x := proc(u,v)
begin
  sin(u)*cos(v):
end_proc:

y := proc(u,v)
begin
  sin(u)*sin(v):
end_proc:

plot3d(Axes = Box, Ticks = 0,
       Title = "Demonstration of Smoothness",
       TitlePosition = Below,
       CameraPoint = [0, -18, 10],
       [Mode=Surface,
       [2+hold(x(u,v)), hold(y(u,v)),cos(u)],
       u = [0,PI], v = [0,2*PI],
        Grid = [20,10],Smoothness = [0,0],
        Style = [HiddenLine, Mesh]],
       [Mode=Surface,
       [hold(x(u,v)),+hold(y(u,v)),cos(u)],
       u = [0,PI], v = [0,2*PI],
        Grid = [20,10],Smoothness = [0,3],
        Style = [HiddenLine, Mesh]],
       [Mode=Surface,
       [-2+hold(x(u,v)),hold(y(u,v)),cos(u)],
       u = [0,PI], v = [0,2*PI],
        Grid = [20,39],Smoothness = [0,0],
        Style = [HiddenLine, Mesh]]
); 
