Description

Class for clusters of 'clone' particles, that is many rigid objects with the same shape and mass.

This can be used to make granular flows, where you have thousands of objects with the same shape. In fact, a single ChParticleCloud object can be more memory-efficient than many ChBody objects, because they share many features, such as mass and collision shape. If you have N different families of shapes in your granular simulations (ex. 50% of particles are large spheres, 25% are small spheres and 25% are polyhedrons) you can simply add three ChParticleCloud objects to the ChSystem. This would be more efficient anyway than creating all shapes as ChBody.

#include <ChParticleCloud.h>

Inheritance diagram for chrono::ChParticleCloud:

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Collaboration diagram for chrono::ChParticleCloud:

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Classes
class	ColorCallback
	Class to be used as a callback interface for dynamic coloring of particles in a cloud. More...

Public Member Functions
	ChParticleCloud (const ChParticleCloud &other)

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

void	EnableCollision (bool state)
	Enable/disable the collision for this cluster of particles.

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

void	SetFixed (bool state)
	Set the state of all particles in the cluster to 'fixed' (default: false). More...

virtual bool	IsActive () const override
	Return true if the particle cluster is currently active and therefore included into the system solver. More...

void	SetLimitSpeed (bool state)
	Enable limiting the linear speed (default: false).

size_t	GetNumParticles () const override
	Get the number of particles.

std::vector< ChParticle * >	GetParticles () const
	Get all particles in the cluster.

const ChVector3d &	GetParticlePos (unsigned int n) const
	Get particle position.

const ChVector3d &	GetParticleVel (unsigned int n) const
	Get particle linear velocity.

ChParticleBase &	Particle (unsigned int n) override
	Access the N-th particle.

const ChParticleBase &	Particle (unsigned int n) const override
	Access the N-th particle.

void	AddCollisionModel (std::shared_ptr< ChCollisionModel > model)
	Add a collision model for particles in this cloud. More...

void	AddCollisionShape (std::shared_ptr< ChCollisionShape > shape, const ChFrame<> &frame=ChFrame<>())
	Add a collision shape for particles in this cloud. More...

void	ResizeNparticles (int newsize) override
	Resize the particle cluster. More...

void	AddParticle (ChCoordsys< double > initial_state=CSYSNORM) override
	Add a new particle to the particle cluster, passing a coordinate system as initial state.

void	RegisterColorCallback (std::shared_ptr< ColorCallback > callback)
	Set callback to dynamically set visualization color (default: none). More...

bool	UseDynamicColors () const
	Return true if using dynamic coloring. More...

ChColor	GetVisualColor (unsigned int n) const
	Get the visualization color for the specified particle. More...

virtual void	IntStateGather (const unsigned int off_x, ChState &x, const unsigned int off_v, ChStateDelta &v, double &T) override
	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) override
	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) override
	From item's state acceleration to global acceleration vector. More...

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

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

virtual void	IntLoadResidual_F (const unsigned int off, ChVectorDynamic<> &R, const double c) override
	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) override
	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) override
	Adds the lumped mass to a Md vector, representing a mass diagonal matrix. 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) override
	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) override
	After a solver solution, fetch values from variables and constraints into vectors: More...

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

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

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

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

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

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

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

void	ForceToRest () override
	Set no speed and no accelerations (but does not change the position)

virtual void	AddCollisionModelsToSystem (ChCollisionSystem *coll_sys) const override
	Add collision models (if any) for all particles to the provided collision system.

virtual void	RemoveCollisionModelsFromSystem (ChCollisionSystem *coll_sys) const override
	Remove the collision models (if any) for all particles from the provided collision system.

virtual void	SyncCollisionModels () override
	Synchronize the position and bounding box of all particle collision models (if any).

void	SetMass (double newmass)
	Mass of each particle. Must be positive.

double	GetMass () const

void	SetInertia (const ChMatrix33<> &newXInertia)
	Set the inertia tensor of each particle.

void	SetInertiaXX (const ChVector3d &iner)
	Set the diagonal part of the inertia tensor of each particle.

ChVector3d	GetInertiaXX () const
	Get the diagonal part of the inertia tensor of each particle.

void	SetInertiaXY (const ChVector3d &iner)
	Set the extra-diagonal part of the inertia tensor of each particle (xy, yz, zx values, the rest is symmetric)

ChVector3d	GetInertiaXY () const
	Get the extra-diagonal part of the inertia tensor of each particle (xy, yz, zx values, the rest is symmetric)

void	SetMaxLinVel (float m_max_speed)
	Set the maximum linear speed (beyond this limit it willbe clamped). More...

float	GetMaxLinVel () const

void	SetMaxAngVel (float m_max_wvel)
	Set the maximum angular speed (beyond this limit it willbe clamped). More...

float	GetMaxAngVel () const

void	ClampSpeed ()
	When this function is called, the speed of particles is clamped into limits posed by max_speed and max_wvel - but remember to put the body in the SetLimitSpeed(true) mode.

void	SetSleepTime (float m_t)
	Set the amount of time which must pass before going automatically in sleep mode when the body has very small movements.

float	GetSleepTime () const

void	SetSleepMinLinVel (float m_t)
	Set the max linear speed to be kept for 'sleep_time' before freezing.

float	GetSleepMinLinVel () const

void	SetSleepMinAngVel (float m_t)
	Set the max linear speed to be kept for 'sleep_time' before freezing.

float	GetSleepMinAngVel () const

virtual void	Update (double mytime, bool update_assets=true) override
	Update all auxiliary data of the particles.

virtual void	Update (bool update_assets=true) override
	Update all auxiliary data of the particles.

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.

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

virtual unsigned int	GetNumCoordsPosLevel () override
	Number of coordinates of the particle cluster. More...

virtual unsigned int	GetNumCoordsVelLevel () override
	Number of coordinates of the particle cluster. More...

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

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

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

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...

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 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 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	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	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	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	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...

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 ()

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

Protected Attributes inherited from chrono::ChPhysicsItem
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

Member Function Documentation

◆ AddCollisionModel()

void chrono::ChParticleCloud::AddCollisionModel ( std::shared_ptr< ChCollisionModel > model )

inline

Add a collision model for particles in this cloud.

This is the "template" collision model that is used by all particles.

◆ AddCollisionShape()

void chrono::ChParticleCloud::AddCollisionShape	(	std::shared_ptr< ChCollisionShape >	shape,
		const ChFrame<> &	frame = `ChFrame<>()`
	)

Add a collision shape for particles in this cloud.

If a collision model does not already exist, it is first created. The resulting model witll be the "template" collision model that is used by all particles.

◆ GetVisualColor()

ChColor chrono::ChParticleCloud::GetVisualColor ( unsigned int n ) const

Get the visualization color for the specified particle.

Return the color given by a ColorCallback, if one was provided. Otherwise return a default color.

◆ IntFromDescriptor()

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

overridevirtual

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 from chrono::ChPhysicsItem.

◆ IntLoadLumpedMass_Md()

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

overridevirtual

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 from chrono::ChPhysicsItem.

◆ IntLoadResidual_F()

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

overridevirtual

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 from chrono::ChPhysicsItem.

◆ IntLoadResidual_Mv()

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

overridevirtual

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 from chrono::ChPhysicsItem.

◆ IntStateGather()

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

overridevirtual

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 from chrono::ChPhysicsItem.

◆ IntStateGatherAcceleration()

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

overridevirtual

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 from chrono::ChPhysicsItem.

◆ IntStateGetIncrement()

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

overridevirtual

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 from chrono::ChPhysicsItem.

◆ IntStateIncrement()

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

overridevirtual

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 from chrono::ChPhysicsItem.

◆ IntStateScatter()

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

overridevirtual

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 from chrono::ChPhysicsItem.

◆ IntStateScatterAcceleration()

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

overridevirtual

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 from chrono::ChPhysicsItem.

◆ IntToDescriptor()

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

overridevirtual

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 from chrono::ChPhysicsItem.

◆ IsActive()

virtual bool chrono::ChParticleCloud::IsActive ( ) const

inlineoverridevirtual

Return true if the particle cluster is currently active and therefore included into the system solver.

A cluster is inactive if it is fixed to ground.

Reimplemented from chrono::ChPhysicsItem.

◆ IsCollisionEnabled()

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

inlineoverridevirtual

Tell if the object is subject to collision.

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

Reimplemented from chrono::ChPhysicsItem.

◆ RegisterColorCallback()

void chrono::ChParticleCloud::RegisterColorCallback ( std::shared_ptr< ColorCallback > callback )

inline

Set callback to dynamically set visualization color (default: none).

If enabled, a visualization system could use this for color-coding of the particles in a cloud.

◆ ResizeNparticles()

void chrono::ChParticleCloud::ResizeNparticles ( int newsize )

overridevirtual

Resize the particle cluster.

This first deletes all existing particles, if any.

Implements chrono::ChIndexedParticles.

◆ SetFixed()

void chrono::ChParticleCloud::SetFixed ( bool state )

inline

Set the state of all particles in the cluster to 'fixed' (default: false).

If true, the particles do not move.

◆ SetMaxAngVel()

void chrono::ChParticleCloud::SetMaxAngVel ( float m_max_wvel )

inline

Set the maximum angular speed (beyond this limit it willbe clamped).

This speed limit is active only if SetLimitSpeed(true) was called.

◆ SetMaxLinVel()

void chrono::ChParticleCloud::SetMaxLinVel ( float m_max_speed )

inline

Set the maximum linear speed (beyond this limit it willbe clamped).

This speed limit is active only if SetLimitSpeed(true) was called.

◆ UseDynamicColors()

bool chrono::ChParticleCloud::UseDynamicColors ( ) const

Return true if using dynamic coloring.

This is the case if a ColorCallback was specified.

◆ VariablesFbIncrementMq()

void chrono::ChParticleCloud::VariablesFbIncrementMq ( )

overridevirtual

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 from chrono::ChPhysicsItem.

◆ VariablesQbIncrementPosition()

void chrono::ChParticleCloud::VariablesQbIncrementPosition ( double step )

overridevirtual

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 from chrono::ChPhysicsItem.

◆ VariablesQbLoadSpeed()

void chrono::ChParticleCloud::VariablesQbLoadSpeed ( )

overridevirtual

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 from chrono::ChPhysicsItem.

◆ VariablesQbSetSpeed()

void chrono::ChParticleCloud::VariablesQbSetSpeed ( double step = 0 )

overridevirtual

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 from chrono::ChPhysicsItem.

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

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

Description

Classes

Public Member Functions

Additional Inherited Members

Member Function Documentation

◆ AddCollisionModel()

◆ AddCollisionShape()

◆ GetVisualColor()

◆ IntFromDescriptor()

◆ IntLoadLumpedMass_Md()

◆ IntLoadResidual_F()

◆ IntLoadResidual_Mv()

◆ IntStateGather()

◆ IntStateGatherAcceleration()

◆ IntStateGetIncrement()

◆ IntStateIncrement()

◆ IntStateScatter()

◆ IntStateScatterAcceleration()

◆ IntToDescriptor()

◆ IsActive()

◆ IsCollisionEnabled()

◆ RegisterColorCallback()

◆ ResizeNparticles()

◆ SetFixed()

◆ SetMaxAngVel()

◆ SetMaxLinVel()

◆ UseDynamicColors()

◆ VariablesFbIncrementMq()

◆ VariablesQbIncrementPosition()

◆ VariablesQbLoadSpeed()

◆ VariablesQbSetSpeed()