UKismetSystemLibrary::BoxTraceMulti

function Engine Blueprint Since 4.0

#include "Kismet/KismetSystemLibrary.h"

Access: public Specifiers: staticBlueprintCallable

Description

Sweeps an oriented box from Start to End against the given Trace Channel and returns every hit encountered, including overlaps before the first blocking hit. Exposed to Blueprint as 'Multi Box Trace By Channel'.

Caveats & Gotchas

• OutHits is sorted along the trace; only the last entry is guaranteed to be a blocking hit, everything before it is a non-blocking overlap.
• Orientation applies to the full sweep, so a box that looks axis-aligned in the editor may sweep diagonally if the actor's rotation isn't identity.
• As with all Multi trace variants, bTraceComplex against dense static meshes is significantly more expensive than the simple-collision path — profile before using it in per-tick logic.

Signature

static ENGINE_API bool BoxTraceMulti(const UObject* WorldContextObject, const FVector Start, const FVector End, FVector HalfSize, const FRotator Orientation, ETraceTypeQuery TraceChannel, bool bTraceComplex, const TArray<AActor*>& ActorsToIgnore, EDrawDebugTrace::Type DrawDebugType, TArray<FHitResult>& OutHits, bool bIgnoreSelf, FLinearColor TraceColor = FLinearColor::Red, FLinearColor TraceHitColor = FLinearColor::Green, float DrawTime = 5.0f)

Parameters

Name	Type	Description	Default
WorldContextObject	const UObject*	World context.	—
Start	const FVector	Start of the sweep.	—
End	const FVector	End of the sweep.	—
HalfSize	FVector	Distance from the center of the box along each axis.	—
Orientation	const FRotator	Orientation of the box.	—
TraceChannel	ETraceTypeQuery	The trace channel to test against.	—
bTraceComplex	bool	True to test against complex collision, false to test against simplified collision.	—
ActorsToIgnore	const TArray<AActor*>&	Actors to exclude from the trace.	—
DrawDebugType	EDrawDebugTrace::Type	Debug draw mode.	—
OutHits	TArray<FHitResult>&	All hits, sorted from Start to End; the blocking hit (if any) is last.	—
bIgnoreSelf	bool	Whether to ignore the world context actor itself.	—
TraceColor	FLinearColor	Debug draw color for the trace.	FLinearColor::Red
TraceHitColor	FLinearColor	Debug draw color for hits.	FLinearColor::Green
DrawTime	float	How long the debug draw persists, in seconds.	5.0f

Return Type

bool

Example

Sweep a box and gather all overlapping hits C++

TArray<FHitResult> Hits;
TArray<AActor*> ActorsToIgnore;
ActorsToIgnore.Add(this);

const FVector Start = GetActorLocation();
const FVector End = Start + GetActorForwardVector() * 300.f;
const FVector HalfSize(50.f, 25.f, 25.f);

bool bHit = UKismetSystemLibrary::BoxTraceMulti(this, Start, End, HalfSize, GetActorRotation(), UEngineTypes::ConvertToTraceType(ECC_Visibility), false, ActorsToIgnore, EDrawDebugTrace::ForDuration, Hits, true);

Version History

Introduced in: 4.0

Version	Status	Notes
5.6	stable	—

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