  Quaternion Manual Reference Scripting
 Scripting > Runtime Classes > Quaternion Quaternion Struct

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.

However, they are based on complex numbers and are not easy to understand intuitively. Thus 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 (The other functions are only for exoctic uses) Quaternion.LookRotation, Quaternion.Angle, Quaternion.Euler, Quaternion.Slerp, Quaternion.FromToRotation, Quaternion.identity

You can use Quaternion.operator * to rotate one rotation by another, or to rotate a vector by a rotation.

Variables
 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. w W component of the Quaternion. Don't modify this directly unless you know quaternions inside out. this [int index] Access the x, y, z, w components using , , ,  respectively. eulerAngles Returns the euler angle representation of the rotation.
Constructors
 Quaternion Constructs new Quaternion with given x,y,z,w components.
Functions
 ToAngleAxis Converts a rotation to angle-axis representation. SetFromToRotation Creates a rotation which rotates from fromDirection to toDirection. SetLookRotation Creates a rotation that looks along forward with the the head upwards along upwards ToString Returns a nicely formatted string of the Quaternion
Class Variables
 identity The identity rotation (Read Only). This quaternion corresponds to "no rotation": the object
Class Functions
 operator * Combines rotations lhs and rhs. operator == Are two quaternions equal to each other? operator != Are two quaternions different from each other? Dot The dot product between two rotations. AngleAxis Creates a rotation which rotates angle degrees around axis. FromToRotation Creates a rotation which rotates from fromDirection to toDirection. LookRotation Creates a rotation that looks along forward with the the head upwards along upwards Slerp Spherically interpolates from towards to by t. Lerp Interpolates from towards to by t and normalizes the result afterwards. Inverse Returns the Inverse of rotation. Angle Returns the angle in degrees between two rotations a and b. 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).