Hello! Could you please tell me how can I build splines on top of the imported dense mesh?
you can use commands like _Section, _Contour or project and pull lines and curves on your mesh, then use _Rebuild to convert your resulting polylines to splines (NURBS) curves.
The closest to create a smooth curve on a mesh is to start eg. the _InterpCrv command and type _PersistentOnMesh. After selecting the mesh all picked points during the curve drawing will be snap constrained on the mesh. Note that this does not force the curve itself to end on the mesh, but you can _Pull and _Rebuild it again to get very close while maintaining the overal smoothness.
c.
Thank you Clement! Very interesting methods. I found that spline snaps on the surface, when you simply snap to vertices, so making a dense enough mesh is the solution for me.