#http://www.mathcurve.com/surfaces/coinconic/coinconic.shtml
vertices = D1:100 D2:100
v = from 0 to (2*PI) D1
u = from -10 to 10 D2
a = rand2(1, 10)
b = rand2(1, 10)
k = b/a
x = u
z = k*u*cos(v)
y = k*a*sin(v)
