com.jme3.bullet.joints

Class SixDofSpringJoint

java.lang.Object

com.jme3.bullet.joints.PhysicsJoint

com.jme3.bullet.joints.SixDofJoint

com.jme3.bullet.joints.SixDofSpringJoint

All Implemented Interfaces:

Savable

public class SixDofSpringJoint
extends SixDofJoint

A 6 degree-of-freedom joint based on Bullet's btGeneric6DofSpringConstraint.

From the Bullet manual:
This generic constraint can emulate a variety of standard constraints, by configuring each of the 6 degrees of freedom (dof). The first 3 dof axis are linear axis, which represent translation of rigidbodies, and the latter 3 dof axis represent the angular motion. Each axis can be either locked, free or limited. On construction of a new btGeneric6DofSpring2Constraint, all axis are locked. Afterwards the axis can be reconfigured. Note that several combinations that include free and/or limited angular degrees of freedom are undefined.

For each axis:

• Lowerlimit = Upperlimit → axis is locked
• Lowerlimit > Upperlimit → axis is free
• Lowerlimit < Upperlimit → axis it limited in that range

Field Summary

Fields inherited from class com.jme3.bullet.joints.PhysicsJoint

collisionBetweenLinkedBodys, nodeA, nodeB, objectId, pivotA, pivotB

Constructor Summary

Constructors

Constructor and Description
SixDofSpringJoint() No-argument constructor needed by SavableClassUtil.
SixDofSpringJoint(PhysicsRigidBody nodeA, PhysicsRigidBody nodeB, Vector3f pivotA, Vector3f pivotB, Matrix3f rotA, Matrix3f rotB, boolean useLinearReferenceFrameA) Instantiate a SixDofSpringJoint.

Method Summary

Modifier and Type	Method and Description
void	enableSpring(int index, boolean onOff) Enable or disable the spring for the indexed degree of freedom.
void	setDamping(int index, float damping) Alter the damping for the indexed degree of freedom.
void	setEquilibriumPoint() Alter the equilibrium points for all degrees of freedom, based on the current constraint position/orientation.
void	setEquilibriumPoint(int index) Alter the equilibrium point of the indexed degree of freedom, based on the current constraint position/orientation.
void	setStiffness(int index, float stiffness) Alter the spring stiffness for the indexed degree of freedom.

Methods inherited from class com.jme3.bullet.joints.SixDofJoint

getAngles, getRotationalLimitMotor, getTranslationalLimitMotor, read, setAngularLowerLimit, setAngularUpperLimit, setLinearLowerLimit, setLinearUpperLimit, write

Methods inherited from class com.jme3.bullet.joints.PhysicsJoint

destroy, finalize, getAppliedImpulse, getBodyA, getBodyB, getObjectId, getPivotA, getPivotB, isCollisionBetweenLinkedBodys, setCollisionBetweenLinkedBodys

Methods inherited from class java.lang.Object

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

Constructor Detail

SixDofSpringJoint

public SixDofSpringJoint()

No-argument constructor needed by SavableClassUtil. Do not invoke directly!

SixDofSpringJoint

public SixDofSpringJoint(PhysicsRigidBody nodeA,
                         PhysicsRigidBody nodeB,
                         Vector3f pivotA,
                         Vector3f pivotB,
                         Matrix3f rotA,
                         Matrix3f rotB,
                         boolean useLinearReferenceFrameA)

Instantiate a SixDofSpringJoint. To be effective, the joint must be added to a physics space.

Parameters:

nodeA - the 1st body connected by the joint (not null, alias created)

nodeB - the 2nd body connected by the joint (not null, alias created)

pivotA - the local offset of the connection point in node A (not null, alias created)

pivotB - the local offset of the connection point in node B (not null, alias created)

rotA - the local orientation of the connection to node A (not null, alias created)

rotB - the local orientation of the connection to node B (not null, alias created)

useLinearReferenceFrameA - true→use node A, false→use node B

Method Detail

enableSpring

public void enableSpring(int index,
                         boolean onOff)

Enable or disable the spring for the indexed degree of freedom.

Parameters:

index - which degree of freedom (≥0, <6)

onOff - true → enable, false → disable

setStiffness

public void setStiffness(int index,
                         float stiffness)

Alter the spring stiffness for the indexed degree of freedom.

Parameters:

index - which degree of freedom (≥0, <6)

stiffness - the desired stiffness

setDamping

public void setDamping(int index,
                       float damping)

Alter the damping for the indexed degree of freedom.

Parameters:

index - which degree of freedom (≥0, <6)

damping - the desired viscous damping ratio (0→no damping, 1→critically damped, default=1)

setEquilibriumPoint

public void setEquilibriumPoint()

Alter the equilibrium points for all degrees of freedom, based on the current constraint position/orientation.

setEquilibriumPoint

public void setEquilibriumPoint(int index)

Alter the equilibrium point of the indexed degree of freedom, based on the current constraint position/orientation.

Parameters:

index - which degree of freedom (≥0, <6)