artisynth.core.mechmodels

Class StaticRigidBodySolver

java.lang.Object

artisynth.core.mechmodels.StaticRigidBodySolver

Direct Known Subclasses:

IKSolver

public abstract class StaticRigidBodySolver
extends java.lang.Object

Base for classes that perform static constraint-based solves on a set of rigid bodies contained within a MechModel.

Constructor Summary

Constructors

Constructor and Description
StaticRigidBodySolver()

Method Summary

Modifier and Type	Method and Description
RigidBody	findFixedBody() Searches the bodies used by this solver for one that should be considers to have a fixed position.
java.util.ArrayList<RigidBody>	getBodies() Returns the bodies associated with this solver.
java.util.ArrayList<RigidTransform3d>	getBodyPoses() Returns the poses of all the bodies associated with this solver.
java.util.ArrayList<BodyConstrainer>	getConstrainers() Returns the constrainers (e.g., joints and other constrainers) used by this solver.
MechModel	getMechModel() Returns the MechModel associated with this solver.
double	getModelSize() Returns a characteristic size for the model.
boolean	isConnectedToGround() Returns true if at least one of the bodies associated with this solver is connected to ground via a BodyConnector.
int	numBodies() Queries the number of rigid bodies associated with this solver.
int	projectToConstraints(double tol, int maxIter) Performs repeated position updates until the error is below a specified tolerance, or the number of iterations exceeds maxIter.
void	resetBodiesDynamic() Restore the dynamic property setting of all the bodies associated with this solver to their value at initialization.
void	restoreModelState() Restores the state of the MechModel.
void	saveModelState() Saves the current state of the MechModel.
void	setBodiesDynamic(boolean dynamic) Sets the dynamic property of all the bodies associated with this solver.
void	setModelSize(double size) Sets a characteristic size for the model.
void	transformBodyPoses(RigidTransform3d T) Transform the poses of all bodies used by this solver, by applying a transform T in world coordinates.

Methods inherited from class java.lang.Object

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

Constructor Detail

StaticRigidBodySolver

public StaticRigidBodySolver()

Method Detail

numBodies

public int numBodies()

Queries the number of rigid bodies associated with this solver.

Returns:

number of bodies associated with this solver

getBodies

public java.util.ArrayList<RigidBody> getBodies()

Returns the bodies associated with this solver. This will return all the bodies, not just those used to initialize the solver.

Returns:

bodies associated with this solver

getBodyPoses

public java.util.ArrayList<RigidTransform3d> getBodyPoses()

Returns the poses of all the bodies associated with this solver. This includes all the bodies, not just those needed to initialize the solver.

getMechModel

public MechModel getMechModel()

Returns the MechModel associated with this solver.

Returns:

MechModel associated with this solver

getConstrainers

public java.util.ArrayList<BodyConstrainer> getConstrainers()

Returns the constrainers (e.g., joints and other constrainers) used by this solver.

Returns:

connectors associated with this solver

getModelSize

public double getModelSize()

Returns a characteristic size for the model. Used to determine convergence tolerances.

setModelSize

public void setModelSize(double size)

Sets a characteristic size for the model. Used to determine convergence tolerances. Specifying a value <= 0 will cause the size to be computed automatically the next time getModelSize() is called.

saveModelState

public void saveModelState()

Saves the current state of the MechModel. This allows the MechModel state to be restored after one or more solve steps.

restoreModelState

public void restoreModelState()

Restores the state of the MechModel.

projectToConstraints

public int projectToConstraints(double tol,
                                int maxIter)

Performs repeated position updates until the error is below a specified tolerance, or the number of iterations exceeds maxIter.

Parameters:

tol - desired tolerance for the error

maxIter - maximum number of iterations

Returns:

iteration count

findFixedBody

public RigidBody findFixedBody()

Searches the bodies used by this solver for one that should be considers to have a fixed position. The first choice is any body that has its grounded property set. The second choice is any body that was non-dynamic when this solver was initialized.

Returns:

grounded body, or null if none found

transformBodyPoses

public void transformBodyPoses(RigidTransform3d T)

Transform the poses of all bodies used by this solver, by applying a transform T in world coordinates. If TBW is the pose of a given body, then the new pose will be given by

 TBW = T TBW
 

Parameters:

T - transform to apply to body poses

setBodiesDynamic

public void setBodiesDynamic(boolean dynamic)

Sets the dynamic property of all the bodies associated with this solver.

Parameters:

dynamic - setting for each body's dynamic property

resetBodiesDynamic

public void resetBodiesDynamic()

Restore the dynamic property setting of all the bodies associated with this solver to their value at initialization.

isConnectedToGround

public boolean isConnectedToGround()

Returns true if at least one of the bodies associated with this solver is connected to ground via a BodyConnector. Note that if the bodies are arranged into two or more disconnected chains, this means that at least one chain is grounded, but not necessarily all of them.

Returns:

true if one of the bodies is connected to ground.