Author Topic: Overlapping UVs and baking Ambient Occlusion maps  (Read 278 times)

Okay, this is something that has completely stumped me. I've recently made Tiny Tina from Borderlands 2 as part of a university assignment. I've even been speaking to the original character modeller on ArtStation about some of his methods and insights. :) However, one thing he mentioned, was that he always overlaps his symmetrical UVs to save space, and his bakes always come out fine. I did the same, and though the Normal map and everything else did come out fine, one map doesn't, which he said would be a problem. The Ambient Occlusion. I'm a little bit stumped on how to get a decent bake for it. I've read that the overlapped pieces should be offsetted by 1. I did that, but they still baked wrong. I've even tried offsetting them and then flipping them so they're facing the opposite way, thinking that would definitely be the answer, but they still came out wrong.

I've linked the low and high via Dropbox in case anyone wants to investigate further. But how do others approach this...? What's the ideal workflow? Thanks.

tina_low - https://www.dropbox.com/s/4j6awzxrf1cp8rm/tina_low.fbx?dl=0
tina_high - https://www.dropbox.com/s/28oi6gn88wc5xtb/tina_high.fbx?dl=0


I've wrote up a few posts on this so you'll have to search a bit more. There are certain cases you can stack and not have the AO messed up (if a piece is symmetrical you can get away with it). Otherwise there is a method where you use a second UV channel just for the AO.
I teach people how to use Substance Painter. :)

Okay, I've just found one of your posts about it in another thread. :) I'll test it out and report back if I have any issues.

Hmm... Kinda struggling with the different channels. It's the post at the bottom of this thread I found:

https://forum.substance3d.com/index.php/topic,33948.0.html

I don't think I'm approaching it right. I'm not using Blender in this case, but 3ds Max. I can't seem to select the desired UVs I want and then move them to channel 2. It's putting everything in the new channel, it seems. :-\

Actually, thinking about it, I'm not sure if the method outlined in that thread would work very well. Even though I have a number of elements that are symmetrical, there's at least one I can think of that has some floating geo on its other side, which casts a slight shadow behind it. That's something that shouldn't be on the opposite side. How would you merge two separate AO bakes out...? Or would I just use the one and ignore the other...?

Yea, I use Blender for most of my examples because the vast majority on here who ask questions use it. It isn't something I use for production or personal work.

For the one that is separate you would need another UV channel and apply the AO. Render both out and it should work. The question is do you feel this is worth the trouble or not in time and resources?
I teach people how to use Substance Painter. :)