No worries just only way I could see round the issue. Even mesh.name = "obj"+meshid+"g"+groups[g].name;
would help a little, at least you could trace out then know what your after. Obj# is no help at all. As for the "Tr" no idea how to set that through Maya. Only seem to have Tf Even if I add Tr to the mtl it doesn't make a difference to the file texture.
