Unreal Engine Plugin Overview

Charon is a versatile plugin tailored for Unreal Engine, designed to facilitate data-driven game design by allowing both developers and game designers to efficiently manage static game data, like units, items, missions, quests, and other. Unlike Unreal Engine’s DataTables, Charon elevates the experience by offering an integrated editing UI directly within Unreal Engine, enabling the modeling of diverse data structures suited to any game genre. It provides a user-friendly interface that requires no special skills for game designers, simplifying the process of data manipulation. For programmers, Charon streamlines development workflows by generating code to load game data seamlessly into the game.

Key Features

• Data Modeling: Define game entities like characters, items, missions, quests, and dialogs to meet the specific needs of your game. Interconnect and fill these tables within one UI.

• Error Control: Implements validation checks to verify the accuracy of input data, reducing the likelihood of errors that could impact gameplay or development.

• Code Generation: Automates the creation of boilerplate code needed to work with your game data, significantly speeding up development time and reducing manual coding errors.

• Spreadsheet Export/Import: Offers seamless integration with spreadsheet software, enabling you to effortlessly populate, edit, and manage your game data in a familiar environment.

• Localization Export/Import: Simplifies the process of preparing game data for translation, making it straightforward to adapt your game for global audiences.

• Modding Support: Empowers your gaming community by providing them with the tools to create and share mods, enhancing the longevity and depth of your game.

• Dynamic Load: Facilitates the dynamic loading of game data, enabling features like A/B testing or the ability to push hot updates directly to your players.

Getting Started

To begin using this plugin, the initial step involves installing the plugin from the Unreal Engine Marketplace. Once installed, you’ll need to enable the plugin for your project through the project settings. Following this, a rebuild of your project’s C++ code is necessary. The final step in the setup process is the creation of your first game data file.

Installation from Marketplace

1. Add to cart Charon plugin in the Unreal Engine Marketplace.

2. Follow the instruction on installing plugin into your project:

1. Click Install to Engine and select the engine version.

2. Open your project and go to Edit → Plugins… window.

3. Type Charon in the Search bar.

4. Check the checkbox near the plugin’s name to enable it.

3. Rebuild project C++ code.

4. Enable plugin in Edit → Plugins… if needed.

Installation from GitHub

1. Clone or download the plugin source code from the GitHub repository.

2. Create a <project-dir>/Plugins/Charon directory.

3. Copy the plugin files into this directory. Ensure Charon.uplugin is located at the path <project-dir>/Plugins/Charon/Charon.uplugin after copying.

4. Remove the "EngineVersion" attribute if your engine doesn’t match the plugin’s engine version.

5. Rebuild the project’s C++ code.

6. Enable the plugin in Edit → Plugins… if needed.

Core Concepts

Data-Driven Design Principles

Data-driven design emphasizes the control of gameplay through data, rather than source code/blueprints, with game mechanics and processes determined by structured data files. For instance, rather than embedding damage calculations directly in the game’s source code, these are defined by data specifying weapon effects and the rules for their application. Or for example, mission progression is not hardcoded; it’s outlined in editable text files, making these aspects of game design highly flexible. This approach not only facilitates quick adjustments during development but also simplifies adding modding support post-release.

• Data Driven Gameplay Elements (UE Documentation)

• Modify Everything! Data-Driven Dynamic Gameplay Effects on ‘For Honor’ (Video)

• Data-driven Design in Unreal (Article)

Understanding the Plugin’s Architecture

Plugin Assets

Working with data in this plugin is akin to how the built-in DataTable functions. There is a data source file, a module containing the code required to load the data, and an asset that will be utilized in the game. Whenever you edit a data source file, you need to re-import this data into the asset. Should the data structure in the source file change, then the C++ code must be regenerated.

For scenarios requiring dynamic loading of game data, this can be accomplished through the TryLoad method on the game data class, which accepts the source JSON file.

Plugin Modules

The Charon plugin is structured into two modules:

• CharonEditor module acts as an Unreal Engine Editor extension. Extension points for the module are declared in the ICharonEditorModule class, and automation of game data processing is facilitated through the FCharonCli class.

• Charon module, houses the core logic and shared code crucial for handling game data files.

Working with the Plugin

Creating Game Data

To create a new game data file within the Unreal Engine Editor, open the Content Drawer, right-click in the desired folder, and select in the Create Advanced Assets section Miscellaneous → Game Data menu option. Name your game data file and proceed according to the instructions in the dialog window that appears.

Detailed guide on how to create game data.

Editing Game Data

To edit a game data file in the Unreal Engine Editor, navigate to the Content Drawer, find the corresponding .uasset file, and double-click it. This action opens a new window featuring a user interface for editing the game data. Remember to reimport and, if necessary, regenerate the source code after completing your edits.

Refencing Game Data in Blueprints

Similar to the DataTable’s FDataTableRowHandle, the Charon plugin introduces a specific type for referencing documents within Blueprints, named FGameDataDocumentReference. This type is housed within the Charon module. Here is example of Game Data Document Reference used to resolve Hero document:

Advanced Features

Localization and Multi-Language Support

Charon facilitates multi-language text support through the Localizable Text data type. When creating a Schema, properties can be defined with various data types, including Localizable Text. Initially, all localizable text defaults to EN-us (US English). Additional languages can be added via Project Settings → Internationalization → Translation Languages in the Charon UI.

Exporting/importing localizable data.

Referencing Unreal Engine Assets

By default, game data files and the Charon editor are unaware of the surrounding content/assets. To reference assets such as sounds, textures, models, or animations. For example you can create a ‘UeSoundAsset’ schema with three properties: Id (required), Path, and Name. Prepare a FJsonObject listing of your assets (see Unreal Engine AssetRegistry module documentation) in following format:

{
    "UeSoundAsset": [{
            "Id": "_Content_Sounds_MySound",
            "Path": "/Content/Sounds/MySound",
            "Name": "MySound"
        }
        /* other assets */
    ],
    /* other document collections to import */
}

Then, import this list into your game data file using the FCharonCli::Import method with EImportMode::Replace import mode. It’s crucial that the Id field of imported records remains stable and unchanged across imports for the same assets.

To streamline the process of importing asset paths, consider leveraging the ICharonEditorModule::OnGameDataPreSynchronization event. This allows for automatic execution of the import routine each time the Import button is clicked in the UI.

After you’ve imported the asset list into the game data file, you can reference them from your documents by adding a Document Reference property with Reference Type → UeSoundAsset to the schema.

Feedback

We welcome and encourage feedback, particularly bug reports and suggestions, to help improve our tool. If you have any questions or would like to share your thoughts, please join our Discord community or reach out to us via email at support@gamedevware.com.

See also

• Basic Navigation and User Interface Overview

• Creating Document Type (Schema)

• Filling Documents

• Frequently Asked Questions (FAQ)

• Glossary