CONIC SECTIONS - AN INTRODUCTION TO THE RATIONAL SPLINES

Abstract

The rational splines have been included in the IGES (International Graphics Exchange Specification) standard for about ten years, but they have been subjects of interest since 1967 [1]. The current kind of rational splines of our days are the NURBS (Non-Uniform Rational B-splines), which are generalizations of B-splines and the rational Bezier curves and surfaces at the same time. The popular scientific articles and the manuals (e.g. [2]) as well frequently mention as an advantage that these spline curves are accurate for conic sections. For this reason, in this article we propose the rational representation of conic sections as an introduction to the NURBS.