SimTK::GeneralContactSubsystem Class Reference

This class performs collision detection for use in contact modeling. More...

Inheritance diagram for SimTK::GeneralContactSubsystem:

Public Member Functions
	GeneralContactSubsystem ()
	GeneralContactSubsystem (MultibodySystem &)
ContactSetIndex	createContactSet ()
	Create a new contact set. More...
int	getNumContactSets () const
	Get the total number of contact sets that have been created. More...
void	addBody (ContactSetIndex index, const MobilizedBody &body, const ContactGeometry &geom, Transform transform)
	Add a body to a contact set. More...
int	getNumBodies (ContactSetIndex set) const
	Get the number of bodies in a contact set. More...
const MobilizedBody &	getBody (ContactSetIndex set, ContactSurfaceIndex index) const
	Get the MobilizedBody in whose reference frame a body is defined. More...
const ContactGeometry &	getBodyGeometry (ContactSetIndex set, ContactSurfaceIndex index) const
	Get the ContactGeometry which defines the shape of a body. More...
ContactGeometry &	updBodyGeometry (ContactSetIndex set, ContactSurfaceIndex index)
	Get a mutable reference to the ContactGeometry which defines the shape of a body. More...
const Transform &	getBodyTransform (ContactSetIndex set, ContactSurfaceIndex index) const
	Get the location and orientation of a body. More...
Transform &	updBodyTransform (ContactSetIndex set, ContactSurfaceIndex index)
	Get a mutable reference to the location and orientation of a body. More...
const Array_< Contact > &	getContacts (const State &state, ContactSetIndex set) const
	Get a list of all contacts between bodies in a contact set. More...
	SimTK_PIMPL_DOWNCAST (GeneralContactSubsystem, Subsystem)
Public Member Functions inherited from SimTK::Subsystem
	Subsystem ()
	Default constructor creates and empty handle with a null Subsystem::Guts pointer. More...
	Subsystem (const Subsystem &)
	Copy constructor clones the Subsystem::Guts object if there is one and makes this the owner handle of the new clone. More...
Subsystem &	operator= (const Subsystem &)
	Copy assignment deletes the Subsystem::Guts object if there is one and then behaves like the copy constructor. More...
	~Subsystem ()
	Destructor deletes the referenced Subsystem::Guts object if this is the owner handle of that object, otherwise does nothing. More...
QIndex	allocateQ (State &s, const Vector &qInit) const
UIndex	allocateU (State &s, const Vector &uInit) const
ZIndex	allocateZ (State &s, const Vector &zInit) const
DiscreteVariableIndex	allocateDiscreteVariable (State &s, Stage g, AbstractValue *v) const
DiscreteVariableIndex	allocateAutoUpdateDiscreteVariable (State &s, Stage invalidates, AbstractValue *v, Stage updateDependsOn) const
CacheEntryIndex	allocateCacheEntry (const State &s, Stage dependsOn, Stage computedBy, AbstractValue *v) const
CacheEntryIndex	allocateCacheEntry (const State &state, Stage g, AbstractValue *v) const
CacheEntryIndex	allocateLazyCacheEntry (const State &state, Stage earliest, AbstractValue *v) const
QErrIndex	allocateQErr (const State &s, int nqerr) const
UErrIndex	allocateUErr (const State &s, int nuerr) const
UDotErrIndex	allocateUDotErr (const State &s, int nudoterr) const
EventTriggerByStageIndex	allocateEventTriggersByStage (const State &s, Stage g, int ntriggers) const
const Vector &	getQ (const State &s) const
const Vector &	getU (const State &s) const
const Vector &	getZ (const State &s) const
const Vector &	getUWeights (const State &s) const
const Vector &	getZWeights (const State &s) const
Vector &	updQ (State &s) const
Vector &	updU (State &s) const
Vector &	updZ (State &s) const
const Vector &	getQDot (const State &s) const
const Vector &	getUDot (const State &s) const
const Vector &	getZDot (const State &s) const
const Vector &	getQDotDot (const State &s) const
Vector &	updQDot (const State &s) const
Vector &	updUDot (const State &s) const
Vector &	updZDot (const State &s) const
Vector &	updQDotDot (const State &s) const
const Vector &	getQErr (const State &s) const
const Vector &	getUErr (const State &s) const
const Vector &	getQErrWeights (const State &s) const
const Vector &	getUErrWeights (const State &s) const
const Vector &	getUDotErr (const State &s) const
const Vector &	getMultipliers (const State &s) const
const Vector &	getEventTriggersByStage (const State &s, Stage g) const
Vector &	updQErr (const State &s) const
Vector &	updUErr (const State &s) const
Vector &	updUDotErr (const State &s) const
Vector &	updMultipliers (const State &s) const
Vector &	updEventTriggersByStage (const State &s, Stage g) const
SystemQIndex	getQStart (const State &s) const
int	getNQ (const State &s) const
SystemUIndex	getUStart (const State &s) const
int	getNU (const State &s) const
SystemZIndex	getZStart (const State &s) const
int	getNZ (const State &s) const
SystemQErrIndex	getQErrStart (const State &s) const
int	getNQErr (const State &s) const
SystemUErrIndex	getUErrStart (const State &s) const
int	getNUErr (const State &s) const
SystemUDotErrIndex	getUDotErrStart (const State &s) const
int	getNUDotErr (const State &s) const
SystemMultiplierIndex	getMultipliersStart (const State &s) const
int	getNMultipliers (const State &s) const
SystemEventTriggerByStageIndex	getEventTriggerStartByStage (const State &s, Stage g) const
int	getNEventTriggersByStage (const State &s, Stage g) const
void	setQ (State &s, const Vector &q) const
void	setU (State &s, const Vector &u) const
void	setZ (State &s, const Vector &z) const
Stage	getStage (const State &s) const
void	advanceToStage (const State &s, Stage g) const
const AbstractValue &	getDiscreteVariable (const State &s, DiscreteVariableIndex index) const
AbstractValue &	updDiscreteVariable (State &s, DiscreteVariableIndex index) const
const AbstractValue &	getCacheEntry (const State &s, CacheEntryIndex index) const
AbstractValue &	updCacheEntry (const State &s, CacheEntryIndex index) const
Real	getDiscreteVarLastUpdateTime (const State &s, DiscreteVariableIndex dx) const
CacheEntryIndex	getDiscreteVarUpdateIndex (const State &s, DiscreteVariableIndex dx) const
const AbstractValue &	getDiscreteVarUpdateValue (const State &s, DiscreteVariableIndex dx) const
AbstractValue &	updDiscreteVarUpdateValue (const State &s, DiscreteVariableIndex dx) const
bool	isDiscreteVarUpdateValueRealized (const State &s, DiscreteVariableIndex dx) const
void	markDiscreteVarUpdateValueRealized (const State &s, DiscreteVariableIndex dx) const
bool	isCacheValueRealized (const State &s, CacheEntryIndex cx) const
void	markCacheValueRealized (const State &s, CacheEntryIndex cx) const
void	markCacheValueNotRealized (const State &s, CacheEntryIndex cx) const
const String &	getName () const
	Obtain the Subsystem name if one was given on construction of the concrete Subsystem. More...
const String &	getVersion () const
	Obtain the Subsystem version string if one was given on construction. More...
bool	isInSystem () const
	Return true if this Subsystem is contained in a System. More...
bool	isInSameSystem (const Subsystem &otherSubsystem) const
	Return true if this Subsystem is contained in the same System as contains the given otherSubsystem. More...
const System &	getSystem () const
	Return a const reference to the System that contains this Subsystem. More...
System &	updSystem ()
	Return a writable reference to the System that contains this Subsystem. More...
void	setSystem (System &system, SubsystemIndex subx)
	Inform this Subsystem of the System that contains it, as well as the SubsystemIndex which the System has assigned to it. More...
SubsystemIndex	getMySubsystemIndex () const
	Return the SubsystemIndex within the containing System. More...
bool	isEmptyHandle () const
	Return true if this handle has a null Subsystem::Guts pointer. More...
bool	isSameSubsystem (const Subsystem &otherSubsystem) const
	Determine if this Subsystem handle refers to the same Subsystem::Guts object as handle otherSubsystem. More...
bool	isOwnerHandle () const
	Is this Subsystem handle the owner of the Subsystem::Guts object it points to? This is true if the handle is empty or if its Guts object points back to this handle. More...
bool	subsystemTopologyHasBeenRealized () const
	Returns true if this Subsystem's realizeTopology() method has been called since the last topological change or call to invalidateSubsystemTopologyCache(). More...
void	invalidateSubsystemTopologyCache () const
	Always call this method when a topological change is made to this Subsystem to indicate that any Stage::Topology cache values may need recomputation. More...
MeasureIndex	adoptMeasure (AbstractMeasure &)
	Obtain the Subsystem name if one was given on construction of the concrete Subsystem. More...
AbstractMeasure	getMeasure (MeasureIndex) const
	Obtain the Subsystem name if one was given on construction of the concrete Subsystem. More...
template<class T >
Measure_< T >	getMeasure_ (MeasureIndex mx) const
	Obtain the Subsystem name if one was given on construction of the concrete Subsystem. More...
const Subsystem::Guts &	getSubsystemGuts () const
	Obtain the Subsystem name if one was given on construction of the concrete Subsystem. More...
Subsystem::Guts &	updSubsystemGuts ()
	Obtain the Subsystem name if one was given on construction of the concrete Subsystem. More...
void	adoptSubsystemGuts (Subsystem::Guts *g)
	Obtain the Subsystem name if one was given on construction of the concrete Subsystem. More...
	Subsystem (Subsystem::Guts *g)
	Obtain the Subsystem name if one was given on construction of the concrete Subsystem. More...
bool	hasGuts () const
	Obtain the Subsystem name if one was given on construction of the concrete Subsystem. More...

Detailed Description

This class performs collision detection for use in contact modeling.

It manages sets of bodies that can potentially interact with each other. At each time step, it identifies all the contacts between them. It does not directly affect the behavior of the system in any way. Instead, it simply provides a service that can be used by other classes to implement forces, events, constraints, etc. that are based on contacts between bodies.

To use this class, first create a "contact set" by calling createContactSet(). A contact set is a group of bodies which can interact with each other. If you create multiple contact sets, the bodies within each one will be checked for contacts with each other, but bodies in different sets will not interact.

Next, add bodies to the contact set. Each one is represented by a ContactGeometry object that describes its shape, the MoblizedBody it is attached to, and a Transform giving the location of the geometry in the MobilizedBody's reference frame.

Finally, call getContacts() to get a list of all contacts which exist between bodies in a contact set. Each Contact specifies two bodies that overlap, along with a description of the contact point, such as its location and normal vector.

Constructor & Destructor Documentation

GeneralContactSubsystem() [1/2]

SimTK::GeneralContactSubsystem::GeneralContactSubsystem

(

)

GeneralContactSubsystem() [2/2]

SimTK::GeneralContactSubsystem::GeneralContactSubsystem ( MultibodySystem &  )

explicit

Member Function Documentation

createContactSet()

ContactSetIndex SimTK::GeneralContactSubsystem::createContactSet

(

)

Create a new contact set.

The return value is an index which can be used to refer to the contact set when calling other methods.

getNumContactSets()

int SimTK::GeneralContactSubsystem::getNumContactSets

(

)

const

Get the total number of contact sets that have been created.

addBody()

void SimTK::GeneralContactSubsystem::addBody	(	ContactSetIndex	index,
		const MobilizedBody &	body,
		const ContactGeometry &	geom,
		Transform	transform
	)

Add a body to a contact set.

Parameters

index	the index of the contact set the body should be added to
body	the MobilizedBody whose reference frame the body is attached to
geom	a ContactGeometry describing the shape of the body
transform	the location and orientation of the ContactGeometry in the MobilizedBody's reference frame

getNumBodies()

int SimTK::GeneralContactSubsystem::getNumBodies

(

ContactSetIndex

set

)

const

Get the number of bodies in a contact set.

getBody()

const MobilizedBody& SimTK::GeneralContactSubsystem::getBody	(	ContactSetIndex	set,
		ContactSurfaceIndex	index
	)		const

Get the MobilizedBody in whose reference frame a body is defined.

Parameters

set	the contact set the body belongs to
index	the index of the body within the contact set

getBodyGeometry()

const ContactGeometry& SimTK::GeneralContactSubsystem::getBodyGeometry	(	ContactSetIndex	set,
		ContactSurfaceIndex	index
	)		const

Get the ContactGeometry which defines the shape of a body.

Parameters

set	the contact set the body belongs to
index	the index of the body within the contact set

updBodyGeometry()

ContactGeometry& SimTK::GeneralContactSubsystem::updBodyGeometry	(	ContactSetIndex	set,
		ContactSurfaceIndex	index
	)

Get a mutable reference to the ContactGeometry which defines the shape of a body.

Parameters

set	the contact set the body belongs to
index	the index of the body within the contact set

getBodyTransform()

const Transform& SimTK::GeneralContactSubsystem::getBodyTransform	(	ContactSetIndex	set,
		ContactSurfaceIndex	index
	)		const

Get the location and orientation of a body.

Parameters

set	the contact set the body belongs to
index	the index of the body within the contact set

updBodyTransform()

Transform& SimTK::GeneralContactSubsystem::updBodyTransform	(	ContactSetIndex	set,
		ContactSurfaceIndex	index
	)

Get a mutable reference to the location and orientation of a body.

Parameters

set	the contact set the body belongs to
index	the index of the body within the contact set

getContacts()

const Array_<Contact>& SimTK::GeneralContactSubsystem::getContacts	(	const State &	state,
		ContactSetIndex	set
	)		const

Get a list of all contacts between bodies in a contact set.

Contacts are calculated at Dynamics stage, so the state must have been realized to at least Dynamics stage. This subsystem is guaranteed to be realized before all ForceSubsystems, however, so a Force may still invoke it to calculate forces based on contacts.

SimTK_PIMPL_DOWNCAST()

SimTK::GeneralContactSubsystem::SimTK_PIMPL_DOWNCAST	(	GeneralContactSubsystem	,
		Subsystem
	)

---

The documentation for this class was generated from the following file:

• GeneralContactSubsystem.h