The core of the tight polyhedral immersion of the projective plane
with one handle. The portion of the surface shown is the "negatively
curved" central projective plane, based on the level sets originally drawn
by Kuiper for his paper in 1960. The top and bottom disks have been
removed (where the positive curvature would have been in his smooth model)
leaving. The top and bottom of this surface would be attached by a
cylinder that forms the "handle" and completes the surface, making it tight.
To manipulate the surface, simply click and drag within the picture. The
object should rotate (perhaps slowly) in response to your mouse movements.
You will need to have the TCL/TK
plugin available from Scriptics.