Perspective projections and removal of degeneracies

In this paper we consider the following problems: (1) computing projections with distinct x-coordinates, (2) computing non-collinear projections, (3) computing non-cocircular projections, and (4) computing projections with non-parallel line segments. Here the word projection means perspective projection, a kind of projection that has received little attention in computational geometry. These problems are relevant to non-degeneracy assumptions and to the robustness of geometric algorithms .