So I'm wondering now - I'f I were to reshape the knee so that the original edge that marked the start of subset 3 ends up being lower than it started off (while keeping the UV relatively intact), that would cause problems right?
Shouldn't do. Generally speaking, the only time you need to worry about the subsets if if there are parts of cloth and parts of visible skin. For most this is simply the head (9) and hands (5).
But if my design encompassed all three leg subsets then perhaps there wouldn't be an issue since they all fit together and don't need to be interchanged with other meshes/textures.
This is correct - if you have long trousers, for example 6, 7, 3, 8 you don't need to worry about the subsets. If you want shorter trousers, then you should cut them off at either the bottom of 3, or the bottom of 8.
For shirts, they'll either cover the body (1), short sleeve (0) and long sleeve (2). or you can cut them off at the bottom of 0 (for short sleeved tshirt) or at the edge of 1 (for a 'vest' type top).
If you look at the model shots - each of those coloured blocks can be told to be a) lower skin texture or b) upper clothing texture. It is symmetrical, so we cannot have one sleeve missing through this method. If anything needs to "cut halfway" on the model, i.e. one sleeve missing, or an open shirt with chest showing, this would need to be made on an attached model, otherwise we have problems with the base skin colours.
On the San Fran woman texture, this would mean that her sleeves are too long, or too short - so they'd have to stop at either the end of "0" or go all the way to the wrist. The trousers would need to either go all the way to the ankle, or move up to the bottom of the knee. The shirt would need the "v neck" removing.
The problem here of course is that your texture is actually correct when compared to the original - there aren't the correct subsets which stop at the right place. Also I've just noticed the female Vault Suit has this "v neck" problem too
I don't know what the best solution is really - as I said - the sleeves / trousers length you have done is correct, but not compatible with the skin colour changing.
I think my personal preference (if possible) would be to add a a few extra subsets to the model - ideally another sleeve length "San Fran sleeves", a "v neck" front and a "leather armour back". I THINK that would cover the remaining models closely enough. Skirts would have to be modelled anyway.
- Leather armour back has this problem - though this could be fairly easily solved by making the back section part of the armour model.
- We'd have to pick one of these "V neck" styles and use it for all three models.
As far as I can tell, assigning extra subsets would mean applying a new material to certain faces on the original model, and naming it correctly - but I don't know if there's anything more that needs to be done to make this work in-game properly i.e. if there's an engine limit on the subsets or anything.
If this is possible, perhaps adding such things (roughly) round here would help us out?
(very rough version, but this wouldn't involve changing the phyisical elements of the model - just the material locations)