Swept Curve Issues

Hi, I have a feeling this may be an issue with my understanding of the underlying geometric principles, but can anyone tell me why the parameter domain only relates to the end portion of my swept surface (as shown by the bounding box in the attached image). The surface has been created by sweeping a line along a NURBS curve.

It also may be worth point out that while the curve is symmetric about two axes, the surface is not when swept along the line, which I also do not understand the reason for.

Any assistance would be much appreciated.


I am no expert on this but I can already tell you people are going to want to see your Dynamo graph. :wink: