Transparent Subsurface for thin parts of objects

[exnpac]

Hi all !

I m currently working on quite small scaled fishes that have quite a lot of sss but tend also to have transparency on the very thin parts like the fins. For the moment we are using of course a mix of SSS and transmission using maps as it was the most obvious solution to achieve this kind of look. Since last update I tried working with the new random walk and I was very impressed with how it works with thin parts and edges. But as usual we want to be able to achieve more 😄 ! I was wondering if it would be possible to create a shader that accurately calculates transparency on thin parts in the SSS as I have the impression that the random walk SSS is quite close to achieve this. Here is an example of materials I'm talking about :

I tried mixing SSS and transmission scattering but never came to a result I was quite satisfied with (and scattering in transmission is quite costly and noisy).

Maybe being able to ouput an AOV of the randomwalk that would drive transmission in the edge would be and idea ?

Looking forward to see if some ideas pop up.

Cheers !

[lee_griggs]

Transmission Scatter and Scatter Anisotropy should be useful for this.

Maybe connecting Curvature to Mix Weight could also help exaggerate it.

I also suggest you watch this video.

[exnpac]

Thanks Lee !

[Slava_91]

You need sss randomwalk with high radius level and painting radius map for control transparent place

https://www.youtube.com/watch?v=VKmuJDwc__I

[T0M0X]

I would like to ask if it's really possible to render clear thin transparent parts with subsurface in Arnold.

I tried new randomwalk_v2 mode too, but I still get weird grey areas in very thin areas (caustics are enabled, I set ray depths to 10 so they are definitely not limiting the result).

Thanks for your help.