ve is most impacted by the characteristics of the vector field...If accuracy is not so important, you can use the curve re-sampling components to create a smoothe curve.…
This equation has the same issue as the code I posted. While the curve is the same, the units are off, as seen in my screenshot where the ymax goes well above 80
a spline? In a more general setting of semi-algebraic sets there is the Tarski-Seidenberg Theorem http://en.wikipedia.org/wiki/Tarski%E2%80%93Seidenberg_theorem that says the projection of a semi-algebraic set is itself a semi-algebraic set. As nurbs surfaces and breps defined by them are semi-algrbaric sets this means that the projection must be reasonably nice. I could not discover whether it is always a spline. There are however reasonably nice ways to get splines from algebraic curves, though we are back to an approximation. It would be nice to have an algorithm that is guaranteed to give the precise splines when they exist (as in the example above) and will otherwise give a good approximation, I was not able to find if one has been written, even in the theoretical literature.…