Freeform splines Original Research Article

In this paper we show how one can construct a regularly parametrized G2-spline surface of arbitrary topology from one control net. The surface is piecewise bisextic around extraordinary points and bicubic elsewhere. Furthermore, the bisextic representation of the surface allows for subdivision algorithms. The underlying ideas can also be used to construct subdividable Gk-splines of bidegree 2k + 2.