#http://www.mathcurve.com/courbes3d/viviani/viviani.shtml

vertices = D1:360 D2:100

u = from 0 to (2*PI) D1
v = from 0 to (2*PI) D2

r = 10

x = r*cos(u+v)*cos(u-v)
y = r*cos(u+v)*sin(u-v)
z = r*sin(u-v)

