chrono::ChParticleCloud Class Reference

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:
Collaboration diagram for chrono::ChParticleCloud:

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 ChParticleCloudClone () 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 ChVector3dGetParticlePos (unsigned int n) const
 Get particle position.
 
const ChVector3dGetParticleVel (unsigned int n) const
 Get particle linear velocity.
 
ChParticleBaseParticle (unsigned int n) override
 Access the N-th particle.
 
const ChParticleBaseParticle (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 M*v term, multiplying mass by a vector, scale and adds to R at given offset: R += c*M*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)
 
ChSystemGetSystem () 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< ChVisualModelGetVisualModel () 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< ChVisualShapeGetVisualShape (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< ChVisualShapeFEAGetVisualShapeFEA (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 () const
 Get the axis-aligned bounding box (AABB) of this object. More...
 
virtual ChVector3d GetCenter () const
 Get a symbolic 'center' of the object. More...
 
virtual void Setup ()
 Perform setup operations. More...
 
void UpdateVisualModel ()
 Utility function to update only the associated visual assets (if any).
 
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 += c*Cq'*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
ChSystemsystem
 parent system
 
std::shared_ptr< ChVisualModelInstancevis_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_voffset for v
vvector to where the q 'unknowns' term of the variables will be copied
off_Loffset for L
Lvector 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
offoffset in Md vector
Mdresult: Md vector, diagonal of the lumped mass matrix
errresult: not touched if lumping does not introduce errors
ca 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
offoffset in R residual
Rresult: the R residual, R += c*F
ca 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
offoffset in R residual
Rresult: the R residual, R += c*M*v
wthe w vector
ca 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_xoffset in x state vector
xstate vector, position part
off_voffset in v state vector
vstate vector, speed part
Ttime

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_aoffset in a accel. vector
aacceleration 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_xoffset in x state vector
x_newstate vector, final position part
xstate vector, initial position part
off_voffset in v state vector
Dvstate 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_xoffset in x state vector
x_newstate vector, position part, incremented result
xstate vector, initial position part
off_voffset in v state vector
Dvstate 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_xoffset in x state vector
xstate vector, position part
off_voffset in v state vector
vstate vector, speed part
Ttime
full_updateperform 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_aoffset in a accel. vector
aacceleration 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_voffset for v and R
vvector copied into the q 'unknowns' term of the variables
Rvector copied into the F 'force' term of the variables
off_Loffset for L and Qc
Lvector copied into the L 'lagrangian ' term of the constraints
Qcvector 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