Centurian Tanker

[PermaGrin]

How does one deal with making a nice AO map (or even map transfers from high polys) with overlapping UVs?

Only ways I have gotten around that was to think about what I had to overlap and delete certain parts during the AO/transfer.

There a way to AO/transfer easily with overlapping UVs?

[dedygan]

PermaGrin. Yes you are right. during baking AO, normal, shadow map e.t.c. overlaped uv-shells create bugs. So they need to be removed from UV(0;1) space. Those, bugs sometimes can appear randomly. But for confidence and and time preserve- better way is removing overlaps from UV(0;1) space.

PS There is no need to delete overlaped parts. Move them out from (0;1) space gives you same results.
PPS Of course all this removing overlaps need to be done with duplicate of original model

[Matroskin]

great breakdown, dedygan.

I also wanted to mention that NOT all the polygons in a model should necessary have the same UV scale or pixel resolution.

Example:

On the following image i circled UVs that correspond to polygons of lower cap of the turret. They could be easily shrinked 2-3 times no problem. They have quite dark and uniform occlusion plus usually no one will see them sufficiently:



Same applies to any surface which is somewhere on the bottom, under something or not visible in other ways. Bottom cap of the hull or hull surfaces that are above the tracks and facing down etc. can fit into such category. I always shrink such UVs a lot and that does not harm quality.

Also wheels don't need to have all unique UVs. They usually get so much dirt that even if u have camo on them, it wont be that visible if the pattern is the same or not. I did once all different camo pattern on wheels (as it happens to be in real life), but then when i put dirt and dust on wheels i could not tell the difference between camo patterns of those wheels. Maximum, u can have 3-4 different UVs for wheels and re-use them. Simply rotating the wheels will reduce the impression of repeated camo pattern.

[Matroskin]

Originally Posted by dedygan

PermaGrin. Yes you are right. during baking AO, normal, shadow map e.t.c. overlaped uv-shells create bugs. So they need to be removed from UV(0;1) space. Those, bugs sometimes can appear randomly. But for confidence and and time preserve- better way is removing overlaps from UV(0;1) space.

PS There is no need to delete overlaped parts. Move them out from (0;1) space gives you same results.
PPS Of course all this removing overlaps need to be done with duplicate of original model

Or u can also select UVs that cause overlap, trnsfer that selection to polygon selection of actual model and detach them to a separate object. Then, u can do baking without problems.
All model components stay on their places and u can attach them together anytime when u finish performing bake.