Yarn Spinner for Unreal

Welcome to Yarn Spinner for Unreal! Yarn Spinner is the friendly dialogue tool that makes it easy for writers to create content, and has powerful features for programmers.

Yarn Spinner for Unreal is designed for Unreal Engine 5.3 and above. It may work on earlier versions, but our current focus is on 5.3.

Important

This plugin is a beta. Please see the list of Known Issues. This release is intended to get early feedback from users. Do not use this plugin in production.

This project's development is supported by an Epic MegaGrant.

Tutorial

To get started with Yarn Spinner for Unreal, we have an end-to-end tutorial available, starting from a blank project and ending with voice-acted interactive conversation!

Installation Instructions

1. If your project is already open in the Unreal Editor, close it.
2. Create a new folder called Plugins in the root of your project. (If you already have this folder, skip this step.)
3. Next, clone this repository and put it in the Plugins folder.
4. Finally, re-open your project. When Unreal Editor asks if you want to build the Yarn Spinner module, say yes.

Known Issues

Yarn Spinner for Unreal is currently at a beta stage of development, and there are a number of important caveats to know.

• Windows support only. Additional platforms will be added in future versions.
• In-memory variable storage only. Variables can be stored and retrieved, but they are not currently stored on disk.
• Limited function support.
  • The following functions are supported: visited, visited_count, string, number, bool.
• String-only command dispatch. Dispatching commands to functions is not implemented; however, when a command is run, the Dialogue Runner emits an OnRunCommand event that contains the command name and an array of its parameters.
• Yarn Project importing takes longer than desired. When you import a Yarn Project asset, it may take several seconds for the process to complete, during which time the Editor will not be responsive.
• String tables may incorrectly cache in the Editor. When you import a Yarn Project, the string table will be populated with its contents. If you make changes to the Yarn files and re-import the Yarn Project, the string table contents will update, but the editor may still hold the cached values from the earlier version, resulting in incorrect lines being displayed. As a workaround for this issue, play the game in Standalone mode. Quitting and relaunching the Editor will also reset this cache.

Troubleshooting

I get a "Plugin 'YarnSpinner' failed to load because module 'YarnSpinner' could not be found" message when I try to play a build of my game.

If your project was created as a Blueprint Project, then Unreal will not include plugins by default. Add a new empty C++ class (of any type), and rebuild your project.

Credits

Yarn Spinner for Unreal was developed by Yarn Spinner Pty Ltd, with enormous amounts of help from Ben Phelan.