UKismetMathLibrary::Atan

function Engine Blueprint Since 4.0

#include "Kismet/KismetMathLibrary.h"

Access: public Specifiers: staticUFUNCTIONBlueprintPure

Description

Returns the inverse tangent (arc tangent) of A in radians, in the range (-π/2, π/2). For converting a 2D direction to an angle use Atan2 instead.

Caveats & Gotchas

• Atan only handles a single ratio and cannot distinguish the full 360° range — use Atan2(Y, X) when you need a quadrant-aware angle from a 2D direction vector.
• Result is in radians; use RadiansToDegrees to convert if your downstream code expects degrees.

Signature

static UE_INL_API double Atan(double A);

Parameters

Name	Type	Description	Default
A	double	The value to compute the arc tangent of.	—

Return Type

double

Example

Angle from a slope ratio C++

double Rise = 1.0, Run = 1.0;
double AngleRad = UKismetMathLibrary::Atan(Rise / Run); // π/4 ≈ 0.785 rad
double AngleDeg = UKismetMathLibrary::RadiansToDegrees(AngleRad); // 45.0

Version History

Introduced in: 4.0

Version	Status	Notes
5.6	stable	—

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