topic Re: Lisp that draws 3 lines similar to the Multi line command in AutoCAD Forum

Lisp that draws 3 lines similar to the Multi line command

joey_rooker — Fri, 30 May 2025 16:41:50 GMT

I wanted to reach out to the community to see if anyone has a LISP routine similar to the AutoCAD multiline command, but with the ability to draw three lines instead of two. Ideally, the center line would be placed on a separate layer from the outer two lines.

At my company, we frequently trace building layouts to create floor plans in AutoCAD that include wall thickness. We also need to trace the same file in Illustrator to generate a single-line wall view. It would be incredibly helpful if we could trace the building once and then separate the centerline from the outer lines, allowing us to use the same traced geometry for both the AutoCAD plan and the Illustrator single-line export.

Re: Lisp that draws 3 lines similar to the Multi line command

DGCSCAD — Fri, 30 May 2025 17:42:11 GMT

I've done something similar using Lee Mac's Double Offset, but it's heavily modified for drawing cables. Thats a good place to start though.

Re: Lisp that draws 3 lines similar to the Multi line command

pendean — Fri, 30 May 2025 20:03:08 GMT

Like this similar post perhaps @joey_rooker (other tips using MLINE are also posted if an option)

https://forums.autodesk.com/t5/visual-lisp-autolisp-and-general/mline-but-three-lines-lisp/td-p/9807993#M68851