virtualx-engine/doc/classes/Quaternion.xml

<?xml version="1.0" encoding="UTF-8" ?>
<class name="Quaternion" version="4.0">
	<brief_description>
		Quaternion.
	</brief_description>
	<description>
		A unit quaternion used for representing 3D rotations. Quaternions need to be normalized to be used for rotation.
		It is similar to Basis, which implements matrix representation of rotations, and can be parametrized using both an axis-angle pair or Euler angles. Basis stores rotation, scale, and shearing, while Quaternion only stores rotation.
		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.
	</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" />
			<argument 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" />
			<argument index="0" name="arc_from" type="Vector3" />
			<argument index="1" name="arc_to" type="Vector3" />
			<description>
			</description>
		</constructor>
		<constructor name="Quaternion">
			<return type="Quaternion" />
			<argument index="0" name="axis" type="Vector3" />
			<argument 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" />
			<argument index="0" name="euler_yxz" type="Vector3" />
			<description>
			</description>
		</constructor>
		<constructor name="Quaternion">
			<return type="Quaternion" />
			<argument index="0" name="from" type="Basis" />
			<description>
				Constructs a quaternion from the given [Basis].
			</description>
		</constructor>
		<constructor name="Quaternion">
			<return type="Quaternion" />
			<argument index="0" name="x" type="float" />
			<argument index="1" name="y" type="float" />
			<argument index="2" name="z" type="float" />
			<argument 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" />
			<argument index="0" name="to" type="Quaternion" />
			<description>
				Returns the angle between this quaternion and [code]to[/code]. This is the magnitude of the angle you would need to rotate by to get from one to the other.
				[b]Note:[/b] This method has an abnormally high amount of floating-point error, so methods such as [code]is_zero_approx[/code] will not work reliably.
			</description>
		</method>
		<method name="cubic_slerp" qualifiers="const">
			<return type="Quaternion" />
			<argument index="0" name="b" type="Quaternion" />
			<argument index="1" name="pre_a" type="Quaternion" />
			<argument index="2" name="post_b" type="Quaternion" />
			<argument index="3" name="weight" type="float" />
			<description>
				Performs a cubic spherical interpolation between quaternions [code]pre_a[/code], this vector, [code]b[/code], and [code]post_b[/code], by the given amount [code]weight[/code].
			</description>
		</method>
		<method name="dot" qualifiers="const">
			<return type="float" />
			<argument index="0" name="with" type="Quaternion" />
			<description>
				Returns the dot product of two quaternions.
			</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" />
			<description>
				Returns Euler angles (in the YXZ convention: when decomposing, 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).
			</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" />
			<argument index="0" name="to" type="Quaternion" />
			<description>
				Returns [code]true[/code] if this quaternion and [code]quat[/code] are approximately equal, by running [method @GlobalScope.is_equal_approx] 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="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" />
			<argument index="0" name="to" type="Quaternion" />
			<argument index="1" name="weight" type="float" />
			<description>
				Returns the result of the spherical linear interpolation between this quaternion and [code]to[/code] by amount [code]weight[/code].
				[b]Note:[/b] Both quaternions must be normalized.
			</description>
		</method>
		<method name="slerpni" qualifiers="const">
			<return type="Quaternion" />
			<argument index="0" name="to" type="Quaternion" />
			<argument index="1" name="weight" type="float" />
			<description>
				Returns the result of the spherical linear interpolation between this quaternion and [code]to[/code] by amount [code]weight[/code], but without checking if the rotation path is not bigger than 90 degrees.
			</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" />
			<description>
			</description>
		</operator>
		<operator name="operator !=">
			<return type="bool" />
			<argument 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" />
			<argument 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" />
			<argument index="0" name="right" type="Vector3" />
			<description>
				Rotates (multiplies) the [Vector3] by the given [Quaternion].
			</description>
		</operator>
		<operator name="operator *">
			<return type="Quaternion" />
			<argument 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" />
			<argument 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" />
			<argument 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" />
			<argument 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" />
			<argument 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" />
			<argument 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" />
			<description>
			</description>
		</operator>
		<operator name="operator ==">
			<return type="bool" />
			<argument 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" />
			<argument 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>