godot/doc/classes/Quaternion.xml

<?xml version="1.0" encoding="UTF-8" ?>
<class name="Quaternion" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="../class.xsd">
	<brief_description>
		A unit quaternion used for representing 3D rotations.
	</brief_description>
	<description>
		Quaternions are similar to [Basis], which implements the matrix representation of rotations. Unlike [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.
		[b]Note:[/b] Quaternions need to be normalized before being used for rotation.
	</description>
	<tutorials>
		<link title="Using 3D transforms">$DOCS_URL/tutorials/3d/using_transforms.html#interpolating-with-quaternions</link>
		<link title="Third Person Shooter Demo">https://godotengine.org/asset-library/asset/678</link>
	</tutorials>
	<constructors>
		<constructor name="Quaternion">
			<return type="Quaternion" />
			<description>
				Constructs a default-initialized quaternion with all components set to [code]0[/code].
			</description>
		</constructor>
		<constructor name="Quaternion">
			<return type="Quaternion" />
			<param index="0" name="from" type="Quaternion" />
			<description>
				Constructs a [Quaternion] as a copy of the given [Quaternion].
			</description>
		</constructor>
		<constructor name="Quaternion">
			<return type="Quaternion" />
			<param index="0" name="arc_from" type="Vector3" />
			<param index="1" name="arc_to" type="Vector3" />
			<description>
				Constructs a quaternion representing the shortest arc between two points on the surface of a sphere with a radius of [code]1.0[/code].
			</description>
		</constructor>
		<constructor name="Quaternion">
			<return type="Quaternion" />
			<param index="0" name="axis" type="Vector3" />
			<param index="1" name="angle" type="float" />
			<description>
				Constructs a quaternion that will rotate around the given axis by the specified angle. The axis must be a normalized vector.
			</description>
		</constructor>
		<constructor name="Quaternion">
			<return type="Quaternion" />
			<param index="0" name="from" type="Basis" />
			<description>
				Constructs a quaternion from the given [Basis].
			</description>
		</constructor>
		<constructor name="Quaternion">
			<return type="Quaternion" />
			<param index="0" name="x" type="float" />
			<param index="1" name="y" type="float" />
			<param index="2" name="z" type="float" />
			<param index="3" name="w" type="float" />
			<description>
				Constructs a quaternion defined by the given values.
			</description>
		</constructor>
	</constructors>
	<methods>
		<method name="angle_to" qualifiers="const">
			<return type="float" />
			<param index="0" name="to" type="Quaternion" />
			<description>
				Returns the angle between this quaternion and [param to]. This is the magnitude of the angle you would need to rotate by to get from one to the other.
				[b]Note:[/b] The magnitude of the floating-point error for this method is abnormally high, so methods such as [code]is_zero_approx[/code] will not work reliably.
			</description>
		</method>
		<method name="dot" qualifiers="const">
			<return type="float" />
			<param index="0" name="with" type="Quaternion" />
			<description>
				Returns the dot product of two quaternions.
			</description>
		</method>
		<method name="exp" qualifiers="const">
			<return type="Quaternion" />
			<description>
			</description>
		</method>
		<method name="from_euler" qualifiers="static">
			<return type="Quaternion" />
			<param index="0" name="euler" type="Vector3" />
			<description>
				Constructs a Quaternion from Euler angles in YXZ rotation order.
			</description>
		</method>
		<method name="get_angle" qualifiers="const">
			<return type="float" />
			<description>
			</description>
		</method>
		<method name="get_axis" qualifiers="const">
			<return type="Vector3" />
			<description>
			</description>
		</method>
		<method name="get_euler" qualifiers="const">
			<return type="Vector3" />
			<param index="0" name="order" type="int" default="2" />
			<description>
				Returns the quaternion's rotation in the form of Euler angles. The Euler order depends on the [param order] parameter, for example using the YXZ convention: since this method decomposes, first Z, then X, and Y last. See the [enum EulerOrder] enum for possible values. The returned vector contains the rotation angles in the format (X angle, Y angle, Z angle).
			</description>
		</method>
		<method name="inverse" qualifiers="const">
			<return type="Quaternion" />
			<description>
				Returns the inverse of the quaternion.
			</description>
		</method>
		<method name="is_equal_approx" qualifiers="const">
			<return type="bool" />
			<param index="0" name="to" type="Quaternion" />
			<description>
				Returns [code]true[/code] if this quaternion and [param to] are approximately equal, by running [method @GlobalScope.is_equal_approx] on each component.
			</description>
		</method>
		<method name="is_finite" qualifiers="const">
			<return type="bool" />
			<description>
				Returns [code]true[/code] if this quaternion is finite, by calling [method @GlobalScope.is_finite] on each component.
			</description>
		</method>
		<method name="is_normalized" qualifiers="const">
			<return type="bool" />
			<description>
				Returns whether the quaternion is normalized or not.
			</description>
		</method>
		<method name="length" qualifiers="const">
			<return type="float" />
			<description>
				Returns the length of the quaternion.
			</description>
		</method>
		<method name="length_squared" qualifiers="const">
			<return type="float" />
			<description>
				Returns the length of the quaternion, squared.
			</description>
		</method>
		<method name="log" qualifiers="const">
			<return type="Quaternion" />
			<description>
			</description>
		</method>
		<method name="normalized" qualifiers="const">
			<return type="Quaternion" />
			<description>
				Returns a copy of the quaternion, normalized to unit length.
			</description>
		</method>
		<method name="slerp" qualifiers="const">
			<return type="Quaternion" />
			<param index="0" name="to" type="Quaternion" />
			<param index="1" name="weight" type="float" />
			<description>
				Returns the result of the spherical linear interpolation between this quaternion and [param to] by amount [param weight].
				[b]Note:[/b] Both quaternions must be normalized.
			</description>
		</method>
		<method name="slerpni" qualifiers="const">
			<return type="Quaternion" />
			<param index="0" name="to" type="Quaternion" />
			<param index="1" name="weight" type="float" />
			<description>
				Returns the result of the spherical linear interpolation between this quaternion and [param to] by amount [param weight], but without checking if the rotation path is not bigger than 90 degrees.
			</description>
		</method>
		<method name="spherical_cubic_interpolate" qualifiers="const">
			<return type="Quaternion" />
			<param index="0" name="b" type="Quaternion" />
			<param index="1" name="pre_a" type="Quaternion" />
			<param index="2" name="post_b" type="Quaternion" />
			<param index="3" name="weight" type="float" />
			<description>
				Performs a spherical cubic interpolation between quaternions [param pre_a], this vector, [param b], and [param post_b], by the given amount [param weight].
			</description>
		</method>
		<method name="spherical_cubic_interpolate_in_time" qualifiers="const">
			<return type="Quaternion" />
			<param index="0" name="b" type="Quaternion" />
			<param index="1" name="pre_a" type="Quaternion" />
			<param index="2" name="post_b" type="Quaternion" />
			<param index="3" name="weight" type="float" />
			<param index="4" name="b_t" type="float" />
			<param index="5" name="pre_a_t" type="float" />
			<param index="6" name="post_b_t" type="float" />
			<description>
				Performs a spherical cubic interpolation between quaternions [param pre_a], this vector, [param b], and [param post_b], by the given amount [param weight].
				It can perform smoother interpolation than [code]spherical_cubic_interpolate()[/code] by the time values.
			</description>
		</method>
	</methods>
	<members>
		<member name="w" type="float" setter="" getter="" default="1.0">
			W component of the quaternion (real part).
			Quaternion components should usually not be manipulated directly.
		</member>
		<member name="x" type="float" setter="" getter="" default="0.0">
			X component of the quaternion (imaginary [code]i[/code] axis part).
			Quaternion components should usually not be manipulated directly.
		</member>
		<member name="y" type="float" setter="" getter="" default="0.0">
			Y component of the quaternion (imaginary [code]j[/code] axis part).
			Quaternion components should usually not be manipulated directly.
		</member>
		<member name="z" type="float" setter="" getter="" default="0.0">
			Z component of the quaternion (imaginary [code]k[/code] axis part).
			Quaternion components should usually not be manipulated directly.
		</member>
	</members>
	<constants>
		<constant name="IDENTITY" value="Quaternion(0, 0, 0, 1)">
			The identity quaternion, representing no rotation. Equivalent to an identity [Basis] matrix. If a vector is transformed by an identity quaternion, it will not change.
		</constant>
	</constants>
	<operators>
		<operator name="operator !=">
			<return type="bool" />
			<param index="0" name="right" type="Quaternion" />
			<description>
				Returns [code]true[/code] if the quaternions are not equal.
				[b]Note:[/b] Due to floating-point precision errors, consider using [method is_equal_approx] instead, which is more reliable.
			</description>
		</operator>
		<operator name="operator *">
			<return type="Quaternion" />
			<param index="0" name="right" type="Quaternion" />
			<description>
				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).
			</description>
		</operator>
		<operator name="operator *">
			<return type="Vector3" />
			<param index="0" name="right" type="Vector3" />
			<description>
				Rotates (multiplies) the [Vector3] by the given [Quaternion].
			</description>
		</operator>
		<operator name="operator *">
			<return type="Quaternion" />
			<param index="0" name="right" type="float" />
			<description>
				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.
			</description>
		</operator>
		<operator name="operator *">
			<return type="Quaternion" />
			<param index="0" name="right" type="int" />
			<description>
				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.
			</description>
		</operator>
		<operator name="operator +">
			<return type="Quaternion" />
			<param index="0" name="right" type="Quaternion" />
			<description>
				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.
			</description>
		</operator>
		<operator name="operator -">
			<return type="Quaternion" />
			<param index="0" name="right" type="Quaternion" />
			<description>
				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.
			</description>
		</operator>
		<operator name="operator /">
			<return type="Quaternion" />
			<param index="0" name="right" type="float" />
			<description>
				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.
			</description>
		</operator>
		<operator name="operator /">
			<return type="Quaternion" />
			<param index="0" name="right" type="int" />
			<description>
				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.
			</description>
		</operator>
		<operator name="operator ==">
			<return type="bool" />
			<param index="0" name="right" type="Quaternion" />
			<description>
				Returns [code]true[/code] if the quaternions are exactly equal.
				[b]Note:[/b] Due to floating-point precision errors, consider using [method is_equal_approx] instead, which is more reliable.
			</description>
		</operator>
		<operator name="operator []">
			<return type="float" />
			<param index="0" name="index" type="int" />
			<description>
				Access quaternion components using their index. [code]q[0][/code] is equivalent to [code]q.x[/code], [code]q[1][/code] is equivalent to [code]q.y[/code], [code]q[2][/code] is equivalent to [code]q.z[/code], and [code]q[3][/code] is equivalent to [code]q.w[/code].
			</description>
		</operator>
		<operator name="operator unary+">
			<return type="Quaternion" />
			<description>
				Returns the same value as if the [code]+[/code] was not there. Unary [code]+[/code] does nothing, but sometimes it can make your code more readable.
			</description>
		</operator>
		<operator name="operator unary-">
			<return type="Quaternion" />
			<description>
				Returns the negative value of the [Quaternion]. This is the same as writing [code]Quaternion(-q.x, -q.y, -q.z, -q.w)[/code]. This operation results in a quaternion that represents the same rotation.
			</description>
		</operator>
	</operators>
</class>