UKismetMathLibrary::Vector4_IsNearlyZero3
#include "Kismet/KismetMathLibrary.h"
Access: public
Specifiers: staticUFUNCTIONBlueprintPure
Description
Returns true if all XYZ components of A are within Tolerance of zero. The W component is not tested. Useful for checking whether a 3D direction vector has degenerated to near-zero before normalizing it.
Caveats & Gotchas
- • W is completely ignored. A vector with a large W component but tiny XYZ will still return true. This can mislead if you are treating W as meaningful (e.g., homogeneous weight).
- • The check is per-component, not on the length: FMath::Abs(X) < Tolerance AND FMath::Abs(Y) < Tolerance AND FMath::Abs(Z) < Tolerance. A vector like (0.0009, 0.0009, 0.0009) with Tolerance=0.001 passes even though its length (~0.00156) is larger than Tolerance.
Signature
static UE_INL_API bool Vector4_IsNearlyZero3(const FVector4& A, float Tolerance = 1.e-4f)Parameters
| Name | Type | Description | Default |
|---|---|---|---|
| A | const FVector4& | The vector to check. | — |
| Tolerance | float | Maximum absolute value each XYZ component may have and still be considered zero. | 1.e-4f |
Return Type
bool Example
Guard normalization to prevent divide-by-zero C++
FVector4 Dir = SomeComputedDirection();
if (!UKismetMathLibrary::Vector4_IsNearlyZero3(Dir))
{
Dir = Dir / UKismetMathLibrary::Vector4_Size3(Dir);
}Version History
Introduced in: 4.0
| Version | Status | Notes |
|---|---|---|
| 5.6 | stable | — |
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