Project Point onto Face

[pkehoe]

I am trying to write a LISP routine where I need to project a point onto a face and return the point on the face. So far, I am not having any luck; so I'm hoping someone here can help.

I have tried to use the sd-proj-pnt-on-face command, but it does not work the way I want. The problem is that the point I am trying to project is not on the face and the sd-proj-pnt-on-face command tries to find the closest point. But what I want is to project the point in a specific direction and find the point where that projection intersects the face. Think about it this way: Say I have a workplane above a face that is at an angle (not parallel) to the workplane. I want to pick a point on the workplane, project that point perpendicular to the workplane and return the point on the face.

Any suggestions?