UKismetMathLibrary::Matrix_TransformVector

function Engine Blueprint Since 4.0

#include "Kismet/KismetMathLibrary.h"

Access: public Specifiers: staticBlueprintPure

Description

Transforms a direction vector by the matrix without applying the translation component. Use for normals, velocity directions, and axes — not for positions.

Caveats & Gotchas

• Translation is ignored (W=0 implicit). If you accidentally call this on a position instead of a direction, the result will be missing the translation offset — use Matrix_TransformPosition for points.
• The return type is FVector4. The W component of the result should be 0 for a pure transform matrix, but callers should not rely on this for projection matrices. Extract XYZ explicitly.

Signature

static UE_INL_API FVector4 Matrix_TransformVector(const FMatrix& M, FVector V)

Parameters

Name	Type	Description	Default
M	const FMatrix&	The transform matrix.	—
V	FVector	The direction vector to transform. Translation is not applied.	—

Return Type

FVector4

Example

Rotate a velocity vector into world space C++

FVector LocalVelocity(0.f, 200.f, 0.f);
FMatrix LocalToWorld = Actor->GetActorTransform().ToMatrixWithScale();
FVector4 WorldVel4 = UKismetMathLibrary::Matrix_TransformVector(LocalToWorld, LocalVelocity);
FVector WorldVelocity(WorldVel4.X, WorldVel4.Y, WorldVel4.Z);

Version History

Introduced in: 4.0

Version	Status	Notes
5.6	stable	—

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