09:41:27
Reply #1


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  • Cestmir Houska
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Hi! The IOR texture slot doesn't work for you?

2019-05-17, 09:54:25
Reply #2


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Thanks for your answer.

The IOR slot is perfectly fine. What I don't know how can I turn off the IOR number(like 99999 in Max) and control it fully with an 1/IOR map.
I tried different settings, but it not works like it should(Max/Corona or Vray).

Okay, before I posted this, I tried it again and it seems I figured it out.
I have to set the IOR 999 at the maximum to turn it off, and the 1/IOR map needs to be inverted.

Can you confirm that this is the right way?
Anyway why do I have to invert the 1/IOR map? It should be consistent in every application.


Ps.: To be honest I'm not a C4D user, just tried to help to a friend.

2019-09-04, 15:39:51
Reply #3

James Vella

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It seems consistent to 3dsmax for me.

1/IOR is an inverse calculation.
So Black = Frensel Disabled (Vray) or 999 (Corona).
White =  Fresnel 1. (Which would give you a completely black sphere for example)

If you want more information about this I have written a short tutorial on the 1/IOR fresnel calculation here (scroll to the bottom of the page):