UKismetMathLibrary::RLerp
#include "Kismet/KismetMathLibrary.h"
Access: public
Specifiers: staticUFUNCTIONBlueprintPure
Description
Linearly interpolates between rotators A and B. When bShortestPath is true the interpolation wraps each Euler component to take the shorter arc, avoiding 359°→1° spinning through 180°.
Caveats & Gotchas
- • bShortestPath operates per-component (Pitch, Yaw, Roll independently), not using quaternion SLERP — for rotations with simultaneous Pitch and Yaw changes this can still produce unexpected intermediate paths. Use quaternion SLERP (FQuat::Slerp) when path continuity matters.
- • Alpha is clamped to [0, 1] internally, so passing values outside that range has no effect — use extrapolation via FMath::Lerp directly on components if you need unclamped blending.
Signature
static ENGINE_API FRotator RLerp(FRotator A, FRotator B, float Alpha, bool bShortestPath);Parameters
| Name | Type | Description | Default |
|---|---|---|---|
| A | FRotator | Start rotation (Alpha=0). | — |
| B | FRotator | End rotation (Alpha=1). | — |
| Alpha | float | Blend factor in [0, 1]. | — |
| bShortestPath | bool | If true, interpolates via the shortest angular path for each component. | — |
Return Type
FRotator Example
Smoothly blend camera rotation toward target C++
FRotator NewRot = UKismetMathLibrary::RLerp(
CurrentCameraRot,
DesiredCameraRot,
FMath::Clamp(DeltaTime * BlendSpeed, 0.f, 1.f),
/*bShortestPath=*/true);
CameraComponent->SetWorldRotation(NewRot);Version History
Introduced in: 4.0
| Version | Status | Notes |
|---|---|---|
| 5.6 | stable | — |
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