artisynth.core.femmodels

Class FrameNodeNodeAttachment

java.lang.Object

artisynth.core.femmodels.FrameNodeNodeAttachment

All Implemented Interfaces:

DynamicAttachment

public class FrameNodeNodeAttachment
extends java.lang.Object
implements DynamicAttachment

Connects a FrameNode3d to a FemNode3d. Let R and p denote the rotation and translation of the frame, vf and wf the translational and rotational frame velocity (world coordinates), xw and vw the position and velocity of the node (world coordinates), and xl and vl the position and velocity of the frame node (frame coordinates). Then the position and velocity relationships are given by

   xl = R^T (xw - p)

   vl = -R^T vf + [xl] R^T wf + R^T vw
 

Constructor Summary

Constructors

Constructor and Description
FrameNodeNodeAttachment(FrameNode3d frameNode, FemNode3d node)

Method Summary

Modifier and Type	Method and Description
void	addBackRefs() Every master component should contain a back reference to each attachment that references it.
void	addMassToMasters()
void	applyForces()
boolean	getDerivative(double[] buf, int idx)
MatrixBlock	getGT(int idx) Returns the transpose of the constraint matrix G associated with the idx-th master component.
DynamicComponent[]	getMasters()
DynamicComponent	getSlave() Returns the slave DynamicMechComponent associated with this attachment.
void	invalidateMasters()
void	mulSubGT(double[] ybuf, int yoff, double[] xbuf, int xoff, int idx) Computes
void	mulSubGTM(MatrixBlock D, MatrixBlock M, int idx) Computes
void	mulSubMG(MatrixBlock D, MatrixBlock M, int idx) Computes
int	numMasters()
void	removeBackRefs() Removes the back reference to this attachment's slave component from each of the master component.
void	setSlaveAffectsStiffness(boolean affects)
boolean	slaveAffectsStiffness()
void	updateAttachment() Update attachment to reflect changes in the slave state.
void	updatePosStates()
void	updateVelStates()

Methods inherited from class java.lang.Object

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

Constructor Detail

FrameNodeNodeAttachment

public FrameNodeNodeAttachment(FrameNode3d frameNode,
                               FemNode3d node)

Method Detail

slaveAffectsStiffness

public boolean slaveAffectsStiffness()

Specified by:

slaveAffectsStiffness in interface DynamicAttachment

setSlaveAffectsStiffness

public void setSlaveAffectsStiffness(boolean affects)

Specified by:

setSlaveAffectsStiffness in interface DynamicAttachment

numMasters

public int numMasters()

Specified by:

numMasters in interface DynamicAttachment

updateAttachment

public void updateAttachment()

Description copied from interface: DynamicAttachment

Update attachment to reflect changes in the slave state.

Specified by:

updateAttachment in interface DynamicAttachment

updatePosStates

public void updatePosStates()

Specified by:

updatePosStates in interface DynamicAttachment

updateVelStates

public void updateVelStates()

Specified by:

updateVelStates in interface DynamicAttachment

applyForces

public void applyForces()

Specified by:

applyForces in interface DynamicAttachment

getSlave

public DynamicComponent getSlave()

Description copied from interface: DynamicAttachment

Returns the slave DynamicMechComponent associated with this attachment. In some cases, the attachment may connect some other entity (such as a mesh vertex) to the master components, in which case this method should return null.

Specified by:

getSlave in interface DynamicAttachment

Returns:

slave DynamicMechComponent, if any

addMassToMasters

public void addMassToMasters()

Specified by:

addMassToMasters in interface DynamicAttachment

getDerivative

public boolean getDerivative(double[] buf,
                             int idx)

Specified by:

getDerivative in interface DynamicAttachment

getMasters

public DynamicComponent[] getMasters()

Specified by:

getMasters in interface DynamicAttachment

invalidateMasters

public void invalidateMasters()

Specified by:

invalidateMasters in interface DynamicAttachment

mulSubMG

public void mulSubMG(MatrixBlock D,
                     MatrixBlock M,
                     int idx)

Description copied from interface: DynamicAttachment

Computes

 D -= M G
 

where D and M are matrices associated with master and slave components, respectively, and G is the constraint matrix for the attachment.

Specified by:

mulSubMG in interface DynamicAttachment

Parameters:

D - dependent matrix associated with a master component

M - matrix associated with a slave component

getGT

public MatrixBlock getGT(int idx)

Description copied from interface: DynamicAttachment

Returns the transpose of the constraint matrix G associated with the idx-th master component.

Specified by:

getGT in interface DynamicAttachment

Parameters:

idx - index of the master component

Returns:

transpose of G associated with idx

mulSubGTM

public void mulSubGTM(MatrixBlock D,
                      MatrixBlock M,
                      int idx)

Description copied from interface: DynamicAttachment

Computes

       T
 D -= G  M
 

where D and M are matrices associated with master and slave components, respectively, and G is the constraint matrix for the attachment.

Specified by:

mulSubGTM in interface DynamicAttachment

Parameters:

D - dependent matrix associated with a master component

M - matrix associated with a slave component

mulSubGT

public void mulSubGT(double[] ybuf,
                     int yoff,
                     double[] xbuf,
                     int xoff,
                     int idx)

Description copied from interface: DynamicAttachment

Computes

       T
 y -= G  x
 

where y and x are vectors associated with master and slave components, respectively, and G is the constraint matrix for the attachment.

Specified by:

mulSubGT in interface DynamicAttachment

Parameters:

ybuf - buffer into which to store result

yoff - offset into ybuf

xbuf - buffer containing right hand side vector

xoff - offset into xbuf

idx - master component index

addBackRefs

public void addBackRefs()

Description copied from interface: DynamicAttachment

Every master component should contain a back reference to each attachment that references it. This method adds the back reference for this attachment to each of the masters.

Specified by:

addBackRefs in interface DynamicAttachment

removeBackRefs

public void removeBackRefs()

Description copied from interface: DynamicAttachment

Removes the back reference to this attachment's slave component from each of the master component.

Specified by:

removeBackRefs in interface DynamicAttachment