Hi Tom, if the generator makes triangulated polygon data then that tends to be a difficult task to convert to NURBS.

One possibility would be to use retopology tools in 3D Coat or something like Topogun to get a quad polygon layout and then use Max's sub-d to NURBS script to convert that to NURBS.

The other possibility is to look at reverse engineering methods which are for converting triangle mesh scanned data into NURBS, often times these work similar to retopology methods where you trace out quad boundaries on the mesh and it fits NURBS surfaces to it. They tend to be rather expensive specialized tools though, see here for some links:

http://moi3d.com/forum/index.php?webtag=MOI&msg=8460.2

- Michael