Quaternion
Quaternions are used to represent rotations.
Read time 3 minutesLast updated 4 days ago
Definition
- Type: Struct
- Namespace: UnityEngine
- Assembly: UnityEngine.CoreModule
- Implements: IEquatable<Quaternion>, IFormattable
public struct Quaternion : IEquatable<Quaternion>, IFormattable
Remarks
A quaternion is a four-tuple of real numbers {x,y,z,w}. A quaternion is a mathematically convenient alternative to the euler angle representation. You can interpolate a quaternion without experiencing gimbal lock. You can also use a quaternion to concatenate a series of rotations into a single representation.
Unity internally uses Quaternions to represent all rotations.
In most cases, you can use existing rotations from methods such as Transform.localRotation or Transform.rotation to construct new rotations. For example, use existing rotations to smoothly interpolate between two rotations. The most used Quaternion functions are as follows: Quaternion.LookRotation, Quaternion.Angle, Quaternion.Euler, Quaternion.Slerp, Quaternion.FromToRotation, and Quaternion.identity.
You can use the Quaternion.operator * to rotate one rotation by another, or to rotate a vector by a rotation.
Note that Unity expects Quaternions to be normalized.
Fields
Value | Description |
|---|---|
| w | W component of the Quaternion. Do not directly modify quaternions. |
| 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
Constructor | Description |
|---|---|
| Quaternion(System.Single,System.Single,System.Single,System.Single) | Constructs new Quaternion with given x,y,z,w components. |
Properties
Property | Description |
|---|---|
| eulerAngles | Returns or sets the euler angle representation of the rotation in degrees. |
| this[] | Access the x, y, z, w components using [0], [1], [2], [3] respectively. |
| normalized | Returns this quaternion with a magnitude of 1 (Read Only). |
Static Properties
Property | Description |
|---|---|
| identity | The identity rotation (Read Only). |
Methods
Method | Description |
|---|---|
| Equals | Performs exact binary comparison of each Quaternion component (x, y, z, w). |
| Normalize | Converts this quaternion to a quaternion with the same orientation but with a magnitude of 1.0. |
| 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 formatted string for this quaternion. |
Static Methods
Method | Description |
|---|---|
| Angle | Returns the angle in degrees between two rotations a and b. The resulting angle ranges from 0 to 180. |
| AngleAxis | Creates a rotation which rotates |
| Dot | The dot product between two rotations. |
| Euler | Converts an input Euler angle rotation specified as three floats to a Quaternion. |
| FromToRotation | Creates a rotation from fromDirection to toDirection. |
| Inverse | Returns the Inverse of rotation. |
| Lerp | Interpolates between a and b by t and normalizes the result afterwards. |
| LerpUnclamped | Interpolates between a and b by t and normalizes the result afterwards. The parameter t is not clamped. |
| LookRotation | Creates a rotation with the specified |
| Normalize | Converts this quaternion to a quaternion with the same orientation but with a magnitude of 1.0. |
| RotateTowards | Rotates a rotation from towards to. |
| Slerp | Spherically linear interpolates between unit quaternions a and b by a ratio of t. |
| SlerpUnclamped | Spherically linear interpolates between unit quaternions a and b by t. |
Operators
Operator | Description |
|---|---|
| operator == | Are two quaternions equal to each other? |
| operator * | Combines rotations lhs and rhs. |