#http://www.mathcurve.com/surfaces/pseudosphere/pseudosphere.shtml

vertices = D1:100 D2:100

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

a = 10

x = a*cos(v)/cosh(u)
y = a*(u - tanh(u))
z = a*sin(v)/cosh(u)

x = limit(x, -25, 25)
y = limit(y, -25, 25)
z = limit(z, -25, 25)
