chrono::ChProximityContainerBase Class Referenceabstract

Description

Class representing the interface for containers of proximity pairs, that is pairs of collision models that have been obtained from the broadphase collision.

There might be implementations of this interface in form of plain CPU linked lists of objects (ex. springs or similar forcefields for cloth simulation etc.) or highly optimized GPU buffers, etc. etc. This is only the basic interface with the features that are in common.

#include <ChProximityContainerBase.h>

Inheritance diagram for chrono::ChProximityContainerBase:
Collaboration diagram for chrono::ChProximityContainerBase:

Public Member Functions

 ChProximityContainerBase (const ChProximityContainerBase &other)
 
virtual int GetNproximities () const =0
 Tell the number of added proximity pairs. To be implemented by child classes.
 
virtual void RemoveAllProximities ()=0
 Remove (delete) all contained proximity pairs. To be implemented by child classes.
 
virtual void BeginAddProximities ()
 The collision system will call BeginAddProximity() before adding all proximity pairs (for example with AddProximity() or similar). More...
 
virtual void AddProximity (collision::ChCollisionModel *modA, collision::ChCollisionModel *modB)=0
 Add a proximity pair between two collision models, storing it into this container. More...
 
virtual void EndAddProximities ()
 The collision system will call this after adding all pairs (for example with AddProximity() or similar). More...
 
void SetAddProximityCallback (ChAddProximityCallback *mcallback)
 Sets a callback to be used each time a proximity pair is added to the container. More...
 
virtual void ReportAllProximities (ChReportProximityCallback *mcallback)=0
 Scans all the contacts and for each proximity pair executes the ReportProximityCallback() function of the user object inherited from ChReportContactCallback. More...
 
virtual void ArchiveOUT (ChArchiveOut &marchive)
 Method to allow serialization of transient data to archives.
 
virtual void ArchiveIN (ChArchiveIn &marchive)
 Method to allow de-serialization of transient data from archives.
 
- Public Member Functions inherited from chrono::ChPhysicsItem
 ChPhysicsItem (const ChPhysicsItem &other)
 
virtual ChPhysicsItemClone () const override
 "Virtual" copy constructor (covariant return type).
 
ChSystemGetSystem () 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< ChAssetGetAssetN (unsigned int num)
 Access the Nth asset in the list of optional assets.
 
virtual ChFrame GetAssetsFrame (unsigned int nclone=0)
 Get the master coordinate system for assets that have some geometric meaning. More...
 
virtual unsigned int GetAssetsFrameNclones ()
 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...
 
virtual bool GetCollide () const
 Tell if the object is subject to collision. More...
 
virtual void SyncCollisionModels ()
 If this physical item contains one or more collision models, sinchronize their coordinates and bounding boxes to the state of the item. More...
 
virtual void AddCollisionModelsToSystem ()
 If this physical item contains one or more collision models, add them to the system's collision engine. More...
 
virtual void RemoveCollisionModelsFromSystem ()
 If this physical item contains one or more collision models, remove them from the system's collision engine. More...
 
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. More...
 
virtual void StreamOUTstate (ChStreamOutBinary &mstream)
 Method to serialize only the state (position, speed) Must be implemented by child classes. 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 SetNoSpeedNoAcceleration ()
 Set zero speed (and zero accelerations) in state, without changing the position. More...
 
virtual int GetDOF ()
 Get the number of scalar coordinates (variables), if any, in this item. More...
 
virtual int GetDOF_w ()
 Get the number of scalar coordinates of variables derivatives (usually = DOF, but might be different than DOF, ex. More...
 
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. More...
 
virtual int GetDOC_d ()
 Get the number of scalar constraints, if any, in this item (only unilateral constr.) Children classes might override this. More...
 
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)
 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 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 M*v term, multiplying mass by a vector, scale and adds to R at given offset: R += c*M*w. 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 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 for a solution: From a vector R into the F 'force' term of the variables From a vector Qc into the Qb 'constraint' term of the constraints From a vector v into the q 'unknowns' term of the variables (for warm starting) From a vector L into the L 'lagrangian ' term of the constraints (for warm starting) 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: To a vector v from the q 'unknowns' term of the variables To a vector L from the L 'lagrangian ' term of the constraints. 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 InjectVariables (ChSystemDescriptor &mdescriptor)
 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. More...
 
virtual void InjectConstraints (ChSystemDescriptor &mdescriptor)
 Tell to a system descriptor that there are contraints of type ChConstraint in this object (for further passing it to a solver) Basically does nothing, but maybe that inherited classes may specialize this. 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 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. More...
 
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)
 

Protected Attributes

ChAddProximityCallbackadd_proximity_callback
 
ChReportProximityCallbackreport_proximity_callback
 
- Protected Attributes inherited from chrono::ChPhysicsItem
ChSystemsystem
 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

virtual void chrono::ChProximityContainerBase::AddProximity ( collision::ChCollisionModel modA,
collision::ChCollisionModel modB 
)
pure virtual

Add a proximity pair between two collision models, storing it into this container.

To be implemented by child classes. Some specialized child classes (ex. one that uses GPU buffers) could implement also other more efficient functions to add many proximity pairs in a batch (so that, for example, a special GPU collision system can exploit it); yet most collision system might still fall back to this function if no other specialized add-functions are found.

Parameters
modAget contact model 1
modBget contact model 2

Implemented in chrono::ChProximityContainerMeshless, and chrono::ChProximityContainerSPH.

virtual void chrono::ChProximityContainerBase::BeginAddProximities ( )
virtual

The collision system will call BeginAddProximity() before adding all proximity pairs (for example with AddProximity() or similar).

By default it deletes all previous contacts. Custom more efficient implementations might reuse contacts if possible.

Reimplemented in chrono::ChProximityContainerMeshless, and chrono::ChProximityContainerSPH.

virtual void chrono::ChProximityContainerBase::EndAddProximities ( )
virtual

The collision system will call this after adding all pairs (for example with AddProximity() or similar).

By default it does nothing.

Reimplemented in chrono::ChProximityContainerMeshless, and chrono::ChProximityContainerSPH.

virtual void chrono::ChProximityContainerBase::ReportAllProximities ( ChReportProximityCallback mcallback)
pure virtual

Scans all the contacts and for each proximity pair executes the ReportProximityCallback() function of the user object inherited from ChReportContactCallback.

Child classes of ChContactContainerBase should try to implement this.

Implemented in chrono::ChProximityContainerMeshless, and chrono::ChProximityContainerSPH.

void chrono::ChProximityContainerBase::SetAddProximityCallback ( ChAddProximityCallback mcallback)

Sets a callback to be used each time a proximity pair is added to the container.

Note that not all child classes can support this function in all circumstances (example, the GPU container won't launch the callback for all its points because of performance optimization)