Dini Surface

Dini surface is also known as the one-soliton surface.

     Dini Surface Parametric Equations

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

Where:

  psi := aa;
  if (psi < 0.001) then  psi := 0.001;
  if (psi > 0.999) then psi := 0.999;
  psi := psi * pi;
  sinpsi := sin(psi);
  cospsi := cos(psi);
  g := (u - cospsi * v) / sinpsi;
  s := exp(g);
  r := (2 * sinpsi) / (s + 1 / s);
  t := r * (s - 1 / s) * 0.5;