Unfolding UV for Human figures -best practices?

Mambo4

when UV mapping a human figure game character
Is there a typical way to cut your UV edges and break the torso, head, and limbs into various pieces? Or is it usually case by case?

what are your general guiding considerations when cutting apart your character's UV?

specifically I'm wondering if splitting the torso into front and back pieces is common?
also maybe hands and feet?

I'm sure that this topic must have a thread somshwere already...but I couldn't find anything in the archivves/wiki about UVs specifically...

greevar

One of the common practices for creating UV maps is to create the seams in places that aren't easily seen (e.g. under the arms, between legs, under the hair, so on) or along seams that exist in the clothing they're wearing (e.g. waist, hems, collars, cuffs, etc.).

Mambo4

I did another search and turned up this thread, which is not human figure specific but does speak bout best practices in UV layouts.

Bal

It's really case by case in my opinion.
Lots of people will give you very specific recommendations, but that can almost be counter-productive really, you'll learn a lot more by just trying what you feel works best, and by discovering little by little the better solutions for different types of situations.

Ideally I just try to keep UV seams on natural seams in the character design (clothes seams, fabric transitions, etc.)
Just to clarify though, I feel having UV seams in an area shouldn't be an excuse for any visible seam on the finished character, there are plenty of tools around to fix these kind of things nowadays.

Mark Dygert

Case by case. Plot out your seams ahead of time, try to tuck them in good places, like along clothing seams, in hard to see areas and a long smoothing breaks.

errr... what Bal said.

Ace-Angel

Hmm, but what if said character has a little bit too much skin showing? What would be the best case for a 'naked' character to be UV mapped, especially in the case of normal maps if he needs to do that.

Bal

Even having normal maps doesn't mean you should have visible seams on the finished character, if they're baked right and the destination engine isn't stupid it should be fine.

But for a naked character it's still gonna depend on context, but I'd just unfold for less deformation. Probably have seams along the back of the head, inside the mouth, around the neck, along the back, on the major joints (wrists, shoulders, waist, this is mostly to arrange the UV shells better in the UV space, cause you can unfold pretty cleanly without these cuts otherwise if you don't mind having a harder time packing your UVs/wasting texture space).

Mambo4

Bal wrote: »

Even having normal maps doesn't mean you should have visible seams on the finished character, if they're baked right and the destination engine isn't stupid it should be fine.

How do you take a texture seam and "bake it right?", to avoid the visible seams?

Mark Dygert

Ace-Angel wrote: »

Hmm, but what if said character has a little bit too much skin showing? What would be the best case for a 'naked' character to be UV mapped, especially in the case of normal maps if he needs to do that.

Normal maps are seamless if you bake them right. There are a few tricks to painting out diffuse seams, skin tone is probably one of the easiest types of seams to fix.

3dsmax >Viewport Canvas allows you to paint on the model, it even has a clone tool. In 2D view wherever you paint on one seam it spreads to all the other effected UV shells. Pretty handy for stuff like that.

The baker will render whatever the difference is between the low poly surface and the high, this includes UV seams and smoothing. As long as you don't change the normals, you'll get a seamless result provided you where smart enough to pad things appropriately.

If you created a seamless diffuse for your high poly you can bake out the diffuse right along with your normal, spec and AO maps.

Mambo4 wrote: »

How do you take a texture seam and "bake it right?", to avoid the visible seams?

If you're baker is synced to your engine it comes out fine. If they aren't, you're going to have all kinds of problems. A normal map will actually account for the shading discrepancy around the seams if there is one, giving you a seamless surface. The only way to get a seam in a normal map is to monkey with the map after its baked, have a seam in your high poly surface or have bake in a way that the engine isn't expecting.

Ace-Angel

That's very strange, I always hid my seams as best possible on crevices and such, because (even on organic blobby characters) I could never get rid of that tiny seam crack in normal maps, so I would also create topolgy and unwrap according on detail of my character, so I could cut around those areas.

I mean sure, Diffuse Maps and Spec Maps, when done right, help alleviate the problem ever so much, but it still is there, and it gets worse when your character deforms during animation.

I'm guessing that's all there is to it? Using Color and Spec maps to hide cracks in your naked characters?

Mark Dygert

You might not have enough edge padding in the normal maps? Without any padding if a UV seam straddles the dead space you'll get a seam, especially when mip-maps come into play.

If everything is synced correctly and padded, there shouldn't be a reason why a UV seam would cause a crack.

Mambo4

great example, mark! explains the idea clearly.

Ace-Angel

Hmm, I need to make another topic about this I guess since I'm hijacking it too much. My padding is always set to 8 for 1K, 14 for 2K and 18 for 4K maps.

And thanks for the pic Mark, a few of my friends will find this lovely!