UKismetSystemLibrary::LineTraceMultiForObjects

function Engine Blueprint Since 4.0

#include "Kismet/KismetSystemLibrary.h"

Access: public Specifiers: staticBlueprintCallable

Description

Traces a line from Start to End and returns every hit against components whose collision responds to one of the given Object Types. Exposed to Blueprint as 'Multi Line Trace For Objects'.

Caveats & Gotchas

• ObjectTypes is the same classification system used by overlap queries (SphereOverlapActors, etc.), so an actor invisible to a Trace Channel query can still show up here if its Object Type matches.
• OutHits contains every matching component along the full line, not just up to a blocking hit — a long line through several dynamic actors returns all of them in one call.
• This has no TraceChannel parameter at all, so channel-based collision responses (Block/Overlap/Ignore) never factor into the result — only the Object Type list does.

Signature

static ENGINE_API bool LineTraceMultiForObjects(const UObject* WorldContextObject, const FVector Start, const FVector End, const TArray<TEnumAsByte<EObjectTypeQuery> > & ObjectTypes, 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 line segment.	—
End	const FVector	End of the line segment.	—
ObjectTypes	const TArray<TEnumAsByte<EObjectTypeQuery>>&	Array of Object Types to trace 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 found along the line.	—
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

Find every pawn and physics body along a line C++

TArray<FHitResult> Hits;
TArray<TEnumAsByte<EObjectTypeQuery>> ObjectTypes;
ObjectTypes.Add(UEngineTypes::ConvertToObjectType(ECC_Pawn));
ObjectTypes.Add(UEngineTypes::ConvertToObjectType(ECC_PhysicsBody));

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

const FVector Start = GetActorLocation();
const FVector End = Start + GetActorForwardVector() * 1000.f;

bool bHit = UKismetSystemLibrary::LineTraceMultiForObjects(this, Start, End, ObjectTypes, false, ActorsToIgnore, EDrawDebugTrace::ForDuration, Hits, true);

Version History

Introduced in: 4.0

Version	Status	Notes
5.6	stable	—

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