Chaos Corona Forum
Chaos Corona for 3ds Max => [Max] Feature Requests => [Max] Resolved Feature Requests => Topic started by: duduche75 on 2014-07-15, 21:01:45
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Hello,
don't know if it's actually a bug or the expected behaviour,
but in a7, plug in an Fresnel IOR map doesn't fully override the IOR value,
it makes kind of blending inbetween.
You don't need to render to see this effect, it's already in the material editor.
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Use fresnel ior of 999 in Corona material to technically disable it.
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It's a feature, not a bug ;)
Your Ior value defines the max (= white in the map), so you can do very subtle adjustments. If you have set your ior to 1,52 then white means 1,52 and black means 1,0
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yep, feature. The map actually goes from 0 to the constant value
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While it may not necessarily be a bug, the current solution in corona is rather clumsy. Vray's model is a lot better in this regard. Let's say you have an object made of two components based on a bitmap. You know you want white part of the bitmap to have IOR of exactly 1.25, and black part to have IOR of exactly 3.1. How do you do it?
With current solution, it will be quite difficult to achieve. With Vray on the other hand, it's quite easy. You plug a Mix map in the fresnel map slot. As a mix texture, you use your IOR bitmap. As a white color slot of Mix map, you plug in Output map with output amount of 1.25, and as a black color slot of Mix map, you plug in Output map with output amount of 3.1. And there you have it... exact fresnel map :)
So then, if you have more complicated map with say 10 different exact IOR numbers, you can just paint shades of gray using floating point values, and then use that as a bitmap with output amount of 100, therefore making it in 0-100 range, and each shade of gray on the map will then interpret the exact same IOR. That's the way Vray works and it makes a sense.
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thats also how corona works, if you set the constant IOR value to 100....
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thats also how corona works, if you set the constant IOR value to 100....
Nevermind then :)
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Thanks everyone for answers, sorry for the delay I just forgotten this thread...
The way Rawalanche describes it is actually what I was intended to do,
so turning constant ior to 100 is the solution for me.
Thanks again !