godot-docs/classes/class_quaternion.rst

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.. _class_Quaternion:

Quaternion
==========

A unit quaternion used for representing 3D rotations.

.. rst-class:: classref-introduction-group

Description
-----------

Quaternions are similar to :ref:`Basis<class_Basis>`, which implements the matrix representation of rotations. Unlike :ref:`Basis<class_Basis>`, which stores rotation, scale, and shearing, quaternions only store rotation.

Quaternions can be parametrized using both an axis-angle pair or Euler angles. Due to their compactness and the way they are stored in memory, certain operations (obtaining axis-angle and performing SLERP, in particular) are more efficient and robust against floating-point errors.

\ **Note:** Quaternions need to be normalized before being used for rotation.

.. note::

	There are notable differences when using this API with C#. See :ref:`doc_c_sharp_differences` for more information.

.. rst-class:: classref-introduction-group

Tutorials
---------

- `Using 3D transforms <../tutorials/3d/using_transforms.html#interpolating-with-quaternions>`__

- `Third Person Shooter Demo <https://godotengine.org/asset-library/asset/678>`__

.. rst-class:: classref-reftable-group

Properties
----------

.. table::
   :widths: auto

   +---------------------------+---------------------------------------+---------+
   | :ref:`float<class_float>` | :ref:`w<class_Quaternion_property_w>` | ``1.0`` |
   +---------------------------+---------------------------------------+---------+
   | :ref:`float<class_float>` | :ref:`x<class_Quaternion_property_x>` | ``0.0`` |
   +---------------------------+---------------------------------------+---------+
   | :ref:`float<class_float>` | :ref:`y<class_Quaternion_property_y>` | ``0.0`` |
   +---------------------------+---------------------------------------+---------+
   | :ref:`float<class_float>` | :ref:`z<class_Quaternion_property_z>` | ``0.0`` |
   +---------------------------+---------------------------------------+---------+

.. rst-class:: classref-reftable-group

Constructors
------------

.. table::
   :widths: auto

   +-------------------------------------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | :ref:`Quaternion<class_Quaternion>` | :ref:`Quaternion<class_Quaternion_constructor_Quaternion>` **(** **)**                                                                                                                    |
   +-------------------------------------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | :ref:`Quaternion<class_Quaternion>` | :ref:`Quaternion<class_Quaternion_constructor_Quaternion>` **(** :ref:`Quaternion<class_Quaternion>` from **)**                                                                           |
   +-------------------------------------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | :ref:`Quaternion<class_Quaternion>` | :ref:`Quaternion<class_Quaternion_constructor_Quaternion>` **(** :ref:`Vector3<class_Vector3>` arc_from, :ref:`Vector3<class_Vector3>` arc_to **)**                                       |
   +-------------------------------------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | :ref:`Quaternion<class_Quaternion>` | :ref:`Quaternion<class_Quaternion_constructor_Quaternion>` **(** :ref:`Vector3<class_Vector3>` axis, :ref:`float<class_float>` angle **)**                                                |
   +-------------------------------------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | :ref:`Quaternion<class_Quaternion>` | :ref:`Quaternion<class_Quaternion_constructor_Quaternion>` **(** :ref:`Basis<class_Basis>` from **)**                                                                                     |
   +-------------------------------------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | :ref:`Quaternion<class_Quaternion>` | :ref:`Quaternion<class_Quaternion_constructor_Quaternion>` **(** :ref:`float<class_float>` x, :ref:`float<class_float>` y, :ref:`float<class_float>` z, :ref:`float<class_float>` w **)** |
   +-------------------------------------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+

.. rst-class:: classref-reftable-group

Methods
-------

.. table::
   :widths: auto

   +-------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | :ref:`float<class_float>`           | :ref:`angle_to<class_Quaternion_method_angle_to>` **(** :ref:`Quaternion<class_Quaternion>` to **)** |const|                                                                                                                                                                                                                                                                                     |
   +-------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | :ref:`float<class_float>`           | :ref:`dot<class_Quaternion_method_dot>` **(** :ref:`Quaternion<class_Quaternion>` with **)** |const|                                                                                                                                                                                                                                                                                             |
   +-------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | :ref:`Quaternion<class_Quaternion>` | :ref:`exp<class_Quaternion_method_exp>` **(** **)** |const|                                                                                                                                                                                                                                                                                                                                      |
   +-------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | :ref:`Quaternion<class_Quaternion>` | :ref:`from_euler<class_Quaternion_method_from_euler>` **(** :ref:`Vector3<class_Vector3>` euler **)** |static|                                                                                                                                                                                                                                                                                   |
   +-------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | :ref:`float<class_float>`           | :ref:`get_angle<class_Quaternion_method_get_angle>` **(** **)** |const|                                                                                                                                                                                                                                                                                                                          |
   +-------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | :ref:`Vector3<class_Vector3>`       | :ref:`get_axis<class_Quaternion_method_get_axis>` **(** **)** |const|                                                                                                                                                                                                                                                                                                                            |
   +-------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | :ref:`Vector3<class_Vector3>`       | :ref:`get_euler<class_Quaternion_method_get_euler>` **(** :ref:`int<class_int>` order=2 **)** |const|                                                                                                                                                                                                                                                                                            |
   +-------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | :ref:`Quaternion<class_Quaternion>` | :ref:`inverse<class_Quaternion_method_inverse>` **(** **)** |const|                                                                                                                                                                                                                                                                                                                              |
   +-------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | :ref:`bool<class_bool>`             | :ref:`is_equal_approx<class_Quaternion_method_is_equal_approx>` **(** :ref:`Quaternion<class_Quaternion>` to **)** |const|                                                                                                                                                                                                                                                                       |
   +-------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | :ref:`bool<class_bool>`             | :ref:`is_finite<class_Quaternion_method_is_finite>` **(** **)** |const|                                                                                                                                                                                                                                                                                                                          |
   +-------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | :ref:`bool<class_bool>`             | :ref:`is_normalized<class_Quaternion_method_is_normalized>` **(** **)** |const|                                                                                                                                                                                                                                                                                                                  |
   +-------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | :ref:`float<class_float>`           | :ref:`length<class_Quaternion_method_length>` **(** **)** |const|                                                                                                                                                                                                                                                                                                                                |
   +-------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | :ref:`float<class_float>`           | :ref:`length_squared<class_Quaternion_method_length_squared>` **(** **)** |const|                                                                                                                                                                                                                                                                                                                |
   +-------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | :ref:`Quaternion<class_Quaternion>` | :ref:`log<class_Quaternion_method_log>` **(** **)** |const|                                                                                                                                                                                                                                                                                                                                      |
   +-------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | :ref:`Quaternion<class_Quaternion>` | :ref:`normalized<class_Quaternion_method_normalized>` **(** **)** |const|                                                                                                                                                                                                                                                                                                                        |
   +-------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | :ref:`Quaternion<class_Quaternion>` | :ref:`slerp<class_Quaternion_method_slerp>` **(** :ref:`Quaternion<class_Quaternion>` to, :ref:`float<class_float>` weight **)** |const|                                                                                                                                                                                                                                                         |
   +-------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | :ref:`Quaternion<class_Quaternion>` | :ref:`slerpni<class_Quaternion_method_slerpni>` **(** :ref:`Quaternion<class_Quaternion>` to, :ref:`float<class_float>` weight **)** |const|                                                                                                                                                                                                                                                     |
   +-------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | :ref:`Quaternion<class_Quaternion>` | :ref:`spherical_cubic_interpolate<class_Quaternion_method_spherical_cubic_interpolate>` **(** :ref:`Quaternion<class_Quaternion>` b, :ref:`Quaternion<class_Quaternion>` pre_a, :ref:`Quaternion<class_Quaternion>` post_b, :ref:`float<class_float>` weight **)** |const|                                                                                                                       |
   +-------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   | :ref:`Quaternion<class_Quaternion>` | :ref:`spherical_cubic_interpolate_in_time<class_Quaternion_method_spherical_cubic_interpolate_in_time>` **(** :ref:`Quaternion<class_Quaternion>` b, :ref:`Quaternion<class_Quaternion>` pre_a, :ref:`Quaternion<class_Quaternion>` post_b, :ref:`float<class_float>` weight, :ref:`float<class_float>` b_t, :ref:`float<class_float>` pre_a_t, :ref:`float<class_float>` post_b_t **)** |const| |
   +-------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+

.. rst-class:: classref-reftable-group

Operators
---------

.. table::
   :widths: auto

   +-------------------------------------+--------------------------------------------------------------------------------------------------------------------+
   | :ref:`bool<class_bool>`             | :ref:`operator !=<class_Quaternion_operator_neq_Quaternion>` **(** :ref:`Quaternion<class_Quaternion>` right **)** |
   +-------------------------------------+--------------------------------------------------------------------------------------------------------------------+
   | :ref:`Quaternion<class_Quaternion>` | :ref:`operator *<class_Quaternion_operator_mul_Quaternion>` **(** :ref:`Quaternion<class_Quaternion>` right **)**  |
   +-------------------------------------+--------------------------------------------------------------------------------------------------------------------+
   | :ref:`Vector3<class_Vector3>`       | :ref:`operator *<class_Quaternion_operator_mul_Vector3>` **(** :ref:`Vector3<class_Vector3>` right **)**           |
   +-------------------------------------+--------------------------------------------------------------------------------------------------------------------+
   | :ref:`Quaternion<class_Quaternion>` | :ref:`operator *<class_Quaternion_operator_mul_float>` **(** :ref:`float<class_float>` right **)**                 |
   +-------------------------------------+--------------------------------------------------------------------------------------------------------------------+
   | :ref:`Quaternion<class_Quaternion>` | :ref:`operator *<class_Quaternion_operator_mul_int>` **(** :ref:`int<class_int>` right **)**                       |
   +-------------------------------------+--------------------------------------------------------------------------------------------------------------------+
   | :ref:`Quaternion<class_Quaternion>` | :ref:`operator +<class_Quaternion_operator_sum_Quaternion>` **(** :ref:`Quaternion<class_Quaternion>` right **)**  |
   +-------------------------------------+--------------------------------------------------------------------------------------------------------------------+
   | :ref:`Quaternion<class_Quaternion>` | :ref:`operator -<class_Quaternion_operator_dif_Quaternion>` **(** :ref:`Quaternion<class_Quaternion>` right **)**  |
   +-------------------------------------+--------------------------------------------------------------------------------------------------------------------+
   | :ref:`Quaternion<class_Quaternion>` | :ref:`operator /<class_Quaternion_operator_div_float>` **(** :ref:`float<class_float>` right **)**                 |
   +-------------------------------------+--------------------------------------------------------------------------------------------------------------------+
   | :ref:`Quaternion<class_Quaternion>` | :ref:`operator /<class_Quaternion_operator_div_int>` **(** :ref:`int<class_int>` right **)**                       |
   +-------------------------------------+--------------------------------------------------------------------------------------------------------------------+
   | :ref:`bool<class_bool>`             | :ref:`operator ==<class_Quaternion_operator_eq_Quaternion>` **(** :ref:`Quaternion<class_Quaternion>` right **)**  |
   +-------------------------------------+--------------------------------------------------------------------------------------------------------------------+
   | :ref:`float<class_float>`           | :ref:`operator []<class_Quaternion_operator_idx_int>` **(** :ref:`int<class_int>` index **)**                      |
   +-------------------------------------+--------------------------------------------------------------------------------------------------------------------+
   | :ref:`Quaternion<class_Quaternion>` | :ref:`operator unary+<class_Quaternion_operator_unplus>` **(** **)**                                               |
   +-------------------------------------+--------------------------------------------------------------------------------------------------------------------+
   | :ref:`Quaternion<class_Quaternion>` | :ref:`operator unary-<class_Quaternion_operator_unminus>` **(** **)**                                              |
   +-------------------------------------+--------------------------------------------------------------------------------------------------------------------+

.. rst-class:: classref-section-separator

----

.. rst-class:: classref-descriptions-group

Constants
---------

.. _class_Quaternion_constant_IDENTITY:

.. rst-class:: classref-constant

**IDENTITY** = ``Quaternion(0, 0, 0, 1)``

The identity quaternion, representing no rotation. Equivalent to an identity :ref:`Basis<class_Basis>` matrix. If a vector is transformed by an identity quaternion, it will not change.

.. rst-class:: classref-section-separator

----

.. rst-class:: classref-descriptions-group

Property Descriptions
---------------------

.. _class_Quaternion_property_w:

.. rst-class:: classref-property

:ref:`float<class_float>` **w** = ``1.0``

W component of the quaternion (real part).

Quaternion components should usually not be manipulated directly.

.. rst-class:: classref-item-separator

----

.. _class_Quaternion_property_x:

.. rst-class:: classref-property

:ref:`float<class_float>` **x** = ``0.0``

X component of the quaternion (imaginary ``i`` axis part).

Quaternion components should usually not be manipulated directly.

.. rst-class:: classref-item-separator

----

.. _class_Quaternion_property_y:

.. rst-class:: classref-property

:ref:`float<class_float>` **y** = ``0.0``

Y component of the quaternion (imaginary ``j`` axis part).

Quaternion components should usually not be manipulated directly.

.. rst-class:: classref-item-separator

----

.. _class_Quaternion_property_z:

.. rst-class:: classref-property

:ref:`float<class_float>` **z** = ``0.0``

Z component of the quaternion (imaginary ``k`` axis part).

Quaternion components should usually not be manipulated directly.

.. rst-class:: classref-section-separator

----

.. rst-class:: classref-descriptions-group

Constructor Descriptions
------------------------

.. _class_Quaternion_constructor_Quaternion:

.. rst-class:: classref-constructor

:ref:`Quaternion<class_Quaternion>` **Quaternion** **(** **)**

Constructs a default-initialized quaternion with all components set to ``0``.

.. rst-class:: classref-item-separator

----

.. rst-class:: classref-constructor

:ref:`Quaternion<class_Quaternion>` **Quaternion** **(** :ref:`Quaternion<class_Quaternion>` from **)**

Constructs a **Quaternion** as a copy of the given **Quaternion**.

.. rst-class:: classref-item-separator

----

.. rst-class:: classref-constructor

:ref:`Quaternion<class_Quaternion>` **Quaternion** **(** :ref:`Vector3<class_Vector3>` arc_from, :ref:`Vector3<class_Vector3>` arc_to **)**

Constructs a quaternion representing the shortest arc between two points on the surface of a sphere with a radius of ``1.0``.

.. rst-class:: classref-item-separator

----

.. rst-class:: classref-constructor

:ref:`Quaternion<class_Quaternion>` **Quaternion** **(** :ref:`Vector3<class_Vector3>` axis, :ref:`float<class_float>` angle **)**

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

.. rst-class:: classref-item-separator

----

.. rst-class:: classref-constructor

:ref:`Quaternion<class_Quaternion>` **Quaternion** **(** :ref:`Basis<class_Basis>` from **)**

Constructs a quaternion from the given :ref:`Basis<class_Basis>`.

.. rst-class:: classref-item-separator

----

.. rst-class:: classref-constructor

:ref:`Quaternion<class_Quaternion>` **Quaternion** **(** :ref:`float<class_float>` x, :ref:`float<class_float>` y, :ref:`float<class_float>` z, :ref:`float<class_float>` w **)**

Constructs a quaternion defined by the given values.

.. rst-class:: classref-section-separator

----

.. rst-class:: classref-descriptions-group

Method Descriptions
-------------------

.. _class_Quaternion_method_angle_to:

.. rst-class:: classref-method

:ref:`float<class_float>` **angle_to** **(** :ref:`Quaternion<class_Quaternion>` to **)** |const|

Returns the angle between this quaternion and ``to``. This is the magnitude of the angle you would need to rotate by to get from one to the other.

\ **Note:** The magnitude of the floating-point error for this method is abnormally high, so methods such as ``is_zero_approx`` will not work reliably.

.. rst-class:: classref-item-separator

----

.. _class_Quaternion_method_dot:

.. rst-class:: classref-method

:ref:`float<class_float>` **dot** **(** :ref:`Quaternion<class_Quaternion>` with **)** |const|

Returns the dot product of two quaternions.

.. rst-class:: classref-item-separator

----

.. _class_Quaternion_method_exp:

.. rst-class:: classref-method

:ref:`Quaternion<class_Quaternion>` **exp** **(** **)** |const|

.. container:: contribute

	There is currently no description for this method. Please help us by :ref:`contributing one <doc_updating_the_class_reference>`!

.. rst-class:: classref-item-separator

----

.. _class_Quaternion_method_from_euler:

.. rst-class:: classref-method

:ref:`Quaternion<class_Quaternion>` **from_euler** **(** :ref:`Vector3<class_Vector3>` euler **)** |static|

Constructs a Quaternion from Euler angles in YXZ rotation order.

.. rst-class:: classref-item-separator

----

.. _class_Quaternion_method_get_angle:

.. rst-class:: classref-method

:ref:`float<class_float>` **get_angle** **(** **)** |const|

.. container:: contribute

	There is currently no description for this method. Please help us by :ref:`contributing one <doc_updating_the_class_reference>`!

.. rst-class:: classref-item-separator

----

.. _class_Quaternion_method_get_axis:

.. rst-class:: classref-method

:ref:`Vector3<class_Vector3>` **get_axis** **(** **)** |const|

.. container:: contribute

	There is currently no description for this method. Please help us by :ref:`contributing one <doc_updating_the_class_reference>`!

.. rst-class:: classref-item-separator

----

.. _class_Quaternion_method_get_euler:

.. rst-class:: classref-method

:ref:`Vector3<class_Vector3>` **get_euler** **(** :ref:`int<class_int>` order=2 **)** |const|

Returns the quaternion's rotation in the form of Euler angles. The Euler order depends on the ``order`` parameter, for example using the YXZ convention: since this method decomposes, first Z, then X, and Y last. See the :ref:`EulerOrder<enum_@GlobalScope_EulerOrder>` enum for possible values. The returned vector contains the rotation angles in the format (X angle, Y angle, Z angle).

.. rst-class:: classref-item-separator

----

.. _class_Quaternion_method_inverse:

.. rst-class:: classref-method

:ref:`Quaternion<class_Quaternion>` **inverse** **(** **)** |const|

Returns the inverse of the quaternion.

.. rst-class:: classref-item-separator

----

.. _class_Quaternion_method_is_equal_approx:

.. rst-class:: classref-method

:ref:`bool<class_bool>` **is_equal_approx** **(** :ref:`Quaternion<class_Quaternion>` to **)** |const|

Returns ``true`` if this quaternion and ``to`` are approximately equal, by running :ref:`@GlobalScope.is_equal_approx<class_@GlobalScope_method_is_equal_approx>` on each component.

.. rst-class:: classref-item-separator

----

.. _class_Quaternion_method_is_finite:

.. rst-class:: classref-method

:ref:`bool<class_bool>` **is_finite** **(** **)** |const|

Returns ``true`` if this quaternion is finite, by calling :ref:`@GlobalScope.is_finite<class_@GlobalScope_method_is_finite>` on each component.

.. rst-class:: classref-item-separator

----

.. _class_Quaternion_method_is_normalized:

.. rst-class:: classref-method

:ref:`bool<class_bool>` **is_normalized** **(** **)** |const|

Returns whether the quaternion is normalized or not.

.. rst-class:: classref-item-separator

----

.. _class_Quaternion_method_length:

.. rst-class:: classref-method

:ref:`float<class_float>` **length** **(** **)** |const|

Returns the length of the quaternion.

.. rst-class:: classref-item-separator

----

.. _class_Quaternion_method_length_squared:

.. rst-class:: classref-method

:ref:`float<class_float>` **length_squared** **(** **)** |const|

Returns the length of the quaternion, squared.

.. rst-class:: classref-item-separator

----

.. _class_Quaternion_method_log:

.. rst-class:: classref-method

:ref:`Quaternion<class_Quaternion>` **log** **(** **)** |const|

.. container:: contribute

	There is currently no description for this method. Please help us by :ref:`contributing one <doc_updating_the_class_reference>`!

.. rst-class:: classref-item-separator

----

.. _class_Quaternion_method_normalized:

.. rst-class:: classref-method

:ref:`Quaternion<class_Quaternion>` **normalized** **(** **)** |const|

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

.. rst-class:: classref-item-separator

----

.. _class_Quaternion_method_slerp:

.. rst-class:: classref-method

:ref:`Quaternion<class_Quaternion>` **slerp** **(** :ref:`Quaternion<class_Quaternion>` to, :ref:`float<class_float>` weight **)** |const|

Returns the result of the spherical linear interpolation between this quaternion and ``to`` by amount ``weight``.

\ **Note:** Both quaternions must be normalized.

.. rst-class:: classref-item-separator

----

.. _class_Quaternion_method_slerpni:

.. rst-class:: classref-method

:ref:`Quaternion<class_Quaternion>` **slerpni** **(** :ref:`Quaternion<class_Quaternion>` to, :ref:`float<class_float>` weight **)** |const|

Returns the result of the spherical linear interpolation between this quaternion and ``to`` by amount ``weight``, but without checking if the rotation path is not bigger than 90 degrees.

.. rst-class:: classref-item-separator

----

.. _class_Quaternion_method_spherical_cubic_interpolate:

.. rst-class:: classref-method

:ref:`Quaternion<class_Quaternion>` **spherical_cubic_interpolate** **(** :ref:`Quaternion<class_Quaternion>` b, :ref:`Quaternion<class_Quaternion>` pre_a, :ref:`Quaternion<class_Quaternion>` post_b, :ref:`float<class_float>` weight **)** |const|

Performs a spherical cubic interpolation between quaternions ``pre_a``, this vector, ``b``, and ``post_b``, by the given amount ``weight``.

.. rst-class:: classref-item-separator

----

.. _class_Quaternion_method_spherical_cubic_interpolate_in_time:

.. rst-class:: classref-method

:ref:`Quaternion<class_Quaternion>` **spherical_cubic_interpolate_in_time** **(** :ref:`Quaternion<class_Quaternion>` b, :ref:`Quaternion<class_Quaternion>` pre_a, :ref:`Quaternion<class_Quaternion>` post_b, :ref:`float<class_float>` weight, :ref:`float<class_float>` b_t, :ref:`float<class_float>` pre_a_t, :ref:`float<class_float>` post_b_t **)** |const|

Performs a spherical cubic interpolation between quaternions ``pre_a``, this vector, ``b``, and ``post_b``, by the given amount ``weight``.

It can perform smoother interpolation than :ref:`spherical_cubic_interpolate<class_Quaternion_method_spherical_cubic_interpolate>` by the time values.

.. rst-class:: classref-section-separator

----

.. rst-class:: classref-descriptions-group

Operator Descriptions
---------------------

.. _class_Quaternion_operator_neq_Quaternion:

.. rst-class:: classref-operator

:ref:`bool<class_bool>` **operator !=** **(** :ref:`Quaternion<class_Quaternion>` right **)**

Returns ``true`` if the quaternions are not equal.

\ **Note:** Due to floating-point precision errors, consider using :ref:`is_equal_approx<class_Quaternion_method_is_equal_approx>` instead, which is more reliable.

.. rst-class:: classref-item-separator

----

.. _class_Quaternion_operator_mul_Quaternion:

.. rst-class:: classref-operator

:ref:`Quaternion<class_Quaternion>` **operator *** **(** :ref:`Quaternion<class_Quaternion>` right **)**

Composes these two quaternions by multiplying them together. This has the effect of rotating the second quaternion (the child) by the first quaternion (the parent).

.. rst-class:: classref-item-separator

----

.. _class_Quaternion_operator_mul_Vector3:

.. rst-class:: classref-operator

:ref:`Vector3<class_Vector3>` **operator *** **(** :ref:`Vector3<class_Vector3>` right **)**

Rotates (multiplies) the :ref:`Vector3<class_Vector3>` by the given **Quaternion**.

.. rst-class:: classref-item-separator

----

.. _class_Quaternion_operator_mul_float:

.. rst-class:: classref-operator

:ref:`Quaternion<class_Quaternion>` **operator *** **(** :ref:`float<class_float>` right **)**

Multiplies each component of the **Quaternion** by the given value. This operation is not meaningful on its own, but it can be used as a part of a larger expression.

.. rst-class:: classref-item-separator

----

.. _class_Quaternion_operator_mul_int:

.. rst-class:: classref-operator

:ref:`Quaternion<class_Quaternion>` **operator *** **(** :ref:`int<class_int>` right **)**

Multiplies each component of the **Quaternion** by the given value. This operation is not meaningful on its own, but it can be used as a part of a larger expression.

.. rst-class:: classref-item-separator

----

.. _class_Quaternion_operator_sum_Quaternion:

.. rst-class:: classref-operator

:ref:`Quaternion<class_Quaternion>` **operator +** **(** :ref:`Quaternion<class_Quaternion>` right **)**

Adds each component of the left **Quaternion** to the right **Quaternion**. This operation is not meaningful on its own, but it can be used as a part of a larger expression, such as approximating an intermediate rotation between two nearby rotations.

.. rst-class:: classref-item-separator

----

.. _class_Quaternion_operator_dif_Quaternion:

.. rst-class:: classref-operator

:ref:`Quaternion<class_Quaternion>` **operator -** **(** :ref:`Quaternion<class_Quaternion>` right **)**

Subtracts each component of the left **Quaternion** by the right **Quaternion**. This operation is not meaningful on its own, but it can be used as a part of a larger expression.

.. rst-class:: classref-item-separator

----

.. _class_Quaternion_operator_div_float:

.. rst-class:: classref-operator

:ref:`Quaternion<class_Quaternion>` **operator /** **(** :ref:`float<class_float>` right **)**

Divides each component of the **Quaternion** by the given value. This operation is not meaningful on its own, but it can be used as a part of a larger expression.

.. rst-class:: classref-item-separator

----

.. _class_Quaternion_operator_div_int:

.. rst-class:: classref-operator

:ref:`Quaternion<class_Quaternion>` **operator /** **(** :ref:`int<class_int>` right **)**

Divides each component of the **Quaternion** by the given value. This operation is not meaningful on its own, but it can be used as a part of a larger expression.

.. rst-class:: classref-item-separator

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.. _class_Quaternion_operator_eq_Quaternion:

.. rst-class:: classref-operator

:ref:`bool<class_bool>` **operator ==** **(** :ref:`Quaternion<class_Quaternion>` right **)**

Returns ``true`` if the quaternions are exactly equal.

\ **Note:** Due to floating-point precision errors, consider using :ref:`is_equal_approx<class_Quaternion_method_is_equal_approx>` instead, which is more reliable.

.. rst-class:: classref-item-separator

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.. _class_Quaternion_operator_idx_int:

.. rst-class:: classref-operator

:ref:`float<class_float>` **operator []** **(** :ref:`int<class_int>` index **)**

Access quaternion components using their index. ``q[0]`` is equivalent to ``q.x``, ``q[1]`` is equivalent to ``q.y``, ``q[2]`` is equivalent to ``q.z``, and ``q[3]`` is equivalent to ``q.w``.

.. rst-class:: classref-item-separator

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.. _class_Quaternion_operator_unplus:

.. rst-class:: classref-operator

:ref:`Quaternion<class_Quaternion>` **operator unary+** **(** **)**

Returns the same value as if the ``+`` was not there. Unary ``+`` does nothing, but sometimes it can make your code more readable.

.. rst-class:: classref-item-separator

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.. _class_Quaternion_operator_unminus:

.. rst-class:: classref-operator

:ref:`Quaternion<class_Quaternion>` **operator unary-** **(** **)**

Returns the negative value of the **Quaternion**. This is the same as writing ``Quaternion(-q.x, -q.y, -q.z, -q.w)``. This operation results in a quaternion that represents the same rotation.

.. |virtual| replace:: :abbr:`virtual (This method should typically be overridden by the user to have any effect.)`
.. |const| replace:: :abbr:`const (This method has no side effects. It doesn't modify any of the instance's member variables.)`
.. |vararg| replace:: :abbr:`vararg (This method accepts any number of arguments after the ones described here.)`
.. |constructor| replace:: :abbr:`constructor (This method is used to construct a type.)`
.. |static| replace:: :abbr:`static (This method doesn't need an instance to be called, so it can be called directly using the class name.)`
.. |operator| replace:: :abbr:`operator (This method describes a valid operator to use with this type as left-hand operand.)`
.. |bitfield| replace:: :abbr:`BitField (This value is an integer composed as a bitmask of the following flags.)`