The window "Domain" displays a domain as a wireframe, a point (u0, v0) in the domain, and the u-constant and v-constant curves through that point in red and green, respectively.

The window "Surface X(u,v)" shows the surface of revolution about the z-axis, X(u,v) = (f(v)*cos(u), f(v)*sin(u), g(v)), for the given domain and the images of the point and the curves from the "Domain" window.

It is possible to change u0, v0, f(v), and g(v) in the control window.