It's a bit complex really - and there may be a better way of doing it. I'll try to explain...
If you imagine the clothing layers like this :
- Armour (leather jacket, armour etc)
- Clothing texture (trousers, shirt etc)
- Base skin texture (white, tanned, brown, black, asian, with or without tattoos)
What we can do, is pick which parts of the texture show :
If we look at Subset Example Man, by default, he would be covered head to toe in "Base skin texture" (in underpants). We can put a clothing layer on top of this, and assign it to certain areas. Most of the clothing we've added doesn't cover the hands or head, some doesn't cover the arms. Those bits are left as their original base texture - so your clothing texture might be a pair of blue jeans and white shirt - as long as the "skin" part is entirely within a "subset", the remaining skin can be any of the base skin tones i.e. if you have a clothing texture which covers 0, 1, 3, 6, 7, 8, it would leave the hands, head and feet free to be whatever base skin colour.
Note that the female models also have a subset 10, which contains a section of the waist.
If we have a V-style neck in the shirt, this will not work, because the painted skin on the V-neck will stay white skinned by default, even if the player texture is black or other skinned.
Solutions to this would be :
a) Modelling anything which doesn't fit to subsets - see
tribal model test here - in this example, I modelled the diagonal strap and "arm thing" - therefore the chest, arms, hands, head all show base skin tone.
b) Make things like the "tribal bra" on the base skin, not the clothing layer (so it would be an alternative to a tattoo), and both clothing and armour can be worn on top of it (this may be the best way for the tribal ones)
c) Make a separate clothing layer for each skin colour (as you have prepared for already) - and find a way to make this work in the engine.
d) Add a few extra subsets to the original model
In reference to the San Fran model, for example, this would be :
a) The shirt has to be made as a model. The trousers can stay as texture
b) Perhaps all clothing that is not part of an armour costume could be base textures?
c) You export the same image, but with different skin colours in the "V neck", and we find a way of making this work
d) We add a "v neck" subset, which all female models must follow
Obviously a problem with this is that it applies to many of the existing models we've done - particularly female ones.
For leather jacket, this is a model. I've tried to make a diagram here :
http://img97.imageshack.us/img97/125/leatherjacketexplanatio.pngThis might explain the whole thing a bit more clearly.
I know that's all a bit messy, but hopefully you can make sense of it.
