VehicleWheel (Libbulletjme API)

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

```
public class VehicleWheel
extends java.lang.Object
```
Information about one wheel of a vehicle, based on Bullet's btWheelInfo.

Field Summary

Fields
Modifier and Type Field and Description

static java.util.logging.Logger logger
message logger for this class

Fields
Modifier and Type	Field and Description
`static java.util.logging.Logger`	`logger` message logger for this class

Constructor Summary

Constructors
Constructor and Description
`VehicleWheel(Vector3f location, Vector3f direction, Vector3f axle, float restLength, float radius, boolean frontWheel)` Instantiate a wheel.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`Vector3f`	`getAxle(Vector3f storeResult)` Determine this wheel's axis direction.
`float`	`getBrake()` Determine this wheel's braking impulse (native field: m_brake).
`Vector3f`	`getCollisionLocation(Vector3f storeResult)` Determine the location where the wheel touches the ground.
`Vector3f`	`getCollisionNormal(Vector3f storeResult)` Determine the normal direction where the wheel touches the ground.
`float`	`getDeltaRotation()` Determine how much this wheel has turned since the last simulation step.
`Vector3f`	`getDirection(Vector3f storeResult)` Determine this wheel's suspension direction.
`float`	`getEngineForce()` Determine this wheel's engine force (native field: m_engineForce).
`float`	`getFrictionSlip()` Determine the friction between this wheel's tire and the ground (native field: m_frictionSlip).
`int`	`getIndex()` Determine the index of this wheel, based on creation order.
`Vector3f`	`getLocation(Vector3f storeResult)` Determine the location where the suspension connects to the chassis.
`float`	`getMaxSuspensionForce()` Determine the maximum force exerted by this wheel's suspension (native field: m_maxSuspensionForce).
`float`	`getMaxSuspensionTravelCm()` Determine the maximum travel distance for this wheel's suspension (native field: m_maxSuspensionTravelCm).
`float`	`getRadius()` Determine the radius of this wheel (native field: m_wheelsRadius).
`float`	`getRestLength()` Determine the rest length of this wheel (native field: m_suspensionRestLength1).
`float`	`getRollInfluence()` Determine this wheel's roll influence (native field: m_rollInfluence).
`float`	`getRotationAngle()` Determine the total rotation of this wheel (native field: m_rotation).
`float`	`getSkidInfo()` Determine to what extent the wheel is skidding (for skid sounds/smoke etcetera).
`float`	`getSteerAngle()` Determine this wheel's steering angle (native field: m_steering).
`float`	`getSuspensionLength()` Determine the length of this wheel's suspension (native field: m_suspensionLength).
`float`	`getSuspensionStiffness()` Determine the stiffness of this wheel's suspension (native field: m_suspensionStiffness).
`float`	`getWheelsDampingCompression()` Determine this wheel's damping when the suspension is compressed (native field: m_wheelsDampingCompression).
`float`	`getWheelsDampingRelaxation()` Determine this wheel's damping when the suspension is expanded (native field: m_wheelsDampingRelaxation).
`Vector3f`	`getWheelWorldLocation(Vector3f storeResult)` Determine this wheel's location.
`Quaternion`	`getWheelWorldRotation(Quaternion storeResult)` Determine this wheel's orientation.
`boolean`	`isApplyLocal()` Test whether physics coordinates should match the local transform of the Spatial.
`boolean`	`isFrontWheel()` Test whether this wheel is a front (steering) wheel (native field: m_bIsFrontWheel).
`void`	`setApplyLocal(boolean applyLocal)` Alter whether physics coordinates should match the local transform of the Spatial.
`void`	`setFrictionSlip(float coeff)` Alter the friction between this wheel's tire and the ground (native field: m_frictionSlip).
`void`	`setFrontWheel(boolean frontWheel)` Alter whether this wheel is a front (steering) wheel (native field: m_bIsFrontWheel).
`void`	`setMaxSuspensionForce(float maxForce)` Alter the maximum force exerted by this wheel's suspension (native field: m_maxSuspensionForce).
`void`	`setMaxSuspensionTravelCm(float travelCm)` Alter the maximum travel distance for this wheel's suspension (native field: m_maxSuspensionTravelCm).
`void`	`setRadius(float radius)` Alter the radius of this wheel (native field: m_wheelsRadius).
`void`	`setRestLength(float restLength)` Alter the rest length of the suspension of this wheel (native field: m_suspensionRestLength1).
`void`	`setRollInfluence(float rollInfluence)` Alter this wheel's roll influence (native field: m_rollInfluence).
`void`	`setRotationAngle(float angle)` Alter the total rotation of this wheel (native field: m_rotation).
`void`	`setSuspensionLength(float length)` Alter the length of this wheel's suspension (native field: m_suspensionLength).
`void`	`setSuspensionStiffness(float stiffness)` Alter the stiffness of this wheel's suspension (native field: m_suspensionStiffness).
`void`	`setVehicleId(long vehicleId, int wheelIndex)` Assign this wheel to a vehicle.
`void`	`setWheelsDampingCompression(float damping)` Alter this wheel's damping when the suspension is compressed (native field: m_wheelsDampingCompression).
`void`	`setWheelsDampingRelaxation(float wheelsDampingRelaxation)` Alter this wheel's damping when the suspension is expanded (native field: m_wheelsDampingRelaxation).
`void`	`updatePhysicsState()` Update this wheel's location and orientation.

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

- Field Detail
  - logger
```
public static final java.util.logging.Logger logger
```
    message logger for this class
- Constructor Detail
  - VehicleWheel
```
public VehicleWheel(Vector3f location,
                    Vector3f direction,
                    Vector3f axle,
                    float restLength,
                    float radius,
                    boolean frontWheel)
```
    Instantiate a wheel.
    
    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
  - getAxle
```
public Vector3f getAxle(Vector3f storeResult)
```
    Determine this wheel's axis direction.
    
    Parameters:
    
    storeResult - storage for the result (modified if not null)
    
    Returns:
    
    a new unit vector (in chassis coordinates, either storeResult or a new instance)
  - getBrake
```
public float getBrake()
```
    Determine this wheel's braking impulse (native field: m_brake).
    
    Returns:
    
    the amount of impulse
  - getCollisionLocation
```
public Vector3f getCollisionLocation(Vector3f storeResult)
```
    Determine the location where the wheel touches the ground.
    
    Parameters:
    
    storeResult - storage for the result (modified if not null)
    
    Returns:
    
    a location vector (in physics-space coordinates, either storeResult or a new instance)
  - getCollisionNormal
```
public Vector3f getCollisionNormal(Vector3f storeResult)
```
    Determine the normal direction where the wheel touches the ground.
    
    Parameters:
    
    storeResult - storage for the result (modified if not null)
    
    Returns:
    
    a unit vector (in physics-space coordinates, either storeResult or a new instance)
  - getDeltaRotation
```
public float getDeltaRotation()
```
    Determine how much this wheel has turned since the last simulation step.
    
    Returns:
    
    the rotation angle (in radians)
  - getDirection
```
public Vector3f getDirection(Vector3f storeResult)
```
    Determine this wheel's suspension direction.
    
    Parameters:
    
    storeResult - storage for the result (modified if not null)
    
    Returns:
    
    a unit vector (in chassis coordinates, either storeResult or a new instance)
  - getEngineForce
```
public float getEngineForce()
```
    Determine this wheel's engine force (native field: m_engineForce).
    
    Returns:
    
    the amount of force applied (TODO positive direction?)
  - getFrictionSlip
```
public float getFrictionSlip()
```
    Determine the friction between this wheel's tire and the ground (native field: m_frictionSlip).
    
    Returns:
    
    the coefficient of friction
  - getIndex
```
public int getIndex()
```
    Determine the index of this wheel, based on creation order.
    
    Returns:
    
    the zero-origin index (≥0)
  - getLocation
```
public Vector3f getLocation(Vector3f storeResult)
```
    Determine the location where the suspension connects to the chassis.
    
    Parameters:
    
    storeResult - storage for the result (modified if not null)
    
    Returns:
    
    a new location vector (in chassis coordinates, either storeResult or a new instance)
  - getMaxSuspensionForce
```
public float getMaxSuspensionForce()
```
    Determine the maximum force exerted by this wheel's suspension (native field: m_maxSuspensionForce).
    
    Returns:
    
    the maximum force
  - getMaxSuspensionTravelCm
```
public float getMaxSuspensionTravelCm()
```
    Determine the maximum travel distance for this wheel's suspension (native field: m_maxSuspensionTravelCm). Note that the units are centimeters ONLY if the physics-space unit is exactly one meter.
    
    Returns:
    
    the maximum amount the suspension can be compressed or expanded, relative to its rest length (in hundredths of a physics-space unit)
  - getRadius
```
public float getRadius()
```
    Determine the radius of this wheel (native field: m_wheelsRadius).
    
    Returns:
    
    the radius (in physics-space units, ≥0)
  - getRestLength
```
public float getRestLength()
```
    Determine the rest length of this wheel (native field: m_suspensionRestLength1).
    
    Returns:
    
    the length
  - getRollInfluence
```
public float getRollInfluence()
```
    Determine this wheel's roll influence (native field: m_rollInfluence).
    
    Returns:
    
    the roll-influence factor
  - getRotationAngle
```
public float getRotationAngle()
```
    Determine the total rotation of this wheel (native field: m_rotation).
    
    Returns:
    
    the angle (in radians)
  - getSkidInfo
```
public float getSkidInfo()
```
    Determine to what extent the wheel is skidding (for skid sounds/smoke etcetera). Don't bother invoking this if the wheel is unsupported---in other words, if PhysicsVehicle.castRay(int) is negative!
    
    Returns:
    
    the relative amount of traction (0→wheel is sliding, 1→wheel has full traction)
  - getSteerAngle
```
public float getSteerAngle()
```
    Determine this wheel's steering angle (native field: m_steering).
    
    Returns:
    
    angle (in radians, 0=straight, left is positive)
  - getSuspensionLength
```
public float getSuspensionLength()
```
    Determine the length of this wheel's suspension (native field: m_suspensionLength).
    
    Returns:
    
    the length (in physics-space units)
  - getSuspensionStiffness
```
public float getSuspensionStiffness()
```
    Determine the stiffness of this wheel's suspension (native field: m_suspensionStiffness).
    
    Returns:
    
    the stiffness constant
  - getWheelsDampingCompression
```
public float getWheelsDampingCompression()
```
    Determine this wheel's damping when the suspension is compressed (native field: m_wheelsDampingCompression).
    
    Returns:
    
    the damping
  - getWheelsDampingRelaxation
```
public float getWheelsDampingRelaxation()
```
    Determine this wheel's damping when the suspension is expanded (native field: m_wheelsDampingRelaxation).
    
    Returns:
    
    the damping
  - getWheelWorldLocation
```
public Vector3f getWheelWorldLocation(Vector3f storeResult)
```
    Determine this wheel's location.
    
    Parameters:
    
    storeResult - storage for the result (modified if not null)
    
    Returns:
    
    a location vector (in physics-space coordinates, either storeResult or a new instance)
  - getWheelWorldRotation
```
public Quaternion getWheelWorldRotation(Quaternion storeResult)
```
    Determine this wheel's orientation.
    
    Parameters:
    
    storeResult - storage for the result (modified if not null)
    
    Returns:
    
    a Quaternion (in physics-space coordinates, either storeResult or a new instance)
  - 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
  - isFrontWheel
```
public boolean isFrontWheel()
```
    Test whether this wheel is a front (steering) wheel (native field: m_bIsFrontWheel).
    
    Returns:
    
    true if front wheel, otherwise false
  - 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)
  - setFrictionSlip
```
public void setFrictionSlip(float coeff)
```
    Alter the friction between this wheel's tire and the ground (native field: m_frictionSlip).
    Should be about 0.8 for realistic cars, but can be increased for better handling. Set large (10000) for kart racers.
    
    Parameters:
    
    coeff - the desired coefficient of friction (default=10.5)
  - setFrontWheel
```
public void setFrontWheel(boolean frontWheel)
```
    Alter whether this wheel is a front (steering) wheel (native field: m_bIsFrontWheel).
    
    Parameters:
    
    frontWheel - true→front wheel, false→non-front wheel
  - setMaxSuspensionForce
```
public void setMaxSuspensionForce(float maxForce)
```
    Alter the maximum force exerted by this wheel's suspension (native field: m_maxSuspensionForce).
    Increase this if your suspension cannot handle the weight of your vehicle.
    
    Parameters:
    
    maxForce - the desired maximum force (default=6000)
  - setMaxSuspensionTravelCm
```
public void setMaxSuspensionTravelCm(float travelCm)
```
    Alter the maximum travel distance for this wheel's suspension (native field: m_maxSuspensionTravelCm). Note that the units are centimeters ONLY if the physics-space unit is exactly one meter.
    
    Parameters:
    
    travelCm - the desired maximum amount the suspension can be compressed or expanded, relative to its rest length (in hundredths of a physics-space unit, default=500)
  - setRadius
```
public void setRadius(float radius)
```
    Alter the radius of this wheel (native field: m_wheelsRadius).
    
    Parameters:
    
    radius - the desired radius (in physics-space units, ≥0, default=0.5)
  - setRestLength
```
public void setRestLength(float restLength)
```
    Alter the rest length of the suspension of this wheel (native field: m_suspensionRestLength1).
    
    Parameters:
    
    restLength - the desired length (default=1)
  - setRollInfluence
```
public void setRollInfluence(float rollInfluence)
```
    Alter this wheel's roll influence (native field: m_rollInfluence).
    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 tires 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 center of mass.
    
    Parameters:
    
    rollInfluence - the desired roll-influence factor (0→no roll torque, 1→realistic behavior, default=1)
  - setRotationAngle
```
public void setRotationAngle(float angle)
```
    Alter the total rotation of this wheel (native field: m_rotation).
    
    Parameters:
    
    angle - the desired angle (in radians)
  - setSuspensionLength
```
public void setSuspensionLength(float length)
```
    Alter the length of this wheel's suspension (native field: m_suspensionLength). Bullet updates the length during every simulation step.
    
    Parameters:
    
    length - the desired length (in physics-space units)
  - setSuspensionStiffness
```
public void setSuspensionStiffness(float stiffness)
```
    Alter the stiffness of this wheel's suspension (native field: m_suspensionStiffness).
    
    Parameters:
    
    stiffness - the desired stiffness constant (10→off-road buggy, 50→sports car, 200→Formula-1 race car, default=5.88)
  - 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)
  - setWheelsDampingCompression
```
public void setWheelsDampingCompression(float damping)
```
    Alter this wheel's damping when the suspension is compressed (native field: m_wheelsDampingCompression).
    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:
    
    damping - the desired damping (0→no damping, default=0.83)
  - setWheelsDampingRelaxation
```
public void setWheelsDampingRelaxation(float wheelsDampingRelaxation)
```
    Alter this wheel's damping when the suspension is expanded (native field: m_wheelsDampingRelaxation).
    Set to k * 2 * FastMath.sqrt(m_suspensionStiffness) where k is the damping ratio:
    k=0: undamped and bouncy, k=1: critical damping, k between 0.1 and 0.3 are good values
    
    Parameters:
    
    wheelsDampingRelaxation - the desired damping (default=0.88)
  - updatePhysicsState
```
public void updatePhysicsState()
```
    Update this wheel's location and orientation.

Class VehicleWheel

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

logger

Constructor Detail

VehicleWheel

Method Detail

getAxle

getBrake

getCollisionLocation

getCollisionNormal

getDeltaRotation

getDirection

getEngineForce

getFrictionSlip

getIndex

getLocation

getMaxSuspensionForce

getMaxSuspensionTravelCm

getRadius

getRestLength

getRollInfluence

getRotationAngle

getSkidInfo

getSteerAngle

getSuspensionLength

getSuspensionStiffness

getWheelsDampingCompression

getWheelsDampingRelaxation

getWheelWorldLocation

getWheelWorldRotation

isApplyLocal

isFrontWheel

setApplyLocal

setFrictionSlip

setFrontWheel

setMaxSuspensionForce

setMaxSuspensionTravelCm

setRadius

setRestLength

setRollInfluence

setRotationAngle

setSuspensionLength

setSuspensionStiffness

setVehicleId

setWheelsDampingCompression

setWheelsDampingRelaxation

updatePhysicsState