The paper discusses rational curve segments and surface patches on qua
dric surfaces. Detailed constructions of rational Bezier patches from
given boundaries on a unit sphere and on a hyperbolic paraboloid are p
resented based on a generalization of the stereographic projection. Th
e method is applied to interpolation with rational curves on quadrics.
The results are extended to rational B-spline representations by disc
ussion of products of B-spline functions. Finally, the generalization
of the constructions to arbitrary nondegenerated quadric surfaces is o
utlined.