Description

Base class for physics items that are part of a simulation.

Such items (e.g., rigid bodies, joints, FEM meshes, etc.) can contain ChVariables or ChConstraints objects.

#include <ChPhysicsItem.h>

Inheritance diagram for chrono::ChPhysicsItem:

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Collaboration diagram for chrono::ChPhysicsItem:

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Public Member Functions
	ChPhysicsItem (const ChPhysicsItem &other)

virtual ChPhysicsItem *	Clone () const override
	"Virtual" copy constructor (covariant return type).

ChSystem *	GetSystem () const
	Get the pointer to the parent ChSystem().

virtual void	SetSystem (ChSystem *m_system)
	Set the pointer to the parent ChSystem(). More...

void	AddVisualModel (std::shared_ptr< ChVisualModel > model)
	Add an (optional) visualization model. More...

std::shared_ptr< ChVisualModel >	GetVisualModel () const
	Access the visualization model (if any). More...

void	AddVisualShape (std::shared_ptr< ChVisualShape > shape, const ChFrame<> &frame=ChFrame<>())
	Add the specified visual shape to the visualization model. More...

std::shared_ptr< ChVisualShape >	GetVisualShape (unsigned int i) const
	Access the specified visualization shape in the visualization model (if any). More...

void	AddVisualShapeFEA (std::shared_ptr< ChVisualShapeFEA > shapeFEA)
	Add the specified FEA visualization object to the visualization model. More...

std::shared_ptr< ChVisualShapeFEA >	GetVisualShapeFEA (unsigned int i) const
	Access the specified FEA visualization object in the visualization model (if any). More...

virtual ChFrame	GetVisualModelFrame (unsigned int nclone=0) const
	Get the reference frame (expressed in and relative to the absolute frame) of the visual model. More...

virtual unsigned int	GetNumVisualModelClones () const
	Return the number of clones of the visual model associated with this physics item. More...

void	AddCamera (std::shared_ptr< ChCamera > camera)
	Attach a ChCamera to this physical item. More...

std::vector< std::shared_ptr< ChCamera > >	GetCameras () const
	Get the set of cameras attached to this physics item.

virtual bool	IsActive () const
	Return true if the object is active and included in dynamics.

virtual bool	IsCollisionEnabled () const
	Tell if the object is subject to collision. More...

virtual void	AddCollisionModelsToSystem (ChCollisionSystem *coll_sys) const
	Add to the provided collision system any collision models managed by this physics item. More...

virtual void	RemoveCollisionModelsFromSystem (ChCollisionSystem *coll_sys) const
	Remove from the provided collision system any collision models managed by this physics item. More...

virtual void	SyncCollisionModels ()
	Synchronize the position and bounding box of any collsion models managed by this physics item.

virtual ChAABB	GetTotalAABB ()
	Get the entire AABB axis-aligned bounding box of the object. More...

virtual void	GetCenter (ChVector3d &mcenter)
	Get a symbolic 'center' of the object. More...

virtual void	Setup ()
	This might recompute the number of coordinates, DOFs, constraints, in case this might change (ex in ChAssembly), as well as state offsets of contained items (ex in ChMesh)

virtual void	Update (double mytime, bool update_assets=true)
	This is an important function, which is called by the owner ChSystem at least once per integration step. More...

virtual void	Update (bool update_assets=true)
	As above, but does not require updating of time-dependent data. More...

virtual void	ForceToRest ()
	Set zero speed (and zero accelerations) in state, without changing the position. More...

virtual unsigned int	GetNumCoordsPosLevel ()
	Get the number of coordinates at the position level. More...

virtual unsigned int	GetNumCoordsVelLevel ()
	Get the number of coordinates at the velocity level. More...

virtual unsigned int	GetNumConstraints ()
	Get the number of scalar constraints.

virtual unsigned int	GetNumConstraintsBilateral ()
	Get the number of bilateral scalar constraints.

virtual unsigned int	GetNumConstraintsUnilateral ()
	Get the number of unilateral scalar constraints.

unsigned int	GetOffset_x ()
	Get offset in the state vector (position part)

unsigned int	GetOffset_w ()
	Get offset in the state vector (speed part)

unsigned int	GetOffset_L ()
	Get offset in the lagrangian multipliers.

void	SetOffset_x (const unsigned int moff)
	Set offset in the state vector (position part) Note: only the ChSystem::Setup function should use this.

void	SetOffset_w (const unsigned int moff)
	Set offset in the state vector (speed part) Note: only the ChSystem::Setup function should use this.

void	SetOffset_L (const unsigned int moff)
	Set offset in the lagrangian multipliers Note: only the ChSystem::Setup function should use this.

virtual void	IntStateGather (const unsigned int off_x, ChState &x, const unsigned int off_v, ChStateDelta &v, double &T)
	From item's state to global state vectors y={x,v} pasting the states at the specified offsets. More...

virtual void	IntStateScatter (const unsigned int off_x, const ChState &x, const unsigned int off_v, const ChStateDelta &v, const double T, bool full_update)
	From global state vectors y={x,v} to item's state (and update) fetching the states at the specified offsets. More...

virtual void	IntStateGatherAcceleration (const unsigned int off_a, ChStateDelta &a)
	From item's state acceleration to global acceleration vector. More...

virtual void	IntStateScatterAcceleration (const unsigned int off_a, const ChStateDelta &a)
	From global acceleration vector to item's state acceleration. More...

virtual void	IntStateGatherReactions (const unsigned int off_L, ChVectorDynamic<> &L)
	From item's reaction forces to global reaction vector. More...

virtual void	IntStateScatterReactions (const unsigned int off_L, const ChVectorDynamic<> &L)
	From global reaction vector to item's reaction forces. More...

virtual void	IntStateIncrement (const unsigned int off_x, ChState &x_new, const ChState &x, const unsigned int off_v, const ChStateDelta &Dv)
	Computes x_new = x + Dt , using vectors at specified offsets. More...

virtual void	IntStateGetIncrement (const unsigned int off_x, const ChState &x_new, const ChState &x, const unsigned int off_v, ChStateDelta &Dv)
	Computes Dt = x_new - x, using vectors at specified offsets. More...

virtual void	IntLoadResidual_F (const unsigned int off, ChVectorDynamic<> &R, const double c)
	Takes the F force term, scale and adds to R at given offset: R += c*F. More...

virtual void	IntLoadResidual_Mv (const unsigned int off, ChVectorDynamic<> &R, const ChVectorDynamic<> &w, const double c)
	Takes the Mv term, multiplying mass by a vector, scale and adds to R at given offset: R += cM*w. More...

virtual void	IntLoadLumpedMass_Md (const unsigned int off, ChVectorDynamic<> &Md, double &err, const double c)
	Adds the lumped mass to a Md vector, representing a mass diagonal matrix. More...

virtual void	IntLoadResidual_CqL (const unsigned int off_L, ChVectorDynamic<> &R, const ChVectorDynamic<> &L, const double c)
	Takes the term Cq'L, scale and adds to R at given offset: R += cCq'*L. More...

virtual void	IntLoadConstraint_C (const unsigned int off, ChVectorDynamic<> &Qc, const double c, bool do_clamp, double recovery_clamp)
	Takes the term C, scale and adds to Qc at given offset: Qc += c*C. More...

virtual void	IntLoadConstraint_Ct (const unsigned int off, ChVectorDynamic<> &Qc, const double c)
	Takes the term Ct, scale and adds to Qc at given offset: Qc += c*Ct. More...

virtual void	IntToDescriptor (const unsigned int off_v, const ChStateDelta &v, const ChVectorDynamic<> &R, const unsigned int off_L, const ChVectorDynamic<> &L, const ChVectorDynamic<> &Qc)
	Prepare variables and constraints to accommodate a solution: More...

virtual void	IntFromDescriptor (const unsigned int off_v, ChStateDelta &v, const unsigned int off_L, ChVectorDynamic<> &L)
	After a solver solution, fetch values from variables and constraints into vectors: More...

virtual void	InjectVariables (ChSystemDescriptor &descriptor)
	Register with the given system descriptor any ChVariable objects associated with this item.

virtual void	InjectConstraints (ChSystemDescriptor &descriptor)
	Register with the given system descriptor any ChConstraint objects associated with this item.

virtual void	LoadConstraintJacobians ()
	Compute and load current Jacobians in encapsulated ChConstraint objects.

virtual void	InjectKRMMatrices (ChSystemDescriptor &descriptor)
	Register with the given system descriptor any ChKRMBlock objects associated with this item.

virtual void	LoadKRMMatrices (double Kfactor, double Rfactor, double Mfactor)
	Compute and load current stiffnes (K), damping (R), and mass (M) matrices in encapsulated ChKRMBlock objects. More...

virtual void	VariablesFbReset ()
	Sets the 'fb' part (the known term) of the encapsulated ChVariables to zero.

virtual void	VariablesFbLoadForces (double factor=1)
	Adds the current forces (applied to item) into the encapsulated ChVariables, in the 'fb' part: qf+=forces*factor.

virtual void	VariablesQbLoadSpeed ()
	Initialize the 'qb' part of the ChVariables with the current value of speeds. More...

virtual void	VariablesFbIncrementMq ()
	Adds M*q (masses multiplied current 'qb') to Fb, ex. More...

virtual void	VariablesQbSetSpeed (double step=0)
	Fetches the item speed (ex. More...

virtual void	VariablesQbIncrementPosition (double step)
	Increment item positions by the 'qb' part of the ChVariables, multiplied by a 'step' factor. More...

virtual void	ConstraintsBiReset ()
	Sets to zero the known term (b_i) of encapsulated ChConstraints.

virtual void	ConstraintsBiLoad_C (double factor=1, double recovery_clamp=0.1, bool do_clamp=false)
	Adds the current C (constraint violation) to the known term (b_i) of encapsulated ChConstraints.

virtual void	ConstraintsBiLoad_Ct (double factor=1)
	Adds the current Ct (partial t-derivative, as in C_dt=0-> [Cq]*q_dt=-Ct) to the known term (b_i) of encapsulated ChConstraints.

virtual void	ConstraintsBiLoad_Qc (double factor=1)
	Adds the current Qc (the vector of C_dtdt=0 -> [Cq]*q_dtdt=Qc ) to the known term (b_i) of encapsulated ChConstraints.

virtual void	ConstraintsFbLoadForces (double factor=1)
	Adds the current link-forces, if any, (caused by springs, etc.) to the 'fb' vectors of the ChVariables referenced by encapsulated ChConstraints.

virtual void	ConstraintsFetch_react (double factor=1)
	Fetches the reactions from the lagrangian multiplier (l_i) of encapsulated ChConstraints. More...

virtual void	ArchiveOut (ChArchiveOut &archive_out) override
	Method to allow serialization of transient data to archives.

virtual void	ArchiveIn (ChArchiveIn &archive_in) override
	Method to allow deserialization of transient data from archives. More...

Public Member Functions inherited from chrono::ChObj
	ChObj (const ChObj &other)

int	GetIdentifier () const
	Get the unique integer identifier of this object. More...

void	SetTag (int tag)
	Set an object integer tag (default: -1). More...

int	GetTag () const
	Get the tag of this object.

void	SetName (const std::string &myname)
	Set the name of this object.

const std::string &	GetName () const
	Get the name of this object.

double	GetChTime () const
	Gets the simulation time of this object.

void	SetChTime (double m_time)
	Sets the simulation time of this object.

virtual std::string &	ArchiveContainerName ()

Protected Attributes
ChSystem *	system
	parent system

std::shared_ptr< ChVisualModelInstance >	vis_model_instance
	instantiated visualization model

std::vector< std::shared_ptr< ChCamera > >	cameras
	set of cameras

unsigned int	offset_x
	offset in vector of state (position part)

unsigned int	offset_w
	offset in vector of state (speed part)

unsigned int	offset_L
	offset in vector of lagrangian multipliers

Protected Attributes inherited from chrono::ChObj
double	ChTime
	object simulation time

std::string	m_name
	object name

int	m_identifier
	object unique identifier

int	m_tag
	user-supplied tag

Friends
class	ChSystem

class	ChAssembly

class	modal::ChModalAssembly

Additional Inherited Members
Protected Member Functions inherited from chrono::ChObj
int	GenerateUniqueIdentifier ()

Member Function Documentation

◆ AddCamera()

void chrono::ChPhysicsItem::AddCamera ( std::shared_ptr< ChCamera > camera )

Attach a ChCamera to this physical item.

Multiple cameras can be attached to the same physics item.

◆ AddCollisionModelsToSystem()

virtual void chrono::ChPhysicsItem::AddCollisionModelsToSystem ( ChCollisionSystem * coll_sys ) const

inlinevirtual

Add to the provided collision system any collision models managed by this physics item.

A derived calss should invoke ChCollisionSystem::Add for each of its collision models.

Reimplemented in chrono::ChParticleCloud, chrono::ChAssembly, chrono::fea::ChMesh, chrono::ChBody, and chrono::ChConveyor.

◆ AddVisualModel()

void chrono::ChPhysicsItem::AddVisualModel ( std::shared_ptr< ChVisualModel > model )

Add an (optional) visualization model.

Not that an instance of the given visual model is associated with this physics ite, thus allowing sharing the same model among multiple items.

◆ AddVisualShape()

void chrono::ChPhysicsItem::AddVisualShape	(	std::shared_ptr< ChVisualShape >	shape,
		const ChFrame<> &	frame = `ChFrame<>()`
	)

Add the specified visual shape to the visualization model.

If this item does not have a visual model, one is created.

◆ AddVisualShapeFEA()

void chrono::ChPhysicsItem::AddVisualShapeFEA ( std::shared_ptr< ChVisualShapeFEA > shapeFEA )

Add the specified FEA visualization object to the visualization model.

If this item does not have a visual model, one is created.

◆ ArchiveIn()

void chrono::ChPhysicsItem::ArchiveIn ( ChArchiveIn & archive_in )

overridevirtual

Method to allow deserialization of transient data from archives.

Method to allow de serialization of transient data from archives.

Reimplemented from chrono::ChObj.

◆ ConstraintsFetch_react()

virtual void chrono::ChPhysicsItem::ConstraintsFetch_react ( double factor = 1 )

inlinevirtual

Fetches the reactions from the lagrangian multiplier (l_i) of encapsulated ChConstraints.

Mostly used after the solver provided the solution in ChConstraints. Also, should convert the reactions obtained from dynamical simulation, from link space to intuitive react_force and react_torque.

Reimplemented in chrono::fea::ChLinkNodeSlopeFrame, chrono::fea::ChLinkNodeFaceRot, chrono::fea::ChLinkNodeFrameGeneric, chrono::ChAssembly, chrono::ChLinkLock, chrono::ChLinkMateGeneric, chrono::ChContactContainerNSC, chrono::fea::ChLinkNodeFace, chrono::fea::ChLinkBeamIGAFrame, chrono::fea::ChLinkNodeFrame, and chrono::fea::ChLinkNodeNode.

◆ ForceToRest()

virtual void chrono::ChPhysicsItem::ForceToRest ( )

inlinevirtual

Set zero speed (and zero accelerations) in state, without changing the position.

Child classes should implement this function if GetNumCoordsPosLevel() > 0. It is used by owner ChSystem for some static analysis.

Reimplemented in chrono::modal::ChModalAssembly, chrono::ChParticleCloud, chrono::ChAssembly, chrono::fea::ChMesh, chrono::ChBody, and chrono::ChShaft.

◆ GetCenter()

void chrono::ChPhysicsItem::GetCenter ( ChVector3d & mcenter )

virtual

Get a symbolic 'center' of the object.

By default this function returns the center of the AABB. It could be overridden by child classes, anyway it must always get a point that must be inside AABB.

◆ GetNumCoordsPosLevel()

virtual unsigned int chrono::ChPhysicsItem::GetNumCoordsPosLevel ( )

inlinevirtual

Get the number of coordinates at the position level.

Might differ from coordinates at velocity level if quaternions are used for rotations.

Reimplemented in chrono::modal::ChModalAssembly, chrono::ChAssembly, chrono::ChShaft, chrono::ChBody, chrono::ChExternalDynamics, chrono::fea::ChMesh, chrono::ChConveyor, chrono::ChIndexedParticles, chrono::ChLinkMotorLinearSpeed, and chrono::ChFeeder.

◆ GetNumCoordsVelLevel()

virtual unsigned int chrono::ChPhysicsItem::GetNumCoordsVelLevel ( )

inlinevirtual

Get the number of coordinates at the velocity level.

Might differ from coordinates at position level if quaternions are used for rotations.

Reimplemented in chrono::modal::ChModalAssembly, chrono::ChAssembly, chrono::ChBody, chrono::fea::ChMesh, chrono::ChConveyor, chrono::ChIndexedParticles, and chrono::ChFeeder.

◆ GetNumVisualModelClones()

virtual unsigned int chrono::ChPhysicsItem::GetNumVisualModelClones ( ) const

inlinevirtual

Return the number of clones of the visual model associated with this physics item.

If the visual model is cloned (for example for a physics item modeling a particle system), this function should return the total number of copies of the visual model, including the "original". The current coordinate frame of a given clone can be obtained by calling GetVisualModelFrame() with the corresponding clone identifier.

Reimplemented in chrono::ChIndexedParticles.

◆ GetTotalAABB()

ChAABB chrono::ChPhysicsItem::GetTotalAABB ( )

virtual

Get the entire AABB axis-aligned bounding box of the object.

The AABB must enclose the collision models, if any. By default is infinite AABB. Should be overridden by child classes.

Reimplemented in chrono::ChBody.

◆ GetVisualModel()

std::shared_ptr< ChVisualModel > chrono::ChPhysicsItem::GetVisualModel ( ) const

Access the visualization model (if any).

Note that this model may be shared with other physics items that may instance it. Returns nullptr if no visual model is present.

◆ GetVisualModelFrame()

virtual ChFrame chrono::ChPhysicsItem::GetVisualModelFrame ( unsigned int nclone = 0 ) const

inlinevirtual

Get the reference frame (expressed in and relative to the absolute frame) of the visual model.

If the visual model is cloned (for example for a physics item modeling a particle system), this function returns the coordinate system of the specified clone.

Reimplemented in chrono::ChBody, chrono::ChLinkRSDA, chrono::ChLinkMarkers, chrono::ChIndexedParticles, chrono::ChLinkBase, and chrono::ChLinkMateGeneric.

◆ GetVisualShape()

std::shared_ptr< ChVisualShape > chrono::ChPhysicsItem::GetVisualShape ( unsigned int i ) const

Access the specified visualization shape in the visualization model (if any).

Note that no range check is performed.

◆ GetVisualShapeFEA()

std::shared_ptr< ChVisualShapeFEA > chrono::ChPhysicsItem::GetVisualShapeFEA ( unsigned int i ) const

Access the specified FEA visualization object in the visualization model (if any).

Note that no range check is performed.

◆ IntFromDescriptor()

virtual void chrono::ChPhysicsItem::IntFromDescriptor	(	const unsigned int	off_v,
		ChStateDelta &	v,
		const unsigned int	off_L,
		ChVectorDynamic<> &	L
	)

inlinevirtual

After a solver solution, fetch values from variables and constraints into vectors:

Parameters

off_v	offset for v
v	vector to where the q 'unknowns' term of the variables will be copied
off_L	offset for L
L	vector to where L 'lagrangian ' term of the constraints will be copied

Reimplemented in chrono::modal::ChModalAssembly, chrono::fea::ChLinkNodeFaceRot, chrono::fea::ChLinkNodeFrameGeneric, chrono::ChParticleCloud, chrono::ChAssembly, chrono::ChLinkLock, chrono::fea::ChMesh, chrono::ChLinkMateGeneric, chrono::ChShaft, chrono::ChContactContainerNSC, chrono::fea::ChLinkNodeFace, chrono::fea::ChLinkBeamIGAFrame, chrono::fea::ChLinkNodeFrame, chrono::ChExternalDynamics, chrono::fea::ChLinkNodeSlopeFrame, and chrono::fea::ChLinkNodeNode.

◆ IntLoadConstraint_C()

virtual void chrono::ChPhysicsItem::IntLoadConstraint_C	(	const unsigned int	off,
		ChVectorDynamic<> &	Qc,
		const double	c,
		bool	do_clamp,
		double	recovery_clamp
	)

inlinevirtual

Takes the term C, scale and adds to Qc at given offset: Qc += c*C.

Parameters

off	offset in Qc residual
Qc	result: the Qc residual, Qc += c*C
c	a scaling factor
do_clamp	apply clamping to c*C?
recovery_clamp	value for min/max clamping of c*C

Reimplemented in chrono::modal::ChModalAssembly, chrono::fea::ChLinkNodeFaceRot, chrono::fea::ChLinkNodeFrameGeneric, chrono::ChAssembly, chrono::ChLinkLock, chrono::ChLinkMateGeneric, chrono::ChContactContainerNSC, chrono::fea::ChLinkNodeFace, chrono::fea::ChLinkBeamIGAFrame, chrono::fea::ChLinkNodeFrame, chrono::fea::ChLinkNodeSlopeFrame, and chrono::fea::ChLinkNodeNode.

◆ IntLoadConstraint_Ct()

virtual void chrono::ChPhysicsItem::IntLoadConstraint_Ct	(	const unsigned int	off,
		ChVectorDynamic<> &	Qc,
		const double	c
	)

inlinevirtual

Takes the term Ct, scale and adds to Qc at given offset: Qc += c*Ct.

Parameters

off	offset in Qc residual
Qc	result: the Qc residual, Qc += c*Ct
c	a scaling factor

Reimplemented in chrono::modal::ChModalAssembly, chrono::ChAssembly, chrono::ChLinkLock, and chrono::ChLinkMateGeneric.

◆ IntLoadLumpedMass_Md()

virtual void chrono::ChPhysicsItem::IntLoadLumpedMass_Md	(	const unsigned int	off,
		ChVectorDynamic<> &	Md,
		double &	err,
		const double	c
	)

inlinevirtual

Adds the lumped mass to a Md vector, representing a mass diagonal matrix.

Used by lumped explicit integrators. If mass lumping is impossible or approximate, adds scalar error to "error" parameter. Md += c*diag(M)

Parameters

off	offset in Md vector
Md	result: Md vector, diagonal of the lumped mass matrix
err	result: not touched if lumping does not introduce errors
c	a scaling factor

Reimplemented in chrono::modal::ChModalAssembly, chrono::ChParticleCloud, chrono::ChAssembly, chrono::fea::ChMesh, chrono::ChShaft, chrono::ChExternalDynamics, and chrono::ChLoadContainer.

◆ IntLoadResidual_CqL()

virtual void chrono::ChPhysicsItem::IntLoadResidual_CqL	(	const unsigned int	off_L,
		ChVectorDynamic<> &	R,
		const ChVectorDynamic<> &	L,
		const double	c
	)

inlinevirtual

Takes the term Cq'*L, scale and adds to R at given offset: R += c*Cq'*L.

Parameters

off_L	offset in L multipliers
R	result: the R residual, R += cCq'L
L	the L vector
c	a scaling factor

Reimplemented in chrono::modal::ChModalAssembly, chrono::fea::ChLinkNodeFaceRot, chrono::fea::ChLinkNodeFrameGeneric, chrono::ChAssembly, chrono::ChLinkLock, chrono::ChLinkMateGeneric, chrono::ChContactContainerNSC, chrono::fea::ChLinkNodeFace, chrono::fea::ChLinkBeamIGAFrame, chrono::fea::ChLinkNodeFrame, chrono::fea::ChLinkNodeSlopeFrame, and chrono::fea::ChLinkNodeNode.

◆ IntLoadResidual_F()

virtual void chrono::ChPhysicsItem::IntLoadResidual_F	(	const unsigned int	off,
		ChVectorDynamic<> &	R,
		const double	c
	)

inlinevirtual

Takes the F force term, scale and adds to R at given offset: R += c*F.

Parameters

off	offset in R residual
R	result: the R residual, R += c*F
c	a scaling factor

Reimplemented in chrono::modal::ChModalAssembly, chrono::ChParticleCloud, chrono::ChAssembly, chrono::fea::ChMesh, chrono::ChShaft, chrono::ChContactContainerSMC, chrono::ChHydraulicActuatorBase, chrono::ChLinkMarkers, chrono::ChExternalDynamics, chrono::ChShaftsTorque, and chrono::ChLoadContainer.

◆ IntLoadResidual_Mv()

virtual void chrono::ChPhysicsItem::IntLoadResidual_Mv	(	const unsigned int	off,
		ChVectorDynamic<> &	R,
		const ChVectorDynamic<> &	w,
		const double	c
	)

inlinevirtual

Takes the M*v term, multiplying mass by a vector, scale and adds to R at given offset: R += c*M*w.

Parameters

off	offset in R residual
R	result: the R residual, R += cMv
w	the w vector
c	a scaling factor

Reimplemented in chrono::modal::ChModalAssembly, chrono::ChParticleCloud, chrono::ChAssembly, chrono::fea::ChMesh, chrono::ChShaft, chrono::ChLoadContainer, and chrono::ChExternalDynamics.

◆ IntStateGather()

virtual void chrono::ChPhysicsItem::IntStateGather	(	const unsigned int	off_x,
		ChState &	x,
		const unsigned int	off_v,
		ChStateDelta &	v,
		double &	T
	)

inlinevirtual

From item's state to global state vectors y={x,v} pasting the states at the specified offsets.

Parameters

off_x	offset in x state vector
x	state vector, position part
off_v	offset in v state vector
v	state vector, speed part
T	time

Reimplemented in chrono::modal::ChModalAssembly, chrono::ChParticleCloud, chrono::ChAssembly, chrono::fea::ChMesh, chrono::ChShaft, and chrono::ChExternalDynamics.

◆ IntStateGatherAcceleration()

virtual void chrono::ChPhysicsItem::IntStateGatherAcceleration	(	const unsigned int	off_a,
		ChStateDelta &	a
	)

inlinevirtual

From item's state acceleration to global acceleration vector.

Parameters

off_a	offset in a accel. vector
a	acceleration part of state vector derivative

Reimplemented in chrono::modal::ChModalAssembly, chrono::ChParticleCloud, chrono::ChAssembly, chrono::fea::ChMesh, chrono::ChShaft, and chrono::ChExternalDynamics.

◆ IntStateGatherReactions()

virtual void chrono::ChPhysicsItem::IntStateGatherReactions	(	const unsigned int	off_L,
		ChVectorDynamic<> &	L
	)

inlinevirtual

From item's reaction forces to global reaction vector.

Parameters

off_L	offset in L vector
L	L vector of reaction forces

Reimplemented in chrono::modal::ChModalAssembly, chrono::fea::ChLinkNodeFaceRot, chrono::fea::ChLinkNodeFrameGeneric, chrono::ChLinkLock, chrono::ChAssembly, chrono::ChLinkMateGeneric, chrono::ChContactContainerNSC, chrono::fea::ChLinkNodeFace, chrono::fea::ChLinkBeamIGAFrame, chrono::fea::ChLinkNodeFrame, chrono::fea::ChLinkNodeSlopeFrame, and chrono::fea::ChLinkNodeNode.

◆ IntStateGetIncrement()

virtual void chrono::ChPhysicsItem::IntStateGetIncrement	(	const unsigned int	off_x,
		const ChState &	x_new,
		const ChState &	x,
		const unsigned int	off_v,
		ChStateDelta &	Dv
	)

inlinevirtual

Computes Dt = x_new - x, using vectors at specified offsets.

By default, when DOF = DOF_w, it does just the difference of two state vectors, but in some cases (ex when using quaternions for rotations) it could do more complex stuff, and children classes might overload it.

Parameters

off_x	offset in x state vector
x_new	state vector, final position part
x	state vector, initial position part
off_v	offset in v state vector
Dv	state vector, increment. Here gets the result

Reimplemented in chrono::modal::ChModalAssembly, chrono::ChParticleCloud, chrono::ChAssembly, and chrono::fea::ChMesh.

◆ IntStateIncrement()

virtual void chrono::ChPhysicsItem::IntStateIncrement	(	const unsigned int	off_x,
		ChState &	x_new,
		const ChState &	x,
		const unsigned int	off_v,
		const ChStateDelta &	Dv
	)

inlinevirtual

Computes x_new = x + Dt , using vectors at specified offsets.

By default, when DOF = DOF_w, it does just the sum, but in some cases (ex when using quaternions for rotations) it could do more complex stuff, and children classes might overload it.

Parameters

off_x	offset in x state vector
x_new	state vector, position part, incremented result
x	state vector, initial position part
off_v	offset in v state vector
Dv	state vector, increment

Reimplemented in chrono::modal::ChModalAssembly, chrono::ChParticleCloud, chrono::ChAssembly, and chrono::fea::ChMesh.

◆ IntStateScatter()

virtual void chrono::ChPhysicsItem::IntStateScatter	(	const unsigned int	off_x,
		const ChState &	x,
		const unsigned int	off_v,
		const ChStateDelta &	v,
		const double	T,
		bool	full_update
	)

inlinevirtual

From global state vectors y={x,v} to item's state (and update) fetching the states at the specified offsets.

Parameters

off_x	offset in x state vector
x	state vector, position part
off_v	offset in v state vector
v	state vector, speed part
T	time
full_update	perform complete update

Reimplemented in chrono::modal::ChModalAssembly, chrono::ChParticleCloud, chrono::ChAssembly, chrono::fea::ChMesh, chrono::ChShaft, and chrono::ChExternalDynamics.

◆ IntStateScatterAcceleration()

virtual void chrono::ChPhysicsItem::IntStateScatterAcceleration	(	const unsigned int	off_a,
		const ChStateDelta &	a
	)

inlinevirtual

From global acceleration vector to item's state acceleration.

Parameters

off_a	offset in a accel. vector
a	acceleration part of state vector derivative

Reimplemented in chrono::modal::ChModalAssembly, chrono::ChParticleCloud, chrono::ChAssembly, chrono::fea::ChMesh, chrono::ChShaft, and chrono::ChExternalDynamics.

◆ IntStateScatterReactions()

virtual void chrono::ChPhysicsItem::IntStateScatterReactions	(	const unsigned int	off_L,
		const ChVectorDynamic<> &	L
	)

inlinevirtual

From global reaction vector to item's reaction forces.

Parameters

off_L	offset in L vector
L	L vector of reaction forces

Reimplemented in chrono::modal::ChModalAssembly, chrono::fea::ChLinkNodeFaceRot, chrono::fea::ChLinkNodeFrameGeneric, chrono::ChLinkLock, chrono::ChAssembly, chrono::ChLinkMateGeneric, chrono::ChContactContainerNSC, chrono::fea::ChLinkNodeFace, chrono::fea::ChLinkBeamIGAFrame, chrono::fea::ChLinkNodeFrame, chrono::fea::ChLinkNodeSlopeFrame, and chrono::fea::ChLinkNodeNode.

◆ IntToDescriptor()

virtual void chrono::ChPhysicsItem::IntToDescriptor	(	const unsigned int	off_v,
		const ChStateDelta &	v,
		const ChVectorDynamic<> &	R,
		const unsigned int	off_L,
		const ChVectorDynamic<> &	L,
		const ChVectorDynamic<> &	Qc
	)

inlinevirtual

Prepare variables and constraints to accommodate a solution:

Parameters

off_v	offset for v and R
v	vector copied into the q 'unknowns' term of the variables
R	vector copied into the F 'force' term of the variables
off_L	offset for L and Qc
L	vector copied into the L 'lagrangian ' term of the constraints
Qc	vector copied into the Qb 'constraint' term of the constraints

Reimplemented in chrono::modal::ChModalAssembly, chrono::fea::ChLinkNodeFaceRot, chrono::fea::ChLinkNodeFrameGeneric, chrono::ChParticleCloud, chrono::ChAssembly, chrono::ChLinkLock, chrono::fea::ChMesh, chrono::ChLinkMateGeneric, chrono::ChShaft, chrono::ChContactContainerNSC, chrono::fea::ChLinkNodeFace, chrono::fea::ChLinkBeamIGAFrame, chrono::fea::ChLinkNodeFrame, chrono::ChExternalDynamics, chrono::fea::ChLinkNodeSlopeFrame, and chrono::fea::ChLinkNodeNode.

◆ IsCollisionEnabled()

virtual bool chrono::ChPhysicsItem::IsCollisionEnabled ( ) const

inlinevirtual

Tell if the object is subject to collision.

Only for interface; child classes may override this, using internal flags.

Reimplemented in chrono::ChParticleCloud, chrono::fea::ChMesh, chrono::ChConveyor, and chrono::ChBody.

◆ LoadKRMMatrices()

virtual void chrono::ChPhysicsItem::LoadKRMMatrices	(	double	Kfactor,
		double	Rfactor,
		double	Mfactor
	)

inlinevirtual

Compute and load current stiffnes (K), damping (R), and mass (M) matrices in encapsulated ChKRMBlock objects.

The resulting KRM blocks represent linear combinations of the K, R, and M matrices, with the specified coefficients Kfactor, Rfactor,and Mfactor, respectively. Note: signs are flipped from the term dF/dx in the integrator: K = -dF/dq and R = -dF/dv.

Reimplemented in chrono::modal::ChModalAssembly, chrono::ChAssembly, chrono::fea::ChMesh, chrono::ChLinkMateGeneric, chrono::ChContactContainerSMC, chrono::ChExternalDynamics, chrono::ChLinkMotionImposed, chrono::ChLoadContainer, and chrono::ChLinkMotorRotationAngle.

◆ RemoveCollisionModelsFromSystem()

virtual void chrono::ChPhysicsItem::RemoveCollisionModelsFromSystem ( ChCollisionSystem * coll_sys ) const

inlinevirtual

Remove from the provided collision system any collision models managed by this physics item.

A derived class should invoke ChCollisionSystem::Remove for each of its collision models.

Reimplemented in chrono::ChParticleCloud, chrono::ChAssembly, chrono::fea::ChMesh, chrono::ChBody, and chrono::ChConveyor.

◆ SetSystem()

void chrono::ChPhysicsItem::SetSystem ( ChSystem * m_system )

virtual

Set the pointer to the parent ChSystem().

Also add to new collision system / remove from old collision system.

Reimplemented in chrono::modal::ChModalAssembly, chrono::ChAssembly, chrono::ChLinkMotorLinearDriveline, chrono::ChLinkMotorRotationDriveline, and chrono::ChConveyor.

◆ Update() [1/2]

virtual void chrono::ChPhysicsItem::Update ( bool update_assets = true )

inlinevirtual

As above, but does not require updating of time-dependent data.

By default, calls Update(mytime) using item's current time.

Reimplemented in chrono::ChParticleCloud, chrono::modal::ChModalAssembly, chrono::ChBody, chrono::ChAssembly, chrono::ChLink, and chrono::ChBodyAuxRef.

◆ Update() [2/2]

void chrono::ChPhysicsItem::Update	(	double	mytime,
		bool	update_assets = `true`
	)

virtual

This is an important function, which is called by the owner ChSystem at least once per integration step.

It may update all auxiliary data of the item, such as matrices if any, etc., depending on the current coordinates. The inherited classes, for example the ChLinkMask, often implement specialized versions of this Update(time) function, because they might need to update inner states, forces, springs, etc. This base version, by default, simply updates the item's time, and update the asset tree, if any.

Reimplemented in chrono::ChLinkMatePlanar, chrono::ChHydraulicActuatorBase, chrono::ChLinkRevoluteTranslational, chrono::ChLinkRevoluteSpherical, chrono::ChExternalDynamics, chrono::ChParticleCloud, chrono::ChBody, chrono::fea::ChLinkNodeFaceRot, chrono::fea::ChLinkNodeFrameGeneric, chrono::ChAssembly, chrono::ChLinkLock, chrono::ChShaft, chrono::ChLinkMarkers, chrono::fea::ChLinkNodeFace, chrono::fea::ChLinkBeamIGAFrame, chrono::fea::ChLinkNodeFrame, chrono::ChShaftsTorqueConverter, chrono::fea::ChLinkNodeSlopeFrame, chrono::fea::ChLinkNodeNode, chrono::ChLink, chrono::ChShaftsTorque, chrono::ChLoadContainer, chrono::ChLinkMotorRotation, chrono::ChLinkMotorLinear, chrono::ChLinkMotor, chrono::ChLinkMateOrthogonal, chrono::ChLinkMateDistanceZ, chrono::ChLinkMateGeneric, chrono::ChContactContainerNSC, chrono::ChContactContainerSMC, and chrono::fea::ChMesh.

◆ VariablesFbIncrementMq()

virtual void chrono::ChPhysicsItem::VariablesFbIncrementMq ( )

inlinevirtual

Adds M*q (masses multiplied current 'qb') to Fb, ex.

if qb is initialized with v_old using VariablesQbLoadSpeed, this method can be used in timestepping schemes that do: M*v_new = M*v_old + forces*dt

Reimplemented in chrono::ChParticleCloud, chrono::ChAssembly, chrono::fea::ChMesh, chrono::ChShaft, and chrono::ChExternalDynamics.

◆ VariablesQbIncrementPosition()

virtual void chrono::ChPhysicsItem::VariablesQbIncrementPosition ( double step )

inlinevirtual

Increment item positions by the 'qb' part of the ChVariables, multiplied by a 'step' factor.

pos+=qb*step If qb is a speed, this behaves like a single step of 1-st order numerical integration (Euler integration).

Reimplemented in chrono::ChParticleCloud, chrono::ChAssembly, chrono::fea::ChMesh, chrono::ChShaft, and chrono::ChExternalDynamics.

◆ VariablesQbLoadSpeed()

virtual void chrono::ChPhysicsItem::VariablesQbLoadSpeed ( )

inlinevirtual

Initialize the 'qb' part of the ChVariables with the current value of speeds.

Note: since 'qb' is the unknown, this function seems unnecessary, unless used before VariablesFbIncrementMq()

Reimplemented in chrono::ChParticleCloud, chrono::ChAssembly, chrono::fea::ChMesh, chrono::ChShaft, and chrono::ChExternalDynamics.

◆ VariablesQbSetSpeed()

virtual void chrono::ChPhysicsItem::VariablesQbSetSpeed ( double step = 0 )

inlinevirtual

Fetches the item speed (ex.

linear and angular vel.in rigid bodies) from the 'qb' part of the ChVariables and sets it as the current item speed. If 'step' is not 0, also should compute the approximate acceleration of the item using backward differences, that is accel=(new_speed-old_speed)/step. Mostly used after the solver provided the solution in ChVariables.

Reimplemented in chrono::ChParticleCloud, chrono::ChAssembly, chrono::fea::ChMesh, chrono::ChShaft, and chrono::ChExternalDynamics.

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

/builds/uwsbel/chrono/src/chrono/physics/ChPhysicsItem.h
/builds/uwsbel/chrono/src/chrono/physics/ChPhysicsItem.cpp

Description

Public Member Functions

Protected Attributes

Friends

Additional Inherited Members

Member Function Documentation

◆ AddCamera()

◆ AddCollisionModelsToSystem()

◆ AddVisualModel()

◆ AddVisualShape()

◆ AddVisualShapeFEA()

◆ ArchiveIn()

◆ ConstraintsFetch_react()

◆ ForceToRest()

◆ GetCenter()

◆ GetNumCoordsPosLevel()

◆ GetNumCoordsVelLevel()

◆ GetNumVisualModelClones()

◆ GetTotalAABB()

◆ GetVisualModel()

◆ GetVisualModelFrame()

◆ GetVisualShape()

◆ GetVisualShapeFEA()

◆ IntFromDescriptor()

◆ IntLoadConstraint_C()

◆ IntLoadConstraint_Ct()

◆ IntLoadLumpedMass_Md()

◆ IntLoadResidual_CqL()

◆ IntLoadResidual_F()

◆ IntLoadResidual_Mv()

◆ IntStateGather()

◆ IntStateGatherAcceleration()

◆ IntStateGatherReactions()

◆ IntStateGetIncrement()

◆ IntStateIncrement()

◆ IntStateScatter()

◆ IntStateScatterAcceleration()

◆ IntStateScatterReactions()

◆ IntToDescriptor()

◆ IsCollisionEnabled()

◆ LoadKRMMatrices()

◆ RemoveCollisionModelsFromSystem()

◆ SetSystem()

◆ Update() [1/2]

◆ Update() [2/2]

◆ VariablesFbIncrementMq()

◆ VariablesQbIncrementPosition()

◆ VariablesQbLoadSpeed()

◆ VariablesQbSetSpeed()