Joseph,
You need to carefully study the drawings in the manual.
You will notice that there is difference between the user defined collection
of points defining a ridge when "fit to user ridges" is used versus
"fit to all ridges". In the former case the ridge line is straight from
corner point to corner point whereas in the latter case the ridge line
goes up and down following the the triangulated surface of the mesh
which is composed of user defined ridges resolved by AC into
many ridges forming triangles.
If you select "all ridges sharp" in the model panel
you can see all ridges that form the surface.
Depending on your purpose, you pick the method you want.
For Instance if you want to see the natural terrain terminate
at the walls of a building in a line that represents the intersection
of the building wall and the terrain surface you would pick "fit to all ridges"
HTH,
Peter Devlin
