Projected intersection of a polyline with a 3DFace with Autolisp

[Kh.mbkh]

How to find all projected intersections of a polyline with a 3DFace with autolisp knowing just the names of those entities (3DFace & polyline).
To do this manually: "snap objects" and chose Projected intersection.

[Kent1Cooper]

This question has come up before with a Line  and a 3Dface, for which I came up with LineIntFace.lsp, >here<.  See further discussion on that thread.  Is your Polyline always of a single line segment?  If so, that could probably be adapted for it easily enough.

[Sea-Haven]

Yeah and its the poor mans version of doing road cross and long sections, next request is draw the section. Have a look at YMG Triangulation over at Cadtutor its free an oldy was EZYSURF also free. Both have lots more options.