UPrimitiveComponent::OnComponentBeginOverlap

property Engine Blueprint Since unknown

#include "Components/PrimitiveComponent.h"

Access: public Specifiers: UPROPERTYBlueprintAssignable

Description

Delegate fired when another component begins overlapping this component. Requires both components to have overlap responses enabled for the relevant channels.

Caveats & Gotchas

• Both components must respond to each other's object type with ECR_Overlap (not ECR_Block or ECR_Ignore) for the event to fire.
• Actor-level overlap events (AActor::OnActorBeginOverlap) are fired after the component-level event. Use the component version when you need the specific component reference.
• Dynamically spawned actors may fire OnComponentBeginOverlap during BeginPlay if they spawn inside an existing overlapping volume — handle this case explicitly.

Signature

FComponentBeginOverlapSignature OnComponentBeginOverlap

Parameters

Name	Type	Description	Default
OverlappedComponent	UPrimitiveComponent*	This component.	—
OtherActor	AActor*	The actor that began overlapping.	—
OtherComp	UPrimitiveComponent*	The specific component on the other actor.	—
OtherBodyIndex	int32	Index of the physics body (relevant for skeletal meshes with multiple bodies).	—
bFromSweep	bool	True if the overlap was detected via a sweep (movement), false if via a proximity check.	—
SweepResult	const FHitResult&	Hit result from the sweep, valid only when bFromSweep is true.	—

Example

Trigger zone that applies a speed boost C++

void ASpeedZone::BeginPlay()
{
	Super::BeginPlay();
	TriggerVolume->OnComponentBeginOverlap.AddDynamic(this, &ASpeedZone::OnOverlapBegin);
	TriggerVolume->OnComponentEndOverlap.AddDynamic(this, &ASpeedZone::OnOverlapEnd);
}

void ASpeedZone::OnOverlapBegin(UPrimitiveComponent* Comp, AActor* OtherActor,
	UPrimitiveComponent* OtherComp, int32 OtherBodyIndex, bool bFromSweep, const FHitResult& Hit)
{
	if (ACharacter* Char = Cast<ACharacter>(OtherActor))
	{
		Char->GetCharacterMovement()->MaxWalkSpeed *= 2.0f;
	}
}

Version History

Introduced in: unknown

Version	Status	Notes
5.6	stable	—

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