[solved] Corona Volume Material Artefacts

[tapeee]

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!

[romullus]

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

[maru]

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