UKismetMathLibrary::FInterpTo

function Engine Blueprint Since 4.0

#include "Kismet/KismetMathLibrary.h"

Access: public Specifiers: staticUFUNCTIONBlueprintPure

Description

Smoothly interpolates a float value from Current toward Target at a rate proportional to the remaining distance, producing an exponential ease-out feel each tick. This is the scalar counterpart of VInterpTo and RInterpTo.

Caveats & Gotchas

• Must be called every frame with that frame's DeltaTime; calling it once does not converge on Target because the step size depends on elapsed time.
• An InterpSpeed of 0 snaps immediately to Target rather than leaving the value unchanged, which trips people up when they intend 0 to mean "disabled".
• Never lands exactly on Target — add an explicit distance check (e.g. FMath::IsNearlyEqual) if you need to know when interpolation has effectively finished.

Signature

static double FInterpTo(double Current, double Target, double DeltaTime, double InterpSpeed)

Parameters

Name	Type	Description	Default
Current	double	The actual value this tick.	—
Target	double	The value being tracked.	—
DeltaTime	double	Time since the last update, typically the frame's delta time.	—
InterpSpeed	double	Interpolation speed; a value of 0 jumps straight to Target.	—

Return Type

double

Example

Smoothly track a target zoom value each tick C++

void AMyCamera::Tick(float DeltaTime)
{
    Super::Tick(DeltaTime);
    CurrentFOV = UKismetMathLibrary::FInterpTo(CurrentFOV, TargetFOV, DeltaTime, 8.0);
    CameraComponent->SetFieldOfView(CurrentFOV);
}

Version History

Introduced in: 4.0

Version	Status	Notes
5.6	stable	—

Feedback

Was this helpful?