This section covers essential math operations available in Unreal Engine 5's C++ environment, primarily utilizing the KismetMathLibrary and FMath classes. These functions are crucial for game logic, physics calculations, and general programming tasks within UE5.

Integer Comparison: Min and Max

Determine the smaller or larger of two integer values.

Min (Int)

#include "Kismet/KismetMathLibrary.h"

int32 A;
int32 B;

int32 Min = UKismetMathLibrary::Min(A, B);

Max (Int)

#include "Kismet/KismetMathLibrary.h"

int32 A;
int32 B;

int32 Max = UKismetMathLibrary::Max(A, B);

Floating-Point Comparison: Min and Max

Find the minimum or maximum value between two floating-point numbers.

Min (Float)

#include "Kismet/KismetMathLibrary.h"

float A;
float B;

float Min = UKismetMathLibrary::FMin(A, B);

Max (Float)

#include "Kismet/KismetMathLibrary.h"

float A;
float B;

float Max = UKismetMathLibrary::FMax(A, B);

Rounding and Absolute Value

Operations for rounding numbers and finding their absolute magnitude.

Ceil

Rounds a float up to the nearest integer.

float A;

int32 Result = FMath::CeilToInt(A);

Floor

Rounds a float down to the nearest integer.

float A;

int32 Result = FMath::FloorToInt(A);

Absolute

Returns the absolute value of an integer or float.

int32 A;
int32 Result1 = FMath::Abs(A);

float B;
float Result2 = FMath::Abs(B);

Value Clamping and Interpolation

Constrain values within a range and smoothly transition between them.

Clamp

Constrains a value to be within a specified minimum and maximum range.

float A;
float Min;
float Max;

float Result = FMath::Clamp(A, Min, Max);

Lerp (Linear Interpolation)

Linearly interpolates between two floats based on an alpha value.

float A;
float B;
float Alpha;

float Result = FMath::Lerp(A, B, Alpha);

Nearly Equal

Checks if two float values are approximately equal within a given tolerance.

float A;
float B;
float ErrorTolerance;

bool Result = FMath::IsNearlyEqual(A, B, ErrorTolerance);

Vector and Rotator Operations

Creating, breaking, and manipulating vectors and rotators.

Make Vector

Constructs a new FVector from X, Y, and Z components.

float X;
float Y;
float Z;

FVector ExampleVector(X, Y, Z);

Make Rotator

Creates a new FRotator from Pitch, Yaw, and Roll values.

float Pitch;
float Yaw;
float Roll;

FRotator ExampleRotator(Pitch, Yaw, Roll);

Break Vector

Access the individual X, Y, and Z components of an FVector.

You can simply access each variable of a FVector by using .X, .Y and .Z.

FVector ExampleVector;

ExampleVector.X;     // X
ExampleVector.Y;     // Y
ExampleVector.Z;     // Z

Break Rotator

Retrieve the Pitch, Yaw, and Roll components from an FRotator.

You can simply access each variable of a FRotator by using .Pitch, .Yaw and .Roll.

FRotator ExampleRotator;

ExampleRotator.Pitch;    // Pitch
ExampleRotator.Yaw;      // Yaw
ExampleRotator.Roll;     // Roll

Vector Length

Calculate the magnitude (length) of a vector.

FVector ExampleVector;

ExampleVector.Size();

Distance (Vector)

Compute the Euclidean distance between two points represented by vectors.

FVector A;
FVector B;

FVector::Distance(A, B);

Normalize (Vector)

Adjust a vector to have a magnitude of 1 while retaining its direction.

FVector ExampleVector;

float Tolerance;

// Normalizes the vector in-place
ExampleVector.Normalize(Tolerance);

Interpolation Functions

Smoothly interpolate between values over time.

FInterp To

Linearly interpolates a float value towards a target value.

float Current;
float Target;
float DeltaTime;
float InterpSpeed;

float Result = FMath::FInterpTo(Current, Target, DeltaTime, InterpSpeed);

VInterp To

Linearly interpolates a vector towards a target vector.

FVector Current;
FVector Target;
float DeltaTime;
float InterpSpeed;

FVector Result = FMath::VInterpTo(Current, Target, DeltaTime, InterpSpeed);

RInterp To

Linearly interpolates a rotator towards a target rotator.

FRotator Current;
FRotator Target;
float DeltaTime;
float InterpSpeed;

FRotator Result = FMath::RInterpTo(Current, Target, DeltaTime, InterpSpeed);

Orientation and Direction

Calculate rotations based on spatial relationships.

Find Look at Rotation

Determines the rotation needed to look from a start point towards a target point.

#include "Kismet/KismetMathLibrary.h"

FVector Start;
FVector Target;

FRotator Result = UKismetMathLibrary::FindLookAtRotation(Start, Target);

Random Number Generation

Generate random integers and floats within specified ranges.

Random Integer

Generates a random integer between 0 and the specified maximum value (inclusive).

#include "Kismet/KismetMathLibrary.h"

int32 Max;

int32 Result = UKismetMathLibrary::RandomInteger(Max);

Random Float

Generates a random float between 0.0 and 1.0.

#include "Kismet/KismetMathLibrary.h"

float Result = UKismetMathLibrary::RandomFloat();

Random Integer in Range

Generates a random integer within a specified minimum and maximum range (inclusive).

#include "Kismet/KismetMathLibrary.h"

int32 Min;
int32 Max;

int32 Result = UKismetMathLibrary::RandomIntegerInRange(Min, Max);

Random Float in Range

Generates a random float within a specified minimum and maximum range.

#include "Kismet/KismetMathLibrary.h"

float Min;
float Max;

float Result = UKismetMathLibrary::RandomFloatInRange(Min, Max);

Further Resources

• Unreal Engine FMath Documentation
• Unreal Engine UKismetMathLibrary Documentation
• MDN Web Docs - Math Object (for conceptual understanding)