Unreal Enhanced Input

Wire player input the modern UE5 way with the Enhanced Input system: data-driven Input
Actions and Mapping Contexts instead of the legacy Project Settings axis/action mappings.
Targets UE 5.8 (Enhanced Input is the default; legacy input is deprecated).

When to use

• Use when adding movement/look/jump/fire input, creating Input Action (IA_) and Input
  Mapping Context (IMC_) assets, applying modifiers/triggers, adding a mapping context to a
  player, or binding actions in C++ or Blueprints.
• Use when the project has IA_*/IMC_* assets or references EnhancedInput.

When not to use: engine-agnostic input architecture (rebinding strategy, buffering,
multi-device design) → input-systems. The Pawn/Character C++ those bindings live in →
unreal-cpp-gameplay.

Core workflow

1. Enable the module/plugin. Enhanced Input is on by default in UE5; for C++ binding add
   "EnhancedInput" to PublicDependencyModuleNames in *.Build.cs.
2. Create Input Actions (IA_). Each has a Value Type: Digital (bool) for buttons,
   Axis1D (float) for triggers, Axis2D (Vector2D) for movement/look.
3. Create an Input Mapping Context (IMC_) that maps keys/buttons to those actions. Use
   Modifiers to shape raw input (Negate, Swizzle Input Axis Values, Dead Zone) — e.g. WASD
   into one Axis2D needs Negate on A/S and a Swizzle on W/S. Use Triggers (Pressed, Hold,
   Tap) to decide when an action fires.
4. Add the mapping context to the player via the EnhancedInputLocalPlayerSubsystem
   (AddMappingContext(IMC, Priority)), usually in BeginPlay/possession.
5. Bind actions to handlers by ETriggerEvent (Triggered, Started, Completed, …) on
   the EnhancedInputComponent, and read the FInputActionValue in the handler.
6. Verify in PIE; the Enhanced Input debugging console commands
   (showdebug enhancedinput) show which actions trigger and their values.

Patterns

1. Add the mapping context (C++ Character)

void AMyCharacter::BeginPlay()
{
    Super::BeginPlay();
    if (APlayerController* PC = Cast<APlayerController>(GetController()))
        if (ULocalPlayer* LP = PC->GetLocalPlayer())
            if (auto* Subsystem = LP->GetSubsystem<UEnhancedInputLocalPlayerSubsystem>())
                Subsystem->AddMappingContext(DefaultMappingContext, /*Priority*/ 0);
}
// DefaultMappingContext is a UPROPERTY(EditAnywhere) TObjectPtr<UInputMappingContext>.

2. Bind actions and read values

void AMyCharacter::SetupPlayerInputComponent(UInputComponent* InputComponent)
{
    Super::SetupPlayerInputComponent(InputComponent);

    // The component is an Enhanced Input component when the plugin is active.
    if (UEnhancedInputComponent* EIC = Cast<UEnhancedInputComponent>(InputComponent))
    {
        EIC->BindAction(MoveAction, ETriggerEvent::Triggered, this, &AMyCharacter::Move);
        EIC->BindAction(LookAction, ETriggerEvent::Triggered, this, &AMyCharacter::Look);
        EIC->BindAction(JumpAction, ETriggerEvent::Started,   this, &ACharacter::Jump);
        EIC->BindAction(JumpAction, ETriggerEvent::Completed, this, &ACharacter::StopJumping);
    }
}

void AMyCharacter::Move(const FInputActionValue& Value)
{
    const FVector2D Axis = Value.Get<FVector2D>();          // Axis2D action
    AddMovementInput(GetActorForwardVector(), Axis.Y);
    AddMovementInput(GetActorRightVector(),   Axis.X);
}

3. Blueprint equivalent (node flow)

Event BeginPlay
  -> Get Controller -> Cast To PlayerController -> Get Local Player
  -> Get EnhancedInputLocalPlayerSubsystem -> Add Mapping Context (IMC_Default, Priority 0)

// IA_Move is exposed as its own event node in the Character's Event Graph:
EnhancedInputAction IA_Move (Triggered)
  -> Action Value (Vector2D) -> Add Movement Input (Forward * Y, Right * X)

Pitfalls

• No input at all — the mapping context was never added (AddMappingContext), or the
  player has no Local Player yet. Add it after possession/BeginPlay.
• Link/compile error binding in C++ — "EnhancedInput" isn't in Build.cs
PublicDependencyModuleNames.
• WASD only moves on two keys / wrong axis — Axis2D needs Modifiers: Negate on the
  negative keys (A, S) and a Swizzle Input Axis Values on the vertical (W/S) so both axes map
  correctly. Raw bindings without modifiers misbehave.
• Get<FVector2D>() returns zero — value-type mismatch: the Input Action is Digital/Axis1D,
  not Axis2D. Match the Get<T>() to the action's Value Type.
• Action fires every frame unexpectedly — Triggered repeats while held for a Down trigger;
  use Started/Completed for one-shots (jump press/release), or a Pressed/Tap trigger.
• Two contexts fight — multiple mapping contexts stack by Priority; a higher-priority
  context can consume a key. Manage with priorities and RemoveMappingContext.

References

• For a complete first-/third-person C++ Character with Enhanced Input (header + source,
  including look/jump and a control-rebind note), read references/cpp-setup.md.
• Primary docs: "Enhanced Input in Unreal Engine"
  (https://dev.epicgames.com/documentation/en-us/unreal-engine/enhanced-input-in-unreal-engine).

Related skills

• input-systems — engine-agnostic input architecture and rebinding strategy.
• unreal-cpp-gameplay — the Character/Pawn class and module setup.
• fps-shooter — composes input with a 3D controller and shooting.