
120 CHAPTER 4. PROXIMITY DRAWINGS
In the (2, 0)-proximity drawings described above, the proximity region chosen for a pair
of vertices x, y is symmetric about the perpendicular bisector of the segment
xy. This
guarantees a certain symmetry in the drawings produce d . This symmetry, however, is
not always desirable. Veltkamp [Vel92, Vel94, Vel95] introduced a family of proximity
regions, called γ-regions, in which the proximity region may lack this symmetry and that
generalize lune-based and circl e-b ase d β-regions. While Veltkamp takes advantage of this
absence of symmetry in constructing object boundaries from a set of points in the context of
visual ...