Hi.

I ran into a strange behaviour when rendering feathers with Karma.
It seems like the one side of barbs (left/right) is reacting very different to light than the other.
In my case, the feathers themselves are very flat, so I would expect the spec highlight to go over them pretty smoothly.
However, as you can see in the screenshots, there is a big difference, comparing the left and right side of the feather.
Also looking at the normal AOV, if looking at a small angle already, left and right side looks very different.

I'm just wondering if that's the expected behaviour or there might be something wrong with my setup.
I already checked with other feather grooms (the SideFX provided Tucan for example) with which that's also happening for me.

Cheers and thanks for your feedback.

Best
Sebastian

I was just having a similar issue with Arnold. I found that setting the curves to 'thick' in the rendergeometrysettings node fixed it. Might be worth trying if that would work for Karma as well. I believe in Karma the equivalent is setting the curves as 'Rounded Curves'

Thanks for the hint.
But that's not the problem in my case. Karma is rendering curves as 'Rounded Curves' by default.
So setting it via rendergeometrysettings didn't change anything for me unfortunately.

any update? my current situation is also using Arnold, but didint help the 'thick' setting..


*EDIT

The current issue is on standardHair Shader.
Ive tried with standardShader then seems better result than HairShaders one. but still there is the normal? issue..
So current situation we probably should pick standard shader?

Hopefully someone has the way to fix this.