UKismetMathLibrary::VLerp

function Engine Blueprint Since 4.0

#include "Kismet/KismetMathLibrary.h"

Access: public Specifiers: staticBlueprintPure

Description

Linearly interpolates between two vectors based on Alpha. Returns A when Alpha is 0 and B when Alpha is 1.

Caveats & Gotchas

• Alpha is not clamped — passing values outside [0,1] will extrapolate beyond A and B. Wrap in FMath::Clamp(Alpha, 0.f, 1.f) if your source is unbounded.
• VLerp interpolates magnitude as well as direction. If A and B have different lengths the result will not maintain either length. Use spherical linear interpolation (Slerp) if constant arc length across unit vectors is required.

Signature

static UE_INL_API FVector VLerp(FVector A, FVector B, float Alpha);

Parameters

Name	Type	Description	Default
A	FVector	Start vector (returned when Alpha=0).	—
B	FVector	End vector (returned when Alpha=1).	—
Alpha	float	Interpolation factor in [0,1]. Values outside this range extrapolate.	—

Return Type

FVector

Example

Smoothly position an object along a segment C++

float Alpha = FMath::Clamp(ElapsedTime / TotalDuration, 0.f, 1.f);
FVector NewPos = UKismetMathLibrary::VLerp(StartLocation, EndLocation, Alpha);
SetActorLocation(NewPos);

Version History

Introduced in: 4.0

Version	Status	Notes
5.6	stable	—

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