With Given Tangent Polygon the Quartic Generalized Ball Closed Curves

An algorithm for constructing the close quartic generalized Ball curves which are tangent to the given polygon is described. The control points of the close quartic generalized Ball curves to be constructed are computed simply by the vertices of the given polygon. The constructed curves are shape-preserving to the polygon. The local modification to the close quartic generalized Ball curves can be completed by simply adjusting the corresponding control parameters. One example is also given.