java.lang.Object

com.jme3.bullet.objects.VehicleWheel

All Implemented Interfaces:: com.jme3.export.Savable, com.jme3.util.clone.JmeCloneable, Cloneable

public class VehicleWheel extends Object implements com.jme3.util.clone.JmeCloneable, com.jme3.export.Savable

Information about one wheel of a vehicle, based on Bullet's btWheelInfo.

Field Summary

Fields

Modifier and Type

Field

Description

static final Logger

logger

message logger for this class
Constructor Summary

Constructors

Modifier

Constructor

Description

protected

VehicleWheel()

No-argument constructor needed by SavableClassUtil.

VehicleWheel(com.jme3.scene.Spatial subtree, com.jme3.math.Vector3f location, com.jme3.math.Vector3f direction, com.jme3.math.Vector3f axle, float restLength, float radius, boolean frontWheel)

Instantiate a wheel.
Method Summary

Modifier and Type

Method

Description

void

applyWheelTransform()

Apply this wheel's physics location and orientation to its visualization, if any.

void

cloneFields(com.jme3.util.clone.Cloner cloner, Object original)

Callback from Cloner to convert this shallow-cloned wheel into a deep-cloned one, using the specified Cloner and original to resolve copied fields.

com.jme3.math.Vector3f

getAxle(com.jme3.math.Vector3f storeResult)

Determine this wheel's axis direction.

float

getBrake()

Determine this wheel's braking impulse (native field: m_brake).

com.jme3.math.Vector3f

getCollisionLocation()

For compatibility with the jme3-jbullet library.

com.jme3.math.Vector3f

getCollisionLocation(com.jme3.math.Vector3f storeResult)

Determine the location where the wheel touches the ground.

com.jme3.math.Vector3f

getCollisionNormal()

For compatibility with the jme3-jbullet library.

com.jme3.math.Vector3f

getCollisionNormal(com.jme3.math.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.

com.jme3.math.Vector3f

getDirection(com.jme3.math.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.

com.jme3.math.Vector3f

getLocation()

For compatibility with the jme3-jbullet library.

com.jme3.math.Vector3f

getLocation(com.jme3.math.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).

com.jme3.scene.Spatial

getWheelSpatial()

Access the scene-graph subtree used to visualize this wheel.

com.jme3.math.Vector3f

getWheelWorldLocation(com.jme3.math.Vector3f storeResult)

Determine this wheel's location.

com.jme3.math.Quaternion

getWheelWorldRotation(com.jme3.math.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).

VehicleWheel

jmeClone()

Create a shallow clone for the JME cloner.

void

read(com.jme3.export.JmeImporter importer)

De-serialize this wheel from the specified importer, 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 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

setWheelSpatial(com.jme3.scene.Spatial subtree)

Alter which scene-graph subtree is used to visualize this wheel.

void

updatePhysicsState()

Update this wheel's location and orientation.

void

write(com.jme3.export.JmeExporter exporter)

Serialize this wheel to the specified exporter, 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 Details
- logger
  
  public static final Logger logger
  
  message logger for this class
Constructor Details
- VehicleWheel
  
  protected VehicleWheel()
  
  No-argument constructor needed by SavableClassUtil.
- VehicleWheel
  
  public VehicleWheel(com.jme3.scene.Spatial subtree, com.jme3.math.Vector3f location, com.jme3.math.Vector3f direction, com.jme3.math.Vector3f axle, float restLength, float radius, boolean frontWheel)
  
  Instantiate a wheel.
  
  Parameters:
  
  subtree - the scene-graph subtree to visualize this wheel (alias created) or null for 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
Method Details
- applyWheelTransform
  
  public void applyWheelTransform()
  
  Apply this wheel's physics location and orientation to its visualization, if any.
- getAxle
  
  public com.jme3.math.Vector3f getAxle(com.jme3.math.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 com.jme3.math.Vector3f getCollisionLocation()
  
  For compatibility with the jme3-jbullet library.
  
  Returns:
  
  a new location vector (in physics-space coordinates, not null)
- getCollisionLocation
  
  public com.jme3.math.Vector3f getCollisionLocation(com.jme3.math.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 com.jme3.math.Vector3f getCollisionNormal()
  
  For compatibility with the jme3-jbullet library.
  
  Returns:
  
  a new unit vector (in physics-space coordinates, not null)
- getCollisionNormal
  
  public com.jme3.math.Vector3f getCollisionNormal(com.jme3.math.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 com.jme3.math.Vector3f getDirection(com.jme3.math.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 com.jme3.math.Vector3f getLocation()
  
  For compatibility with the jme3-jbullet library. The jme3-jbullet version returns a pre-existing vector instead of a new one.
  
  Returns:
  
  a new location vector (in physics-space coordinates, not null)
- getLocation
  
  public com.jme3.math.Vector3f getLocation(com.jme3.math.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
- getWheelSpatial
  
  public com.jme3.scene.Spatial getWheelSpatial()
  
  Access the scene-graph subtree used to visualize this wheel.
  
  Returns:
  
  the pre-existing instance, or null
- getWheelWorldLocation
  
  public com.jme3.math.Vector3f getWheelWorldLocation(com.jme3.math.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 com.jme3.math.Quaternion getWheelWorldRotation(com.jme3.math.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)
- setWheelSpatial
  
  public void setWheelSpatial(com.jme3.scene.Spatial subtree)
  
  Alter which scene-graph subtree is used to visualize this wheel.
  
  Parameters:
  
  subtree - the subtree to use (alias created) or null for none
- updatePhysicsState
  
  public void updatePhysicsState()
  
  Update this wheel's location and orientation.
- cloneFields
  
  public void cloneFields(com.jme3.util.clone.Cloner cloner, Object original)
  
  Callback from Cloner to convert this shallow-cloned wheel into a deep-cloned one, using the specified Cloner and original to resolve copied fields.
  
  Specified by:
  
  cloneFields in interface com.jme3.util.clone.JmeCloneable
  
  Parameters:
  
  cloner - the Cloner that's cloning this wheel (not null)
  
  original - the instance from which this wheel was shallow-cloned (unused)
- jmeClone
  
  public VehicleWheel jmeClone()
  
  Create a shallow clone for the JME cloner.
  
  Specified by:
  
  jmeClone in interface com.jme3.util.clone.JmeCloneable
  
  Returns:
  
  a new instance
- read
  
  public void read(com.jme3.export.JmeImporter importer) throws IOException
  
  De-serialize this wheel from the specified importer, for example when loading from a J3O file.
  
  Specified by:
  
  read in interface com.jme3.export.Savable
  
  Parameters:
  
  importer - (not null)
  
  Throws:
  
  IOException - from the importer
- write
  
  public void write(com.jme3.export.JmeExporter exporter) throws IOException
  
  Serialize this wheel to the specified exporter, for example when saving to a J3O file.
  
  Specified by:
  
  write in interface com.jme3.export.Savable
  
  Parameters:
  
  exporter - (not null)
  
  Throws:
  
  IOException - from the exporter

Class VehicleWheel

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Details

logger

Constructor Details

VehicleWheel

VehicleWheel

Method Details

applyWheelTransform

getAxle

getBrake

getCollisionLocation

getCollisionLocation

getCollisionNormal

getCollisionNormal

getDeltaRotation

getDirection

getEngineForce

getFrictionSlip

getIndex

getLocation

getLocation

getMaxSuspensionForce

getMaxSuspensionTravelCm

getRadius

getRestLength

getRollInfluence

getRotationAngle

getSkidInfo

getSteerAngle

getSuspensionLength

getSuspensionStiffness

getWheelsDampingCompression

getWheelsDampingRelaxation

getWheelSpatial

getWheelWorldLocation

getWheelWorldRotation

isApplyLocal

isFrontWheel

setApplyLocal

setFrictionSlip

setFrontWheel

setMaxSuspensionForce

setMaxSuspensionTravelCm

setRadius

setRestLength

setRollInfluence

setRotationAngle

setSuspensionLength

setSuspensionStiffness

setVehicleId

setWheelsDampingCompression

setWheelsDampingRelaxation

setWheelSpatial

updatePhysicsState

cloneFields

jmeClone

read

write