How can I fillet 3 faces (ie a vertex of a cube) in Nurbs at the same time?

[Anonymous]

Hello, I'm being forced to model something up in Nurbs on 3ds Max because its being made into a mould and unfortunately the only file type the machine can take requires a nurbs model.

I have been modelling with 3ds max for a long time but I haven't really used Nurbs.

This seems like a silly question, but how do I simply fillet / bevel 3 or more faces at the same time with Nurbs.

For example the corner of a cube. This is very easy with normal polygon modelling, but in Nurbs the fillet options seem to be restricted to only 2 "CV Surfaces".

If I create a cube and convert to nurbs and try and fillet two perpendicular faces (ie two vertical sides at 90 degrees) and then fillet the top then there is a portion left over sticking up.

See image

If I select two vertical sides of the cube, each being a "CV surface", join then, it automatically fillets without much control in a whacky way and then if I fillet between the top face and the two sides which are joined together it creates edges / corners which are just all kinds of stuffed.

See image

If I select this single cv surface which is two faces joined together in a stuffed up way, and then fillet it with the top the rounding is also whacky - see image.

Can anyone tell me what the correct method to do this is. If I have to cut back the corner the radius of the wanted fillet, draw a curve and then use multi - trim I will but that has also had bad results. I'd assume there would be an easier solution, this should be basically the easiest thing in 3ds max and I've spent hours trying to figure it out or find a single tutorial about Nurbs in 3ds Max which discusses this specifically - ie filleting 3 faces not just 2.

[leeminardi]

The following may not be satisfactory  but it's worth mentioning.

1. Convert the shape to an editable poly
2. Select the 3 edges and chamfer.  Set number of segments as desired (I used 5).
3. Convert editable poly yo Editable Patch.
4. Convert Editable Patch to NURBS.

In the process of converting to Editable Patch the smooth polys of the chamfer (fillet) become flat which may not be satisfactory for your application.