Module API_intro

The Blender Game Engine Python API Reference

See release notes for updates, changes and new functionality in the Game Engine Python API.

See update notes for bugfixes and changes released since 2.49.

See Blender/Python API if your not looking for GameEngine docs.

Blender Game Engine Modules:

Modules that include methods for accessing GameEngine data and functions.

• GameLogic utility functons for game logic.
• GameKeys keyboard input and event conversion.
• Rasterizer display and rendering.
• GameTypes contains all the python types spesific to the GameEngine.

Undocumented modules:

• VideoTexture
• PhysicsConstraints

Additional Modules:

These modules have no GameEngine specific functionality but are useful in many cases.

• Mathutils
• Geometry
• BGL

Introduction:

This reference documents the Blender Python API, a growing collection of Python modules (libraries) that give access to part of the program's internal data and functions.

Through scripting Blender can be extended in real-time via Python, an impressive high level, multi-paradigm, open source language. Newcomers are recommended to start with the tutorial that comes with it.

This opens many interesting possibilities not available with logic bricks.

Game Engine API Stability:

When writing python scripts there are a number of situations you should avoid to prevent crashes or unstable behavior. While the API tries to prevent problems there are some situations where error checking would be too time consuming.

Known cases:

• Memory Limits.

  There is nothing stopping you from filling a list or making a string so big that that causes blender to run out of memory, in this case python should rasie a MemoryError, but its likely blender will crash before this point.

• Accessing any data that has been freed.

  For instance accessing a KX_GameObject after its End Object actuator runs. This will cause a SystemError, however for KX_MeshProxy, KX_VertexProxy and KX_VertexProxy it will crash the blender game engine.

  See: GameTypes.PyObjectPlus.invalid which many types inherit.

• Mixing KX_GameObject between scenes.

  For instance tracking/parenting an KX_GameObject object to an object from other scene.

External Modules:

Since 2.49 support for importing modules has been added.

This allows you to import any blender textblock with a .py extension.

External python scripts may be imported as modules when the script is in the same directory as the blend file.

The current blend files path is included in the sys.path for loading modules. All linked libraries will also be included so you can be sure when linking in assets from another blend file the scripts will load too.

A note to newbie script writers:

Interpreted languages are known to be much slower than compiled code, but for many applications the difference is negligible or acceptable. Also, with profiling (or even simple direct timing with Blender.sys.time) to identify slow areas and well thought optimizations, the speed can be considerably improved in many cases. Try some of the best BPython scripts to get an idea of what can be done, you may be surprised.