This is one of the things that, frankly, drives me nuts about UV mapping in Wings. 1) It uses the same texture name, for everything, so if you are adding more than one map to the object, and you forget to rename the texture *and* the material, each time you make one, you end up with a damn mess. Second - While you can create a new texture, by going to the material, picking "select" from that, then bringing up the UV window, the windows shows your "selected" map, but also every other bloody map that you have applied. It doesn't export any of them to your texture, unless you make the mistake of clicking on one that isn't selected, but.. it does show all of them, not just the one you want. Oh, right, and, of course, if you already have textures applied, forget opening the UV window, and trying to adjust it to match the texture, because, odds are, its going to generate an auvBG image, then show your map overlayed on that, instead of showing the texture that the material you have selected actually has applied to it (and, since you can fine tune the map this way, but only when you *first* add a map, and haven't yet closed the UV window, trying to adjust it after is... completely useless.)
All of these behaviors are, imho, not expected, and, for a while at least, having all of the maps showing up in the window, confused the hell out of me, like for almost a year, until, literally, about three days ago, when I decided to just see what would happen if I created a new texture from it (someone wanted to map, so they could redo the texture I made for something).
I mean, there may be "some" cases where you want to see where all of the maps end up, like, for example, you are making a bridge, so you are using the same texture every place, but just placing the lines of the UV so they line up with the texture properly, but when you can't consistently figure out what is going on, and it doesn't let you, say, "hide unselected UV lines", or something like that... I think you can select then hide them one at a time, but if they overlap... that just isn't going to work.
Oh, right.. another issue with this behavior.. Try taking a professional mesh, with insane amounts of geometry, with the map already there, and then open the UV window, then.. go out for lunch, and dinner, and.. what ever else you need to do, in the hope that, when you get back, you actually have a map to look at, instead of just a frozen program. It has to fumble all the stuff together for the entire bloody model, since none of the parts, in something like an obj import, are separate objects when they import (there isn't even an option to have it do so), and the result may be 20+ overlapping maps, in one UV window, if/when it ever untangles them all, so it can display them.
All of these behaviors are, imho, not expected, and, for a while at least, having all of the maps showing up in the window, confused the hell out of me, like for almost a year, until, literally, about three days ago, when I decided to just see what would happen if I created a new texture from it (someone wanted to map, so they could redo the texture I made for something).
I mean, there may be "some" cases where you want to see where all of the maps end up, like, for example, you are making a bridge, so you are using the same texture every place, but just placing the lines of the UV so they line up with the texture properly, but when you can't consistently figure out what is going on, and it doesn't let you, say, "hide unselected UV lines", or something like that... I think you can select then hide them one at a time, but if they overlap... that just isn't going to work.
Oh, right.. another issue with this behavior.. Try taking a professional mesh, with insane amounts of geometry, with the map already there, and then open the UV window, then.. go out for lunch, and dinner, and.. what ever else you need to do, in the hope that, when you get back, you actually have a map to look at, instead of just a frozen program. It has to fumble all the stuff together for the entire bloody model, since none of the parts, in something like an obj import, are separate objects when they import (there isn't even an option to have it do so), and the result may be 20+ overlapping maps, in one UV window, if/when it ever untangles them all, so it can display them.