Cardioids $r=1-\sin(\theta)$ are simple. Creating a surface by rotating one about its omphalos, less simple. Creating a mesh which indicates the tangent of the surface relative to this axis is far beyond my present scope.
Even on Wolfram the surfaces they show which are supposed to be this shape (does it have a name?) visibly have a strange flatness around the equator which looks incorrect.
Pointers?
My intention is modeling the gravitational curve of visible universe. The outward curved surface pole representing deep voids with least curve. The navel/omphalos representing event horizon with most extreme curve. Ideally a mesh indicative of surface tangent would then be applied.
Thank you.