De Boor's Algorithm

Once we know how to do knot insertion, de Boor's algorithm is not far away. We just multiply every control point by its weight, converting the NURBS curve to a 4D B-spline curve,perform de Boor's algorithm on this 4D B-spline curve, and then project the resulting curve back to 3D by dividing the first three components with the fourth and keeping the fourth component as its new weight.