Automatically cutting sections with Lisp routine?

[lwindsor73]

Hi there,

I am looking for a solution to increase productivity through AutoCAD.

When cutting sections through 3D geometry consisting of only 3D Polylines.

WHen I do this manually, i use a line at z=0 than use the APPARENT INTERSECTION object snap to trace along this line and the intersections of the 3D geometry which creates a straight line through this section that can be then flipped up (i have worked this part out with an action macro) to create a 2D section of the slice. (please see image below to see what I am talking about)

Would it be possible to automate this routine by using Lisp? 

If so I would be very appreciative if you could show me how as this would be a very big timesaver when cutting a vast number of these sections again in the future.

SAMPLE DWG ATTACHED

*I am aware that Civil 3D can do this but I primarily work with Autocad and the SECTIONPLANE command doesnt appear to work with polylines, only preexisting 3D elements*

Many thanks!

[Sea-Haven]

Yeah can be done, did it like 30 years ago, the plines or lines must have a Z you just draw a line over all the linework and get all say plines then do a insersectwith and get a distance away from start point and Z value. do a sort and hey have a section. I really dont know if still have it.

Look into TIN modelling by YMG TriangV0.6.7.lsp may be a later version pretty sure did sections. So convert your 3dline work to a tin.

Better still is get the TIN that made the contours a more accurate method. It should be 3dfaces which can cut sections again.