Chaos Corona Forum

Chaos Corona for 3ds Max => [Max] General Discussion => Topic started by: fleksor on 2020-03-24, 05:05:44

Title: [solved] Corona Volume Material Artefacts
Post by: fleksor on 2020-03-24, 05:05:44

Hi

Does anyone know how I can avoid these black artefacts when making Corona Volume Mtl clouds?  (See attached example)

I have been following this tutorial precisely: (www.youtube.com/watch?v=t6R3JwCy02M)

but seem to get what looks like some sort of polygonal overlap render artefacts once I apply a second layer of displacement or coronaDisplacement for detail.

(I am using Max2017)

Has anyone seen this before?
Thanks for any help!

Title: Re: Corona Volume Material Artefacts
Post by: romullus on 2020-03-24, 09:43:58

What Corona version you are using? I think this kind of artefacts should be fixed in V5.

Title: Re: Corona Volume Material Artefacts
Post by: maru on 2020-03-25, 11:31:46

These are flipped normals. The new medium solver is more sensitive to such things (since it's normal-based).
The solution is to either:
- Make sure there are no flipped normals in the model (e.g. use the Relax modifier)
or
- Go to Devel/Debug rollout (https://coronarenderer.freshdesk.com/support/solutions/articles/12000021288) and enable the "Use legacy medium resolving" checkbox at top-left