UKismetMathLibrary::Matrix_ContainsNaN

function Engine Blueprint Since 4.0

#include "Kismet/KismetMathLibrary.h"

Access: public Specifiers: staticUFUNCTIONBlueprintPure

Description

Returns true if any of the 16 float elements of the matrix is NaN. Use this as a guard before operations that would propagate NaN silently (inverse, rotation extraction, etc.).

Caveats & Gotchas

• Checks for NaN only, not for Inf. A matrix can pass this check and still be degenerate if it contains infinite values — pair with a separate Inf check if the matrix originates from user-supplied or network data.
• In Shipping builds UE may disable some floating-point checks; behaviour of NaN propagation is platform-dependent on consoles with aggressive FP optimisations. Validate at the boundary where data enters the system, not deep inside the simulation.

Signature

static UE_INL_API bool Matrix_ContainsNaN(const FMatrix& M)

Parameters

Name	Type	Description	Default
M	const FMatrix&	The matrix to check for NaN values.	—

Return Type

bool

Example

Guard before matrix inversion C++

FMatrix M = ComputeSomething();
if (UKismetMathLibrary::Matrix_ContainsNaN(M))
{
    UE_LOG(LogTemp, Warning, TEXT("Degenerate matrix detected, skipping inversion"));
    return;
}
FMatrix Inv = UKismetMathLibrary::Matrix_GetInverse(M);

Version History

Introduced in: 4.0

Version	Status	Notes
5.6	stable	—

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