Mapped IOR?

[mferster]

Hey there,

so I've been doing some experiments with mapped fresnel IOR after looking at this old thread
https://forum.corona-renderer.com/index.php?topic=4602.0
, but I'm running into some issues. Maybe something has changed since this thread?

No matter what constant fresnel IOR value I set, the mapped black value always comes out as 999 IOR and the white value always comes out to 1.

Just looking for some clarification. From what I interpreted out of that thread is that if i set my constant ior value to 5, the white values in my maps should also be IOR 5 and blacks should be 1.

But that's not what I'm seeing from my tests. Am I missing something?

[romullus]

Yes, IOR mapping was changed to be consistent with other packages. Now IOR is mapped as 1/x. So when your input is white, IOR is 1/1=1 and when input is black, IOR is 1/0,00..1=100..0->999

[mferster]

Alright, cool.

So if i wanted a specific IOR represented in my map.. what's the most accurate method of converting a specific IOR in that range to a grey value?

edit* nevermind I'm dumb, I was overthinking it way too much. You just divide 255 by whatever IOR value you are aiming for.

edit 2 And load bitmap as gamma 1.0.... for anyone else who may search for this later