UKismetMathLibrary::RandomUnitVectorInConeInRadians

function Engine Blueprint Since 4.0

#include "Kismet/KismetMathLibrary.h"

Access: public Specifiers: staticUFUNCTIONBlueprintPure

Description

Returns a random unit vector within a symmetric cone around ConeDir, with uniform distribution on the sphere surface inside the cone.

Caveats & Gotchas

• ConeHalfAngleInRadians should be in [0, PI]; values outside this range produce undefined behavior. For full-sphere scatter, use RandomUnitVector directly.
• Not thread-safe (NotBlueprintThreadSafe); uses the global FMath random state. For deterministic results, use a seeded FRandomStream.

Signature

static UE_INL_API FVector RandomUnitVectorInConeInRadians(FVector ConeDir, float ConeHalfAngleInRadians);

Parameters

Name	Type	Description	Default
ConeDir	FVector	Center direction of the cone.	—
ConeHalfAngleInRadians	float	Half-angle of the cone from its axis to its edge, in radians.	—

Return Type

FVector

Example

Randomize bullet spread within a 5-degree half-angle C++

FVector AimDir = GetActorForwardVector();
float HalfAngle = FMath::DegreesToRadians(5.f);
FVector BulletDir = UKismetMathLibrary::RandomUnitVectorInConeInRadians(AimDir, HalfAngle);
SpawnProjectile(GetActorLocation(), BulletDir);

Version History

Introduced in: 4.0

Version	Status	Notes
5.6	stable	—

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