avatartest does not find your relative files because it loads the data from the current VFS path, ie '/'. So, when you designate a relative path, say 'factories/myfact', it will try to find it relatively to the current path, ie in '/factories/myfact' and will fail since you meant '/data/mymesh/factories/myfact'.
That is, your files are named relatively to the directory where you put them, so you must first go to that directory in order for the system to find them.
So the solution would simply be to add something like that just before avatarTest->loader->Load():
csRef<iVFS> vfs = csQueryRegistry<iVFS> (avatarTest->GetObjectRegistry());