network tool

 From:  Michael Gibson
1031.3 In reply to 1031.1 
Hi Val, all NURBS surfaces are 4-sided patches, so what happens when you use 3 curves is you end up with a surface that has one edge compressed down to a point. So that can kind of effect the symmetry of the shape.

If you have some examples that don't behave well, can you please post them here so I can take a look?

You may also get better results using sweep instead for this case.

- Michael