UnrealEnginePython

Embed Python in Unreal Engine 4

Teaser (by Kite & Lightning): https://twitter.com/KNLstudio/status/932657812466843648

Fixing Mixamo RootMotion tuturial: https://github.com/20tab/UnrealEnginePython/blob/master/tutorials/FixingMixamoRootMotionWithPython.md

Funny snippets for working with StaticMesh and SkeletalMesh assets: https://github.com/20tab/UnrealEnginePython/blob/master/tutorials/SnippetsForStaticAndSkeletalMeshes.md

More tutorials: https://github.com/20tab/UnrealEnginePython/tree/master/tutorials

Project Status (IMPORTANT)

Currently (as april 2020) the project is on hold: between 2016 and 2018 20tab invested lot of resources in it but unfortunately epic (during 2018) decided to suddenly release its own implementation and the request made for a megagrant in 2019 by the original plugin author was rejected too.

As this plugin (still) has way more features than the Epic one and many contributors, we are currently looking for new maintainers helping us to keep it alive, checking PR and issues. If you are interested in working on it a few hours a week, drop us a line at info@20tab.com to discuss about it.

If you are interested in game logic scripting/modding in Unreal Engine 4 consider giving a look at the LuaMachine project (https://github.com/rdeioris/LuaMachine/).

The plugin should work up to unreal engine version 4.23 and there are forks/pull requests for 4.24. Since 4.25 Epic refactored the UProperty subsystem, so if you want to port the plugin to a version >= 4.25 you should make a lot of search & replace (basically renaming UProperty to FProperty and Cast to CastField should be enough)

How and Why ?

This is a plugin embedding a whole Python VM (versions 3.x [the default and suggested one] and 2.7) In Unreal Engine 4 (both the editor and runtime).

The Python VM tries to give easy access to all of the UE4 internal api + its reflection system. This means you can use the plugin to write other plugins, to automate tasks, to write unit tests and to implement gameplay elements.

It is not meant as a way to avoid blueprints or c++ but as a good companion to them (albeit reducing the amount of c++ required for coding a game could be an interesting thing ;). If your development pipeline is already python-based (Maya, Blender, ...), this plugin could easily help you in integrating unreal into it.

If you want to have an idea of what the plugin can do, jump here: https://github.com/20tab/UnrealEnginePython/blob/master/tutorials/YourFirstAutomatedPipeline.md

In addition to this, the plugin automatically adds an actor class (PyActor), a pawn class (PyPawn), a character class (PyCharacter) and a component class (PythonComponent) for "gentle" integration of python in your games.

In the spirit of automating tasks, even wrappers for third party libraries used by UE4 are exposed in a 'pythonic' way. As an example the FbxSdk is exposed to allow low-level interaction with Fbx files. This is an example extracting animation curves: https://github.com/20tab/UnrealEnginePython/blob/master/examples/fbx_curves_extractor.py

Another funny feature (well, a side effect ;) is that you can change your python code even after the project has been packaged. You can potentially build a completely new game from an already packaged one.

Once the plugin is installed and enabled, you get access to the 'PythonConsole' item in the 'Development Menu', you can use it to trigger python commands directly from the editor. There is even an experimental Editor/IDE included, you can run it from the Window/Layout/Python Editor menu item.

All of the exposed engine features are under the 'unreal_engine' virtual module (it is completely coded in c into the plugin, so do not expect to run 'import unreal_engine' from a standard python shell)

The minimal supported Unreal Engine version is 4.12, while the latest is 4.23

We support official python.org releases as well as IntelPython and Anaconda distributions.

Note: this plugin has nothing to do with the experimental 'PythonScriptPlugin' included in Unreal Engine >= 4.19. We aim at full integration with engine and editor (included the Slate api, check here: https://github.com/20tab/UnrealEnginePython/blob/master/docs/Slate_API.md), as well as support for the vast majority of python features like asyncio, coroutines, generators, threads and third party modules.

Binary installation on Windows (64 bit)

Check in the releases page (https://github.com/20tab/UnrealEnginePython/releases) if there is a binary version that matches your configuration (otherwise open an issue asking us for it [please specify the python version too]) and download it.

Binary releases are in two forms: standard and embedded. Standard uses the python installation of your system, so ensure the python installation directory is in your system PATH environment variable (otherwise you will get an error while loading your project). Embedded releases include an embedded python installation so you do not need to have python in your system.

Create (if it does not already exist) a Plugins directory in your project root directory (at the same level of Content/ and the .uproject file) and unzip the plugin into it. If your project is named FooBar you will end with FooBar/Plugins/UnrealEnginePython.

Open your project and go to the Edit/Plugins menu. Go to the bottom and under "Project/Scripting Languages" enable UnrealEnginePython.

Restart your project and you should see the PythonConsole under the "Window/Developer Tools" menu

Binary releases are mainly useful for editor scripting, if you want to package your project for distribution and you need the python runtime, you need a source release (see below).

If instead, you want to package your project without python, just remember to change the UnrealEnginePython.uplugin to have this line: https://github.com/20tab/UnrealEnginePython/blob/master/UnrealEnginePython.uplugin#L20 set as "Editor" instead of "Runtime"

Installation from sources on Windows (64 bit)

Currently python3.6, python3.5 and python2.7 are supported. It is highly suggested to have a python system wide installation (by default the official python distributions are installed in user's home directory) with the PATH environment variable including it (if you change the PATH variable remember to reboot the system before running the build procedure, this is not strictly required but will ensure the PATH is updated). If the PATH variable does not contain the path of your python installation you will see a warning in the build log/output.

Download a source official release or simply clone the repository for latest updates:

git clone https://github.com/20tab/UnrealEnginePython

By default the build procedure will try to discover your python installation looking at hardcoded known paths. If you want to specify a custom python installation (or the autodetection simply fails) you can change it in the Source/UnrealEnginePython/UnrealEnginePython.Build.cs file at this line: https://github.com/20tab/UnrealEnginePython/blob/master/Source/UnrealEnginePython/UnrealEnginePython.Build.cs#L10

Note: ensure you have a 64bit python installation

choose a project you want to install the plugin into, open the file explorer (you can do it from the epic launcher too) and:

• create a Plugins/ directory (if it does not exist) in your project and copy the directory UnrealEnginePython into it
• from the file explorer right click on the project main file and choose 'generate visual studio project files'
• open visual studio, you should now see Plugins/UnrealEnginePython in your solution explorer
• run the compilation from visual studio
• once the compilation ends, double check the python libraries can be found by the plugin (they must be in the system PATH like previously described, or brutally copy them in the Binaries/Win64 directory of the just built plugin)
• now you can re-run the unreal engine editor

If all goes well, you will see 'Python Console' in the "Window/Developer Tools" menu

If you want to package your project (it is required only if you need to have a python VM at runtime, read: your game logic is programmed in python) ensure the Content/Scripts/ue_site.py file is in your project (it can be empty). At the end of the build procedure ensure to copy all of your required python scripts in the final directory. Remember that unless you add an embedded python in your final build, the final users of your project will require python installed in his/her system.

If you want to package without python, just remember to change the UnrealEnginePython.uplugin to have this line: https://github.com/20tab/UnrealEnginePython/blob/master/UnrealEnginePython.uplugin#L20 set as "Editor" instead of "Runtime"

Binaries installation on MaxOSX

Check in the releases page (https://github.com/20tab/UnrealEnginePython/releases) if there is a binary version that matches your configuration (otherwise open an issue asking us for it [please specify the python version too]) and download it.

Binary releases for MacOSX expects an official python installation (the packages you get from python.org).

Create (if it does not already exist) a Plugins directory in your project root directory (at the same level of Content/ and the .uproject file) and unzip the plugin into it. If your project is named FooBar you will end with FooBar/Plugins/UnrealEnginePython.

Open your project and go to the Edit/Plugins menu. Go to the bottom and under "Project/Scripting Languages" enable UnrealEnginePython.

Restart your project and you should see the PythonConsole under the "Window/Developer Tools" menu

Binary releases are mainly useful for editor scripting, if you want to package your project for distribution and you need the python runtime, you need a source release (see below).

If instead, you want to package your project without python, just remember to change the UnrealEnginePython.uplugin to have this line: https://github.com/