lisp needed

[Anonymous]

I need a lisp to join points in a drawing with a polyline. Imagine a dwg file containing bunch of points that actually taken from a point cloud creating a u shape channel. I need the very inside lines of that channel which can be created as joining the inner points. It may not be very clear but i can give further information. Anyone can help me with this?  

[john.uhden]

I am really not familiar with a point cloud, other than I would expect it to be raining down a deluge of points.

To get the inside of the U, I would probably compute the centroid of the cloud and then compare distances somehow.

But I am also guessing that you have no lisp experience and are hoping to pick up a solution at the drive-thru.  Please tell me I am wrong.

[Anonymous]

why my repllies arre not shown?

[john.uhden]

@Anonymous wrote "why my repllies arre not shown?"

I don't know about any other replies, but this one did show.  It might have been an IDTENT error.

[dgorsman]

Working directly with point clouds in LISP isn't possible.  If a selection of points are provided, such as by user selection, then they can be prioritized/aligned/etc. to generate a direction for a pre-defined channel shape.  That's pretty stiff math though, making this a big "ask".

If the OP would show what they already have, especially with program flow, that would go a long way towards getting more help.

[ahsattarian3]

If still needed, I can help u.