Stratégie algorithmique pour le traitement complet des courbes offset

Abstract

The objective of this survey is the direct passage from a Bézier complex curve of high degree to a succession of offset curves, of lower degree. The retained strategy consists in treating all singular cases, before constructing the offset curves, starting from the points' normal of the main curve, one counts the exact points of the offset, and uses them for the detection and the localization of intersections by a specific treatment; we subdivide the main Bézier's curve in several portions curves, at the points that correspond to points of intersection found in the previous stage, and we eliminate all portions of curves displaying a singularity. In the same way a test is launch for the detection of an isolated cusp point in the extreme portion. One constructs then, the offset curves by subdo-reduced approximation, for the retrained curves' portions