@techreport{mon-sto-06-hull-tr, author = {Arnaldo J. Montagner and Jorge Stolfi}, title = {General Convex Hull Using the {Gem} Data Structure}, institution = {Institute of Computing, Univ. of Campinas}, number = {IC-06-11}, pages = {14}, year = 2006, month = may, abstract = {We describe in detail a general algorithm for constructing the convex hull of a finite set of points in Euclidean space of arbitrary dimension $n$. The algorithm handles degenerate situations, such as non-simplicial faces and point sets contained in a lower-dimensional subspace. The topology of the hull is kept in a \emph{graph encoded map} (\emph{gem}) \emph{data structure}, a novel representation for $n$-dimensional triangulations. The gem representation, which was introduced as a mathematical device by S. Lins in 1982, extends the \emph{cell-tuple} (or \emph{generalized map}) representation proposed by Brisson and Lienhardt to maps that are not barycentric subdivisions, to manifolds with borders, and to non-manifold (but triangulable) topological spaces.}, altkeys = {mon-sto-06-convex} }