After using AutoCAD and programming in Autolisp almost constantly for some twenty odd years, I thought it was time
to share some of what I've learned. This section is dedicated to all things about Autolisp, giving code examples and
techniques that I have yet to see out on the web. I hope you find the information here useful, and please
contact me
if you have an AutoCAD Lisp project you'd like to discuss. Also, these pages are just getting started, so please
check back as I'll be adding content as work permits.

All program code on this site was written by me, so if you decide to use some of the code fragments and examples
in your own work, please respect the work and keep my copyright info in the code. A link from your site would be
appreciated as well. If you don't have a website, please help promote my site by passing along a link to my site to
other fellow AutoCAD users and Autolisp programmer(s) via e-mail. Thanks.
- Jeff Winship
Pixel Graphics, Inc. - Litigation & Court Graphics
AutoLisp Programming Index Page
Kingwood, Texas
Copyright 2019 - Pixel Graphics, Inc. All rights reserved.
Overview of AutoCAD's Autolisp - Why you should use it
Free Autolisp Tutorials
Reading Data Files from Autolisp - How To, Tips & Techniques                              Posted April 15, 2008
Page Last Updated 11/8/2019
Creating and Using Functions in Autolisp                                                        Posted April 17, 2008
Getting and Using Data from AutoCAD Entities                                                        Posted April 22, 2008
Autolisp Function Tutorial - Dividing a 3D line into equal segments                        Posted April 27, 2008
Free Autolisp Programs
Dividing a 3D Face into Equal Sub-Faces - Div_faces.lsp                Posted April 27, 2008
    This free Autolisp program subdivides an AutoCAD 3d face primitive into sub-faces. The number of faces
    it's broken into is set by the user. It works for both three and four sided 3d faces, and gives the user
    interactive ability to flip the orientation of the cuts.
Autolisp Tutorial - Drawing a line between the midpoints of two lines                     Posted   May 3, 2008
    This free Autolisp tutorial comes from a question e-mailed to me from a beginning Autolisp programmer.
    Interestingly enough, almost all of the code needed is already in my previous tutorials. I'll show you
    how to scavenge code fragments, rewrite a command as a function, and put it all together.
Intersection of a Line and a Plane - LinePlaneInt.lsp                     Posted   May 3, 2008
    This free Autolisp program draws a point in AutoCAD at the intersection of a 3D line and a 3D plane. The
    point is plotted whether or not the line actually passes inside the perimeter of the defining points.
Inset a 3D Face - InsetFace.lsp                                                  Posted   May 4, 2008
    This free Autolisp program draws a point at the intersection of a 3D line and a 3D plane in AutoCAD. The
    point is plotted whether or not the line actually passes inside the perimeter of the defining points.
Feedback and Suggestions
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Reducing Vertices in a Polyline - PolySimp.lsp                        Posted November 3, 2019
    This free Autolisp program intelligently reduces the number of vertices in a polyline. This can come in
    handy when you receive a drawing that has contours that have a huge number of excess points or
    other cases.