Should inverted UV shells be avoided at all costs?

Jarjarniks

Hey guys, I'm in the unwrapping phase of a weapon, and I have been unable to find any information about whether or not inverted UV shells are okay, or something you should avoid at all costs. Sometimes when you mirror/flip a UV island, you can get stuff to fit a lot tighter/more efficiently. Obviously whatever texture information you put on it would be mirrored on the object, but if you are just aware of it is it a big deal? I'm also unsure as to what effect inverted UV shells can have on your normal map bakes.

This is not about mirroring an object and offsetting the mirrored UV shell by 1, to save texture res and ensuring that no normal map seams are visible. I'm talking about having a full object whose UV shells are just inverted.

Any and all info would be appreciated!  

Thanks for reading!

Scruples

It makes the uv's less readable otherwise it's fine to have inverted UV shells.

Jarjarniks

Super, thanks for the help!

Farfarer

It's not an issue, quite a common practice

So long as, if you're using normal maps, the engine can cope with mirrored UVs (almost any engine you use today will be able to manage).

Deadly Nightshade

It's perfectly fine to use inverted shells - same goes for stacked shells.
The only problem I've had with mirrored/stacked shells has been with dDo: but that can always be cleaned up by customizing the masks.