CONSTRAINT-BASED PARAMETRIC CONICS FOR CAD

We describe how to construct conic blending arcs from constraints, usi ng a unified rational parametric representation that combines the sepa rate cases of blending parallel and non-parallel edges. The possible c onstraints are that the are must have a given distance from a line, a point, or a circle, or else intersect a circle or a line at a prescrib ed angle. Our representation is easily converted into a rational B-spl ine with positive weights, and is therefore compatible with internal r epresentations used by most solid modeling systems. Finally, we discus s how we integrated this work with an algebraic constraint solver.