I do not understand the comments in geom_bsplinecurve.hxx:
1. On a periodic curve the first and the last multicities must be the same.
2. On periodic curves, Poles.Length() == Sum(Mults(i)) except the first or last
While from some intro to bspline, (http://tom.cs.byu.edu/~455/bs.pdf by Thomas W. Sederberg), the condition of knot and control vertices of periodic bspline are :
"This requires that the first n control points are
identical to the last n, and the first n parameter intervals in the knot vector are identical to the last n intervals as in Figure 9."
Are those statements for OpenCascade and Intro to Bspline equivalent?