I have been messing around with NURBS curves. Is there a particular reason that NURBS have a minimum order of 2? (Order 2 is linear, behaves almost identical to poly line, interestingly, the order 2 NURBS is less smooth when an object follows the curve).

My worry for allowing order 2 NURBS curves is that people will be confused by the “curve” acting like a line. I, myself, was confused when I first discovered this. A better minimum might be 3, so that the curve retains some kind of curvature properties no matter what you do. In my case, I deleted all but one or two vertices, which demoted the curve to order 2.

Current behaviour: NURBS curves are demoted down to order 2 when vertices are deleted, however they are never incremented up when the number of vertices are increased. This makes sense, to avoid breaking math, while allowing any order of curve when modelling.

Basically, I want to know if there is a use case for order 2 NURBS curves, and adjust the minimum order of curves to 3 if it would make sense.