Sorry. There has been a problem in maya nurbs modelling since maya 3.0. You had to export and re-import to fix it. I thought it was obj but it is fxb.

apparently it was version 8.5 where it was removed. Here is part of an old post I made....

==========old post==================

Back when nurbs were in fasion a common problem with maya cv curves and nurbs surfaces was that sometimes their parameterization would become wonky.

An example would be taking a nurbs patch and cutting it into smaller patches and the parameterization say was 3 by 4 in uv and you split it into 2 3 by 2 patches. The parameterization of the new patches in v would not go from 0 to 2 as you would expect.

Now you could rebuild the surfaces but this would shift the isoparms effecting the new surface and every surface they come in contact with and if you are building a model with hundred of patches this could turn into a bloody nightmare!

In the old days the way to fix this was to export the nurbs surface in dxf and then import it back into the scene. This would some how correct the parameterization and NOT shift the isoparms.

However since Autodesk has taken over maya in version 8.5 the old dxf exprt is no longer available and now their is only the fxb export which does not fix the problem like the dxf export did.

So it was dxf that I was thinking of and as I look at maya 2009 they still do not have dxf export anymore which really BORKS nurbs modeling because I have confirmed the parameterization bug still remains!