This post can also be read at the old site here There you can see the figures, too. Here I can see the figures in the preview window, but not after the blog post has been saved. Strange...
Make_clothes now supports multiple UV layers.
Give your character a nice sweater (Libraries > Clothes > Sweater). The sweater has some non-trivial texture, visible both in MH and in Blender after export with MHX. In particular, note that the collar is black but the cloth under the collar is green; they are located in different positions in texture space.
The loaded file has two UV layers. The Mask UV layer must conform to the body mesh. It is used by masks coming from other clothes, to ensure that obscured parts of the sweater are invisible. Unfortunately, this means that the collar will share UV space with the part of the sweater below it. If we added a scarf, say, it must obscure both the collar and the upper part of the sweater.
The Texture UV layer can be chosen at will. It is used to texture the sweater, but it does not affect any other object. In this UV layer the collar does not coincide with other faces. Thus the collar can be black and the rest of the sweater green.
In make_clothes, there are three new properties to control which UV layer is used for the mask, the texture, and for export to the obj file. The UV maps are numbered starting with 0. This is a bit rough, and I may do something more user-friendly later, but it works if you do it right. The obj layer is used by obj and collada export and by the MH gui. Typically the obj and texture layers are the same.
It is possible to use more than two UV layers, if you check the Blender materials option. That will use the settings of the material in the Blender file. However, this is still a rather uninvestigated topic and may contain bugs.