ABSTRACT
Intersection problems are fundamental in CAGD, and continue to be an im portant topic of research especially for surfaces. At least two approaches axe possible. The first one is to consider general parametric surfaces, see [1,6]. Only a surface evaluator and a derivative evaluator have to be provided. The second one is to consider specific surface modeling and take advantage of ge ometric properties. This principally concerns Bezier or B-splines (rational or not) and their well-known convex hull property. In our method, we con sider B-splines or NURBS because it corresponds to a local scheme modeling. Notice that numerous CAD systems axe based on these modelings.
