artisynth.core.mechmodels

Class HingeJoint

java.lang.Object

artisynth.core.modelbase.ModelComponentBase

artisynth.core.modelbase.RenderableComponentBase

artisynth.core.mechmodels.BodyConnector

artisynth.core.mechmodels.JointBase

artisynth.core.mechmodels.HingeJoint

All Implemented Interfaces:

Constrainer, CopyableComponent, HasCoordinateFrame, HasNumericState, ModelComponent, PostScannable, RenderableComponent, TransformableGeometry, ScalableUnits, java.lang.Cloneable, HasProperties, HierarchyNode, HasRenderProps, IsRenderable, IsSelectable, Renderable, Scannable

Direct Known Subclasses:

RevoluteJoint

public class HingeJoint
extends JointBase
implements CopyableComponent

Implements a 1 DOF revolute joint, in which frame C rotates counter-clockwise about the z axis of frame D by an angle theta.

The theta value is available (in degrees) as a property which can be read and also, under appropriate circumstances, set. Setting this value causes an adjustment in the positions of one or both bodies connected to this joint, along with adjacent bodies connected to them, with preference given to bodies that are not attached to ``ground''. If this is done during simulation, and particularly if one or both of the bodies connected to this joint are moving dynamically, the results will be unpredictable and will likely conflict with the simulation.

Nested Class Summary

Nested classes/interfaces inherited from interface artisynth.core.modelbase.ModelComponent

ModelComponent.NavpanelVisibility

Field Summary

Fields

Modifier and Type	Field and Description
static PropertyList	myProps
static int	THETA_IDX

Fields inherited from class artisynth.core.mechmodels.JointBase

DEFAULT_SHAFT_LENGTH, DEFAULT_SHAFT_RADIUS

Fields inherited from class artisynth.core.mechmodels.BodyConnector

debug, useOldDerivativeMethod

Fields inherited from class artisynth.core.modelbase.ModelComponentBase

enforceUniqueCompositeNames, enforceUniqueNames, myNumber, NULL_OBJ, useCompactPathNames

Fields inherited from interface artisynth.core.modelbase.CopyableComponent

COPY_REFERENCES, REST_POSITION

Fields inherited from interface artisynth.core.modelbase.TransformableGeometry

TG_ARTICULATED, TG_DRAGGER, TG_PRESERVE_ORIENTATION, TG_SIMULATING

Fields inherited from interface maspack.render.IsRenderable

TRANSPARENT, TWO_DIMENSIONAL

Constructor Summary

Constructors

Constructor and Description
HingeJoint() Creates a HingeJoint which is not attached to any bodies.
HingeJoint(ConnectableBody bodyA, ConnectableBody bodyB, RigidTransform3d TDW) Creates a HingeJoint connecting two connectable bodies, bodyA and bodyB.
HingeJoint(ConnectableBody bodyA, ConnectableBody bodyB, RigidTransform3d TCW, RigidTransform3d TDW) Creates a HingeJoint connecting two connectable bodies, bodyA and bodyB.
HingeJoint(ConnectableBody bodyA, RigidTransform3d TDW) Creates a HingeJoint connecting a single connectable body, bodyA, to ground.
HingeJoint(RigidBody bodyA, ConnectableBody bodyB, Point3d originD, Vector3d zaxis) Creates a HingeJoint connecting two connectable bodies, bodyA and bodyB.
HingeJoint(RigidBody bodyA, RigidTransform3d TCA, RigidBody bodyB, RigidTransform3d TDB) Creates a HingeJoint connecting two rigid bodies, bodyA and bodyB.

Method Summary

Modifier and Type	Method and Description
PropertyList	getAllPropertyInfo() Returns a list giving static information about all properties exported by this object.
double	getMaxTheta() Queries the upper theta range limit for this joint, in degrees.
double	getMinTheta() Queries the lower theta range limit for this joint, in degrees.
double	getTheta() Queries this joint's theta value, in degrees.
DoubleInterval	getThetaRange() Queries the theta range limits for this joint, in degrees.
boolean	isThetaLocked() Queries whether the theta coordinate for this joint is locked.
void	render(Renderer renderer, int flags) Render this object using the functionality of the supplied Renderer.
void	setMaxTheta(double max) Sets the upper theta range limit for this joint, in degrees.
void	setMinTheta(double min) Sets the lower theta range limit for this joint, in degrees.
void	setTheta(double theta) Sets this joint's theta value, in degrees.
void	setThetaLocked(boolean locked) Set whether the theta coordinate for this joint is locked.
void	setThetaRange(double min, double max) Sets the theta range limits for this joint, in degrees.
void	setThetaRange(DoubleInterval range) Sets the theta range limits for this joint, in degrees.
void	updateBounds(Vector3d pmin, Vector3d pmax) Update the minimum and maximum points for this object.

Methods inherited from class artisynth.core.mechmodels.JointBase

addCoordinateSolveBlocks, addCoordinateVelJacobian, applyCoordinateForce, coordinatesToTCD, getCoordinate, getCoordinateDeg, getCoordinateIndex, getCoordinateMotionType, getCoordinateName, getCoordinateRange, getCoordinateRangeDeg, getCoordinates, getCoordinateSpeed, getCoordinateValue, getMaxCoordinate, getMaxCoordinateDeg, getMinCoordinate, getMinCoordinateDeg, getPosition, getShaftLength, getShaftRadius, getStoredCoordinates, getStoredTCD, getStoredTCD, isCoordinateLocked, numCoordinates, setCoordinate, setCoordinateDeg, setCoordinateLocked, setCoordinateName, setCoordinateRange, setCoordinateRangeDeg, setCoordinates, setShaftLength, setShaftRadius

Methods inherited from class artisynth.core.mechmodels.BodyConnector

addBilateralConstraints, addFrictionConstraints, addMasterBlocks, addTransformableDependencies, addUnilateralConstraints, computeConstraintMatrixA, computeConstraintMatrixB, connectToHierarchy, copy, disconnectFromHierarchy, findAttachedBodies, getActivation, getAxisLength, getBilateralForceInA, getBilateralForceInA, getBilateralForceInB, getBilateralForceInB, getBilateralForceInC, getBilateralForceInC, getBilateralForces, getBilateralInfo, getBilateralSizes, getBodyA, getBodyB, getCompliance, getConstrainedComponents, getConstraint, getConstraintFlags, getConstraintForce, getCopyReferences, getCoupling, getCurrentTCD, getCurrentTCW, getCurrentTCW, getCurrentTDW, getCurrentTDW, getDamping, getDrawFrameC, getDrawFrameD, getFrameAttachmentA, getFrameAttachmentB, getFrictionForces, getFrictionState, getHardReferences, getLinearCompliance, getPenetrationTol, getPenetrationTolMode, getPose, getRenderFrame, getRotaryCompliance, getRotaryLimitTol, getRotaryLimitTolMode, getState, getStateVersion, getTransformDGeometryOnly, getTransformPositionOnly, getUnilateralForceInA, getUnilateralForceInA, getUnilateralForceInB, getUnilateralForceInB, getUnilateralForceInC, getUnilateralForceInC, getUnilateralForces, getUnilateralInfo, getUnilateralSizes, getUnilateralState, hasState, isActive, isConnectedToBodies, isDuplicatable, isEnabled, isNotAttached, maxFrictionConstraintSets, numBilateralConstraints, numConstraints, numEngagedUnilateralConstraints, numUnilateralConstraints, prerender, printConnectedBodies, printConstraintInfo, scaleDistance, scaleMass, setAlwaysAdjustBodyA, setAxisLength, setBilateralForces, setBodies, setBodies, setBodies, setBodies, setCompliance, setCurrentTCW, setCurrentTDW, setDamping, setDrawFrameC, setDrawFrameD, setEnabled, setFrictionForces, setFrictionState, setLinearCompliance, setPenetrationTol, setPenetrationTolMode, setRotaryCompliance, setRotaryLimitTol, setRotaryLimitTolMode, setState, setTransformDGeometryOnly, setTransformPositionOnly, setUnilateralForces, setUnilateralState, transformGeometry, transformGeometry, updateAttachments, updateConstraints, zeroForces

Methods inherited from class artisynth.core.modelbase.RenderableComponentBase

createRenderProps, defaultRenderPropsAreNull, getRenderHints, getRenderProps, getSelection, isSelectable, isVisible, numSelectionQueriesNeeded, setRenderProps, setVisible, updateRenderProps

Methods inherited from class artisynth.core.modelbase.ModelComponentBase

checkFlag, checkName, checkNameUniqueness, clearFlag, clone, createTempFlag, getChildren, getGrandParent, getName, getNameRange, getNavpanelVisibility, getNavpanelVisibility, getNumber, getParent, getProperty, getSoftReferences, hasChildren, isFixed, isMarked, isScanning, isSelected, isWritable, makeValidName, makeValidName, notifyParentOfChange, postscan, printReferences, recursivelyContained, recursivelyContains, removeTempFlag, scan, setFixed, setFlag, setMarked, setName, setNavpanelVisibility, setNavpanelVisibility, setNumber, setParent, setScanning, setSelected, setWritable, updateReferences, write

Methods inherited from class java.lang.Object

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

Methods inherited from interface artisynth.core.modelbase.CopyableComponent

copy, getCopyReferences, isDuplicatable

Methods inherited from interface artisynth.core.modelbase.ModelComponent

connectToHierarchy, disconnectFromHierarchy, getHardReferences, getName, getNavpanelVisibility, getNumber, getParent, getSoftReferences, hasState, isFixed, isMarked, isSelected, notifyParentOfChange, scan, setFixed, setMarked, setName, setNumber, setParent, setSelected, setWritable, updateReferences

Methods inherited from interface maspack.properties.HasProperties

getProperty

Methods inherited from interface maspack.properties.HierarchyNode

getChildren, hasChildren

Methods inherited from interface artisynth.core.modelbase.PostScannable

postscan

Methods inherited from interface maspack.util.Scannable

isWritable, write

Methods inherited from interface artisynth.core.modelbase.HasNumericState

advanceState, getAuxVarDerivative, getAuxVarState, numAuxVars, requiresAdvance, setAuxVarState

Field Detail

THETA_IDX

public static final int THETA_IDX

See Also:

Constant Field Values

myProps

public static PropertyList myProps

Constructor Detail

HingeJoint

public HingeJoint()

Creates a HingeJoint which is not attached to any bodies. It can subsequently be connected using one of the setBodies methods.

HingeJoint

public HingeJoint(RigidBody bodyA,
                  RigidTransform3d TCA,
                  RigidBody bodyB,
                  RigidTransform3d TDB)

Creates a HingeJoint connecting two rigid bodies, bodyA and bodyB. If A and B describe the coordinate frames of bodyA and bodyB, then TCA and TDB give the (fixed) transforms from the joint's C and D frames to A and B, respectively. Since C and D are specified independently, the joint transform TCD may not necessarily be initialized to the identity.

Specifying bodyB as null will cause bodyA to be connected to ground, with TDB then being the same as TDW.

Parameters:

bodyA - rigid body A

TCA - transform from joint frame C to body frame A

bodyB - rigid body B (or null)

TDB - transform from joint frame D to body frame B

HingeJoint

public HingeJoint(ConnectableBody bodyA,
                  ConnectableBody bodyB,
                  RigidTransform3d TCW,
                  RigidTransform3d TDW)

Creates a HingeJoint connecting two connectable bodies, bodyA and bodyB. The joint frames C and D are located independently with respect to world coordinates by TCW and TDW.

Specifying bodyB as null will cause bodyA to be connected to ground.

Parameters:

bodyA - body A

bodyB - body B (or null)

TCW - initial transform from joint frame C to world

TDW - initial transform from joint frame D to world

HingeJoint

public HingeJoint(ConnectableBody bodyA,
                  ConnectableBody bodyB,
                  RigidTransform3d TDW)

Creates a HingeJoint connecting two connectable bodies, bodyA and bodyB. The joint frames D and C are assumed to be initially coincident, so that theta will have an initial value of 0. D (and C) is located by TDW, which gives the transform from D to world coordinates.

Parameters:

bodyA - body A

bodyB - body B

TDW - initial transform from joint frames D and C to world

HingeJoint

public HingeJoint(ConnectableBody bodyA,
                  RigidTransform3d TDW)

Creates a HingeJoint connecting a single connectable body, bodyA, to ground. The joint frames D and C are assumed to be initially coincident, so that theta will have an initial value of 0. D (and C) is located by TDW, which gives the transform from D to world coordinates.

Parameters:

bodyA - body A

TDW - initial transform from joint frames D and C to world

HingeJoint

public HingeJoint(RigidBody bodyA,
                  ConnectableBody bodyB,
                  Point3d originD,
                  Vector3d zaxis)

Creates a HingeJoint connecting two connectable bodies, bodyA and bodyB. The joint frames D and C are assumed to be initially coincident, so that theta will have an initial value of 0. D (and C) is located (with respect to world) so that its origin is at originD and its z axis in the direction of zaxis, with the remaining orientation of D chosen to be aligned as closely as possible with the world.

Specifying bodyB as null will cause bodyA to be connected to ground.

Parameters:

bodyA - body A

bodyB - body B, or null if bodyA is connected to ground.

originD - origin of frame D (world coordinates)

zaxis - direction of frame D's z axis (world coordinates)

Method Detail

getAllPropertyInfo

public PropertyList getAllPropertyInfo()

Description copied from interface: HasProperties

Returns a list giving static information about all properties exported by this object.

Specified by:

getAllPropertyInfo in interface HasProperties

Overrides:

getAllPropertyInfo in class JointBase

Returns:

static information for all exported properties

getTheta

public double getTheta()

Queries this joint's theta value, in degrees. See setTheta(double) for more details.

Returns:

current theta value

setTheta

public void setTheta(double theta)

Sets this joint's theta value, in degrees. This describes the clockwise rotation of frame C about the z axis of frame D. See this class's Javadoc header for a discussion of what happens when this value is set.

Parameters:

theta - new theta value

getThetaRange

public DoubleInterval getThetaRange()

Queries the theta range limits for this joint, in degrees. See setThetaRange(DoubleInterval) for more details.

Returns:

theta range limits for this joint

getMinTheta

public double getMinTheta()

Queries the lower theta range limit for this joint, in degrees.

Returns:

lower theta range limit

getMaxTheta

public double getMaxTheta()

Queries the upper theta range limit for this joint, in degrees.

Returns:

upper theta range limit

setThetaRange

public void setThetaRange(DoubleInterval range)

Sets the theta range limits for this joint, in degrees. The default range is [-inf, inf], which implies no limits. If theta travels beyond these limits during dynamic simulation, unilateral constraints will be activated to enforce them. Setting the lower limit to -inf or the upper limit to inf removes the lower or upper limit, respectively. Specifying range as null will set the range to (-inf, inf).

Parameters:

range - theta range limits for this joint

setThetaRange

public void setThetaRange(double min,
                          double max)

Sets the theta range limits for this joint, in degrees. This is a convenience wrapper for setThetaRange(DoubleInterval).

Parameters:

min - minimum theta value

max - maximum theta value

setMaxTheta

public void setMaxTheta(double max)

Sets the upper theta range limit for this joint, in degrees. Setting a value of inf removes the upper limit.

Parameters:

max - upper theta range limit

setMinTheta

public void setMinTheta(double min)

Sets the lower theta range limit for this joint, in degrees. Setting a value of -inf removes the lower limit.

Parameters:

min - lower theta range limit

isThetaLocked

public boolean isThetaLocked()

Queries whether the theta coordinate for this joint is locked.

Returns:

true if theta is locked

setThetaLocked

public void setThetaLocked(boolean locked)

Set whether the theta coordinate for this joint is locked.

Parameters:

locked - if true, locks theta

updateBounds

public void updateBounds(Vector3d pmin,
                         Vector3d pmax)

Description copied from interface: IsRenderable

Update the minimum and maximum points for this object. In an x-y-z coordinate system with x directed to the right and y directed upwards, the minimum and maximum points can be thought of as defining the left-lower-far and right-upper-near corners of a bounding cube. This method should only reduce the elements of the minimum point and increase the elements of the maximum point, since it may be used as part of an iteration to determine the bounding cube for several different objects.

Specified by:

updateBounds in interface IsRenderable

Overrides:

updateBounds in class BodyConnector

Parameters:

pmin - minimum point

pmax - maximum point

render

public void render(Renderer renderer,
                   int flags)

Description copied from interface: IsRenderable

Render this object using the functionality of the supplied Renderer.

Specified by:

render in interface IsRenderable

Overrides:

render in class BodyConnector

Parameters:

renderer - provides the functionality used to perform the rendering.

flags - flags that may be used to control different aspects of the rendering. Flags are defined in Renderer and currently include Renderer.HIGHLIGHT and Renderer.SORT_FACES.