1. Epic GamesDeveloper
  3. TQuat

TQuat

Floating point quaternion that can represent a rotation about an axis in 3-D space.

Unreal Engine C++ API Reference > Runtime > Core > Math

Inheritance Hierarchy

References

   
Module Core
Header /Engine/Source/Runtime/Core/Public/Math/MathFwd.h
Include #include "Math/MathFwd.h"

Syntax

template<typename T>  
struct TQuat

Remarks

Floating point quaternion that can represent a rotation about an axis in 3-D space. The X, Y, Z, W components also double as the Axis/Angle format.

Order matters when composing quaternions: C = A * B will yield a quaternion C that logically first applies B then A to any subsequent transformation (right first, then left). Note that this is the opposite order of FTransform multiplication.

Example: LocalToWorld = (LocalToWorld * DeltaRotation) will change rotation in local space by DeltaRotation. Example: LocalToWorld = (DeltaRotation * LocalToWorld) will change rotation in world space by DeltaRotation.

Variables

  Type Name Description
Public variable T W The quaternion's W-component.
Public variable T X The quaternion's X-component.
Public variable T Y The quaternion's Y-component.
Public variable T Z The quaternion's Z-component.

Constructors

  Type Name Description
Public function  

TQuat ()

 Default constructor (no initialization).
Public function  

TQuat ( EForceInit
)

 Creates and initializes a new quaternion, with the W component either 0 or 1.
Public function  

TQuat ( T V
)

 Initializes all elements to V
Public function  

TQuat ( const TRotator< T >& R
)

 Creates and initializes a new quaternion from the given rotator.
Public function  

TQuat ( const TMatrix< T >& M
)

 Creates and initializes a new quaternion from the given matrix.
Public function  

TQuat ( const TQuat< FArg >& From
)

 Conversion to other type.
Protected function  

TQuat ( const QuatVectorRegister& V
)

 Creates and initializes a new quaternion from the XYZW values in the given VectorRegister4Float.
Public function  

TQuat ( TVector< T > Axis,
T AngleRad
)

 Creates and initializes a new quaternion from the a rotation around the given axis.
Public function  

TQuat ( T InX,
T InY,
T InZ,
T InW
)

 Constructor.

Functions

  Type Name Description
Public function Const T

AngularDistance ( const TQuat< T >& Q
)

 Find the angular distance between two rotation quaternions (in radians)
Public function Static void

CalcTangents ( const TQuat< T >& PrevP,
const TQuat< T >& P,
const TQuat< T >& NextP,
T Tension,
TQuat< T >& OutTan
)

 Calculate tangents between given points
Public function Const bool Utility to check if there are any non-finite values (NaN or Inf) in this Quat.
Public function Const void

DiagnosticCheckNaN ( const TCHAR* Message
)

  
Public function Const void  
Public function void

EnforceShortestArcWith ( const TQuat< T >& OtherQuat
)

 Enforce that the delta between this Quaternion and another one represents the shortest possible rotation angle
Public function Const bool

Equals ( const TQuat< T >& Q,
T Tolerance
)

 Checks whether another Quaternion is equal to this, within specified tolerance.
Public function Static T

Error ( const TQuat< T >& Q1,
const TQuat< T >& Q2
)

 Error measure (angle) between two quaternions, ranged [0..1].
Public function Static T

ErrorAutoNormalize ( const TQuat< T >& A,
const TQuat< T >& B
)

 TQuat::Error with auto-normalization.
Public function Const TVector< T >

Euler ()

 Convert a Quaternion into floating-point Euler angles (in degrees).
Public function Const TQuat< T >

Exp ()

 Exp should really only be used after Log.
Public function Static TQuat< T >

FastBilerp ( const TQuat< T >& P00,
const TQuat< T >& P10,
const TQuat< T >& P01,
const TQuat< T >& P11,
T FracX,
T FracY
)

 Bi-Linear Quaternion interpolation. Result is NOT normalized.
Public function Static TQuat< T >

FastLerp ( const TQuat< T >& A,
const TQuat< T >& B,
const T Alpha
)

 Fast Linear Quaternion Interpolation. Result is NOT normalized.
Public function Static TQuat< T >

FindBetween ( const TVector< T >& Vector1,
const TVector< T >& Vector2
)

 Generates the 'smallest' (geodesic) rotation between two vectors of arbitrary length.
Public function Static TQuat< T >

FindBetweenNormals ( const TVector< T >& Normal1,
const TVector< T >& Normal2
)

 Generates the 'smallest' (geodesic) rotation between two normals (assumed to be unit length).
Public function Static TQuat< T >

FindBetweenVectors ( const TVector< T >& Vector1,
const TVector< T >& Vector2
)

 Generates the 'smallest' (geodesic) rotation between two vectors of arbitrary length.
Public function Const T Get the angle in radians of this quaternion
Public function Const TVector< T > Get the forward direction (X axis) after it has been rotated by this Quaternion.
Public function Const TVector< T > Get the right direction (Y axis) after it has been rotated by this Quaternion.
Public function Const TVector< T > Get the up direction (Z axis) after it has been rotated by this Quaternion.
Public function Const TVector< T > Get the forward direction (X axis) after it has been rotated by this Quaternion.
Public function Const TQuat< T >

GetNormalized ( T Tolerance
)

 Get a normalized copy of this quaternion. If it is too small, returns an identity quaternion.
Public function Const TVector< T > Get the right direction (Y axis) after it has been rotated by this Quaternion.
Public function Const TVector< T > Get the axis of rotation of the Quaternion.
Public function Const T

GetTwistAngle ( const TVector< T >& TwistAxis
)

 Get the twist angle (in radians) for a specified axis
Public function Const TVector< T > Get the up direction (Z axis) after it has been rotated by this Quaternion.
Public function Const bool

Identical ( const TQuat* Q,
const uint32 PortFlags
)

 Identical implementation for TQuat properties.
Public function bool

InitFromString ( const FString& InSourceString
)

 Initialize this TQuat from a FString.
Public function Const TQuat< T >

Inverse ()

 : Requires this quaternion to be normalized.
Public function Const bool

IsIdentity ( T Tolerance
)

 Checks whether this Quaternion is an Identity Quaternion. Assumes Quaternion tested is normalized.
Public function Const bool Return true if this quaternion is normalized.
Public function Const TQuat< T >

Log ()

  
Public function Static TQuat< T >

MakeFromEuler ( const TVector< T >& Euler
)

 Convert a vector of floating-point Euler angles (in degrees) into a Quaternion.
Public function Static TQuat< T >

MakeFromRotationVector ( const TVector< T >& RotationVector
)

 Constructs a quaternion corresponding to the rotation vector.
Public function Static TQuat< T >

MakeFromRotator ( const TRotator< T >& R
)

  
Public function Static TQuat< T >  
Public function bool

NetSerialize ( FArchive& Ar,
UPackageMap* Map,
bool& bOutSuccess
)

 Serializes the vector compressed for e.g. network transmission.
Public function void

Normalize ( T Tolerance
)

 Normalize this quaternion if it is large enough.
Public function Const TVector< T >

RotateVector ( TVector< T > V
)

 Rotate a vector by this quaternion.
Public function Const TRotator< T >

Rotator ()

 Get the TRotator representation of this Quaternion.
Public function bool  
Public function bool  
Public function Const T

Size ()

 Get the length of this quaternion.
Public function Const T Get the length squared of this quaternion.
Public function Static TQuat< T >

Slerp ( const TQuat< T >& Quat1,
const TQuat< T >& Quat2,
T Slerp
)

 Spherical interpolation. Will correct alignment. Result is normalized.
Public function Static TQuat< T >

Slerp_NotNormalized ( const TQuat< T >& Quat1,
const TQuat< T >& Quat2,
T Slerp
)

 Spherical interpolation. Will correct alignment. Result is NOT normalized.
Public function Static TQuat< T >

SlerpFullPath ( const TQuat< T >& quat1,
const TQuat< T >& quat2,
T Alpha
)

 Simpler Slerp that doesn't do any checks for 'shortest distance' etc.
Public function Static TQuat< T >

SlerpFullPath_NotNormalized ( const TQuat< T >& quat1,
const TQuat< T >& quat2,
T Alpha
)

 Simpler Slerp that doesn't do any checks for 'shortest distance' etc.
Public function Static TQuat< T >

Squad ( const TQuat< T >& quat1,
const TQuat< T >& tang1,
const TQuat< T >& quat2,
const TQuat< T >& tang2,
T Alpha
)

 Given start and end quaternions of quat1 and quat2, and tangents at those points tang1 and tang2, calculate the point at Alpha (between 0 and 1) between them.
Public function Static TQuat< T >

SquadFullPath ( const TQuat< T >& quat1,
const TQuat< T >& tang1,
const TQuat< T >& quat2,
const TQuat< T >& tang2,
T Alpha
)

 Simpler Squad that doesn't do any checks for 'shortest distance' etc.
Public function Const void

ToAxisAndAngle ( TVector< T >& Axis,
float& Angle
)

 Get the axis and angle of rotation of this quaternion
Public function Const void

ToAxisAndAngle ( TVector< T >& Axis,
double& Angle
)

 Get the axis and angle of rotation of this quaternion
Public function Const void

ToMatrix ( TMatrix< T >& Mat
)

 Get the TMatrix representation of this Quaternion and store it in Mat
Public function Const TMatrix< T > Get the TMatrix representation of this Quaternion.
Public function Const TVector< T > Get the rotation vector corresponding to this quaternion.
Public function Const FString Get a textual representation of the vector.
Public function Const void

ToSwingTwist ( const TVector< T >& InTwistAxis,
TQuat< T >& OutSwing,
TQuat< T >& OutTwist
)

 Get the swing and twist decomposition for a specified axis
Public function Const TVector< T >

UnrotateVector ( TVector< T > V
)

 Rotate a vector by the inverse of this quaternion.
Public function Const TVector< T >

Vector ()

 Convert a rotation into a unit vector facing in its direction.

Operators

  Type Name Description
Public function Const TQuat< T >

operator- ( const TQuat< T >& Q
)

 Gets the result of subtracting a Quaternion to this.
Public function Const TQuat< T > Negates the quaternion. Note that this represents the same rotation.
Public function Const bool

operator!= ( const TQuat< T >& Q
)

 Checks whether two quaternions are not identical.
Public function Const TQuat< T >

operator* ( const FArg Scale
)

 Get the result of scaling this quaternion.
Public function Const TMatrix< T >

operator* ( const TMatrix< T >& M
)

 Multiply this by a matrix.
Public function Const TVector< T >

operator* ( const TVector< T >& V
)

 Rotate a vector by this quaternion.
Public function Const TQuat< T >

operator* ( const TQuat< T >& Q
)

 Gets the result of multiplying this by another quaternion (this * Q).
Public function TQuat< T >

operator*= ( const FArg Scale
)

 Multiply this quaternion by a scaling factor.
Public function TQuat< T >

operator*= ( const TQuat< T >& Q
)

 Multiply this by a quaternion (this = this * Q).
Public function Const TQuat< T >

operator/ ( const FArg Scale
)

 Divide this quaternion by scale.
Public function TQuat< T >

operator/= ( const FArg Scale
)

 Divide this quaternion by scale.
Public function Const T

operator| ( const TQuat< T >& Q
)

 Calculates dot product of two quaternions.
Public function Const TQuat< T >

operator+ ( const TQuat< T >& Q
)

 Gets the result of adding a Quaternion to this.
Public function TQuat< T >

operator+= ( const TQuat< T >& Q
)

 Adds to this quaternion.
Public function TQuat< T >

operator-= ( const TQuat< T >& Q
)

 Subtracts another quaternion from this.
Public function Const bool

operator== ( const TQuat< T >& Q
)

 Checks whether two quaternions are identical.

Typedefs

Name Description
FReal Can't have a TEMPLATE_REQUIRES in the declaration because of the forward declarations, so check for allowed types here.
QuatVectorRegister  

Constants

Name Description
Identity Identity quaternion.

Ask questions and help your peers Developer Forums

Write your own tutorials or read those from others Learning Library

On this page