   Inserting knots in closed NURBS
  Hello everyone!I got a pretty specific problem concerning NURBS. I try to work with closed NURBS and alter their shape by altering the control points. I also want to introduce new knots, but in case of closed nurbs the introduction makes the last control points differ from the first control points. This is a problem since for a fixed number of knots I always change the first control points together with the correspondig control points at the end. But after inserting a knot they differ as explained before, so I can''t do that anymore. Does anyone have an idea how to overcome this problem?Thanks in advance!Wilfried 