Book Image

Python Scripting in Blender

By : Paolo Acampora
5 (1)
Book Image

Python Scripting in Blender

5 (1)
By: Paolo Acampora

Overview of this book

Blender, a powerful open source 3D software, can be extended and powered up using the Python programming language. This book teaches you how to automate laborious operations using scripts, and expand the set of available commands, graphic interfaces, tools, and event responses, which will enable you to add custom features to meet your needs and bring your creative ideas to life. The book begins by covering essential Python concepts and showing you how to create a basic add-on. You’ll then gain a solid understanding of the entities that affect the look of Blender’s objects such as modifiers, constraints, and materials. As you advance, you’ll get to grips with the animation system in Blender and learn how to set up its behavior using Python. The examples, tools, patterns, and best practices present throughout the book will familiarize you with the Python API and build your knowledge base, along with enabling you to produce valuable code that empowers the users and is ready for publishing or production. By the end of this book, you’ll be able to successfully design add-ons that integrate seamlessly with the software and its ecosystem.
Table of Contents (19 chapters)
1
Part 1: Introduction to Python
7
Part 2: Interactive Tools and Animation
13
Part 3: Delivering Output

Adding modal behavior

In user interfaces, the term modal designates a sub-window or widget that takes all the user interaction for itself, until the operation is ended explicitly.

Usually, operators are designed to return to the main application immediately. If we don’t want that, they should be added to the window manager’s modal handlers.

The operator is then considered modal and will listen to the user inputs until it’s closed manually.

We can make PunchClock modal and use mouse movement to set our clock. Modal operators have two requirements:

  • invoke adds the operator to the handlers and returns 'RUNNING_MODAL'.
  • modal is implemented and returns 'RUNNING_MODAL'. It returns 'FINISHED' when a user ends it, or 'CANCELLED' to exit with no changes.

We will start to implement the modal execution by changing invoke and its return value.

Adding the operator to the modal handlers

Instead of passing...