Legacy Documentation: Version 4.3.0
QuaternionNamespace: UnityEngine
Description

Quaternions are used to represent rotations.

They are compact, don't suffer from gimbal lock and can easily be interpolated. Unity internally uses Quaternions to represent all rotations.

Tthey are based on complex numbers and are not easy to understand intuitively. You almost never access or modify individual Quaternion components (x,y,z,w); most often you would just take existing rotations (e.g. from the Transform) and use them to construct new rotations (e.g. to smoothly interpolate between two rotations). The Quaternion functions that you use 99% of the time are: Quaternion.LookRotation, Quaternion.Angle, Quaternion.Euler, Quaternion.Slerp, Quaternion.FromToRotation, and Quaternion.identity. (The other functions are only for exotic uses.)

You can use the Quaternion.operator * to rotate one rotation by another, or to rotate a vector by a rotation.
Static Variables
identity The identity rotation (Read Only). This quaternion corresponds to "no rotation": the object.
Variables
eulerAngles Returns the euler angle representation of the rotation.
this[int] Access the x, y, z, w components using [0], [1], [2], [3] respectively.
w W component of the Quaternion. Don't modify this directly unless you know quaternions inside out.
x X component of the Quaternion. Don't modify this directly unless you know quaternions inside out.
y Y component of the Quaternion. Don't modify this directly unless you know quaternions inside out.
z Z component of the Quaternion. Don't modify this directly unless you know quaternions inside out.
Constructors
Quaternion Constructs new Quaternion with given x,y,z,w components.
Functions
Equals
GetHashCode
Set Set x, y, z and w components of an existing Quaternion.
SetFromToRotation Creates a rotation which rotates from fromDirection to toDirection.
SetLookRotation Creates a rotation with the specified forward and upwards directions.
ToAngleAxis Converts a rotation to angle-axis representation.
ToString Returns a nicely formatted string of the Quaternion.
Static Functions
Angle Returns the angle in degrees between two rotations a and b.
AngleAxis Creates a rotation which rotates angle degrees around axis.
Dot The dot product between two rotations.
Euler Returns a rotation that rotates z degrees around the z axis, x degrees around the x axis, and y degrees around the y axis (in that order).
FromToRotation Creates a rotation which rotates from fromDirection to toDirection.
Inverse Returns the Inverse of rotation.
Lerp Interpolates between from and to by t and normalizes the result afterwards.
LookRotation Creates a rotation with the specified forward and upwards directions.
RotateTowards Rotates a rotation from towards to.
Slerp Spherically interpolates between from and to by t.
Operators
operator != Are two quaternions different from each other?
operator * Combines rotations lhs and rhs.
operator == Are two quaternions equal to each other?