In some Alias tutorials, I noticed that Alias handles curves on surface and common NURBS curves differently.
- Alias defines a "curve-on-surface" as "a type of curve that exists in the parameter space of a surface".
- In Alias command "Project", there are two options allowing users to decide a curve on surface or a NURBS curve to produce. If a NURBS curve is choosed, what you get is a NURBS curve approximating the projection surface with certain deviation.
From my limited experience, NX seems not to adopt Alias' concept of "curve-on-surface", and produces only NURBS curves with the three commands: Project Curve, Intersection Curve and Curve on Surface.
Is my understanding right? Thanks for your comments!