Prevent occlusion for some meshes on the same UV tile / AO on movable parts
Hello,
I'm creating a game-ready weapon model and have started to bake my ambient occlusion maps, but have run into some problems with my first try.
(Each movable component of this model is its own mesh so that it can be manipulated. Below I'll just be talking about two meshes that are from the same UV tile)
I created this charging handle and it has a latch that is asymmetrical. This part of the upper receiver of the gun has flipped UV's, so it projects to the other side where I now have a problem:
It's casting the AO of the latch despite it not being there, which is obviously a problem but it also got me thinking. My initial idea was to prevent the charging handle from casting AO onto the upper receiver and only onto itself, while the upper receiver can cast AO onto it all it wants (if that's even possible), but then I'll have another problem. When the charging handle is retracted, the viewer will see AO being casted onto it while there shouldn't be like this:
(It also just has a sudden end because the mesh is colliding with the inside of the upper receiver)
So maybe I just want the charging handle to have it's AO separate from the others meshes on the same UV tile, but is that how this is usually done in videogames? This model is just for my portfolio and it's only built to be rendered in Marmoset Toolbag 3, but how would AO normally work if this was to be used in say, Unreal Engine 5 for example?
From what I'm researching, AO only show details when they're not in direct light, so does the terrible suntan on the charging handle not matter? What should I do?
Thanks for the help
Replies
I haven't seen what software you are using to bake. In Marmoset there is a handy checkbox in the map options that allows you to assign AO to parts individually or collectively. So maybe your bake soft has that option. Can you separate objects into baking sets?
Isolate it (in marmoset you can just hit "exclude when ignoring groups" ) or you can simply move it off to the side so it can bake ao without any of the other meshes getting in the way. You should avoid baking AO onto things that move around/dynamic, it as you've illustrated that it wouldn't logically make sense.
However, you can have the AO of the un-retracted charging handle object bake onto the receiver if you want that sorta detail, since you'd lose out on it by moving the charging handle away/excluding it. Just duplicate the charging handle, name it something different, and the volume of it will cast ao. No other maps will get affected as its not named anything in particular to be in their bake groups, so there wouldn't be any bleeding.
Can't believe I didn't think of just moving the meshes apart, lol. That's what I was looking for, thanks for the help! ☺️
Remember you can also add AO casters to moved meshes, like a box that is just in the highpoly and moved somewhere where you still want AO even if its moved away from the original space