UWorld::SweepMultiByChannel

function Engine Since 4.0

#include "Engine/World.h"

Access: public Specifiers: const

Description

Sweeps a collision shape from Start to End and returns all overlapping hits along the path, plus the first blocking hit. Unlike SweepSingleByChannel, this collects every overlap — useful for multi-hit detection such as piercing projectiles or area sweeps.

Caveats & Gotchas

• Results are sorted: initial overlaps come first, with the first blocking hit appended at the end. Only one blocking hit is ever returned — the sweep stops generating results after the first blocking contact.
• Returns true only if OutHits contains a blocking hit. Overlaps alone return false — check each FHitResult.bBlockingHit individually if you need to detect pure overlaps.
• OutHits is not cleared before the sweep — always empty or reset the array before calling to avoid accumulating stale results.

Signature

bool SweepMultiByChannel(TArray<struct FHitResult>& OutHits, const FVector& Start, const FVector& End, const FQuat& Rot, ECollisionChannel TraceChannel, const FCollisionShape& CollisionShape, const FCollisionQueryParams& Params = FCollisionQueryParams::DefaultQueryParam, const FCollisionResponseParams& ResponseParam = FCollisionResponseParams::DefaultResponseParam) const

Parameters

Name	Type	Description	Default
OutHits	TArray<struct FHitResult>&	Array populated with all hits found during the sweep.	—
Start	const FVector&	World-space start location of the shape.	—
End	const FVector&	World-space end location of the shape.	—
Rot	const FQuat&	Rotation of the shape, held constant throughout the sweep.	—
TraceChannel	ECollisionChannel	The collision channel used to determine which components to hit.	—
CollisionShape	const FCollisionShape&	The shape to sweep — supports Box, Sphere, or Capsule.	—
Params	const FCollisionQueryParams&	Additional query parameters such as actors to ignore.	FCollisionQueryParams::DefaultQueryParam
ResponseParam	const FCollisionResponseParams&	Response container controlling blocking vs overlap behaviour per channel.	FCollisionResponseParams::DefaultResponseParam

Return Type

bool

Example

Capsule sweep collecting all hits along a path C++

TArray<FHitResult> Hits;
FCollisionShape Capsule = FCollisionShape::MakeCapsule(34.f, 88.f);
FCollisionQueryParams Params;
Params.AddIgnoredActor(this);

bool bBlocked = GetWorld()->SweepMultiByChannel(
    Hits,
    GetActorLocation(),
    GetActorLocation() + GetActorForwardVector() * 500.f,
    FQuat::Identity,
    ECC_Pawn,
    Capsule,
    Params
);

for (const FHitResult& Hit : Hits)
{
    if (AActor* HitActor = Hit.GetActor())
    {
        UE_LOG(LogTemp, Log, TEXT("Hit: %s (blocking: %s)"),
            *HitActor->GetName(),
            Hit.bBlockingHit ? TEXT("yes") : TEXT("no"));
    }
}

Version History

Introduced in: 4.0

Version	Status	Notes
5.6	stable	—

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