vikinglady, Try k3DSurf; it's a great piece of software.  Here's an image of a Klein Bottle shown within K3DSurf http://TropicalEarth.smugmug.com/photos/125808140-L.jpg  I render these mathematical constructs as OBJ's and then import then into Bryce & Carrara.  K3DSurf is free and you can find it at http://k3dsurf.sourceforge.net/  I really enjoy using it.  Regards -