UKismetMathLibrary::Vector4_IsUnit3

function Engine Blueprint Since 4.0

#include "Kismet/KismetMathLibrary.h"

Access: public Specifiers: staticBlueprintPure

Description

Returns true if the XYZ components of the vector have a squared length within SquaredLenthTolerance of 1.0, ignoring W. Use this as a fast unit-length guard before operations that require a normalized direction.

Caveats & Gotchas

• Note the typo in the parameter name — 'SquaredLenthTolerance' (missing 'g') matches the actual C++ declaration; don't be surprised if autocompletion shows the misspelled name.
• W is not tested; a vector with W far from 0 or 1 can still pass this check, so it does not validate homogeneous coordinate conventions.

Signature

static UE_INL_API bool Vector4_IsUnit3(const FVector4& A, float SquaredLenthTolerance = 1.e-4f);

Parameters

Name	Type	Description	Default
A	const FVector4&	The vector to test.	—
SquaredLenthTolerance	float	Allowed deviation from 1.0 in squared length. Default 1e-4.	1.e-4f

Return Type

bool

Example

Assert direction is normalized before use C++

FVector4 Dir = GetSomeDirection();
ensure(UKismetMathLibrary::Vector4_IsUnit3(Dir));
// Safe to use Dir as a unit direction

Version History

Introduced in: 4.0

Version	Status	Notes
5.6	stable	—

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