icosa0 - icosa4 provide a description of regular polyeders derived from the Icosahedron (icosa0) by sequential triangulation of surface triangles
a list with components
vertices - array of dimension
c(3,nv). containing cartesian coordinate of the
indices - Indices of vertices that define surface triangles of the polyeder.
edges - Indices of vertices that define edges of the polyeder.
nv - number of vertices
ne - number of edges
ni - number of triangles