Creating add-ons for Blender

Learn to write Blender add-ons with this fast paced, information dense primer. Now updated for Blender 2.93 (and works with 2.92 as well).

A practical primer

This primer on writing Blender add-ons aims to be short an sweet and pretty fast paced. This means that we cover quite a lot of concepts in a short time but I have provided links to additional information where relevant.
You also need to have some experience in writing Python programs but other than that you will find that writing Blender add-ons is surprisingly simple. Almost anything is possible due to the large amount of built-in functionality available from within Python and this huge collection of classes and functions might be a little bewildering to navigate but the basics of a Blender add-on are easy to grasp in just a few hours.

In this primer you will start with an almost trivial add-on and work your way to a full fledged add-on that manipulates meshes and is fully integrated with Blender's own graphical user interface, complete with user configurable properties and custom icons.

Multiple formats

Formatting books with program listings is always a challenge but the .zip file that you can download when purchasing this e-book contains an .epub version of the book (readable by most e-readers), a .mobi version (readable by most Kindles) and a .pdf version.

Also, the source code accompanying the book is available on GitHub.

Table of contents

• Introduction
  • Introduction to the 2.93 edition
  • Overview
  • Notes on code
  • Troubleshooting
• A Blender add-on: the basics
  • Example: move an object
  • The anatomy of an add-on
    • bl_info
    • An Operator class
    • The execute() function
    • Registering and adding a menu entry
  • Distributing and installing an add-on
• A Blender add-on: more complexity
  • Example: Arranging selected objects in a circle
  • The add-on information
  • Defining an operator class
  • The poll() function
  • The execute() function
  • The register() and unregister() functions
  • Bundling an add-on with multiple files
• Adding properties
  • Example: a configurable radius
  • Adding an property
  • Example: a configurable orientation
  • More property types
  • Working with the property values
  • Layout
  • Presets
• Working with meshes
  • Example: Working with bmeshes
  • Creating a bmesh
  • Working with elements
  • Custom Data Layers
  • Loops - vertex colors
• Creating meshes
  • Example: creating a ladder
  • The Ladder operator and its properties
  • Adding a mesh object to a scene
  • Creating mesh geometry
  • Removing doubles
  • Adding modifiers
  • Smooth shading
• Parametric objects
  • Example: a parametric ladder
  • Defining object properties
  • The Ladder operator
  • A panel in the toolbar section
  • A better ladder mesh
    • Mesh elements
    • Adding the stile
    • Adding the rung
    • Bridging the components
    • Duplication
    • Skewing
  • Animating object properties
    • Application handlers
• Additional information
  • About the author
  • Acknowledgments
  • Additional information on Blender add-ons