Hi Oskar, getting the original NURBS vertex normals through does tend to help a lot with making the rendered surface preserve all the shading characteristics of the original NURBS model.

But if you want to edit the model to change it, then you're going to be in a different category because that means you're trying to make something that looks different from the NURBS model instead of something that looks exactly like it.

In that kind of situation, your best bet is to use the "Divide larger than" setting in MoI to make polygons diced up into small regular sizes, that should help reduce shading glitches, and also at the same time you'll probably need that in order to do decent deformation of the objects as well.

See these previous posts for some examples of how you would want to have the mesh look:
http://moi3d.com/forum/index.php?webtag=MOI&msg=2833.5
http://moi3d.com/forum/index.php?webtag=MOI&msg=1084.2
http://moi3d.com/forum/index.php?webtag=MOI&msg=1549.4
http://moi3d.com/forum/index.php?webtag=MOI&msg=804.26


I'm not entirely sure if I understand the kind of thing you're trying to do though, if you only want to modify just one region of your model instead of modifying most of it, you might want to separate your model into some different chunks or something so that the majority of it can have the proper vertex normals and get the nice extra smooth and accurate shading on it and only do the editing on certain regions.

Maybe if you could post an example of one of your sample results it would help to illustrate.

- Michael