VehicleWheel (jMonkeyEngine3)

java.lang.Object
- com.jme3.bullet.objects.VehicleWheel

All Implemented Interfaces:

Savable
```
public class VehicleWheel
extends java.lang.Object
implements Savable
```
Information about one wheel of a PhysicsVehicle.

Field Summary

Fields
Modifier and Type	Field and Description
`protected Vector3f`	`axle` axis direction (in chassis coordinates, typically to the right/-1,0,0)
`protected Vector3f`	`direction` suspension direction (in chassis coordinates, typically down/0,-1,0)
`protected float`	`frictionSlip` copy of coefficient of friction between tyre and ground (0.8→realistic car, 10000→kart racer, default=10.5)
`protected boolean`	`frontWheel` copy of wheel type: true→front (steering) wheel, false→non-front wheel
`protected Vector3f`	`location` location where the suspension connects to the chassis (in chassis coordinates)
`protected float`	`maxSuspensionForce` copy of maximum force exerted by the suspension (default=6000)
`protected float`	`maxSuspensionTravelCm` copy of maximum suspension travel distance (in centimeters, default=500)
`protected float`	`radius` copy of wheel radius (in physics-space units, >0)
`protected float`	`restLength` copy of rest length of the suspension (in physics-space units)
`protected float`	`rollInfluence` copy of roll-influence factor (0→no roll torque, 1→realistic behavior, default=1)
`protected float`	`suspensionStiffness` copy of suspension stiffness constant (10→off-road buggy, 50→sports car, 200→Formula-1 race car, default=20)
`protected Quaternion`	`tmp_inverseWorldRotation`
`protected Matrix3f`	`tmp_Matrix`
`protected long`	`wheelId` unique identifier of the btRaycastVehicle
`protected int`	`wheelIndex` 0-origin index among the vehicle's wheels (≥0)
`protected float`	`wheelsDampingCompression` copy of suspension damping when compressed (0→no damping, default=4.4)
`protected float`	`wheelsDampingRelaxation` copy of suspension damping when expanded (0→no damping, default=2.3)
`protected Spatial`	`wheelSpatial` associated spatial, or null if none
`protected Vector3f`	`wheelWorldLocation` wheel location in physics-space coordinates
`protected Quaternion`	`wheelWorldRotation` wheel orientation in physics-space coordinates

Constructor Summary

Constructors
Modifier	Constructor and Description
`protected`	`VehicleWheel()` No-argument constructor needed by SavableClassUtil.
	`VehicleWheel(Spatial spat, Vector3f location, Vector3f direction, Vector3f axle, float restLength, float radius, boolean frontWheel)` Instantiate a wheel.
	`VehicleWheel(Vector3f location, Vector3f direction, Vector3f axle, float restLength, float radius, boolean frontWheel)` Instantiate a wheel without an associated spatial.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`applyWheelTransform()` Apply this wheel's physics location and orientation to its associated spatial, if any.
`Vector3f`	`getAxle()` Access this wheel's axle direction.
`Vector3f`	`getCollisionLocation()` Copy the location where the wheel collides with the ground.
`Vector3f`	`getCollisionLocation(Vector3f vec)` Copy the location where the wheel touches the ground.
`Vector3f`	`getCollisionNormal()` Copy the normal where the wheel touches the ground.
`Vector3f`	`getCollisionNormal(Vector3f vec)` Copy the normal where the wheel touches the ground.
`float`	`getDeltaRotation()` Calculate how much this wheel has turned since the last physics step.
`float`	`getDeltaRotation(long wheelId, int wheelIndex)`
`Vector3f`	`getDirection()` Access this wheel's suspension direction.
`float`	`getFrictionSlip()` Read the friction between this wheel's tyre and the ground.
`PhysicsCollisionObject`	`getGroundObject()` returns the object this wheel is in contact with or null if no contact
`Vector3f`	`getLocation()` Access the location where the suspension connects to the chassis.
`float`	`getMaxSuspensionForce()` Read the maximum force exerted by this wheel's suspension.
`float`	`getMaxSuspensionTravelCm()` Read the travel distance for this wheel's suspension.
`float`	`getRadius()` Read the radius of this wheel.
`float`	`getRestLength()` Read the rest length of this wheel.
`float`	`getRollInfluence()` Read this wheel's roll influence.
`float`	`getSkidInfo()` Calculate to what extent the wheel is skidding (for skid sounds/smoke etc.)
`float`	`getSkidInfo(long wheelId, int wheelIndex)`
`float`	`getSuspensionStiffness()` Read the stiffness constant for this wheel's suspension.
`long`	`getWheelId()` Read the id of the btRaycastVehicle.
`float`	`getWheelsDampingCompression()` Read this wheel's damping when the suspension is compressed.
`float`	`getWheelsDampingRelaxation()` Read this wheel's damping when the suspension is expanded.
`Spatial`	`getWheelSpatial()` Access the spatial associated with this wheel.
`void`	`getWheelWorldLocation(Vector3f store)` Copy this wheel's physics-space location to the specified vector.
`void`	`getWheelWorldRotation(Quaternion store)` Copy this wheel's physics-space orientation to the specified quaternion.
`boolean`	`isApplyLocal()` Test whether physics coordinates should match the local transform of the Spatial.
`boolean`	`isFrontWheel()` Test whether this wheel is a front wheel.
`void`	`read(JmeImporter im)` De-serialize this wheel, for example when loading from a J3O file.
`void`	`setApplyLocal(boolean applyLocal)` Alter whether physics coordinates should match the local transform of the Spatial.
`void`	`setFrictionSlip(float frictionSlip)` Alter the friction between this wheel's tyre and the ground.
`void`	`setFrontWheel(boolean frontWheel)` Alter whether this wheel is a front (steering) wheel.
`void`	`setMaxSuspensionForce(float maxSuspensionForce)` Alter the maximum force exerted by this wheel's suspension.
`void`	`setMaxSuspensionTravelCm(float maxSuspensionTravelCm)` Alter the travel distance for this wheel's suspension.
`void`	`setRadius(float radius)` Alter the radius of this wheel.
`void`	`setRestLength(float restLength)` Alter the rest length of the suspension of this wheel.
`void`	`setRollInfluence(float rollInfluence)` Alter this wheel's roll influence.
`void`	`setSuspensionStiffness(float suspensionStiffness)` Alter the stiffness constant for this wheel's suspension.
`void`	`setVehicleId(long vehicleId, int wheelIndex)` Assign this wheel to a vehicle.
`void`	`setWheelsDampingCompression(float wheelsDampingCompression)` Alter this wheel's damping when the suspension is compressed.
`void`	`setWheelsDampingRelaxation(float wheelsDampingRelaxation)` Alter this wheel's damping when the suspension is expanded.
`void`	`setWheelSpatial(Spatial wheelSpatial)` Alter which spatial is associated with this wheel.
`void`	`updatePhysicsState()` Update this wheel's location and orientation in physics space.
`void`	`write(JmeExporter ex)` Serialize this wheel, for example when saving to a J3O file.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - wheelId
```
protected long wheelId
```
    unique identifier of the btRaycastVehicle
  - wheelIndex
```
protected int wheelIndex
```
    0-origin index among the vehicle's wheels (≥0)
  - frontWheel
```
protected boolean frontWheel
```
    copy of wheel type: true→front (steering) wheel, false→non-front wheel
  - location
```
protected Vector3f location
```
    location where the suspension connects to the chassis (in chassis coordinates)
  - direction
```
protected Vector3f direction
```
    suspension direction (in chassis coordinates, typically down/0,-1,0)
  - axle
```
protected Vector3f axle
```
    axis direction (in chassis coordinates, typically to the right/-1,0,0)
  - suspensionStiffness
```
protected float suspensionStiffness
```
    copy of suspension stiffness constant (10→off-road buggy, 50→sports car, 200→Formula-1 race car, default=20)
  - wheelsDampingRelaxation
```
protected float wheelsDampingRelaxation
```
    copy of suspension damping when expanded (0→no damping, default=2.3)
  - wheelsDampingCompression
```
protected float wheelsDampingCompression
```
    copy of suspension damping when compressed (0→no damping, default=4.4)
  - frictionSlip
```
protected float frictionSlip
```
    copy of coefficient of friction between tyre and ground (0.8→realistic car, 10000→kart racer, default=10.5)
  - rollInfluence
```
protected float rollInfluence
```
    copy of roll-influence factor (0→no roll torque, 1→realistic behavior, default=1)
  - maxSuspensionTravelCm
```
protected float maxSuspensionTravelCm
```
    copy of maximum suspension travel distance (in centimeters, default=500)
  - maxSuspensionForce
```
protected float maxSuspensionForce
```
    copy of maximum force exerted by the suspension (default=6000)
  - radius
```
protected float radius
```
    copy of wheel radius (in physics-space units, >0)
  - restLength
```
protected float restLength
```
    copy of rest length of the suspension (in physics-space units)
  - wheelWorldLocation
```
protected Vector3f wheelWorldLocation
```
    wheel location in physics-space coordinates
  - wheelWorldRotation
```
protected Quaternion wheelWorldRotation
```
    wheel orientation in physics-space coordinates
  - wheelSpatial
```
protected Spatial wheelSpatial
```
    associated spatial, or null if none
  - tmp_Matrix
```
protected Matrix3f tmp_Matrix
```
  - tmp_inverseWorldRotation
```
protected final Quaternion tmp_inverseWorldRotation
```
- Constructor Detail
  - VehicleWheel
```
protected VehicleWheel()
```
    No-argument constructor needed by SavableClassUtil. Do not invoke directly!
  - VehicleWheel
```
public VehicleWheel(Spatial spat,
                    Vector3f location,
                    Vector3f direction,
                    Vector3f axle,
                    float restLength,
                    float radius,
                    boolean frontWheel)
```
    Instantiate a wheel.
    
    Parameters:
    
    spat - the associated spatial, or null if none
    
    location - the location where the suspension connects to the chassis (in chassis coordinates, not null, unaffected)
    
    direction - the suspension direction (in chassis coordinates, not null, unaffected, typically down/0,-1,0)
    
    axle - the axis direction (in chassis coordinates, not null, unaffected, typically right/-1,0,0)
    
    restLength - the rest length of the suspension (in physics-space units)
    
    radius - the wheel's radius (in physics-space units, ≥0)
    
    frontWheel - true→front (steering) wheel, false→non-front wheel
  - VehicleWheel
```
public VehicleWheel(Vector3f location,
                    Vector3f direction,
                    Vector3f axle,
                    float restLength,
                    float radius,
                    boolean frontWheel)
```
    Instantiate a wheel without an associated spatial.
    
    Parameters:
    
    location - the location where the suspension connects to the chassis (in chassis coordinates, not null, unaffected)
    
    direction - the suspension direction (in chassis coordinates, not null, unaffected, typically down/0,-1,0)
    
    axle - the axis direction (in chassis coordinates, not null, unaffected, typically right/-1,0,0)
    
    restLength - the rest length of the suspension (in physics-space units)
    
    radius - the wheel's radius (in physics-space units, ≥0)
    
    frontWheel - true→front (steering) wheel, false→non-front wheel
- Method Detail
  - updatePhysicsState
```
public void updatePhysicsState()
```
    Update this wheel's location and orientation in physics space.
  - applyWheelTransform
```
public void applyWheelTransform()
```
    Apply this wheel's physics location and orientation to its associated spatial, if any.
  - getWheelId
```
public long getWheelId()
```
    Read the id of the btRaycastVehicle.
    
    Returns:
    
    the unique identifier (not zero)
  - setVehicleId
```
public void setVehicleId(long vehicleId,
                         int wheelIndex)
```
    Assign this wheel to a vehicle.
    
    Parameters:
    
    vehicleId - the id of the btRaycastVehicle (not zero)
    
    wheelIndex - index among the vehicle's wheels (≥0)
  - isFrontWheel
```
public boolean isFrontWheel()
```
    Test whether this wheel is a front wheel.
    
    Returns:
    
    true if front wheel, otherwise false
  - setFrontWheel
```
public void setFrontWheel(boolean frontWheel)
```
    Alter whether this wheel is a front (steering) wheel.
    
    Parameters:
    
    frontWheel - true→front wheel, false→non-front wheel
  - getLocation
```
public Vector3f getLocation()
```
    Access the location where the suspension connects to the chassis.
    
    Returns:
    
    the pre-existing location vector (in chassis coordinates, not null)
  - getDirection
```
public Vector3f getDirection()
```
    Access this wheel's suspension direction.
    
    Returns:
    
    the pre-existing direction vector (in chassis coordinates, not null)
  - getAxle
```
public Vector3f getAxle()
```
    Access this wheel's axle direction.
    
    Returns:
    
    the pre-existing direction vector (not null)
  - getSuspensionStiffness
```
public float getSuspensionStiffness()
```
    Read the stiffness constant for this wheel's suspension.
    
    Returns:
    
    the stiffness constant
  - setSuspensionStiffness
```
public void setSuspensionStiffness(float suspensionStiffness)
```
    Alter the stiffness constant for this wheel's suspension.
    
    Parameters:
    
    suspensionStiffness - the desired stiffness constant (10→off-road buggy, 50→sports car, 200→Formula-1 race car, default=20)
  - getWheelsDampingRelaxation
```
public float getWheelsDampingRelaxation()
```
    Read this wheel's damping when the suspension is expanded.
    
    Returns:
    
    the damping
  - setWheelsDampingRelaxation
```
public void setWheelsDampingRelaxation(float wheelsDampingRelaxation)
```
    Alter this wheel's damping when the suspension is expanded.
    Set to k * 2 * FastMath.sqrt(m_suspensionStiffness) where k is the damping ratio:
    k = 0.0 undamped and bouncy, k = 1.0 critical damping, k between 0.1 and 0.3 are good values
    
    Parameters:
    
    wheelsDampingRelaxation - the desired damping (default=2.3)
  - getWheelsDampingCompression
```
public float getWheelsDampingCompression()
```
    Read this wheel's damping when the suspension is compressed.
    
    Returns:
    
    the damping
  - setWheelsDampingCompression
```
public void setWheelsDampingCompression(float wheelsDampingCompression)
```
    Alter this wheel's damping when the suspension is compressed.
    Set to k * 2 * FastMath.sqrt(m_suspensionStiffness) where k is the damping ratio:
    k = 0.0 undamped and bouncy, k = 1.0 critical damping, k between 0.1 and 0.3 are good values
    
    Parameters:
    
    wheelsDampingCompression - the desired damping (default=4.4)
  - getFrictionSlip
```
public float getFrictionSlip()
```
    Read the friction between this wheel's tyre and the ground.
    
    Returns:
    
    the coefficient of friction
  - setFrictionSlip
```
public void setFrictionSlip(float frictionSlip)
```
    Alter the friction between this wheel's tyre and the ground.
    Should be about 0.8 for realistic cars, but can increased for better handling. Set large (10000.0) for kart racers.
    
    Parameters:
    
    frictionSlip - the desired coefficient of friction (default=10.5)
  - getRollInfluence
```
public float getRollInfluence()
```
    Read this wheel's roll influence.
    
    Returns:
    
    the roll-influence factor
  - setRollInfluence
```
public void setRollInfluence(float rollInfluence)
```
    Alter this wheel's roll influence.
    The roll-influence factor reduces (or magnifies) the torque contributed by this wheel that tends to cause the vehicle to roll over. This is a bit of a hack, but it's quite effective.
    If the friction between the tyres and the ground is too high, you may reduce this factor to prevent the vehicle from rolling over. You should also try lowering the vehicle's centre of mass.
    
    Parameters:
    
    rollInfluence - the desired roll-influence factor (0→no roll torque, 1→realistic behaviour, default=1)
  - getMaxSuspensionTravelCm
```
public float getMaxSuspensionTravelCm()
```
    Read the travel distance for this wheel's suspension.
    
    Returns:
    
    the maximum travel distance (in centimeters)
  - setMaxSuspensionTravelCm
```
public void setMaxSuspensionTravelCm(float maxSuspensionTravelCm)
```
    Alter the travel distance for this wheel's suspension.
    
    Parameters:
    
    maxSuspensionTravelCm - the desired maximum travel distance (in centimetres, default=500)
  - getMaxSuspensionForce
```
public float getMaxSuspensionForce()
```
    Read the maximum force exerted by this wheel's suspension.
    
    Returns:
    
    the maximum force
  - setMaxSuspensionForce
```
public void setMaxSuspensionForce(float maxSuspensionForce)
```
    Alter the maximum force exerted by this wheel's suspension.
    Increase this if your suspension cannot handle the weight of your vehicle.
    
    Parameters:
    
    maxSuspensionForce - the desired maximum force (default=6000)
  - getRadius
```
public float getRadius()
```
    Read the radius of this wheel.
    
    Returns:
    
    the radius (in physics-space units, ≥0)
  - setRadius
```
public void setRadius(float radius)
```
    Alter the radius of this wheel.
    
    Parameters:
    
    radius - the desired radius (in physics-space units, ≥0, default=0.5)
  - getRestLength
```
public float getRestLength()
```
    Read the rest length of this wheel.
    
    Returns:
    
    the length
  - setRestLength
```
public void setRestLength(float restLength)
```
    Alter the rest length of the suspension of this wheel.
    
    Parameters:
    
    restLength - the desired length (default=1)
  - getGroundObject
```
public PhysicsCollisionObject getGroundObject()
```
    returns the object this wheel is in contact with or null if no contact
    
    Returns:
    
    the PhysicsCollisionObject (PhysicsRigidBody, PhysicsGhostObject)
  - getCollisionLocation
```
public Vector3f getCollisionLocation(Vector3f vec)
```
    Copy the location where the wheel touches the ground.
    
    Parameters:
    
    vec - storage for the result (not null, modified)
    
    Returns:
    
    a new location vector (in physics-space coordinates, not null)
  - getCollisionLocation
```
public Vector3f getCollisionLocation()
```
    Copy the location where the wheel collides with the ground.
    
    Returns:
    
    a new location vector (in physics-space coordinates)
  - getCollisionNormal
```
public Vector3f getCollisionNormal(Vector3f vec)
```
    Copy the normal where the wheel touches the ground.
    
    Parameters:
    
    vec - storage for the result (not null, modified)
    
    Returns:
    
    a unit vector (in physics-space coordinates, not null)
  - getCollisionNormal
```
public Vector3f getCollisionNormal()
```
    Copy the normal where the wheel touches the ground.
    
    Returns:
    
    a new unit vector (in physics-space coordinates, not null)
  - getSkidInfo
```
public float getSkidInfo()
```
    Calculate to what extent the wheel is skidding (for skid sounds/smoke etc.)
    
    Returns:
    
    the relative amount of traction (0→wheel is sliding, 1→wheel has full traction)
  - getSkidInfo
```
public float getSkidInfo(long wheelId,
                         int wheelIndex)
```
  - getDeltaRotation
```
public float getDeltaRotation()
```
    Calculate how much this wheel has turned since the last physics step.
    
    Returns:
    
    the rotation angle (in radians)
  - getDeltaRotation
```
public float getDeltaRotation(long wheelId,
                              int wheelIndex)
```
  - read
```
public void read(JmeImporter im)
          throws java.io.IOException
```
    De-serialize this wheel, for example when loading from a J3O file.
    
    Specified by:
    
    read in interface Savable
    
    Parameters:
    
    im - importer (not null)
    
    Throws:
    
    java.io.IOException - from importer
  - write
```
public void write(JmeExporter ex)
           throws java.io.IOException
```
    Serialize this wheel, for example when saving to a J3O file.
    
    Specified by:
    
    write in interface Savable
    
    Parameters:
    
    ex - exporter (not null)
    
    Throws:
    
    java.io.IOException - from exporter
  - getWheelSpatial
```
public Spatial getWheelSpatial()
```
    Access the spatial associated with this wheel.
    
    Returns:
    
    the pre-existing instance, or null
  - setWheelSpatial
```
public void setWheelSpatial(Spatial wheelSpatial)
```
    Alter which spatial is associated with this wheel.
    
    Parameters:
    
    wheelSpatial - the desired spatial, or null for none
  - isApplyLocal
```
public boolean isApplyLocal()
```
    Test whether physics coordinates should match the local transform of the Spatial.
    
    Returns:
    
    true if matching local transform, false if matching world transform
  - setApplyLocal
```
public void setApplyLocal(boolean applyLocal)
```
    Alter whether physics coordinates should match the local transform of the Spatial.
    
    Parameters:
    
    applyLocal - true→match local transform, false→match world transform (default=false)
  - getWheelWorldRotation
```
public void getWheelWorldRotation(Quaternion store)
```
    Copy this wheel's physics-space orientation to the specified quaternion.
    
    Parameters:
    
    store - storage for the result (not null, modified)
  - getWheelWorldLocation
```
public void getWheelWorldLocation(Vector3f store)
```
    Copy this wheel's physics-space location to the specified vector.
    
    Parameters:
    
    store - storage for the result (not null, modified)

Class VehicleWheel

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

wheelId

wheelIndex

frontWheel

location

direction

axle

suspensionStiffness

wheelsDampingRelaxation

wheelsDampingCompression

frictionSlip

rollInfluence

maxSuspensionTravelCm

maxSuspensionForce

radius

restLength

wheelWorldLocation

wheelWorldRotation

wheelSpatial

tmp_Matrix

tmp_inverseWorldRotation

Constructor Detail

VehicleWheel

VehicleWheel

VehicleWheel

Method Detail

updatePhysicsState

applyWheelTransform

getWheelId

setVehicleId

isFrontWheel

setFrontWheel

getLocation

getDirection

getAxle

getSuspensionStiffness

setSuspensionStiffness

getWheelsDampingRelaxation

setWheelsDampingRelaxation

getWheelsDampingCompression

setWheelsDampingCompression

getFrictionSlip

setFrictionSlip

getRollInfluence

setRollInfluence

getMaxSuspensionTravelCm

setMaxSuspensionTravelCm

getMaxSuspensionForce

setMaxSuspensionForce

getRadius

setRadius

getRestLength

setRestLength

getGroundObject

getCollisionLocation

getCollisionLocation

getCollisionNormal

getCollisionNormal

getSkidInfo

getSkidInfo

getDeltaRotation

getDeltaRotation

read

write

getWheelSpatial

setWheelSpatial

isApplyLocal

setApplyLocal

getWheelWorldRotation

getWheelWorldLocation