Package com.google.ar.sceneform.math

Class Quaternion

java.lang.Object

com.google.ar.sceneform.math.Quaternion

public class Quaternion
extends java.lang.Object

A Sceneform quaternion class for floats.

Quaternion operations are Hamiltonian using the right-hand-rule convention.

Field Summary

Fields

Modifier and Type	Field	Description
float	w
float	x
float	y
float	z

Constructor Summary

Constructors

Constructor	Description
Quaternion()	Construct Quaternion and set to Identity
Quaternion(float x, float y, float z, float w)	Construct Quaternion and set each value.
Quaternion(Quaternion q)	Construct Quaternion using values from another Quaternion
Quaternion(Vector3 eulerAngles)	Construct Quaternion based on eulerAngles.
Quaternion(Vector3 axis, float angle)	Construct Quaternion using an axis/angle to define the rotation

Method Summary

Modifier and Type	Method	Description
static Quaternion	axisAngle(Vector3 axis, float degrees)	Get a new Quaternion using an axis/angle to define the rotation
static boolean	equals(Quaternion lhs, Quaternion rhs)	Compare two Quaternions
boolean	equals(java.lang.Object other)	Returns true if the other object is a Quaternion and the dot product is 1.0 +/- a tolerance.
static Quaternion	eulerAngles(Vector3 eulerAngles)	Get a new Quaternion using eulerAngles to define the rotation.
int	hashCode()
static Quaternion	identity()	Get a Quaternion set to identity
static Vector3	inverseRotateVector(Quaternion q, Vector3 src)
Quaternion	inverted()	Get a Quaternion with the opposite rotation
static Quaternion	lookRotation(Vector3 forwardInWorld, Vector3 desiredUpInWorld)	Get a new Quaternion representing a rotation towards a specified forward direction.
static Quaternion	multiply(Quaternion lhs, Quaternion rhs)	Create a Quaternion by combining two Quaternions multiply(lhs, rhs) is equivalent to performing the rhs rotation then lhs rotation Ordering is important for this operation.
boolean	normalize()	Rescales the quaternion to the unit length.
Quaternion	normalized()	Get a Quaternion with a matching rotation but scaled to unit length.
static Vector3	rotateVector(Quaternion q, Vector3 src)	Rotates a Vector3 by a Quaternion
static Quaternion	rotationBetweenVectors(Vector3 start, Vector3 end)	Get a new Quaternion representing the rotation from one vector to another.
void	set(float qx, float qy, float qz, float qw)	Set each value and normalize the Quaternion
void	set(Quaternion q)	Copy values from another Quaternion into this one
void	set(Vector3 axis, float angle)	Update this Quaternion using an axis/angle to define the rotation
void	setIdentity()	Set the Quaternion to identity
static Quaternion	slerp(Quaternion start, Quaternion end, float t)
java.lang.String	toString()

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Field Detail

x

public float x

y

public float y

z

public float z

w

public float w

Constructor Detail

Quaternion

public Quaternion()

Construct Quaternion and set to Identity

Quaternion

public Quaternion(float x,
                  float y,
                  float z,
                  float w)

Construct Quaternion and set each value. The Quaternion will be normalized during construction

Quaternion

public Quaternion(Quaternion q)

Construct Quaternion using values from another Quaternion

Quaternion

public Quaternion(Vector3 axis,
                  float angle)

Construct Quaternion using an axis/angle to define the rotation

Parameters:

axis - Sets rotation direction

angle - Angle size in degrees

Quaternion

public Quaternion(Vector3 eulerAngles)

Construct Quaternion based on eulerAngles.

Parameters:

eulerAngles - - the angle in degrees for each axis.

See Also:

eulerAngles(Vector3 eulerAngles)

Method Detail

set

public void set(Quaternion q)

Copy values from another Quaternion into this one

set

public void set(Vector3 axis,
                float angle)

Update this Quaternion using an axis/angle to define the rotation

set

public void set(float qx,
                float qy,
                float qz,
                float qw)

Set each value and normalize the Quaternion

setIdentity

public void setIdentity()

Set the Quaternion to identity

normalize

public boolean normalize()

Rescales the quaternion to the unit length.

If the Quaternion can not be scaled, it is set to identity and false is returned.

Returns:

true if the Quaternion was non-zero

normalized

public Quaternion normalized()

Get a Quaternion with a matching rotation but scaled to unit length.

Returns:

the quaternion scaled to the unit length, or zero if that can not be done.

inverted

public Quaternion inverted()

Get a Quaternion with the opposite rotation

Returns:

the opposite rotation

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

rotateVector

public static Vector3 rotateVector(Quaternion q,
                                   Vector3 src)

Rotates a Vector3 by a Quaternion

Returns:

The rotated vector

inverseRotateVector

public static Vector3 inverseRotateVector(Quaternion q,
                                          Vector3 src)

multiply

public static Quaternion multiply(Quaternion lhs,
                                  Quaternion rhs)

Create a Quaternion by combining two Quaternions multiply(lhs, rhs) is equivalent to performing the rhs rotation then lhs rotation Ordering is important for this operation.

Returns:

The combined rotation

slerp

public static Quaternion slerp(Quaternion start,
                               Quaternion end,
                               float t)

axisAngle

public static Quaternion axisAngle(Vector3 axis,
                                   float degrees)

Get a new Quaternion using an axis/angle to define the rotation

Parameters:

axis - Sets rotation direction

degrees - Angle size in degrees

eulerAngles

public static Quaternion eulerAngles(Vector3 eulerAngles)

Get a new Quaternion using eulerAngles to define the rotation.

The rotations are applied in Z, Y, X order. This is consistent with other graphics engines. One thing to note is the coordinate systems are different between Sceneform and Unity, so the same angles used here will have cause a different orientation than Unity. Carefully check your parameter values to get the same effect as in other engines.

Parameters:

eulerAngles - - the angles in degrees.

rotationBetweenVectors

public static Quaternion rotationBetweenVectors(Vector3 start,
                                                Vector3 end)

Get a new Quaternion representing the rotation from one vector to another.

lookRotation

public static Quaternion lookRotation(Vector3 forwardInWorld,
                                      Vector3 desiredUpInWorld)

Get a new Quaternion representing a rotation towards a specified forward direction. If upInWorld is orthogonal to forwardInWorld, then the Y axis is aligned with desiredUpInWorld.

equals

public static boolean equals(Quaternion lhs,
                             Quaternion rhs)

Compare two Quaternions

Tests for equality by calculating the dot product of lhs and rhs. lhs and -lhs will not be equal according to this function.

equals

public boolean equals(java.lang.Object other)

Returns true if the other object is a Quaternion and the dot product is 1.0 +/- a tolerance.

Overrides:

equals in class java.lang.Object

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object

identity

public static Quaternion identity()

Get a Quaternion set to identity