Hi Felix,

> Out of curiosity, instead of a sweep type method, would it be
> possible to scale radially (as it is) and scale say axially as well.

I'm not really sure if it's feasible to do that - the method that I was describing as scaling actually has to do with computing some particular weight values in the control point grid for the surface of revolution. That ends up having an effect that is similar to scaling the surface towards the axis at each control point of the rail, but I don't really know if it is feasible to control the scaling in some other way using the same method. I don't believe that other scaling directions are mentioned in the NURBS research literature for this type of NURBS surface creation.

This type of surface construction is also often called a "Swung surface" if you want to look up any research papers on it.

- Michael