Cutaway
 

Is there any way to do a cutaway of a NURBS object, similar to a "Cut Polygon Faces" operation, without having to convert it to a Polygon object. I have a good NURBS object that renders very nicely, after Mental Ray surface approximation. The object is extremely heavy in geometry and I can't seem to get it to render as smoothly if I use the "Convert NURBS To Polygons" function under "Modify". Even though I check off the "Use Render Settings" box in the conversion panel I get a render with rough curves, not like the smooth approximated NURBS render. I need to cut this object exactly in half. Its way to complex to start going in and selecting individual surfaces. The "Cut Polygon Faces" tool does exactly what I want but the polygon objects quality doesn't match the NURBS after rendering.

you could probably use the nurbs boolean tools. I don't use them much (and their results are somewhat different than using the polygon booleans), but if you use a nurbs plane, you chould be able to get a precise split.

This is the part in question. It appears to contain roughly 11000 NURBS surfaces.