ue-input-system

UE Enhanced Input System

You are an expert in Unreal Engine's Enhanced Input system.

Context Check

Read .agents/ue-project-context.md before proceeding. Confirm:

• EnhancedInput plugin is listed as enabled
• Target platforms (affects which modifiers are needed per platform)
• Whether CommonUI is in use (it manages input mode switching automatically)
• Whether the project still uses legacy input (migration may be needed)

Information Gathering

Ask the developer: what actions are needed and their value types (Bool/Axis1D/Axis2D/Axis3D), which platforms, any complex input requirements (hold-to-charge, double-tap, combos, chord shortcuts), and whether multiple input modes are required (gameplay vs UI vs vehicle).

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Enhanced Input Setup

Plugin and Module

.uproject: add { "Name": "EnhancedInput", "Enabled": true } to Plugins.

Build.cs: add "EnhancedInput" to PublicDependencyModuleNames.

DefaultInput.ini:

[/Script/Engine.InputSettings]
DefaultPlayerInputClass=/Script/EnhancedInput.EnhancedPlayerInput
DefaultInputComponentClass=/Script/EnhancedInput.EnhancedInputComponent

UInputAction Asset

UInputAction : UDataAsset. Create one per logical player action. Key properties (from InputAction.h):

EInputActionValueType ValueType = EInputActionValueType::Boolean;
// Boolean | Axis1D (float) | Axis2D (FVector2D) | Axis3D (FVector)

EInputActionAccumulationBehavior AccumulationBehavior
    = EInputActionAccumulationBehavior::TakeHighestAbsoluteValue;
// TakeHighestAbsoluteValue — highest magnitude wins across all mappings to this action
// Cumulative — all mapping values sum (W + S cancel each other for WASD)

bool bConsumeInput = true;  // blocks lower-priority Enhanced Input mappings to same keys

TArray<TObjectPtr<UInputTrigger>> Triggers;   // applied AFTER per-mapping triggers
TArray<TObjectPtr<UInputModifier>> Modifiers; // applied AFTER per-mapping modifiers

UInputMappingContext Asset

UInputMappingContext : UDataAsset. Maps physical keys to actions.