I added just one line to the STORMTROOPER_PC0016.obj (that is the helmet) at the beginning of the file (line 2): usemtl STORMTROOPER_PC0000.dds and I got this result, if I open it with Noesis. Normally you have to add at least two lines. All uv-map data is in the files.
I did not had the feeling that anyone is using my tool. So I did not put more energie in it. Maybe I did not upload the lastest version.
From my point of view the ghg gsc files are very complex. There are a lot of relative pointer in them. They do not only contain textures, vertices and indices. There are also info for bones, materials, and many more where I have no idea what they are for. I will never try to create a ghg or gsc file.
My tool does only use the position, normal and uv-map information from the vertices. But sometimes there are also boneweights and bonemaps. And there are different levels of detail in them.
I once wrote a noesis script, where I also extracted the bones (no bonemap, no boneweight, no textures).
I do not know to what format I should extract them. I once tried dae but that was a failure. Currently I am looking at fbx. But there is no good documentation (afaik).