SetInputModeGameAndUI — set input for both game and UI

SetInputMode GameAndUI — allow both game and UI input

Widget Blueprint

A UMG (Unreal Motion Graphics) UI Blueprint. Holds the visual hierarchy + the logic graph for menus, HUDs, and panels.

Widget data binding: update UI automatically when variable changes

METHOD 1 - Function Binding (auto-updates every frame, easy but has perf cost): In Widget BP: select TextBlock → Details → Content → Text → click 'Bind' → Create Binding → connect your data (e.g. GetPlayerHealth as Text). METHOD 2 - Event-driven (recommended, update only when needed): In owning actor: when data changes → CastTo<WBP_HUD>(HUDWidget) → call custom function 'UpdateHealth(NewHealth)' on widget. In Widget BP: UpdateHealth function → SetText(HealthText, Conv_FloatToString(NewHealth)). KEY: Function bindings run every frame. For frequently-changing data (Tick-speed), use Event-driven approach instead to avoid perf issues.

SetInputMode UIOnly — give all input to UI (show cursor)

SetInputModeUIOnly — set input to UI only

Anchor

Defines where a Canvas Panel widget pins to its parent (corners, edges, center). Anchored UI scales with screen size.

SetText on TextBlock — set display text on UI text widget

UTextBlock::SetText. Bind widget reference with BindWidget meta or GetWidgetFromName.

Interactable interface system with line trace from camera

Pattern: BPI_Interactable interface with Interact(APawn* Caller) and GetInteractText(). Player Tick: GetPlayerCameraManager → GetCameraLocation/Rotation → LineTraceSingle(CamLoc, CamLoc + Forward*InteractDistance) → BreakHitResult → HitActor → DoesImplementInterface(BPI_Interactable) → True: show UI prompt, store as FocusedActor. Interact input → call Interact(Self) on FocusedActor.

Main menu with widget switching and button navigation

Pattern: WBP_MainMenu with WidgetSwitcher containing panels (Main, Options, Credits). Buttons: OnClicked → SetActiveWidgetIndex(WidgetSwitcher, PanelIndex). Play button: RemoveFromParent → OpenLevel(GameMap). Quit: QuitGame. Level BP BeginPlay: CreateWidget(MainMenu) → AddToViewport → SetInputModeUIOnly → SetShowMouseCursor(true).