How would one determine the number of control points for a U-spline? A Google search on B-splines gives the formula m=n+p+1, where m is the number of knots, n is the number of control points, and p is the polynomial degree of the spline. The knot vector concept is a bit fuzzy for me from when I last used it a couple of years ago, and also, U-splines don’t use knot vectors, so that may or may not be helpful. What intuition can I gain on this question?

I’m also interested in the extension of this from 1d to higher-dimensional U-splines.