Lyra Input Overview

Lyra combines different UE5 systems and plugins together to coordinate a coherent input strategy.

For a 5 minute high level conceptual overview, see my YT video: UE5 Lyra Input Overview

Key Concepts

• Common UI manages input mode changes during gameplay via Common UI Action Router
• Enhanced Input receives all input that is directed to the game, filtered by active Input Mapping Contexts
• UI Manager Subsystem manages the Lyra UI Policy
  • defines UI Layers UI.Layer.* prioritized for input capture
• Lyra HUD Layout implements UI.Layer.Game, the Game HUD
• By default, Game Feature Actions like LAS_ShooterGame_StandardHUD define:
  • which HUD Layout class to use
  • which Activatable Widget classes to instantiate for each UI Extension Point
• You can manage the addition/removal of other HUD Layouts and/or widgets during Gameplay
• You can override Native Player Input handling by deriving from ULyraHeroComponent

Input Handling Overview

Lyra uses Common UI together with Enhanced Input to manage Player Input. Be familiar with both.

These UE5 plugins are integrated via the Lyra UI Policy, which defines a HUD as being comprised of prioritized layers of Activatable Widgets.

The Escape key (the “back” button) activates the Game Menu widget, which suspends Player Game Input while the menu is open, for example.

Common UI controls if, when and how input makes it to the Game. If/when you want to explicitly change input modes in your Game, you must use the Common UI Action Router to do so.

When Activatable Widgets activate and deactivate, they can optionally change the input mode and/or focus themselves for input to support MKB, Gamepad, VR controllers, etc. The settings are all customizable by input device and platform.

In particular, they should agree on the value of Get Desired Input Config, hopefully via a shared implementation.

When no Activatable Widget is modifying the input mode, the input flows to the Game itself via Enhanced Input, as triggered by any active Input Mapping Contexts at the given point in Playtime.

Input Mapping Contexts (IMC)

Input Mapping Context management during Gameplay allows you to activate or deactivate any given IMC based on the context. For example, possessing a Vehicle or ejecting from it might change the active IMC compared to movement on foot.

Lyra uses Game Feature Actions to initialize default IMCs, and you can add your own IMC swapping logic to dynamically change inputs during Gameplay.

Player Input is managed by the Lyra Hero Component

• If you want custom input handling, you must derive from ULyraHeroComponent

The Lyra Hero Component activates the Native & Ability Input Actions for the Player Pawn.

• For a pawn to receive player input, it must have a ULyraHeroComponent component
  • ULyraHeroComponent as a base class is required by Lyra, including but not limited to:
    • ULyraGameplayAbility
      • To manage ability camera modes
      • Also exposes the Hero Component to BPs that may use it for other reasons
    • Game Feature Actions having to do with input management:
      • GameFeatureAction_AddInputBinding
      • GameFeatureAction_AddInputConfig
      • GameFeatureAction_AddInputContextMapping
• ULyraHeroComponent works in conjunction with ULyraPawnExtensionComponent to activate the inputs on the pawn
  • Thus, the pawn must also have a ULyraPawnExtensionComponent and fully support the IGameFrameworkInitStateInterface
  • See ULyraHeroComponent::InitializePlayerInput for implementation details
    • This gets called during the pawn initialization process while transitioning to InitState.DataInitialized
  • This requires the player to be using ULyraInputComponent for input, which is configured in the Project Settings

References

• Official Epic Lyra Input Docs
• ULyraSettingsLocal