<title>Approximation of sweep surfaces by tensor product NURBS</title>

Abstract

Methods for approximating sweep surfaces by tensor product NURBS are presented. Sweep surfaces are generated by sweeping a (possibly deforming) NURBS cross-section curve along a NURBS axis curve. A general form for NURBS approximation to sweep surfaces is derived and expressed in terms of the approximation to a set of offset curves of the axis curve. The actual algorithm used to construct the surface approximation depends on the nature of the desired deformation and change in orientation that the cross-section undergoes as it is swept along the axis.