UKismetMathLibrary::LinearColor_Distance

function Engine Blueprint Since 4.0

#include "Kismet/KismetMathLibrary.h"

Access: public Specifiers: staticUFUNCTIONBlueprintPure

Description

Computes the Euclidean distance between two linear colors treated as 4D vectors (R, G, B, A). Useful for threshold checks like "are these colors similar enough?".

Caveats & Gotchas

• Operates in linear (HDR) color space — colors with values outside [0,1] are valid inputs and will produce distances greater than sqrt(4).
• The alpha channel is included in the distance calculation, so two colors that differ only in opacity will still have a non-zero distance.

Signature

static UE_INL_API float LinearColor_Distance(FLinearColor C1, FLinearColor C2);

Parameters

Name	Type	Description	Default
C1	FLinearColor	First color point.	—
C2	FLinearColor	Second color point.	—

Return Type

float

Example

Check if two colors are perceptually close C++

FLinearColor A = FLinearColor(1.f, 0.f, 0.f, 1.f);
FLinearColor B = FLinearColor(0.9f, 0.05f, 0.05f, 1.f);
float Dist = UKismetMathLibrary::LinearColor_Distance(A, B);
if (Dist < 0.2f)
{
    // Colors are close enough
}

Version History

Introduced in: 4.0

Version	Status	Notes
5.6	stable	—

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