Non-uniform Quadratic B-spline Subdivision Non-uniform Quadratic B-spline Curves P knot intervals:d-1 ddi+i knots::-4.8+14+2 For a quadratic B-spline curve,a knot interval di is assigned to each control point P;. A knot interval is the difference between two adjacent knots in the knot vector,i.e.,the parameter length of a B-spline curve segment. ZHuang.G Wang Non-Uniform Recursive Doo-Sabin Surfaces (NURDSes) Non-uniform Quadratic B-spline Subdivision Non-uniform Quadratic B-spline Curves For a quadratic B-spline curve, a knot interval di is assigned to each control point Pi . A knot interval is the difference between two adjacent knots in the knot vector, i.e., the parameter length of a B-spline curve segment. Z Huang, G Wang Non-Uniform Recursive Doo-Sabin Surfaces (NURDSes)