UKismetMathLibrary::Matrix_TransformVector4
#include "Kismet/KismetMathLibrary.h"
Access: public
Specifiers: staticBlueprintPure
Description
Transforms a homogeneous FVector4 by the full 4x4 matrix. The W component of the input vector participates in the multiply, so translation is applied only when W=1.
Caveats & Gotchas
- • Setting V.W = 0 transforms a direction vector (translation is ignored); setting V.W = 1 transforms a position. Mixing up W values is a common source of incorrect translation application.
- • The result is an untransformed FVector4 — no perspective divide is performed. For projection matrices you must divide XYZ by the resulting W yourself.
Signature
static UE_INL_API FVector4 Matrix_TransformVector4(const FMatrix& M, FVector4 V)Parameters
| Name | Type | Description | Default |
|---|---|---|---|
| M | const FMatrix& | The matrix to transform with. | — |
| V | FVector4 | The homogeneous 4D vector to transform. | — |
Return Type
FVector4 Example
Transform a homogeneous position through a projection matrix C++
FVector4 ClipSpacePos = UKismetMathLibrary::Matrix_TransformVector4(ProjectionMatrix, FVector4(WorldPos, 1.0f));
// Perspective divide to get NDC
FVector NDC(ClipSpacePos.X / ClipSpacePos.W, ClipSpacePos.Y / ClipSpacePos.W, ClipSpacePos.Z / ClipSpacePos.W);Tags
Version History
Introduced in: 4.0
| Version | Status | Notes |
|---|---|---|
| 5.6 | stable | — |
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