Package com.jme3.bullet.objects

Class VehicleWheel

java.lang.Object

com.jme3.bullet.objects.VehicleWheel

All Implemented Interfaces:

Savable

public class VehicleWheel
extends Object
implements Savable

Stores info about one wheel of a PhysicsVehicle

Field Summary

Fields

Modifier and Type	Field	Description
protected Vector3f	axle
protected Vector3f	direction
protected float	frictionSlip
protected boolean	frontWheel
protected Vector3f	location
protected float	maxSuspensionForce
protected float	maxSuspensionTravelCm
protected float	radius
protected float	restLength
protected float	rollInfluence
protected float	suspensionStiffness
protected final Quaternion	tmp_inverseWorldRotation
protected Matrix3f	tmp_Matrix
protected com.bulletphysics.dynamics.vehicle.WheelInfo	wheelInfo
protected float	wheelsDampingCompression
protected float	wheelsDampingRelaxation
protected Spatial	wheelSpatial
protected Vector3f	wheelWorldLocation
protected Quaternion	wheelWorldRotation

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	VehicleWheel()
	VehicleWheel(Vector3f location, Vector3f direction, Vector3f axle, float restLength, float radius, boolean frontWheel)
	VehicleWheel(Spatial spat, Vector3f location, Vector3f direction, Vector3f axle, float restLength, float radius, boolean frontWheel)

Method Summary

Modifier and Type	Method	Description
void	applyWheelTransform()
Vector3f	getAxle()
Vector3f	getCollisionLocation()	returns the location where the wheel collides with the ground (world space)
Vector3f	getCollisionLocation(Vector3f vec)	returns the location where the wheel collides with the ground (world space)
Vector3f	getCollisionNormal()	returns the normal where the wheel collides with the ground (world space)
Vector3f	getCollisionNormal(Vector3f vec)	returns the normal where the wheel collides with the ground (world space)
float	getDeltaRotation()	returns how many degrees the wheel has turned since the last physics step.
Vector3f	getDirection()
float	getFrictionSlip()
PhysicsCollisionObject	getGroundObject()	returns the object this wheel is in contact with or null if no contact
Vector3f	getLocation()
float	getMaxSuspensionForce()
float	getMaxSuspensionTravelCm()
float	getRadius()
float	getRestLength()
float	getRollInfluence()
float	getSkidInfo()	returns how much the wheel skids on the ground (for skid sounds/smoke etc.) 0.0 = wheels are sliding, 1.0 = wheels have traction.
float	getSuspensionStiffness()
com.bulletphysics.dynamics.vehicle.WheelInfo	getWheelInfo()
float	getWheelsDampingCompression()
float	getWheelsDampingRelaxation()
Spatial	getWheelSpatial()
void	getWheelWorldLocation(Vector3f store)	write the content of the wheelWorldLocation into the store
void	getWheelWorldRotation(Quaternion store)	write the content of the wheelWorldRotation into the store
boolean	isApplyLocal()
boolean	isFrontWheel()
void	read(JmeImporter im)
void	setApplyLocal(boolean applyLocal)
void	setFrictionSlip(float frictionSlip)	the coefficient of friction between the tyre and the ground.
void	setFrontWheel(boolean frontWheel)
void	setMaxSuspensionForce(float maxSuspensionForce)	The maximum suspension force, raise this above the default 6000 if your suspension cannot handle the weight of your vehicle.
void	setMaxSuspensionTravelCm(float maxSuspensionTravelCm)	the maximum distance the suspension can be compressed (centimetres)
void	setRadius(float radius)
void	setRestLength(float restLength)
void	setRollInfluence(float rollInfluence)	reduces the rolling torque applied from the wheels that cause the vehicle to roll over.
void	setSuspensionStiffness(float suspensionStiffness)	the stiffness constant for the suspension.
void	setWheelInfo(com.bulletphysics.dynamics.vehicle.WheelInfo wheelInfo)
void	setWheelsDampingCompression(float wheelsDampingCompression)	the damping coefficient for when the suspension is compressed.
void	setWheelsDampingRelaxation(float wheelsDampingRelaxation)	the damping coefficient for when the suspension is expanding.
void	setWheelSpatial(Spatial wheelSpatial)
void	updatePhysicsState()
void	write(JmeExporter ex)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

wheelInfo

protected com.bulletphysics.dynamics.vehicle.WheelInfo wheelInfo

frontWheel

protected boolean frontWheel

location

protected Vector3f location

direction

protected Vector3f direction

axle

protected Vector3f axle

suspensionStiffness

protected float suspensionStiffness

wheelsDampingRelaxation

protected float wheelsDampingRelaxation

wheelsDampingCompression

protected float wheelsDampingCompression

frictionSlip

protected float frictionSlip

rollInfluence

protected float rollInfluence

maxSuspensionTravelCm

protected float maxSuspensionTravelCm

maxSuspensionForce

protected float maxSuspensionForce

radius

protected float radius

restLength

protected float restLength

wheelWorldLocation

protected Vector3f wheelWorldLocation

wheelWorldRotation

protected Quaternion wheelWorldRotation

wheelSpatial

protected Spatial wheelSpatial

tmp_Matrix

protected Matrix3f tmp_Matrix

tmp_inverseWorldRotation

protected final Quaternion tmp_inverseWorldRotation

Constructor Details

VehicleWheel

protected VehicleWheel()

VehicleWheel

public VehicleWheel(Spatial spat,
 Vector3f location,
 Vector3f direction,
 Vector3f axle,
 float restLength,
 float radius,
 boolean frontWheel)

VehicleWheel

public VehicleWheel(Vector3f location,
 Vector3f direction,
 Vector3f axle,
 float restLength,
 float radius,
 boolean frontWheel)

Method Details

updatePhysicsState

public void updatePhysicsState()

applyWheelTransform

public void applyWheelTransform()

getWheelInfo

public com.bulletphysics.dynamics.vehicle.WheelInfo getWheelInfo()

setWheelInfo

public void setWheelInfo(com.bulletphysics.dynamics.vehicle.WheelInfo wheelInfo)

isFrontWheel

public boolean isFrontWheel()

setFrontWheel

public void setFrontWheel(boolean frontWheel)

getLocation

public Vector3f getLocation()

getDirection

public Vector3f getDirection()

getAxle

public Vector3f getAxle()

getSuspensionStiffness

public float getSuspensionStiffness()

setSuspensionStiffness

public void setSuspensionStiffness(float suspensionStiffness)

the stiffness constant for the suspension. 10.0 - Offroad buggy, 50.0 - Sports car, 200.0 - F1 Car

Parameters:

suspensionStiffness - the desired stiffness coefficient (10→off-road buggy, 50→sports car, 200→Formula-1 race car, default=20)

getWheelsDampingRelaxation

public float getWheelsDampingRelaxation()

setWheelsDampingRelaxation

public void setWheelsDampingRelaxation(float wheelsDampingRelaxation)

the damping coefficient for when the suspension is expanding. See the comments for setWheelsDampingCompression for how to set k.

Parameters:

wheelsDampingRelaxation - the desired damping coefficient (default=2.3)

getWheelsDampingCompression

public float getWheelsDampingCompression()

setWheelsDampingCompression

public void setWheelsDampingCompression(float wheelsDampingCompression)

the damping coefficient for when the suspension is compressed. Set to k * 2.0 * FastMath.sqrt(m_suspensionStiffness) so k is proportional to critical damping.
k = 0.0 undamped/bouncy, k = 1.0 critical damping
0.1 to 0.3 are good values

Parameters:

wheelsDampingCompression - the desired damping coefficient (default=4.4)

getFrictionSlip

public float getFrictionSlip()

setFrictionSlip

public void setFrictionSlip(float frictionSlip)

the coefficient of friction between the tyre and the ground. Should be about 0.8 for realistic cars, but can be increased for better handling. Set large (10000.0) for kart racers

Parameters:

frictionSlip - the desired coefficient of friction between tyre and ground (0.8→realistic car, 10000→kart racer, default=10.5)

getRollInfluence

public float getRollInfluence()

setRollInfluence

public void setRollInfluence(float rollInfluence)

reduces the rolling torque applied from the wheels that cause the vehicle to roll over. This is a bit of a hack, but it's quite effective. 0.0 = no roll, 1.0 = physical behaviour. If m_frictionSlip is too high, you'll need to reduce this to stop the vehicle rolling over. You should also try lowering the vehicle's centre of mass

Parameters:

rollInfluence - the rollInfluence to set

getMaxSuspensionTravelCm

public float getMaxSuspensionTravelCm()

setMaxSuspensionTravelCm

public void setMaxSuspensionTravelCm(float maxSuspensionTravelCm)

the maximum distance the suspension can be compressed (centimetres)

Parameters:

maxSuspensionTravelCm - 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)

getMaxSuspensionForce

public float getMaxSuspensionForce()

setMaxSuspensionForce

public void setMaxSuspensionForce(float maxSuspensionForce)

The maximum suspension force, raise this above the default 6000 if your suspension cannot handle the weight of your vehicle.

Parameters:

maxSuspensionForce - the desired maximum force per wheel (default=6000)

getRadius

public float getRadius()

setRadius

public void setRadius(float radius)

getRestLength

public float getRestLength()

setRestLength

public void setRestLength(float restLength)

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)

returns the location where the wheel collides with the ground (world space)

Parameters:

vec - storage for the result (not null, modified)

Returns:

a location vector (in physics-space coordinates)

getCollisionLocation

public Vector3f getCollisionLocation()

returns the location where the wheel collides with the ground (world space)

Returns:

a new location vector (in physics-space coordinates)

getCollisionNormal

public Vector3f getCollisionNormal(Vector3f vec)

returns the normal where the wheel collides with the ground (world space)

Parameters:

vec - storage for the result (not null, modified)

Returns:

a unit vector (in physics-space coordinates)

getCollisionNormal

public Vector3f getCollisionNormal()

returns the normal where the wheel collides with the ground (world space)

Returns:

a new unit vector (in physics-space coordinates)

getSkidInfo

public float getSkidInfo()

returns how much the wheel skids on the ground (for skid sounds/smoke etc.)
0.0 = wheels are sliding, 1.0 = wheels have traction.

Returns:

the relative amount of traction (0→wheel is sliding, 1→wheel has full traction)

getDeltaRotation

public float getDeltaRotation()

returns how many degrees the wheel has turned since the last physics step.

Returns:

the rotation angle (in radians)

read

public void read(JmeImporter im)
          throws IOException

Specified by:

read in interface Savable

Throws:

IOException

write

public void write(JmeExporter ex)
           throws IOException

Specified by:

write in interface Savable

Throws:

IOException

getWheelSpatial

public Spatial getWheelSpatial()

Returns:

the wheelSpatial

setWheelSpatial

public void setWheelSpatial(Spatial wheelSpatial)

Parameters:

wheelSpatial - the wheelSpatial to set

isApplyLocal

public boolean isApplyLocal()

setApplyLocal

public void setApplyLocal(boolean applyLocal)

getWheelWorldRotation

public void getWheelWorldRotation(Quaternion store)

write the content of the wheelWorldRotation into the store

Parameters:

store - storage for the result (not null, modified)

getWheelWorldLocation

public void getWheelWorldLocation(Vector3f store)

write the content of the wheelWorldLocation into the store

Parameters:

store - storage for the result (not null, modified)