com.jme3.bullet.joints

Class SixDofSpringJoint

java.lang.Object

com.jme3.bullet.NativePhysicsObject

com.jme3.bullet.joints.PhysicsJoint

com.jme3.bullet.joints.Constraint

com.jme3.bullet.joints.SixDofJoint

com.jme3.bullet.joints.SixDofSpringJoint

All Implemented Interfaces:

java.lang.Comparable<NativePhysicsObject>

public class SixDofSpringJoint
extends SixDofJoint

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

From the Bullet manual:

For each axis:

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

It is recommended to use the btGeneric6DofSpring2Constraint, it has some improvements over the original btGeneric6Dof(Spring)Constraint.

See Also:

New6Dof

Field Summary

Fields

Modifier and Type	Field and Description
static java.util.logging.Logger	logger3 message logger for this class

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

logger2

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

logger15, pivotA, pivotB

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

logger

Fields inherited from class com.jme3.bullet.NativePhysicsObject

loggerN

Constructor Summary

Constructors

Constructor and Description
SixDofSpringJoint(PhysicsRigidBody rigidBodyA, PhysicsRigidBody rigidBodyB, Vector3f pivotInA, Vector3f pivotInB, Matrix3f rotInA, Matrix3f rotInB, boolean useLinearReferenceFrameA) Instantiate a double-ended SixDofSpringJoint.
SixDofSpringJoint(PhysicsRigidBody rigidBodyB, Vector3f pivotInB, Vector3f pivotInWorld, Matrix3f rotInB, Matrix3f rotInWorld, JointEnd linearReferenceFrame) Instantiate a single-ended SixDofSpringJoint.

Method Summary

Modifier and Type	Method and Description
protected long	createJoint(long bodyIdA, long bodyIdB, Vector3f pivotInA, Matrix3f rotInA, Vector3f pivotInB, Matrix3f rotInB, boolean useLinearReferenceFrameA) Create a double-ended btGeneric6DofSpringConstraint.
protected long	createJoint1(long bodyIdB, Vector3f pivotInB, Matrix3f rotInB, boolean useLinearReferenceFrameB) Create a single-ended btGeneric6DofSpringConstraint.
void	enableSpring(int dofIndex, boolean onOff) Enable or disable the spring for the indexed degree of freedom.
float	getDamping(int dofIndex) Read the damping of the indexed degree of freedom.
float	getEquilibriumPoint(int dofIndex) Read the equilibrium point of the indexed degree of freedom.
float	getStiffness(int dofIndex) Read the spring stiffness of the indexed degree of freedom.
boolean	isSpringEnabled(int dofIndex) Test whether the spring for the indexed degree of freedom is enabled.
void	setDamping(int dofIndex, 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 joint's current location/orientation.
void	setEquilibriumPoint(int dofIndex) Alter the equilibrium point of the indexed degree of freedom, based on the joint's current location/orientation.
void	setStiffness(int dofIndex, float stiffness) Alter the spring stiffness for the indexed degree of freedom.

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

getAngles, getAngularLowerLimit, getAngularUpperLimit, getFrameTransform, getLinearLowerLimit, getLinearUpperLimit, getPivotOffset, getRotationalLimitMotor, getTranslationalLimitMotor, setAngularLowerLimit, setAngularUpperLimit, setLinearLowerLimit, setLinearUpperLimit

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

getAppliedImpulse, getBodyA, getBodyB, getBreakingImpulseThreshold, getConstraintType, getOverrideIterations, getPivot, getPivotA, getPivotB, isCollisionBetweenLinkedBodies, isEnabled, isFeedback, overrideIterations, setBreakingImpulseThreshold, setCollisionBetweenLinkedBodies, setEnabled, setFeedback, setPivotInA, setPivotInB

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

countEnds, destroy, findEnd, findOtherBody, getBody, getPhysicsSpace, setBodyA, setBodyB, setNativeId, setPhysicsSpace, toString

Methods inherited from class com.jme3.bullet.NativePhysicsObject

compareTo, countTrackers, dumpTrackers, equals, freeUnusedObjects, hasAssignedNativeObject, hashCode, nativeId, reassignNativeId, setNativeIdNotTracked, unassignNativeObject

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

logger3

public static final java.util.logging.Logger logger3

message logger for this class

Constructor Detail

SixDofSpringJoint

public SixDofSpringJoint(PhysicsRigidBody rigidBodyB,
                         Vector3f pivotInB,
                         Vector3f pivotInWorld,
                         Matrix3f rotInB,
                         Matrix3f rotInWorld,
                         JointEnd linearReferenceFrame)

Instantiate a single-ended SixDofSpringJoint.

To be effective, the joint must be added to the body's PhysicsSpace and the body must be dynamic.

Parameters:

rigidBodyB - the body to constrain (not null, alias created)

pivotInB - the pivot location in B's scaled local coordinates (not null, unaffected)

pivotInWorld - the pivot location in physics-space coordinates (not null, unaffected)

rotInB - the orientation of the joint in B's local coordinates (rotation matrix, not null, unaffected)

rotInWorld - the orientation of the joint in physics-space coordinates (rotation matrix, not null, unaffected)

linearReferenceFrame - which end to use as the linear reference frame (not null)

SixDofSpringJoint

public SixDofSpringJoint(PhysicsRigidBody rigidBodyA,
                         PhysicsRigidBody rigidBodyB,
                         Vector3f pivotInA,
                         Vector3f pivotInB,
                         Matrix3f rotInA,
                         Matrix3f rotInB,
                         boolean useLinearReferenceFrameA)

Instantiate a double-ended SixDofSpringJoint.

To be effective, the joint must be added to the PhysicsSpace of both bodies. Also, the bodies must be distinct and at least one of them must be dynamic.

Parameters:

rigidBodyA - the body for the A end (not null, alias created)

rigidBodyB - the body for the B end (not null, alias created)

pivotInA - the pivot location in A's scaled local coordinates (not null, unaffected)

pivotInB - the pivot location in B's scaled local coordinates (not null, unaffected)

rotInA - the orientation of the joint in A's local coordinates (not null, unaffected)

rotInB - the orientation of the joint in B's local coordinates (not null, unaffected)

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

Method Detail

enableSpring

public void enableSpring(int dofIndex,
                         boolean onOff)

Enable or disable the spring for the indexed degree of freedom. Enabling a spring also enables the corresponding limit motor. Disabling a spring also disables the corresponding limit motor.

Parameters:

dofIndex - which degree of freedom (0→X translation, 1→Y translation, 2→Z translation, 3→X rotation, 4→Y rotation, 5→Z rotation)

onOff - true → enable, false → disable (default=false)

getDamping

public float getDamping(int dofIndex)

Read the damping of the indexed degree of freedom.

Parameters:

dofIndex - which degree of freedom (0→X translation, 1→Y translation, 2→Z translation, 3→X rotation, 4→Y rotation, 5→Z rotation)

Returns:

the viscous damping ratio

getEquilibriumPoint

public float getEquilibriumPoint(int dofIndex)

Read the equilibrium point of the indexed degree of freedom.

Parameters:

dofIndex - which degree of freedom (0→X translation, 1→Y translation, 2→Z translation, 3→X rotation, 4→Y rotation, 5→Z rotation)

Returns:

the equilibrium point

getStiffness

public float getStiffness(int dofIndex)

Read the spring stiffness of the indexed degree of freedom.

Parameters:

dofIndex - which degree of freedom (0→X translation, 1→Y translation, 2→Z translation, 3→X rotation, 4→Y rotation, 5→Z rotation)

Returns:

the stiffness

isSpringEnabled

public boolean isSpringEnabled(int dofIndex)

Test whether the spring for the indexed degree of freedom is enabled.

Parameters:

dofIndex - which degree of freedom (0→X translation, 1→Y translation, 2→Z translation, 3→X rotation, 4→Y rotation, 5→Z rotation)

Returns:

true if enabled, otherwise false

setDamping

public void setDamping(int dofIndex,
                       float damping)

Alter the damping for the indexed degree of freedom.

Parameters:

dofIndex - which degree of freedom (0→X translation, 1→Y translation, 2→Z translation, 3→X rotation, 4→Y rotation, 5→Z rotation)

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 joint's current location/orientation.

setEquilibriumPoint

public void setEquilibriumPoint(int dofIndex)

Alter the equilibrium point of the indexed degree of freedom, based on the joint's current location/orientation.

Parameters:

dofIndex - which degree of freedom (0→X translation, 1→Y translation, 2→Z translation, 3→X rotation, 4→Y rotation, 5→Z rotation)

setStiffness

public void setStiffness(int dofIndex,
                         float stiffness)

Alter the spring stiffness for the indexed degree of freedom.

Parameters:

dofIndex - which degree of freedom (0→X translation, 1→Y translation, 2→Z translation, 3→X rotation, 4→Y rotation, 5→Z rotation)

stiffness - the desired stiffness (default=0)

createJoint

protected long createJoint(long bodyIdA,
                           long bodyIdB,
                           Vector3f pivotInA,
                           Matrix3f rotInA,
                           Vector3f pivotInB,
                           Matrix3f rotInB,
                           boolean useLinearReferenceFrameA)

Create a double-ended btGeneric6DofSpringConstraint.

Overrides:

createJoint in class SixDofJoint

Parameters:

bodyIdA - the ID of the body for the A end (not zero)

bodyIdB - the ID of the body for the B end (not zero)

pivotInA - the pivot location in A's scaled local coordinates (not null, unaffected)

rotInA - the orientation of the joint in A's local coordinates (not null, unaffected)

pivotInB - the pivot location in B's scaled local coordinates (not null, unaffected)

rotInB - the orientation of the joint in B's local coordinates (not null, unaffected)

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

Returns:

the ID of the new joint

createJoint1

protected long createJoint1(long bodyIdB,
                            Vector3f pivotInB,
                            Matrix3f rotInB,
                            boolean useLinearReferenceFrameB)

Create a single-ended btGeneric6DofSpringConstraint.

Overrides:

createJoint1 in class SixDofJoint

Parameters:

bodyIdB - the ID of the body for the B end (not zero)

pivotInB - the pivot location in B's scaled local coordinates (not null, unaffected)

rotInB - the orientation of the joint in B's local coordinates (not null, unaffected)

useLinearReferenceFrameB - true→use body A, false→use body B

Returns:

the ID of the new joint