SELFINTERSECTION OF COMPOSITE CURVES AND SURFACES

This paper provides computationally tractable conditions to determine whether a composite spline curve or patch selfintersects, according to a definition that includes the important limiting cases of cusps, sin gularities, and tangential intersections of adjacent components. These results follow upon our exposition of necessary and sufficient condit ions to preclude such selfintersections. The paper includes a numerica l example illustrating the results, and discusses an important applica tion. namely, guaranteeing that a finite curvilinear simplicial comple x in R-3, made up of properly-joined parametric patches, will retain i ts original topological form when its control points are perturbed. (C ) 1998 Elsevier Science B.V.