Editing Real projective plane (section)

=== Roman surface ===
[[Image:Steiner's Roman Surface.gif|thumb|An animation of the Roman surface]]
Steiner's [[Roman surface]] is a more degenerate map of the projective plane into 3-space, containing a [[cross-cap]].

[[File:Tetrahemihexahedron.png|thumb|The [[tetrahemihexahedron]] is a polyhedral representation of the real projective plane.]]
A [[Polyhedron|polyhedral]] representation is the [[tetrahemihexahedron]],{{sfn|ps=|Richter}} which has the same general form as Steiner's Roman surface, shown here.