Maya- Problem with rendering glass in Arnold

Yogev

So I have this weird issue when trying to render glass in Arnold, and I'm not really sure what's causing it.
When I render, I got some kind of "artifacts"-

When I smooth the mesh, those "artifacts" disappear-


Anyone has an idea what's causing it, and how to remove those artifacts from the unsmoothed version?
I use the aiStandardSurface material for this one.

Axi5

Have you checked your normals?

Yogev

Axi5 said:

Have you checked your normals?

Do you mean to use display normals on the object?
I'm not really sure what I'm looking for.

Axi5

You're looking for flipped normals in those problem areas, check both sides since it's transparent. To make it easier you can enable Backface Culling and see if you can find holes in your mesh.

On another note, why wouldn't you smooth it for a render anyway?

Yogev

Axi5 said:

You're looking for flipped normals in those problem areas, check both sides since it's transparent. To make it easier you can enable Backface Culling and see if you can find holes in your mesh.

On another note, why wouldn't you smooth it for a render anyway?

I enabled Backface Culling, and I don't see any holes in the mesh or any shading issues. Could it be a UV issue?

This glass piece is part of a bigger model, which I plan to put on Sketchfab. If I smooth the whole model the polycount will be too high.
Also, I'd think it's a good idea to find out what's causing the issue, just in case it happens again with another model.

Axi5

> Could it be a UV issue?

Nah not likely, this looks more like a ray trace issue. They like lots of geometry else you get the odd artifact like this, typically with shadows on round surfaces but wouldn't be surprised if reflections had an issue too.

It seems to look fine in the GL window so it's probably fine.