A variation of the method used to design a cardioid with straight lines. I wasn't aware that it will give a sphere.

Use it with a 7cm diameter christmas ball : like this

scale 1.5

scale =0.5 rz=9

Following the edges of the icosidodecahedron

A shape derived from Pedoe's method to contruct a cardioid as the envelop of a set of circlesThis model was used for the cover of last Marillion al...