- A surface is displayed in the "Level Curves" window.
- A height is chosen by changing the value of c in the control window, and the level curve at this height is displayed in red on the surface.
- The level set is displayed in green in the "Domain" window.
- Two points on the level set and the corresponding level curve are chosen by changing the value of v0 in the control window.
- Readouts in the control window display the normal curvature,
geodesic curvature, and geodesic torsion at the two specified points on
the level curve.