They look much better than rounded rectangles, and probably work with less and more equally spaced polygons in 3d. You can probably calculate the points as slices in azimuth, or as a continuous helical spiral.
They give larger curvature smoothness than rounded rectangles, and superformula gives a wide variety of shapes and smooth transition between a circle and a square with changing parameters.
Superformula is a generalisation of superellipse, and works in 2D and 3D. Superellipsoid is the 3D counterpart:
* [Superformula - Wikipedia] (https://en.wikipedia.org/wiki/Superformula)
* [Superellipse - Wikipedia](https://en.wikipedia.org/wiki/Superellipse)
* [Superellipsoid - Wikipedia](https://en.wikipedia.org/wiki/Superellipsoid)
Squircle is a special case of superellipse with parameters a and b equal and n set to 4:
* [Squircle - Wikipedia](https://en.wikipedia.org/wiki/Squircle)
Danish Piet Hein invented the Superegg:
* [Superegg - Wikipedia](https://en.wikipedia.org/wiki/Superegg)