Horizontal Box

Lays out children left-to-right. Same Size pin model as Vertical Box.

Vertical Box

Lays out children top-to-bottom. Children's Size pins control how space is distributed.

Canvas Panel

Free-form widget layout — children positioned via anchors + offsets. Most flexible, but easy to misalign.

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.

BoxTraceSingle — box sweep for collision detection

Less (float) — A < B

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.

Pickup and collectible system with overlap trigger

Pattern: Pickup actor with SphereCollision(overlap), StaticMesh visual. OnComponentBeginOverlap → CastTo PlayerCharacter → Success: call AddScore/AddItem interface on player → PlaySoundAtLocation → SpawnEmitterAtLocation → DestroyActor(self). Set collision to OverlapOnlyPawn for performance.

Damage number popup floating text in world space

Pattern: WBP_DamageNumber widget with TextBlock. On damage dealt: CreateWidget(WBP_DamageNumber) → SetText(Damage amount) → AddToViewport. Tick: ProjectWorldLocationToScreen(DamageLocation + UpOffset) → SetPositionInViewport. Timeline Alpha 0→1 over 1s: SetColorAndOpacity(FadeOut) + move up. OnFinished: RemoveFromParent. Alternative: use WidgetComponent in world space.

Overlap

Two collision shapes occupying the same space without blocking. Use for triggers (volume, pickup).