# Quat¶

Quaternion.

## Description¶

A unit quaternion used for representing 3D rotations.

It is similar to Basis, which implements matrix representation of rotations, and can be parametrized using both an axis-angle pair or Euler angles. But due to its compactness and the way it is stored in memory, certain operations (obtaining axis-angle and performing SLERP, in particular) are more efficient and robust against floating-point errors.

Quaternions need to be (re)normalized.

## Properties¶

 float w `1.0` float x `0.0` float y `0.0` float z `0.0`

## Methods¶

 Quat Quat ( Basis from ) Quat Quat ( Vector3 euler ) Quat Quat ( Vector3 axis, float angle ) Quat Quat ( float x, float y, float z, float w ) Quat cubic_slerp ( Quat b, Quat pre_a, Quat post_b, float t ) float dot ( Quat b ) Vector3 Quat inverse ( ) bool is_equal_approx ( Quat quat ) bool float length ( ) float Quat void set_axis_angle ( Vector3 axis, float angle ) void set_euler ( Vector3 euler ) Quat slerp ( Quat b, float t ) Quat slerpni ( Quat b, float t ) Vector3 xform ( Vector3 v )

## Constants¶

• IDENTITY = Quat( 0, 0, 0, 1 ) --- The identity rotation. Equivalent to an identity matrix. If a vector is transformed by an identity quaternion, it will not change.

## Property Descriptions¶

 Default `1.0`

W component of the quaternion.

 Default `0.0`

X component of the quaternion.

 Default `0.0`

Y component of the quaternion.

 Default `0.0`

Z component of the quaternion.

## Method Descriptions¶

Returns the rotation matrix corresponding to the given quaternion.

Returns a quaternion that will perform a rotation specified by Euler angles (in the YXZ convention: first Z, then X, and Y last), given in the vector format as (X angle, Y angle, Z angle).

Returns a quaternion that will rotate around the given axis by the specified angle. The axis must be a normalized vector.

Returns a quaternion defined by these values.

Performs a cubic spherical-linear interpolation with another quaternion.

Returns the dot product of two quaternions.

Returns Euler angles (in the YXZ convention: first Z, then X, and Y last) corresponding to the rotation represented by the unit quaternion. Returned vector contains the rotation angles in the format (X angle, Y angle, Z angle).

Returns the inverse of the quaternion.

Returns `true` if this quaterion and `quat` are approximately equal, by running @GDScript.is_equal_approx on each component.

• bool is_normalized ( )

Returns whether the quaternion is normalized or not.

Returns the length of the quaternion.

• float length_squared ( )

Returns the length of the quaternion, squared.

• Quat normalized ( )

Returns a copy of the quaternion, normalized to unit length.

Sets the quaternion to a rotation which rotates around axis by the specified angle, in radians. The axis must be a normalized vector.

Sets the quaternion to a rotation specified by Euler angles (in the YXZ convention: first Z, then X, and Y last), given in the vector format as (X angle, Y angle, Z angle).

Performs a spherical-linear interpolation with another quaternion.

Performs a spherical-linear interpolation with another quaterion without checking if the rotation path is not bigger than 90°.

Transforms the vector `v` by this quaternion.