Quaternion (jMonkeyEngine3)

java.lang.Object
- com.jme3.math.Quaternion

All Implemented Interfaces:

Savable, java.io.Serializable, java.lang.Cloneable
```
public final class Quaternion
extends java.lang.Object
implements Savable, java.lang.Cloneable, java.io.Serializable
```
Used to efficiently represent rotations and orientations in 3-dimensional space, without risk of gimbal lock. Each instance has 4 single-precision components: 3 imaginary components (X, Y, and Z) and a real component (W).
Mathematically, quaternions are an extension of complex numbers. In mathematics texts, W often appears first, but in JME it always comes last.

See Also:

Serialized Form

Field Summary

Fields
Modifier and Type	Field and Description
`static Quaternion`	`DIRECTION_Z` Another shared instance of the identity quaternion (0, 0, 0, 1).
`static Quaternion`	`IDENTITY` Shared instance of the identity quaternion (0, 0, 0, 1).
`protected float`	`w` The real (W) component.
`protected float`	`x` The first imaginary (X) component.
`protected float`	`y` The 2nd imaginary (Y) component.
`protected float`	`z` The 3rd imaginary (Z) component.
`static Quaternion`	`ZERO` Shared instance of the zero quaternion (0, 0, 0, 0).

Constructor Summary

Constructors
Constructor and Description
`Quaternion()` Instantiates an identity quaternion: all components zeroed except `w`, which is set to 1.
`Quaternion(float[] angles)` Instantiates a quaternion from Tait-Bryan angles, applying the rotations in x-z-y extrinsic order or y-z'-x" intrinsic order.
`Quaternion(float x, float y, float z, float w)` Instantiates a quaternion with specified components.
`Quaternion(Quaternion q)` Instantiates a copy of the argument.
`Quaternion(Quaternion q1, Quaternion q2, float interp)` Instantiates a quaternion by interpolating between the specified quaternions.

Method Summary

All Methods Instance Methods Concrete Methods Deprecated Methods
Modifier and Type	Method and Description
`Quaternion`	`add(Quaternion q)` Adds the argument and returns the sum as a new instance.
`Quaternion`	`addLocal(Quaternion q)` Adds the argument and returns the (modified) current instance.
`void`	`apply(Matrix3f matrix)` Applies the rotation represented by the argument to the current instance.
`Quaternion`	`clone()` Creates a copy.
`float`	`dot(Quaternion q)` Returns the dot product with the argument.
`boolean`	`equals(java.lang.Object o)` Tests for exact equality with the argument, distinguishing -0 from 0.
`Quaternion`	`fromAngleAxis(float angle, Vector3f axis)` Sets the quaternion from the specified rotation angle and axis of rotation.
`Quaternion`	`fromAngleNormalAxis(float angle, Vector3f axis)` Sets the quaternion from the specified rotation angle and normalized axis of rotation.
`Quaternion`	`fromAngles(float[] angles)` Sets the quaternion from the specified Tait-Bryan angles, applying the rotations in x-z-y extrinsic order or y-z'-x" intrinsic order.
`Quaternion`	`fromAngles(float xAngle, float yAngle, float zAngle)` Sets the quaternion from the specified Tait-Bryan angles, applying the rotations in x-z-y extrinsic order or y-z'-x" intrinsic order.
`Quaternion`	`fromAxes(Vector3f[] axis)` Sets the quaternion from the specified orthonormal basis.
`Quaternion`	`fromAxes(Vector3f xAxis, Vector3f yAxis, Vector3f zAxis)` Sets the quaternion from the specified orthonormal basis.
`Quaternion`	`fromRotationMatrix(float m00, float m01, float m02, float m10, float m11, float m12, float m20, float m21, float m22)` Sets the quaternion from a rotation matrix with the specified elements.
`Quaternion`	`fromRotationMatrix(Matrix3f matrix)` Sets the quaternion from the specified rotation matrix.
`Vector3f`	`getRotationColumn(int i)` Calculates one of the basis vectors of the rotation.
`Vector3f`	`getRotationColumn(int i, Vector3f store)` Calculates one of the basis vectors of the rotation.
`float`	`getW()` Returns the W (real) component.
`float`	`getX()` Returns the X component.
`float`	`getY()` Returns the Y component.
`float`	`getZ()` Returns the Z component.
`int`	`hashCode()` Returns a hash code.
`Quaternion`	`inverse()` Returns the multiplicative inverse.
`Quaternion`	`inverseLocal()` Inverts the quaternion and returns the (modified) current instance.
`boolean`	`isIdentity()` Compares with the identity quaternion, without distinguishing -0 from 0.
`boolean`	`isSimilar(Quaternion other, float epsilon)` Tests for approximate equality with the specified quaternion, using the specified tolerance.
`void`	`loadIdentity()` Sets all components to zero except `w`, which is set to 1.
`Quaternion`	`lookAt(Vector3f direction, Vector3f up)` Convenience method to set the quaternion based on a "look" (Z-axis) direction and an "up" (Y-axis) direction.
`Quaternion`	`mult(float scalar)` Multiplies with the scalar argument and returns the product as a new instance.
`Quaternion`	`mult(Quaternion q)` Multiplies by the argument and returns the product as a new instance.
`Quaternion`	`mult(Quaternion q, Quaternion storeResult)` Multiplies by the specified quaternion and returns the product in a 3rd quaternion.
`Vector3f`	`mult(Vector3f v)` Rotates the argument vector and returns the result as a new vector.
`Vector3f`	`mult(Vector3f v, Vector3f store)` Rotates a specified vector and returns the result in another vector.
`Quaternion`	`multLocal(float scalar)` Multiplies by the scalar argument and returns the (modified) current instance.
`Quaternion`	`multLocal(float qx, float qy, float qz, float qw)` Multiplies by a quaternion with the specified components and returns the (modified) current instance.
`Quaternion`	`multLocal(Quaternion q)` Multiplies by the argument and returns the (modified) current instance.
`Vector3f`	`multLocal(Vector3f v)` Rotates the argument vector.
`void`	`negate()` Deprecated. The naming of this method doesn't follow convention. Please use `normalizeLocal()` instead.
`Quaternion`	`negateLocal()` Negates all 4 components and returns the (modified) current instance.
`void`	`nlerp(Quaternion q2, float blend)` Interpolates quickly between the current instance and `q2` using nlerp, and stores the result in the current instance.
`float`	`norm()` Returns the norm, defined as the dot product of the quaternion with itself.
`Quaternion`	`normalizeLocal()` Scales the quaternion to have norm=1 and returns the (modified) current instance.
`Quaternion`	`opposite()`
`Quaternion`	`opposite(Quaternion store)` Returns a rotation with the same axis and the angle increased by 180 degrees.
`Quaternion`	`oppositeLocal()` Changes the quaternion to a rotation with the same axis and the angle increased by 180 degrees.
`void`	`read(JmeImporter importer)` De-serializes from the specified importer, for example when loading from a J3O file.
`void`	`readExternal(java.io.ObjectInput in)` Sets the quaternion from an `ObjectInput` object.
`Quaternion`	`set(float x, float y, float z, float w)` Sets all 4 components to specified values.
`Quaternion`	`set(Quaternion q)` Copies all 4 components from the argument.
`void`	`slerp(Quaternion q2, float changeAmount)` Interpolates between the current instance and `q2` and stores the result in the current instance.
`Quaternion`	`slerp(Quaternion q1, Quaternion q2, float t)` Interpolates between the specified quaternions and stores the result in the current instance.
`Quaternion`	`subtract(Quaternion q)` Subtracts the argument and returns difference as a new instance.
`Quaternion`	`subtractLocal(Quaternion q)` Subtracts the argument and returns the (modified) current instance.
`float`	`toAngleAxis(Vector3f axisStore)` Converts the quaternion to a rotation angle and axis of rotation, storing the axis in the argument (if it's non-null) and returning the angle.
`float[]`	`toAngles(float[] angles)` Converts to equivalent Tait-Bryan angles, to be applied in x-z-y intrinsic order or y-z'-x" extrinsic order, for instance by `fromAngles(float[])`.
`void`	`toAxes(Vector3f[] axes)` Converts the quaternion to a rotated coordinate system and stores the resulting axes in the argument.
`Matrix3f`	`toRotationMatrix()` Converts to an equivalent rotation matrix.
`Matrix3f`	`toRotationMatrix(Matrix3f result)` Converts to an equivalent rotation matrix.
`Matrix4f`	`toRotationMatrix(Matrix4f result)` Sets the rotation component of the specified transform matrix.
`java.lang.String`	`toString()` Returns a string representation.
`Matrix4f`	`toTransformMatrix(Matrix4f store)` Sets the rotation component of the specified transform matrix.
`void`	`write(JmeExporter e)` Serializes to the specified exporter, for example when saving to a J3O file.
`void`	`writeExternal(java.io.ObjectOutput out)` Writes the quaternion to an `ObjectOutput` object.

Methods inherited from class java.lang.Object
finalize, getClass, notify, notifyAll, wait, wait, wait

- Field Detail
  - IDENTITY
```
public static final Quaternion IDENTITY
```
    Shared instance of the identity quaternion (0, 0, 0, 1). Do not modify!
    This is the usual representation for a null rotation.
  - DIRECTION_Z
```
public static final Quaternion DIRECTION_Z
```
    Another shared instance of the identity quaternion (0, 0, 0, 1). Do not modify!
  - ZERO
```
public static final Quaternion ZERO
```
    Shared instance of the zero quaternion (0, 0, 0, 0). Do not modify!
    The zero quaternion doesn't represent any valid rotation.
  - x
```
protected float x
```
    The first imaginary (X) component. Not an angle!
  - y
```
protected float y
```
    The 2nd imaginary (Y) component. Not an angle!
  - z
```
protected float z
```
    The 3rd imaginary (Z) component. Not an angle!
  - w
```
protected float w
```
    The real (W) component. Not an angle!
- Constructor Detail
  - Quaternion
```
public Quaternion()
```
    Instantiates an identity quaternion: all components zeroed except w, which is set to 1.
  - Quaternion
```
public Quaternion(float x,
                  float y,
                  float z,
                  float w)
```
    Instantiates a quaternion with specified components.
    
    Parameters:
    
    x - the desired X component
    
    y - the desired Y component
    
    z - the desired Z component
    
    w - the desired W component
  - Quaternion
```
public Quaternion(float[] angles)
```
    Instantiates a quaternion from Tait-Bryan angles, applying the rotations in x-z-y extrinsic order or y-z'-x" intrinsic order.
    
    Parameters:
    
    angles - an array of Tait-Bryan angles (in radians, exactly 3 elements, the X angle in angles[0], the Y angle in angles[1], and the Z angle in angles[2], not null, unaffected)
  - Quaternion
```
public Quaternion(Quaternion q1,
                  Quaternion q2,
                  float interp)
```
    Instantiates a quaternion by interpolating between the specified quaternions.
    Uses slerp(com.jme3.math.Quaternion, com.jme3.math.Quaternion, float), which is fast but inaccurate.
    
    Parameters:
    
    q1 - the desired value when interp=0 (not null, unaffected)
    
    q2 - the desired value when interp=1 (not null, may be modified)
    
    interp - the fractional change amount
  - Quaternion
```
public Quaternion(Quaternion q)
```
    Instantiates a copy of the argument.
    
    Parameters:
    
    q - the quaternion to copy (not null, unaffected)
- Method Detail
  - getX
```
public float getX()
```
    Returns the X component. The quaternion is unaffected.
    
    Returns:
    
    the value of the x component
  - getY
```
public float getY()
```
    Returns the Y component. The quaternion is unaffected.
    
    Returns:
    
    the value of the y component
  - getZ
```
public float getZ()
```
    Returns the Z component. The quaternion is unaffected.
    
    Returns:
    
    the value of the z component
  - getW
```
public float getW()
```
    Returns the W (real) component. The quaternion is unaffected.
    
    Returns:
    
    the value of the w component
  - set
```
public Quaternion set(float x,
                      float y,
                      float z,
                      float w)
```
    Sets all 4 components to specified values.
    
    Parameters:
    
    x - the desired X component
    
    y - the desired Y component
    
    z - the desired Z component
    
    w - the desired W component
    
    Returns:
    
    the (modified) current instance (for chaining)
  - set
```
public Quaternion set(Quaternion q)
```
    Copies all 4 components from the argument.
    
    Parameters:
    
    q - the quaternion to copy (not null, unaffected)
    
    Returns:
    
    the (modified) current instance (for chaining)
  - loadIdentity
```
public void loadIdentity()
```
    Sets all components to zero except w, which is set to 1.
  - isIdentity
```
public boolean isIdentity()
```
    Compares with the identity quaternion, without distinguishing -0 from 0. The current instance is unaffected.
    
    Returns:
    
    true if the current quaternion equals the identity, otherwise false
  - fromAngles
```
public Quaternion fromAngles(float[] angles)
```
    Sets the quaternion from the specified Tait-Bryan angles, applying the rotations in x-z-y extrinsic order or y-z'-x" intrinsic order.
    
    Parameters:
    
    angles - an array of Tait-Bryan angles (in radians, exactly 3 elements, the X angle in angles[0], the Y angle in angles[1], and the Z angle in angles[2], not null, unaffected)
    
    Returns:
    
    the (modified) current instance (for chaining)
    
    Throws:
    
    java.lang.IllegalArgumentException - if angles.length != 3
  - fromAngles
```
public Quaternion fromAngles(float xAngle,
                             float yAngle,
                             float zAngle)
```
    Sets the quaternion from the specified Tait-Bryan angles, applying the rotations in x-z-y extrinsic order or y-z'-x" intrinsic order.
    
    Parameters:
    
    xAngle - the X angle (in radians)
    
    yAngle - the Y angle (in radians)
    
    zAngle - the Z angle (in radians)
    
    Returns:
    
    the (modified) current instance (for chaining)
    
    See Also:
    
    http://www.euclideanspace.com/maths/geometry/rotations/conversions/eulerToQuaternion/index.htm
  - toAngles
```
public float[] toAngles(float[] angles)
```
    Converts to equivalent Tait-Bryan angles, to be applied in x-z-y intrinsic order or y-z'-x" extrinsic order, for instance by fromAngles(float[]). The current instance is unaffected.
    
    Parameters:
    
    angles - storage for the result, or null for a new float[3]
    
    Returns:
    
    an array of 3 angles (in radians, either angles or a new float[3], the X angle in angles[0], the Y angle in angles[1], and the Z angle in angles[2])
    
    Throws:
    
    java.lang.IllegalArgumentException - if angles.length != 3
    
    See Also:
    
    http://www.euclideanspace.com/maths/geometry/rotations/conversions/quaternionToEuler/index.htm
  - fromRotationMatrix
```
public Quaternion fromRotationMatrix(Matrix3f matrix)
```
    Sets the quaternion from the specified rotation matrix. Does not verify that the argument is a valid rotation matrix.
    
    Parameters:
    
    matrix - the input matrix (not null, unaffected)
    
    Returns:
    
    the (modified) current instance (for chaining)
  - fromRotationMatrix
```
public Quaternion fromRotationMatrix(float m00,
                                     float m01,
                                     float m02,
                                     float m10,
                                     float m11,
                                     float m12,
                                     float m20,
                                     float m21,
                                     float m22)
```
    Sets the quaternion from a rotation matrix with the specified elements. Does not verify that the arguments form a valid rotation matrix.
    
    Parameters:
    
    m00 - the matrix element in row 0, column 0
    
    m01 - the matrix element in row 0, column 1
    
    m02 - the matrix element in row 0, column 2
    
    m10 - the matrix element in row 1, column 0
    
    m11 - the matrix element in row 1, column 1
    
    m12 - the matrix element in row 1, column 2
    
    m20 - the matrix element in row 2, column 0
    
    m21 - the matrix element in row 2, column 1
    
    m22 - the matrix element in row 2, column 2
    
    Returns:
    
    the (modified) current instance (for chaining)
  - toRotationMatrix
```
public Matrix3f toRotationMatrix()
```
    Converts to an equivalent rotation matrix. The current instance is unaffected.
    Note: the result is created from a normalized version of the current instance.
    
    Returns:
    
    a new 3x3 rotation matrix
  - toRotationMatrix
```
public Matrix3f toRotationMatrix(Matrix3f result)
```
    Converts to an equivalent rotation matrix. The current instance is unaffected.
    Note: the result is created from a normalized version of the current instance.
    
    Parameters:
    
    result - storage for the result (not null)
    
    Returns:
    
    result, configured as a 3x3 rotation matrix
  - toTransformMatrix
```
public Matrix4f toTransformMatrix(Matrix4f store)
```
    Sets the rotation component of the specified transform matrix. The current instance is unaffected.
    Note: preserves the translation component of store but not its scaling component.
    Note: the result is created from a normalized version of the current instance.
    
    Parameters:
    
    store - storage for the result (not null)
    
    Returns:
    
    store, with 9 of its 16 elements modified
  - toRotationMatrix
```
public Matrix4f toRotationMatrix(Matrix4f result)
```
    Sets the rotation component of the specified transform matrix. The current instance is unaffected.
    Note: preserves the translation and scaling components of result.
    Note: the result is created from a normalized version of the current instance.
    
    Parameters:
    
    result - storage for the result (not null)
    
    Returns:
    
    result, with 9 of its 16 elements modified
  - getRotationColumn
```
public Vector3f getRotationColumn(int i)
```
    Calculates one of the basis vectors of the rotation. The current instance is unaffected.
    Note: the result is created from a normalized version of the current instance.
    
    Parameters:
    
    i - which basis vector to retrieve (≥0, <3, 0→X-axis, 1→Y-axis, 2→Z-axis)
    
    Returns:
    
    the basis vector (a new Vector3f)
  - getRotationColumn
```
public Vector3f getRotationColumn(int i,
                                  Vector3f store)
```
    Calculates one of the basis vectors of the rotation. The current instance is unaffected.
    Note: the result is created from a normalized version of the current instance.
    
    Parameters:
    
    i - which basis vector to retrieve (≥0, <3, 0→X-axis, 1→Y-axis, 2→Z-axis)
    
    store - storage for the result, or null for a new Vector3f
    
    Returns:
    
    the basis vector (either store or a new Vector3f)
    
    Throws:
    
    java.lang.IllegalArgumentException - if index is not 0, 1, or 2
  - fromAngleAxis
```
public Quaternion fromAngleAxis(float angle,
                                Vector3f axis)
```
    Sets the quaternion from the specified rotation angle and axis of rotation. This method creates garbage, so use fromAngleNormalAxis(float, com.jme3.math.Vector3f) if the axis is known to be normalized.
    
    Parameters:
    
    angle - the desired rotation angle (in radians)
    
    axis - the desired axis of rotation (not null, unaffected)
    
    Returns:
    
    the (modified) current instance (for chaining)
  - fromAngleNormalAxis
```
public Quaternion fromAngleNormalAxis(float angle,
                                      Vector3f axis)
```
    Sets the quaternion from the specified rotation angle and normalized axis of rotation. If the axis might not be normalized, use fromAngleAxis(float, com.jme3.math.Vector3f) instead.
    
    Parameters:
    
    angle - the desired rotation angle (in radians)
    
    axis - the desired axis of rotation (not null, length=1, unaffected)
    
    Returns:
    
    the (modified) current instance (for chaining)
  - toAngleAxis
```
public float toAngleAxis(Vector3f axisStore)
```
    Converts the quaternion to a rotation angle and axis of rotation, storing the axis in the argument (if it's non-null) and returning the angle.
    If the quaternion has x*x + y*y + z*z == 0, then (1,0,0) is stored and 0 is returned. (This might happen if the rotation angle is very close to 0.)
    Otherwise, the quaternion is assumed to be normalized (norm=1). No error checking is performed; the caller must ensure that the quaternion is normalized.
    In all cases, the current instance is unaffected.
    
    Parameters:
    
    axisStore - storage for the axis (modified if not null)
    
    Returns:
    
    the rotation angle (in radians)
  - slerp
```
public Quaternion slerp(Quaternion q1,
                        Quaternion q2,
                        float t)
```
    Interpolates between the specified quaternions and stores the result in the current instance.
    
    Parameters:
    
    q1 - the desired value when interp=0 (not null, unaffected)
    
    q2 - the desired value when interp=1 (not null, may be modified)
    
    t - the fractional change amount
    
    Returns:
    
    the (modified) current instance (for chaining)
  - slerp
```
public void slerp(Quaternion q2,
                  float changeAmount)
```
    Interpolates between the current instance and q2 and stores the result in the current instance.
    This method is often more accurate than nlerp(com.jme3.math.Quaternion, float), but slower.
    
    Parameters:
    
    q2 - the desired value when changeAmnt=1 (not null, may be modified)
    
    changeAmount - the fractional change amount
  - nlerp
```
public void nlerp(Quaternion q2,
                  float blend)
```
    Interpolates quickly between the current instance and q2 using nlerp, and stores the result in the current instance.
    This method is often faster than slerp(com.jme3.math.Quaternion, float), but less accurate.
    
    Parameters:
    
    q2 - the desired value when blend=1 (not null, unaffected)
    
    blend - the fractional change amount
  - add
```
public Quaternion add(Quaternion q)
```
    Adds the argument and returns the sum as a new instance. The current instance is unaffected.
    Seldom used. To combine rotations, use mult(com.jme3.math.Quaternion) instead of this method.
    
    Parameters:
    
    q - the quaternion to add (not null, unaffected)
    
    Returns:
    
    a new Quaternion
  - addLocal
```
public Quaternion addLocal(Quaternion q)
```
    Adds the argument and returns the (modified) current instance.
    Seldom used. To combine rotations, use multLocal(com.jme3.math.Quaternion) or mult(com.jme3.math.Quaternion, com.jme3.math.Quaternion) instead of this method.
    
    Parameters:
    
    q - the quaternion to add (not null, unaffected unless it's this)
    
    Returns:
    
    the (modified) current instance
  - subtract
```
public Quaternion subtract(Quaternion q)
```
    Subtracts the argument and returns difference as a new instance. The current instance is unaffected.
    
    Parameters:
    
    q - the quaternion to subtract (not null, unaffected)
    
    Returns:
    
    a new Quaternion
  - subtractLocal
```
public Quaternion subtractLocal(Quaternion q)
```
    Subtracts the argument and returns the (modified) current instance.
    To quantify the similarity of 2 normalized quaternions, use dot(com.jme3.math.Quaternion).
    
    Parameters:
    
    q - the quaternion to subtract (not null, unaffected unless it's this)
    
    Returns:
    
    the (modified) current instance
  - mult
```
public Quaternion mult(Quaternion q)
```
    Multiplies by the argument and returns the product as a new instance. The current instance is unaffected.
    This method is used to combine rotations. Note that quaternion multiplication is noncommutative, so generally q * p != p * q.
    
    Parameters:
    
    q - the right factor (not null, unaffected)
    
    Returns:
    
    this * q (a new Quaternion)
  - mult
```
public Quaternion mult(Quaternion q,
                       Quaternion storeResult)
```
    Multiplies by the specified quaternion and returns the product in a 3rd quaternion. The current instance is unaffected, unless it's storeResult.
    This method is used to combine rotations. Note that quaternion multiplication is noncommutative, so generally q * p != p * q.
    It is safe for q and storeResult to be the same object. However, if this and storeResult are the same object, the result is undefined.
    
    Parameters:
    
    q - the right factor (not null, unaffected unless it's res)
    
    storeResult - storage for the product, or null for a new Quaternion
    
    Returns:
    
    this * q (either storeResult or a new Quaternion)
  - apply
```
public void apply(Matrix3f matrix)
```
    Applies the rotation represented by the argument to the current instance.
    
    Parameters:
    
    matrix - the rotation matrix to apply (not null, unaffected)
  - fromAxes
```
public Quaternion fromAxes(Vector3f[] axis)
```
    Sets the quaternion from the specified orthonormal basis.
    The 3 basis vectors describe the axes of a rotated coordinate system. They are assumed to be normalized, mutually orthogonal, and in right-hand order. No error checking is performed; the caller must ensure that the specified vectors represent a right-handed coordinate system.
    
    Parameters:
    
    axis - the array of desired basis vectors (not null, array length=3, each vector having length=1, unaffected)
    
    Returns:
    
    the (modified) current instance (for chaining)
    
    Throws:
    
    java.lang.IllegalArgumentException - if axis.length != 3
  - fromAxes
```
public Quaternion fromAxes(Vector3f xAxis,
                           Vector3f yAxis,
                           Vector3f zAxis)
```
    Sets the quaternion from the specified orthonormal basis.
    The 3 basis vectors describe the axes of a rotated coordinate system. They are assumed to be normalized, mutually orthogonal, and in right-hand order. No error checking is performed; the caller must ensure that the specified vectors represent a right-handed coordinate system.
    
    Parameters:
    
    xAxis - the X axis of the desired coordinate system (not null, length=1, unaffected)
    
    yAxis - the Y axis of the desired coordinate system (not null, length=1, unaffected)
    
    zAxis - the Z axis of the desired coordinate system (not null, length=1, unaffected)
    
    Returns:
    
    the (modified) current instance (for chaining)
  - toAxes
```
public void toAxes(Vector3f[] axes)
```
    Converts the quaternion to a rotated coordinate system and stores the resulting axes in the argument. The current instance is unaffected.
    The resulting vectors form the basis of a rotated coordinate system. They will be normalized, mutually orthogonal, and in right-hand order.
    
    Parameters:
    
    axes - storage for the results (not null, length=3, each element non-null, elements modified)
    
    Throws:
    
    java.lang.IllegalArgumentException - if axes.length != 3
  - mult
```
public Vector3f mult(Vector3f v)
```
    Rotates the argument vector and returns the result as a new vector. The current instance is unaffected.
    Despite the name, the result differs from the mathematical definition of vector-quaternion multiplication.
    
    Parameters:
    
    v - the vector to rotate (not null, unaffected)
    
    Returns:
    
    a new Vector3f
  - multLocal
```
public Vector3f multLocal(Vector3f v)
```
    Rotates the argument vector. Despite the name, the current instance is unaffected.
    Despite the name, the result differs from the mathematical definition of vector-quaternion multiplication.
    
    Parameters:
    
    v - the vector to rotate (not null)
    
    Returns:
    
    the (modified) vector v
  - multLocal
```
public Quaternion multLocal(Quaternion q)
```
    Multiplies by the argument and returns the (modified) current instance.
    This method is used to combine rotations. Note that quaternion multiplication is noncommutative, so generally q * p != p * q.
    
    Parameters:
    
    q - the right factor (not null, unaffected unless it's this)
    
    Returns:
    
    the (modified) current instance (for chaining)
  - multLocal
```
public Quaternion multLocal(float qx,
                            float qy,
                            float qz,
                            float qw)
```
    Multiplies by a quaternion with the specified components and returns the (modified) current instance.
    This method is used to combine rotations. Note that quaternion multiplication is noncommutative, so generally q * p != p * q.
    
    Parameters:
    
    qx - the X component of the right factor
    
    qy - the Y component of the right factor
    
    qz - the Z component of the right factor
    
    qw - the W component of the right factor
    
    Returns:
    
    the (modified) current instance (for chaining)
  - mult
```
public Vector3f mult(Vector3f v,
                     Vector3f store)
```
    Rotates a specified vector and returns the result in another vector. The current instance is unaffected.
    It is safe for v and store to be the same object.
    Despite the name, the result differs from the mathematical definition of vector-quaternion multiplication.
    
    Parameters:
    
    v - the vector to rotate (not null, unaffected unless it's store)
    
    store - storage for the result, or null for a new Vector3f
    
    Returns:
    
    the rotated vector (either store or a new Vector3f)
  - mult
```
public Quaternion mult(float scalar)
```
    Multiplies with the scalar argument and returns the product as a new instance. The current instance is unaffected.
    
    Parameters:
    
    scalar - the scaling factor
    
    Returns:
    
    a new Quaternion
  - multLocal
```
public Quaternion multLocal(float scalar)
```
    Multiplies by the scalar argument and returns the (modified) current instance.
    
    Parameters:
    
    scalar - the scaling factor
    
    Returns:
    
    the (modified) current instance (for chaining)
  - dot
```
public float dot(Quaternion q)
```
    Returns the dot product with the argument. The current instance is unaffected.
    This method can be used to quantify the similarity of 2 normalized quaternions.
    
    Parameters:
    
    q - the quaternion to multiply (not null, unaffected)
    
    Returns:
    
    the dot product
  - norm
```
public float norm()
```
    Returns the norm, defined as the dot product of the quaternion with itself. The current instance is unaffected.
    
    Returns:
    
    the sum of the squared components (not negative)
  - normalizeLocal
```
public Quaternion normalizeLocal()
```
    Scales the quaternion to have norm=1 and returns the (modified) current instance. For a quaternion with norm=0, the result is undefined.
    
    Returns:
    
    the (modified) current instance (for chaining)
  - inverse
```
public Quaternion inverse()
```
    Returns the multiplicative inverse. For a quaternion with norm=0, null is returned. Either way, the current instance is unaffected.
    
    Returns:
    
    a new Quaternion or null
  - inverseLocal
```
public Quaternion inverseLocal()
```
    Inverts the quaternion and returns the (modified) current instance. For a quaternion with norm=0, the current instance is unchanged.
    
    Returns:
    
    the current instance (for chaining)
  - negate
```
@Deprecated
public void negate()
```
    Deprecated. The naming of this method doesn't follow convention. Please use normalizeLocal() instead.
    
    Negates all 4 components.
  - negateLocal
```
public Quaternion negateLocal()
```
    Negates all 4 components and returns the (modified) current instance.
    
    Returns:
    
    the (modified) current instance (for chaining)
  - toString
```
public java.lang.String toString()
```
    Returns a string representation. The current instance is unaffected. The format is:
    (X.XXXX, Y.YYYY, Z.ZZZZ, W.WWWW)
    
    Overrides:
    
    toString in class java.lang.Object
    
    Returns:
    
    the string representation
    
    See Also:
    
    Object.toString()
  - equals
```
public boolean equals(java.lang.Object o)
```
    Tests for exact equality with the argument, distinguishing -0 from 0. The current instance is unaffected.
    
    Overrides:
    
    equals in class java.lang.Object
    
    Parameters:
    
    o - the object to compare (may be null, unaffected)
    
    Returns:
    
    true if equal, otherwise false
  - isSimilar
```
public boolean isSimilar(Quaternion other,
                         float epsilon)
```
    Tests for approximate equality with the specified quaternion, using the specified tolerance. The current instance is unaffected.
    To quantify the similarity of 2 normalized quaternions, use dot(com.jme3.math.Quaternion).
    
    Parameters:
    
    other - the quaternion to compare (not null, unaffected)
    
    epsilon - the tolerance for each component
    
    Returns:
    
    true if all 4 components are within tolerance, otherwise false
  - hashCode
```
public int hashCode()
```
    Returns a hash code. If two quaternions are logically equivalent, they will return the same hash code. The current instance is unaffected.
    
    Overrides:
    
    hashCode in class java.lang.Object
    
    Returns:
    
    the hash code value
    
    See Also:
    
    Object.hashCode()
  - readExternal
```
public void readExternal(java.io.ObjectInput in)
                  throws java.io.IOException
```
    Sets the quaternion from an ObjectInput object.
    Used with serialization. Should not be invoked directly by application code.
    
    Parameters:
    
    in - the object to read from (not null)
    
    Throws:
    
    java.io.IOException - if the ObjectInput cannot read a float
    
    See Also:
    
    Externalizable
  - writeExternal
```
public void writeExternal(java.io.ObjectOutput out)
                   throws java.io.IOException
```
    Writes the quaternion to an ObjectOutput object.
    Used with serialization. Should not be invoked directly by application code.
    
    Parameters:
    
    out - the object to write to (not null)
    
    Throws:
    
    java.io.IOException - if the ObjectOuput cannot write a float
    
    See Also:
    
    Externalizable
  - lookAt
```
public Quaternion lookAt(Vector3f direction,
                         Vector3f up)
```
    Convenience method to set the quaternion based on a "look" (Z-axis) direction and an "up" (Y-axis) direction.
    If either vector has length=0, the result is undefined.
    If the vectors are parallel, the result is undefined.
    
    Parameters:
    
    direction - the desired Z-axis direction (in local coordinates, not null, length>0, unaffected)
    
    up - the desired Y-axis direction (in local coordinates, not null, length>0, unaffected, typically (0,1,0) )
    
    Returns:
    
    the (modified) current instance (for chaining)
  - write
```
public void write(JmeExporter e)
           throws java.io.IOException
```
    Serializes to the specified exporter, for example when saving to a J3O file. The current instance is unaffected.
    
    Specified by:
    
    write in interface Savable
    
    Parameters:
    
    e - the exporter to use (not null)
    
    Throws:
    
    java.io.IOException - from the exporter
  - read
```
public void read(JmeImporter importer)
          throws java.io.IOException
```
    De-serializes from the specified importer, for example when loading from a J3O file.
    
    Specified by:
    
    read in interface Savable
    
    Parameters:
    
    importer - the importer to use (not null)
    
    Throws:
    
    java.io.IOException - from the importer
  - opposite
```
public Quaternion opposite()
```
    Returns:
    
    A new quaternion that describes a rotation that would point you in the exact opposite direction of this Quaternion.
  - opposite
```
public Quaternion opposite(Quaternion store)
```
    Returns a rotation with the same axis and the angle increased by 180 degrees. If the quaternion isn't normalized, or if the rotation angle is very small, the result is undefined.
    The current instance is unaffected, unless store is this.
    
    Parameters:
    
    store - storage for the result, or null for a new Quaternion
    
    Returns:
    
    either store or a new Quaternion
  - oppositeLocal
```
public Quaternion oppositeLocal()
```
    Changes the quaternion to a rotation with the same axis and the angle increased by 180 degrees. If the quaternion isn't normalized, or if the rotation angle is very small, the result is undefined.
    
    Returns:
    
    the (modified) current instance
  - clone
```
public Quaternion clone()
```
    Creates a copy. The current instance is unaffected.
    
    Overrides:
    
    clone in class java.lang.Object
    
    Returns:
    
    a new instance, equivalent to the current one

Class Quaternion

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

IDENTITY

DIRECTION_Z

ZERO

x

y

z

w

Constructor Detail

Quaternion

Quaternion

Quaternion

Quaternion

Quaternion

Method Detail

getX

getY

getZ

getW

set

set

loadIdentity

isIdentity

fromAngles

fromAngles

toAngles

fromRotationMatrix

fromRotationMatrix

toRotationMatrix

toRotationMatrix

toTransformMatrix

toRotationMatrix

getRotationColumn

getRotationColumn

fromAngleAxis

fromAngleNormalAxis

toAngleAxis

slerp

slerp

nlerp

add

addLocal

subtract

subtractLocal

mult

mult

apply

fromAxes

fromAxes

toAxes

mult

multLocal

multLocal

multLocal

mult

mult

multLocal

dot

norm

normalizeLocal

inverse

inverseLocal

negate

negateLocal

toString

equals

isSimilar

hashCode

readExternal

writeExternal

lookAt

write

read

opposite

opposite