TRIMSPLIT for AutoCAD 2017

TRIMSPLIT version 1.4.1, updated for AutoCAD 2017 is now available at Autodesk Exchange. The App can be downloaded in four localized versions besides the original English one.

The localized versions published are:



On YouTube: a demonstration of the way the new version of the STRIM and SSPLIT 3DSolid modeling commands can streamline your modeling workflow.

This App can be dowloaded at AutoCAD Exchange.


Programming 3D: the MESH!

Among the features added to recent AutoCAD® software releases, subdivision surfaces (also known as MESH entities) are especially interesting. These entities are exposed in the classic entity list format. So, our good old AutoLISP® can be used for creating and modifying them.

By calculating the coordinates for their vertices from different math formulas, we can create an unlimited variety of 3D shapes. By smoothing these meshes, converting them to surfaces and solids, and applying the different surface and solid editing tools, we can explore a vast universe of 3D forms. These forms can be used as masses in Autodesk® Revit software for the development of new design concepts.

These videos are my presentation to Autodesk University 2012 Virtual. They demonstrate some of the functions developed for my book AutoCAD expert's Visual LISP, Part 4: 3D Programming. This part is also available as the Kindle e-book Programming 3D.

 Download Class Handout
 Download Class Dataset


What this is all about...

If you have ever tinkered with some AutoLISP program you downloaded from the Internet and thought "Gosh, what's this all about?" you definitely need this book!

AutoLISP is all about really controlling AutoCAD. If AutoCAD doesn't have it, I wont wait for them developers to add it in some future Release...  I'll make it up.

For example, I was fed up with copying one solid part so I could subtract it from another without losing the original. So I went to work and in a couple of days I came up with STRIM, The 3DSolids trimming App you can now download from Autodesk Exchange. Using it you can select a bunch of "trimming" solids whose volume will be subtracted from another bunch of solids selected to be trimmed. They say "time is money" and this tool I'm sharing with you all has sure saved me a lot of time. The new version of STRIM incorporates a "select All" option which goes a step further in streamlining your workflow as you can see in this Video.

Once I solved the trimming, I wondered if sometimes I would need not to TRIM the solids, but instead to SPLIT them in a way that all the portions overlapping would be split into separate solids.
So I put AutoLISP to work again. And here came SSPLIT, the other App I'm sharing.

These two tools are now packed into a single Application: TRIMSPLIT, available for downloading at the the AutoCAD Exchange Apps website.

But I don't want to keep the way it's done secret. I've been a teacher all my life and that's a thing I really enjoy. So if you wish to do things like this, then this books can help you. Be it in the Paperback edition or the Kindle e-books.

Hope you enjoy them. I look forward for your feedback.


Announcing the Kindle Edition

Making a 9.6 x 6.7 x 1.3 inches paperback weighing about 2.8 pounds available worldwide implies shipping costs and delays which can discourage interested readers in far-away locations.
Now, with the assistance of Amazon KDP we are proud to announce the availability of AutoCAD expert's Visual LISP as an e-book.
In order to facilitate its downloading, this 656 pages book has been divided into four Volumes.
Volumes 1, 2, 3 and 4 can be purchased at AMAZON. Clicking on the cover images will take you to the Kindle Store!

KINDLE e-books can be read in your browser,  your Smartphone, your Computer or your Tablet using any of the FREE Reading Apps that can be downloaded here.


Part 1. Introduction

Buy this book from CreateSpace eStore

The spirit of Lisp hacking can be expressed in two sentences.
Programming should be fun. Programs should be beautiful.

Paul Graham, in his preface to ANSI Common Lisp.

This quote summarizes perfectly this book's spirit. This Introduction includes an overview to AutoLISP and Visual LISP and a tutorial which reveals the way we can achieve our desired results with this programming environment.
Chapter 1. AutoLISP/Visual LISP
Chapter 2. A Visual LISP Project, Step by Step

Part 2. The Language and its Development Environment

This is a book that addresses a wide range of readers, from those without expertise in programming to those who, skilled in AutoLISP programming seek information about how profit in their work from the new features that Visual LISP has been adding to AutoCAD since release 2000. In this part of the book we intend to describe the language’s fundamental principles, not the detailed syntax of each of each of the functions used or the programming methodology.
This part of the book includes the essential information needed to program with Visual LISP. This information relates primarily to the operation of the two most frequently used tools in the Visual LISP Integrated Development Environment: the Console and the Editor. We will use these two tools in learning the programming language.
To reaching this goal the following Chapters are devoted:
Chapter 3. The Visual LISP IDE.
Chapter 4. Evaluating Expressions.
Chapter 5. User-defined Functions.
Chapter 6. ActiveX Data and Structures.
Chapter 7. Data Entry.
Chapter 8. File Operations.
Chapter 9. Debugging Visual LISP Code.

Part 3. Controlling AutoCAD from Visual LISP

In this part of the book we will study the techniques available to create new drawing entities and objects, for selecting them according to precise selection filters and for transforming them. As has been our approach from the beginning, but now applying it in the solution of practical tasks, we will continue developing a library of functions, a real programmer’s toolbox which we will be using in the applications which will be developed in the rest of the book.
This subject will be developed in the next three Chapters:

Part 4. 3D Programming

3D represents a major breakthrough for Computer Aided Design applications like AutoCAD. Aside from seeing a realistic representation of the designed object, understandable even for those unfamiliar with the technical drawing conventions, it offers the advantage that, instead of drawing each projection separately, we can now generate all the views automatically from the three-dimensional model. We can even take advantage of new techniques of stereolithography, generating and sending through the new  _3DPRINT command a STL file created from our 3D model to a specialized company that will return in a few days the plastic model of our design.
It is with AutoCAD 2012 that we finally have complete implementations of the three classical paradigms for modeling three-dimensional objects:
  • Constructive Solid Geometry (CSG).
  • Procedural or NURBS Surfaces.
  • Subdivision surfaces.
AutoCAD solves the dilemma about which three-dimensional object modeling method to use  -solids, surfaces or meshes- in a very practical way, allowing us to freely combine the three of them. Meshes, Surfaces and Solids can be converted into each other. Solids can be sliced using Surfaces; a portion of space completely bounded by Surfaces can become a Solid; Surfaces can be thickened so that they become Solids. This makes AutoCAD today a perfectly valid application for the creation and management of 3D objects. And compels us to explore in a book like this, dedicated to Visual LISP programming, its ability to operate in this environment.
These subjects are developed in the following Chapters:

Part 5. Advanced Programming

In this final part of the book we have grouped a number of topics that go beyond the creation of graphic objects. These topics include:
  • Programming reactors that can trigger actions depending on the occurrence of certain events.
  • Creating graphical user interfaces for the management of our programs.
  • Adding alphanumeric information to the drawing, in most cases associated with graphic objects and the creation of tables using that information within the drawing.
  • Managing other applications in the Windows environment using Visual LISP programs.
  • Creating Visual LISP compiled applications operating in their own namespace.
These subjects the following Chapters are devoted:


About the Book

This book is the product of eighteen years teaching Computer Aided Design to Civil and Industrial Engineering students at the University of Cantabria. During this time I have published two books about Visual LISP programming for AutoCAD. Back in 2003 the book Programación en AutoCAD con Visual LISP published by McGraw-Hill, which I wrote in collaboration with Professor César Otero was the first one dealing with this subject in Spanish. For ten years it has been the main resource in Spanish for Visual LISP programming. I still receive messages asking me where to buy it. It is impossible, since it is now out of print.

A couple of years ago I undertook the task of preparing an updated version. The new functionalities added since 2003 to AutoCAD required a thorough revision and rewriting of the text. The new book Experto AutoCAD con Visual LISP is updated to Release 2012. But being written in Spanish limits this kind of book’s readers. My English speaking friends have encouraged me to prepare an English version which may reach a wider audience. During this time AutoCAD 2013 has been released, so the English edition has been updated to cover the few changes introduced from 2012 to 2013.

Back in 2003 when the first book was published, AutoLISP was not "in fashion". Not even with Visual LISP’s new contributions. Fashion followers then bet on the novelty represented by VBA. But fashion is not always rationally justified. In that book we aimed to demonstrate that the availability of other Windows dialog box modalities was not reason enough to forgo what had been our way of customizing AutoCAD for more than 15 years. That’s why we ended our book with a chapter devoted to Chad Wanless’s ObjectDCL, a plug-in which allowed the use of this kind of Graphic User Interface with AutoLISP. VBA, like all fashions, passed away. It’s over and those who opted for it are now hastily rewriting their applications. But AutoLISP/Visual LISP is still here. And ObjectDCL, now OpenDCL, has become an open source project which we can use free of charge. And once more it deserved the new book’s last chapter.

I wish this book will guide he who uses AutoCAD in becoming a real expert. That kind of AutoCAD expert that is acquainted with, understands and can manipulate the program’s inner workings to achieve the desired output in a fast and efficient way. He who is not satisfied with what comes out of the box, but demands more.

Among the most significant new contributions of recent versions we have 3D modeling, including surfaces associativity. To them, and other advanced techniques, including parameterization, reactors, user graphic interfaces and compiling applications, more than half of this new book is devoted.

The source code for all the examples included in the book can be freely downloaded here. You can also visit my website: www.togores.net where I have published other materials related to computer-aided design developed during the last twenty years. I hope that you will not only learn from this book, but that you will enjoy doing it.