UKismetMathLibrary::Vector_MirrorByPlane
#include "Kismet/KismetMathLibrary.h"
Access: public
Specifiers: staticBlueprintPure
Description
Mirrors a vector (as a position) across a plane. Unlike MirrorVectorByNormal, this accounts for the plane's offset from the origin via the W component of FPlane.
Caveats & Gotchas
- • FPlane stores its normal in X/Y/Z and its distance from origin in W. Forgetting to set W=0 when you mean to mirror across a plane through the origin will introduce an unexpected translation in the result.
- • This mirrors the vector as a *point* relative to the plane, not just its direction. If you only want to reflect a direction about a normal (ignoring the plane's position), use GetReflectionVector instead.
Signature
static UE_INL_API FVector Vector_MirrorByPlane(FVector A, const FPlane& InPlane);Parameters
| Name | Type | Description | Default |
|---|---|---|---|
| A | FVector | The vector (treated as a point) to mirror. | — |
| InPlane | const FPlane& | The plane to mirror across, defined by a normal and a W offset. | — |
Return Type
FVector Example
Mirror a spawn point across the ground plane C++
// Plane at Z=0 facing up (W=0 means through origin)
FPlane GroundPlane(FVector::UpVector, 0.f);
FVector Mirrored = UKismetMathLibrary::Vector_MirrorByPlane(SpawnPos, GroundPlane);
// Mirrored.Z = -SpawnPos.ZTags
Version History
Introduced in: 4.0
| Version | Status | Notes |
|---|---|---|
| 5.6 | stable | — |
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