mod.io Plugin Integration

What has been integrated?

ARPG includes the following plugins:

• Modio Core: ARPG implements the core functionality for interacting with the mod.io service, including user authentication, subscription management, etc.
• Component UI: The template UI has been dropped into this project, as well as a custom built Mod Browser using components and functionality provided by the Component UI plugin.
• ModioUGC: Adding support for UGC to be authored specifically for ARPG, and then loaded at runtime by leveraging the AssetManager and AssetRegistry.

mod.io Core Plugin

The mod.io Core Plugin is the core plugin that the rest of the mod.io product suite depends on. It provides functionality to interact with the mod.io services, such as user authentication, content searching & filtering, subscription management & downloading and more.

More information about the mod.io Core Plugin can be found in the mod.io Core Plugin documentation.

Integration with Action RPG

Initialization of the mod.io Core Plugin has been implemented in the ActionRPGModioSubsystem class. This also handles the set up and initialization of the UGC Provider for ModioUGC, to discoverability and loading of UGC.

Additional heavy lifting is done by the UModioAuthSubsystem class, which handles the user authentication flow (SSO where supported, also by email).

note

This project does not include all platform-specific authentication methods where NDAs are required.

mod.io Authentication

mod.io Component UI Plugin

The mod.io Component UI Plugin is a framework providing a set of specifications, UI components, and editor tooling to allow UE developers to rapidly integrate mod.io plugin data and events into their game's UI, either directly into existing screens or in dedicated browser and discovery sections.

More information about the mod.io Component UI Plugin can be found in the mod.io Component UI Plugin documentation.

Integration with Action RPG

Within the Component UI Plugin, there is a Template UI, which is a working, fully featured mod browser that can be dropped into projects. ARPG uses this Template UI as one example of how to interact with the Core Plugin and ModioUGC Plugin to provide a mod browser experience.

The Template UI is located in the following path: Plugins/ModioComponentUI/Content/UI/Templates/Default/WBP_ModioModBrowser.uasset

The browser can be accessed from the main menu, under Mods.

Template UI

It also includes a set of components that can be used to build custom UIs, which we've used to create a simple mod browser in the style of the existing Action RPG UI.

The Template UI is located in the following path: Content/Modding/UGC_Dialogs/WBP_UGC_ModioModBrowser.uasset

The browser can be accessed from the main menu, under Mod Example.

Custom Mod Browser

Session Browser

ARPG also uses the Template UI Session Browser to demonstrate how UGC can be shared between players in an online session. Players can browse sessions, inspect the UGC installed on a session, temporarily install any missing UGC, and then join.

The Session Browser can be accessed from its own button on the main menu, Session Browser.

How it is implemented

The Template UI talks to sessions through the IModioUISessionManagementProvider interface. The Component UI plugin ships a default implementation, UModioUIDefaultSessionManagementProvider, which uses Unreal's Online Subsystem session interface to find, create, join, start, end and destroy sessions.

ARPG extends the default provider with UActionRPGSessionManagementProvider, which adds the ability to generate fake sessions for testing (see below). The provider is created and registered with UModioUISubsystem::SetSessionManagementProvider inside ActionRPGModioSubsystem, alongside the registration of the online portal interface.

UActionRPGOnlineModManagementSubsystem exposes Blueprint-callable wrappers (FindSessions, CreateSession, JoinSession, etc.) that forward to whichever provider is registered, as well as ARPG-specific helpers for syncing a session's UGC to the client as a Temporary Mod Set.

Testing the Session Browser

There are two ways to test the Session Browser in ARPG.

Real sessions via Steam

ARPG uses the Steam Online Subsystem by default to advertise and discover sessions. To create and find real sessions:

• Run a packaged (non-editor) build of ARPG. The Steam integration is disabled in the editor and when launching with -nosteam.
• The Steam client must be running and logged in.
• The Steam account must own the Steam app configured in Config/DefaultEngine.ini (SteamDevAppId under [OnlineSubsystemSteam]). If you do not have access to the mod.io app, set SteamDevAppId to your own Steam App ID, or to 480 (Spacewar, Valve's public test app).
• To join a session you need a second client running on a separate machine with a different Steam account.

Fake sessions (no Steam required)

If you want to test the Session Browser UI and UGC installation flow without Steam, ARPG can populate the browser with generated sessions that reference real UGC on the ARPG game profile. Enable this using either:

• The console command modio.FakeSessions 1, then refresh the Session Browser.
• The launch argument -AddFakeSessions.

note

Fake sessions are for UI testing only. You can browse them, view their UGC and install it temporarily, but you cannot join them.

ModioUGC Plugin

The ModioUGC Plugin is a plugin that provides functionality to create, manage, and load user-generated content (UGC) in Unreal Engine projects. It allows developers to create downloadable content (DLC) plugins that can be shared and loaded at runtime, enabling mod support in games.

More information about the ModioUGC Plugin can be found in the ModioUGC Plugin documentation.

Integration with Action RPG

As mentioned earlier in the mod.io Core Plugin section, the ModioUGC Plugin is initialized in the ActionRPGModioSubsystem class. This subsystem is responsible for managing the UGC Provider, which is an implementation of the IUGCProvider interface that allows for loading and discovering UGC.

ARPG has it's own implementation of the UGC Provider, the ActionRPG_UGCProvider class. This class is an aggregate of the examples supplied by the ModioUGC Plugin - ModioUGCProvider and ModioUGCProviderSideLoaded. This allows loading UGC which has been authored and uploaded to the mod.io service, as well as side loading UGC from a specific folder for rapid iteration.

Beyond this, the usage of the ModioUGC Plugin is primarily in the rest of the ActionRPG project, where UGC can be consumed in their relevant areas. Read more about this in the Moddable Weapons section, which describes how weapons are loaded into the game using the AssetManager and AssetRegistry.

note

There are some settings that are required to be set in the project to enable the ModioUGC Plugin specifically for in-editor testing. These settings are documented in the ModioUGC Plugin documentation.