Overlap

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

OnComponentBeginOverlap — overlap event on specific component

Bind to specific UPrimitiveComponent. More precise than actor overlap.

Event ActorBeginOverlap — fires when another actor overlaps this actor

Requires 'Generate Overlap Events' enabled on the collision component.

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.

EventActorBeginOverlap — fires when another actor overlaps this actor

Requires Generate Overlap Events enabled on both actors.

OnComponentEndOverlap — end overlap on specific component

OnComponentBeginOverlap

Fires when another actor starts overlapping a Collision component. Use for triggers, pickups, hit detection.

EventActorEndOverlap — fires when overlap ends

Event ActorEndOverlap — fires when overlapping actor leaves

Overlap trigger: detect player entering a zone and do something once

Pattern: EventActorBeginOverlap → CastTo<BP_Character>(Object=OtherActor) → Cast Succeeded → DoOnce → [your action here]. Key pins: EventActorBeginOverlap outputs 'OverlappedActor' and 'OtherActor'. CastTo input is 'Object', exec outputs are 'Cast Succeeded' and 'Cast Failed'. DoOnce exec output is 'Completed'.