UKismetMathLibrary::EqualEqual_QuatQuat

function Engine Blueprint Since 4.0

#include "Kismet/KismetMathLibrary.h"

Access: public Specifiers: staticBlueprintPure

Description

Returns true if two quaternions are equal within a per-component tolerance. Maps to the == operator in Blueprints.

Caveats & Gotchas

• Two quaternions that represent the same rotation can have opposite signs (Q and -Q are equivalent rotations) — this function compares components directly, so Q != -Q even though they rotate identically. Normalize and check both cases if rotation-equivalence matters.
• The default tolerance of 1e-4 compares components, not angular difference — use Quat_AngularDistance for rotation-based comparison.

Signature

static UE_INL_API bool EqualEqual_QuatQuat(const FQuat& A, const FQuat& B, float Tolerance = 1.e-4f)

Parameters

Name	Type	Description	Default
A	const FQuat&	First quaternion to compare.	—
B	const FQuat&	Second quaternion to compare.	—
Tolerance	float	Maximum per-component absolute difference allowed for equality.	1.e-4f

Return Type

bool

Example

Compare two quaternions with default tolerance C++

FQuat A = FRotator(0, 90, 0).Quaternion();
FQuat B = FRotator(0, 90, 0).Quaternion();
bool bSame = UKismetMathLibrary::EqualEqual_QuatQuat(A, B);
// bSame == true

Version History

Introduced in: 4.0

Version	Status	Notes
5.6	stable	—

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