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 ChParticlesClones 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 ChParticlesClones objects to the ChSystem. This would be more efficient anyway than creating all shapes as ChBody.
#include <ChParticlesClones.h>
Public Member Functions | |
ChParticlesClones (const ChParticlesClones &other) | |
virtual ChParticlesClones * | Clone () const override |
"Virtual" copy constructor (covariant return type). | |
void | SetCollide (bool mcoll) |
Enable/disable the collision for this cluster of particles. More... | |
virtual bool | GetCollide () const override |
Tell if the object is subject to collision. More... | |
void | SetLimitSpeed (bool mlimit) |
Trick. More... | |
bool | GetLimitSpeed () const |
size_t | GetNparticles () const override |
Get the number of particles. | |
ChParticleBase & | GetParticle (unsigned int n) override |
Access the N-th particle. | |
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. More... | |
void | SetMaterialSurface (const std::shared_ptr< ChMaterialSurface > &mnewsurf) |
Set the material surface for contacts. | |
std::shared_ptr< ChMaterialSurface > & | GetMaterialSurface () |
Set the material surface for contacts. | |
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) 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 | 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 | 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 |
Tell to a system descriptor that there are variables of type ChVariables in this object (for further passing it to a solver) Basically does nothing, but maybe that inherited classes may specialize this. | |
void | SetNoSpeedNoAcceleration () override |
Set no speed and no accelerations (but does not change the position) | |
collision::ChCollisionModel * | GetCollisionModel () |
Access the collision model for the collision engine: this is the 'sample' collision model that is used by all particles. More... | |
virtual void | SyncCollisionModels () override |
Synchronize coll.models coordinates and bounding boxes to the positions of the particles. | |
virtual void | AddCollisionModelsToSystem () override |
If this physical item contains one or more collision models, add them to the system's collision engine. | |
virtual void | RemoveCollisionModelsFromSystem () override |
If this physical item contains one or more collision models, remove them from the system's collision engine. | |
void | UpdateParticleCollisionModels () |
After you added collision shapes to the sample coll.model (the one that you access with GetCollisionModel() ) you need to call this function so that all collision models of particles will reference the sample coll.model. | |
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 ChVector<> &iner) |
Set the diagonal part of the inertia tensor of each particle. | |
ChVector | GetInertiaXX () const |
Get the diagonal part of the inertia tensor of each particle. | |
void | SetInertiaXY (const ChVector<> &iner) |
Set the extra-diagonal part of the inertia tensor of each particle (xy, yz, zx values, the rest is symmetric) | |
ChVector | GetInertiaXY () const |
Get the extra-diagonal part of the inertia tensor of each particle (xy, yz, zx values, the rest is symmetric) | |
void | SetMaxSpeed (float m_max_speed) |
Trick. More... | |
float | GetMaxSpeed () const |
void | SetMaxWvel (float m_max_wvel) |
Trick. More... | |
float | GetMaxWvel () 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 | SetSleepMinSpeed (float m_t) |
Set the max linear speed to be kept for 'sleep_time' before freezing. | |
float | GetSleepMinSpeed () const |
void | SetSleepMinWvel (float m_t) |
Set the max linear speed to be kept for 'sleep_time' before freezing. | |
float | GetSleepMinWvel () 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 &marchive) override |
Method to allow serialization of transient data to archives. | |
virtual void | ArchiveIN (ChArchiveIn &marchive) override |
Method to allow deserialization of transient data from archives. | |
Public Member Functions inherited from chrono::ChIndexedParticles | |
ChIndexedParticles (const ChIndexedParticles &other) | |
virtual int | GetDOF () override |
Number of coordinates of the particle cluster, x7 because with quaternions for rotation. | |
virtual int | GetDOF_w () override |
Number of coordinates of the particle cluster, x6 because derivatives es. angular vel. | |
virtual ChFrame | GetAssetsFrame (unsigned int nclone=0) override |
Get the master coordinate system for the assets (this will return the main coordinate system of the rigid body) More... | |
virtual unsigned int | GetAssetsFrameNclones () override |
Optionally, a ChPhysicsItem can return multiple asset coordinate systems; this can be helpful if, for example, when a ChPhysicsItem contains 'clones' with the same assets (ex. 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() and also add to new collision system / remove from old coll.system. | |
void | AddAsset (std::shared_ptr< ChAsset > masset) |
Add an optional asset (it can be used to define visualization shapes, es ChSphereShape, or textures, or custom attached properties that the user can define by creating his class inherited from ChAsset) | |
std::vector< std::shared_ptr< ChAsset > > & | GetAssets () |
Access to the list of optional assets. | |
std::shared_ptr< ChAsset > | GetAssetN (unsigned int num) |
Access the Nth asset in the list of optional assets. | |
virtual void | GetTotalAABB (ChVector<> &bbmin, ChVector<> &bbmax) |
Get the entire AABB axis-aligned bounding box of the object. More... | |
virtual void | GetCenter (ChVector<> &mcenter) |
Get a symbolic 'center' of the object. More... | |
virtual void | StreamINstate (ChStreamInBinary &mstream) |
Method to deserialize only the state (position, speed) Must be implemented by child classes. | |
virtual void | StreamOUTstate (ChStreamOutBinary &mstream) |
Method to serialize only the state (position, speed) Must be implemented by child classes. | |
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 int | GetDOC () |
Get the number of scalar constraints, if any, in this item. | |
virtual int | GetDOC_c () |
Get the number of scalar constraints, if any, in this item (only bilateral constr.) Children classes might override this. | |
virtual int | GetDOC_d () |
Get the number of scalar constraints, if any, in this item (only unilateral constr.) Children classes might override this. | |
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 &mdescriptor) |
Tell to a system descriptor that there are constraints of type ChConstraint in this object (for further passing it to a solver) Basically does nothing, but maybe that inherited classes may specialize this. | |
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 | ConstraintsLoadJacobians () |
Adds the current jacobians in encapsulated ChConstraints. | |
virtual void | ConstraintsFetch_react (double factor=1) |
Fetches the reactions from the lagrangian multiplier (l_i) of encapsulated ChConstraints. More... | |
virtual void | InjectKRMmatrices (ChSystemDescriptor &mdescriptor) |
Tell to a system descriptor that there are items of type ChKblock in this object (for further passing it to a solver) Basically does nothing, but maybe that inherited classes may specialize this. | |
virtual void | KRMmatricesLoad (double Kfactor, double Rfactor, double Mfactor) |
Adds the current stiffness K and damping R and mass M matrices in encapsulated ChKblock item(s), if any. More... | |
Public Member Functions inherited from chrono::ChObj | |
ChObj (const ChObj &other) | |
int | GetIdentifier () const |
Gets the numerical identifier of the object. | |
void | SetIdentifier (int id) |
Sets the numerical identifier of the object. | |
double | GetChTime () const |
Gets the simulation time of this object. | |
void | SetChTime (double m_time) |
Sets the simulation time of this object. | |
const char * | GetName () const |
Gets the name of the object as C Ascii null-terminated string -for reading only! | |
void | SetName (const char myname[]) |
Sets the name of this object, as ascii string. | |
std::string | GetNameString () const |
Gets the name of the object as C Ascii null-terminated string. | |
void | SetNameString (const std::string &myname) |
Sets the name of this object, as std::string. | |
void | MFlagsSetAllOFF (int &mflag) |
void | MFlagsSetAllON (int &mflag) |
void | MFlagSetON (int &mflag, int mask) |
void | MFlagSetOFF (int &mflag, int mask) |
int | MFlagGet (int &mflag, int mask) |
virtual std::string & | ArchiveContainerName () |
Additional Inherited Members | |
Protected Attributes inherited from chrono::ChPhysicsItem | |
ChSystem * | system |
parent system | |
std::vector< std::shared_ptr< ChAsset > > | assets |
set of assets | |
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 |
the time of simulation for the object | |
Member Function Documentation
◆ AddParticle()
|
overridevirtual |
Add a new particle to the particle cluster, passing a coordinate system as initial state.
NOTE! Define the sample collision shape using GetCollisionModel()->... before adding particles!
Implements chrono::ChIndexedParticles.
◆ GetCollide()
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inlineoverridevirtual |
Tell if the object is subject to collision.
Only for interface; child classes may override this, using internal flags.
Reimplemented from chrono::ChPhysicsItem.
◆ GetCollisionModel()
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inline |
Access the collision model for the collision engine: this is the 'sample' collision model that is used by all particles.
To get a non-null pointer, remember to SetCollide(true), before.
◆ IntFromDescriptor()
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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.
◆ IntLoadResidual_F()
|
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()
|
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 += c*M*v w the w vector c a scaling factor
Reimplemented from chrono::ChPhysicsItem.
◆ IntStateGather()
|
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()
|
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.
◆ IntStateIncrement()
|
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()
|
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
Reimplemented from chrono::ChPhysicsItem.
◆ IntStateScatterAcceleration()
|
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()
|
overridevirtual |
Prepare variables and constraints to accommodate a solution:
- Parameters
-
off_v offset for v and R v vector that will be copied into the q 'unknowns' term of the variables (for warm starting) R vector that will be copied into the F 'force' term of the variables off_L offset for L and Qc L vector that will be copied into the L 'lagrangian ' term of the constraints (for warm starting) Qc vector that will be copied into the Qb 'constraint' term of the constraints
Reimplemented from chrono::ChPhysicsItem.
◆ ResizeNparticles()
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overridevirtual |
Resize the particle cluster.
Also clear the state of previously created particles, if any. NOTE! Define the sample collision shape using GetCollisionModel()->... before adding particles!
Implements chrono::ChIndexedParticles.
◆ SetCollide()
void chrono::ChParticlesClones::SetCollide | ( | bool | mcoll | ) |
Enable/disable the collision for this cluster of particles.
After setting ON, remember RecomputeCollisionModel() before anim starts (it is not automatically recomputed here because of performance issues.)
◆ SetLimitSpeed()
|
inline |
Trick.
Set the maximum linear speed (beyond this limit it will be clamped). This is useful in virtual reality and real-time simulations, because it reduces the risk of bad collision detection. The realism is limited, but the simulation is more stable.
◆ SetMaxSpeed()
|
inline |
Trick.
Set the maximum linear speed (beyond this limit it will be clamped). This is useful in virtual reality and real-time simulations, because it reduces the risk of bad collision detection. This speed limit is active only if you set SetLimitSpeed(true);
◆ SetMaxWvel()
|
inline |
Trick.
Set the maximum angular speed (beyond this limit it will be clamped). This is useful in virtual reality and real-time simulations, because it reduces the risk of bad collision detection. This speed limit is active only if you set SetLimitSpeed(true);
◆ 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()
|
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 (Eulero integration).
Reimplemented from chrono::ChPhysicsItem.
◆ 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()
|
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/ChParticlesClones.h
- /builds/uwsbel/chrono/src/chrono/physics/ChParticlesClones.cpp