Create widget and add to viewport for HUD

Pattern: BeginPlay → CreateWidget(WidgetClass, GetPlayerController(0)) → store as variable → AddToViewport(Widget, ZOrder=0). Remove: RemoveFromParent(Widget). Toggle: SetVisibility(Collapsed/Visible). Create once, toggle visibility — never recreate every frame. For interaction: SetInputModeUIOnly + SetShowMouseCursor.

Widget health bar HUD that updates from player health variable

Pattern: WBP_HealthBar with ProgressBar(HealthBar, BindWidget). Player BeginPlay: CreateWidget(WBP_HealthBar, PC) → SET WidgetRef → AddToViewport. On health change: WidgetRef → SetPercent(HealthBar, CurrentHealth/MaxHealth). Alternative: use property binding in widget designer for auto-update.

Widget Blueprint

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

Create a Blueprint for a health pickup that restores health when overlapped by the player

Health and damage system with ApplyDamage and EventAnyDamage

Dealing damage: Event → ApplyDamage(TargetActor, BaseDamage, InstigatorController, DamageCauser, DamageTypeClass). Receiving: EventAnyDamage → Damage output → Subtract_FloatFloat(CurrentHealth, Damage) → FClamp(Result, 0, MaxHealth) → SET CurrentHealth → Branch(CurrentHealth <= 0) → True: DestroyActor. Initialize CurrentHealth=MaxHealth in BeginPlay.

Health system: take damage, clamp health, check death

Pattern: EventAnyDamage → Subtract_FloatFloat(A=CurrentHealth, B=Damage) → Clamp(Value=Result, Min=0, Max=MaxHealth) → SetVariable(Health=ClampResult) → Branch(Condition=(Health <= 0)) → True: call OnDeath custom event. Variables needed: Health (float), MaxHealth (float). EventAnyDamage output pin is 'Damage' (float). Clamp inputs: 'Value', 'Min', 'Max'. All floats.

Create a Blueprint for a door that opens when the player overlaps a trigger and closes when they leave

ApplyRadialDamage — deal area damage in a radius

Elevator or moving platform with timeline and trigger

Pattern: Variables StartLocation(Vector), EndLocation(Vector). BeginPlay: SET StartLocation=GetActorLocation. Timeline MoveTimeline(Alpha 0→1 over Duration). Trigger overlap/button press → Play Timeline. Timeline Update: VLerp(StartLocation, EndLocation, Alpha) → SetActorLocation(Self, Result, bSweep=true). Finished: Delay → Reverse Timeline.

ApplyPointDamage — deal point damage with hit info