Description

Class for rigid bodies.

A rigid body is an entity which can move in 3D space, and can be constrained to other rigid bodies using ChLink objects. Rigid bodies can contain auxiliary references (the ChMarker objects) and forces (the ChForce objects). These objects have mass and inertia properties. A shape can also be associated to the body, for collision detection.

Further info at the Rigid bodies manual page.

#include <ChBody.h>

Inheritance diagram for chrono::ChBody:

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Collaboration diagram for chrono::ChBody:

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Public Member Functions
	ChBody (collision::ChCollisionSystemType collision_type=collision::ChCollisionSystemType::BULLET)
	Build a rigid body.

	ChBody (std::shared_ptr< collision::ChCollisionModel > new_collision_model)
	Build a rigid body with a different collision model.

	ChBody (const ChBody &other)

virtual	~ChBody ()
	Destructor.

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

void	SetBodyFixed (bool state)
	Sets the 'fixed' state of the body. More...

bool	GetBodyFixed () const
	Return true if this body is fixed to ground.

void	SetEvalContactCn (bool state)
	If true, the normal restitution coefficient is evaluated from painted material channel.

bool	GetEvalContactCn () const

void	SetEvalContactCt (bool state)
	If true, the tangential restitution coefficient is evaluated from painted material channel.

bool	GetEvalContactCt () const

void	SetEvalContactKf (bool state)
	If true, the kinetic friction coefficient is evaluated from painted material channel.

bool	GetEvalContactKf () const

void	SetEvalContactSf (bool state)
	If true, the static friction coefficient is evaluated from painted material channel.

bool	GetEvalContactSf () const

void	SetCollide (bool state)
	Enable/disable the collision for this rigid body. More...

virtual bool	GetCollide () const override
	Return true if collision is enabled for this body.

void	SetShowCollisionMesh (bool state)
	Show collision mesh in 3D views.

bool	GetShowCollisionMesh () const
	Return true if collision mesh is shown in 3D views.

void	SetLimitSpeed (bool state)
	Enable the maximum linear speed limit (beyond this limit it will be clamped). More...

bool	GetLimitSpeed () const
	Return true if maximum linear speed is limited.

void	SetNoGyroTorque (bool state)
	Deactivate the gyroscopic torque (quadratic term). More...

bool	GetNoGyroTorque () const
	Return true if gyroscopic torque is deactivated.

void	SetUseSleeping (bool state)
	Enable/disable option for setting bodies to "sleep". More...

bool	GetUseSleeping () const
	Return true if 'sleep' mode is activated.

void	SetSleeping (bool state)
	Force the body in sleeping mode or not (usually this state change is not handled by users, anyway, because it is mostly automatic).

bool	GetSleeping () const
	Return true if this body is currently in 'sleep' mode.

bool	TrySleeping ()
	Test if a body could go in sleeping state if requirements are satisfied. More...

bool	IsActive ()
	Return true if the body is active; i.e. More...

void	SetId (int id)
	Set body id for indexing (internal use only)

unsigned int	GetId ()
	Set body id for indexing (internal use only)

void	SetGid (unsigned int id)
	Set global body index (internal use only)

unsigned int	GetGid () const
	Get the global body index (internal use only)

virtual int	GetDOF () override
	Number of coordinates of body: 7 because uses quaternions for rotation.

virtual int	GetDOF_w () override
	Number of coordinates of body: 6 because derivatives use angular velocity.

virtual ChVariables &	Variables () override
	Return a reference to the encapsulated ChVariablesBody, representing states (pos, speed, or accel.) and forces. More...

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

void	SetCollisionModel (std::shared_ptr< collision::ChCollisionModel > new_collision_model)
	Change the collision model.

std::shared_ptr< collision::ChCollisionModel >	GetCollisionModel ()
	Access the collision model for the collision engine. More...

virtual void	SyncCollisionModels () override
	Synchronize coll.model coordinate and bounding box to the position of the body.

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.

virtual const ChFrameMoving &	GetFrame_COG_to_abs () const
	Get the rigid body coordinate system that represents the GOG (Center of Gravity). More...

virtual const ChFrameMoving &	GetFrame_REF_to_abs () const
	Get the rigid body coordinate system that is used for defining the collision shapes and the ChMarker objects. More...

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)

virtual void	GetTotalAABB (ChVector<> &bbmin, ChVector<> &bbmax) override
	Get the entire AABB axis-aligned bounding box of the object, as defined by the collision model (if any).

virtual void	StreamINstate (ChStreamInBinary &mstream) override
	Method to deserialize only the state (position, speed)

virtual void	StreamOUTstate (ChStreamOutBinary &mstream) override
	Method to serialize only the state (position, speed)

void	SetDensity (float mdensity)
	The density of the rigid body, as [mass]/[unit volume]. More...

void	AddMarker (std::shared_ptr< ChMarker > amarker)
	Attach a marker to this body.

void	AddForce (std::shared_ptr< ChForce > aforce)
	Attach a force to this body.

void	RemoveMarker (std::shared_ptr< ChMarker > amarker)
	Remove a specific marker from this body. Warning: linear time search.

void	RemoveForce (std::shared_ptr< ChForce > aforce)
	Remove a specific force from this body. Warning: linear time search.

void	RemoveAllForces ()
	Remove all markers at once. More...

void	RemoveAllMarkers ()
	Remove all markers at once. More...

std::shared_ptr< ChMarker >	SearchMarker (const char *m_name)
	Finds a marker from its ChObject name.

std::shared_ptr< ChForce >	SearchForce (const char *m_name)
	Finds a force from its ChObject name.

const std::vector< std::shared_ptr< ChMarker > > &	GetMarkerList () const
	Gets the list of children markers. More...

const std::vector< std::shared_ptr< ChForce > > &	GetForceList () const
	Gets the list of children forces. More...

ChVector	Point_World2Body (const ChVector<> &mpoint)

ChVector	Point_Body2World (const ChVector<> &mpoint)

ChVector	Dir_World2Body (const ChVector<> &dir)

ChVector	Dir_Body2World (const ChVector<> &dir)

ChVector	RelPoint_AbsSpeed (const ChVector<> &mrelpoint)

ChVector	RelPoint_AbsAcc (const ChVector<> &mrelpoint)

void	SetMass (double newmass)
	Set the body mass. More...

double	GetMass ()
	Get the body mass.

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

const ChMatrix33 &	GetInertia () const
	Get the inertia tensor, expressed in the local coordinate system. More...

const ChMatrix33 &	GetInvInertia () const
	Get the inverse of the inertia matrix.

void	SetInertiaXX (const ChVector<> &iner)
	Set the diagonal part of the inertia tensor (Ixx, Iyy, Izz values). More...

ChVector	GetInertiaXX () const
	Get the diagonal part of the inertia tensor (Ixx, Iyy, Izz values). More...

void	SetInertiaXY (const ChVector<> &iner)
	Set the off-diagonal part of the inertia tensor (Ixy, Ixz, Iyz values). More...

ChVector	GetInertiaXY () const
	Get the extra-diagonal part of the inertia tensor (Ixy, Ixz, Iyz values). More...

void	SetMaxSpeed (float m_max_speed)
	Set the maximum linear speed (beyond this limit it will be clamped). More...

float	GetMaxSpeed () const

void	SetMaxWvel (float m_max_wvel)
	Set the maximum angular speed (beyond this limit it will be clamped). More...

float	GetMaxWvel () const

void	ClampSpeed ()
	Clamp the body speed to the provided limits. More...

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

void	ComputeQInertia (ChMatrix44<> &mQInertia)
	Computes the 4x4 inertia tensor in quaternion space, if needed.

void	ComputeGyro ()
	Computes the gyroscopic torque. More...

void	Accumulate_force (const ChVector<> &force, const ChVector<> &appl_point, bool local)
	Add an applied force to the body's accumulator (as an increment). More...

void	Accumulate_torque (const ChVector<> &torque, bool local)
	Add an applied torque to the body's accumulator (as an increment). More...

void	Empty_forces_accumulators ()
	Clear the force and torque accumulators.

const ChVector &	Get_accumulated_force () const
	Return the current value of the accumulator force. More...

const ChVector &	Get_accumulated_torque () const
	Return the current value of the accumulator torque. More...

void	UpdateMarkers (double mytime)
	Update all children markers of the rigid body, at current body state.

void	UpdateForces (double mytime)
	Update all children forces of the rigid body, at current body state.

void	UpdateTime (double mytime)
	Update local time of rigid body, and time-dependent data.

virtual void	Update (double mytime, bool update_assets=true) override
	Update all auxiliary data of the rigid body and of its children (markers, forces..), at given time.

virtual void	Update (bool update_assets=true) override
	Update all auxiliary data of the rigid body and of its children (markers, forces..)

ChVector	GetAppliedForce ()
	Return the resultant applied force on the body. More...

ChVector	GetAppliedTorque ()
	Return the resultant applied torque on the body. More...

ChVector	GetContactForce ()
	Get the resultant contact force acting on this body.

ChVector	GetContactTorque ()
	Get the resultant contact torque acting on this body.

virtual ChPhysicsItem *	GetPhysicsItem () override
	This is only for backward compatibility.

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. More...

virtual void	LoadableGetVariables (std::vector< ChVariables * > &mvars) override
	Get the pointers to the contained ChVariables, appending to the mvars vector.

virtual void	LoadableStateIncrement (const unsigned int off_x, ChState &x_new, const ChState &x, const unsigned int off_v, const ChStateDelta &Dv) override
	Increment all DOFs using a delta.

virtual void	LoadableGetStateBlock_x (int block_offset, ChState &mD) override
	Gets all the DOFs packed in a single vector (position part)

virtual void	LoadableGetStateBlock_w (int block_offset, ChStateDelta &mD) override
	Gets all the DOFs packed in a single vector (speed part)

virtual void	ComputeNF (const double U, const double V, const double W, ChVectorDynamic<> &Qi, double &detJ, const ChVectorDynamic<> &F, ChVectorDynamic<> state_x, ChVectorDynamic<> state_w) override
	Evaluate Q=N'*F, for Q generalized lagrangian load, where N is some type of matrix evaluated at point P(U,V,W) assumed in absolute coordinates, and F is a load assumed in absolute coordinates. 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 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 void	GetCenter (ChVector<> &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 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 += 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 &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 ()

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

void	To_abs_forcetorque (const ChVector<> &force, const ChVector<> &appl_point, bool local, ChVector<> &resultforce, ChVector<> &resulttorque)
	Transform a force applied at a point on the body into a force and moment applied to the COM and expressed in the absolute frame. More...

Public Member Functions inherited from chrono::ChFrameMoving< double >
	ChFrameMoving (const ChVector< double > &mv=ChVector< double >(0, 0, 0), const ChQuaternion< double > &mq=ChQuaternion< double >(1, 0, 0, 0))
	Construct from pos and rot (as a quaternion)

	ChFrameMoving (const ChVector< double > &mv, const ChMatrix33< double > &ma)
	Construct from pos and rotation (as a 3x3 matrix)

	ChFrameMoving (const ChCoordsys< double > &mc)
	Construct from a coordsys.

	ChFrameMoving (const ChFrame< double > &mc)
	Construct from a frame.

	ChFrameMoving (const ChFrameMoving< double > &other)
	Copy constructor, build from another moving frame.

virtual	~ChFrameMoving ()
	Destructor.

ChFrameMoving< double > &	operator= (const ChFrameMoving< double > &other)
	Assignment operator: copy from another moving frame.

ChFrameMoving< double > &	operator= (const ChFrame< double > &other)
	Assignment operator: copy from another frame.

bool	operator== (const ChFrameMoving< double > &other) const
	Returns true for identical frames.

bool	operator!= (const ChFrameMoving< double > &other) const
	Returns true for different frames.

ChFrameMoving< double >	operator>> (const ChFrameMoving< double > &Fb) const
	The '>>' operator transforms a coordinate system, so transformations can be represented with this syntax: new_frame = old_frame >> tr_frame; For a sequence of transformations, i.e. More...

ChFrameMoving< double >	operator* (const ChFrameMoving< double > &Fb) const
	The '' operator transforms a coordinate system, so transformations can be represented with this syntax: new_frame = tr_frame old_frame; For a sequence of transformations, i.e. More...

ChFrameMoving< double > &	operator>>= (const ChFrameMoving< double > &T)
	Performs pre-multiplication of this frame by another frame, for example: A>>=T means A'=T*A ; or A'=A >> T.

ChFrameMoving< double > &	operator>>= (const ChVector< double > &D)
	Performs pre-multiplication of this frame by a vector D, to 'move' by a displacement D:

ChFrameMoving< double > &	operator>>= (const ChQuaternion< double > &R)
	Performs pre-multiplication of this frame by a quaternion R, to 'rotate' it by R:

ChFrameMoving< double > &	operator>>= (const ChCoordsys< double > &F)
	Performs pre-multiplication of this frame by a ChCoordsys F:

ChFrameMoving< double > &	operator>>= (const ChFrame< double > &F)
	Performs pre-multiplication of this frame by a ChFrame F:

ChFrameMoving< double > &	operator%= (const ChFrameMoving< double > &T)
	Performs pre-multiplication of this frame by another frame, for example: A%=T means A'=T*A ; or A'=A >> T Note: DEPRECATED, use >>= instead.

ChFrameMoving< double > &	operator*= (const ChFrameMoving< double > &T)
	Performs post-multiplication of this frame by another frame, for example: A=T means A'=AT ; or A'=T >> A.

ChCoordsys< double > &	GetCoord_dt ()
	Return both current rotation and translation speeds as a coordsystem object, with vector and quaternion.

const ChCoordsys< double > &	GetCoord_dt () const

ChCoordsys< double > &	GetCoord_dtdt ()
	Return both current rotation and translation accelerations as a coordsystem object, with vector and quaternion.

const ChCoordsys< double > &	GetCoord_dtdt () const

ChVector< double > &	GetPos_dt ()
	Return the current speed as a 3d vector.

const ChVector< double > &	GetPos_dt () const

ChVector< double > &	GetPos_dtdt ()
	Return the current acceleration as a 3d vector.

const ChVector< double > &	GetPos_dtdt () const

ChQuaternion< double > &	GetRot_dt ()
	Return the current rotation speed as a quaternion.

const ChQuaternion< double > &	GetRot_dt () const

ChQuaternion< double > &	GetRot_dtdt ()
	Return the current rotation acceleration as a quaternion.

const ChQuaternion< double > &	GetRot_dtdt () const

ChVector< double >	GetWvel_loc () const
	Computes the actual angular speed (expressed in local coords)

ChVector< double >	GetWvel_par () const
	Computes the actual angular speed (expressed in parent coords)

ChVector< double >	GetWacc_loc () const
	Computes the actual angular acceleration (expressed in local coords)

ChVector< double >	GetWacc_par () const
	Computes the actual angular acceleration (expressed in parent coords)

virtual void	SetCoord_dt (const ChCoordsys< double > &mcoord_dt)
	Set both linear speed and rotation speed as a single ChCoordsys derivative.

virtual void	SetPos_dt (const ChVector< double > &mvel)
	Set the linear speed.

virtual void	SetRot_dt (const ChQuaternion< double > &mrot_dt)
	Set the rotation speed as a quaternion. More...

virtual void	SetWvel_loc (const ChVector< double > &wl)
	Set the rotation speed from given angular speed (expressed in local csys)

virtual void	SetWvel_par (const ChVector< double > &wp)
	Set the rotation speed from given angular speed (expressed in parent csys)

virtual void	SetCoord_dtdt (const ChCoordsys< double > &mcoord_dtdt)
	Set both linear acceleration and rotation acceleration as a single ChCoordsys derivative.

virtual void	SetPos_dtdt (const ChVector< double > &macc)
	Set the linear acceleration.

virtual void	SetRot_dtdt (const ChQuaternion< double > &mrot_dtdt)
	Set the rotation acceleration as a quaternion derivative. More...

virtual void	SetWacc_loc (const ChVector< double > &al)
	Set the rotation acceleration from given angular acceleration (expressed in local csys) Note: even when the local angular acceleration is zero, you are still encouraged to call this method bacause q_dtdt might be nonzero due to nonzero q_dt in case of rotational motion.

virtual void	SetWacc_par (const ChVector< double > &ap)
	Set the rotation speed from given angular speed (expressed in parent csys)

void	Compute_Adt (ChMatrix33< double > &mA_dt) const
	Computes the time derivative of rotation matrix, mAdt.

void	Compute_Adtdt (ChMatrix33< double > &mA_dtdt)
	Computes the 2nd time derivative of rotation matrix, mAdtdt.

ChMatrix33< double >	GetA_dt ()
	Computes and returns an Adt matrix (-note: prefer using Compute_Adt() directly for better performance)

ChMatrix33< double >	GetA_dtdt ()
	Computes and returns an Adt matrix (-note: prefer using Compute_Adtdt() directly for better performance)

void	ConcatenatePreTransformation (const ChFrameMoving< double > &T)
	Apply a transformation (rotation and translation) represented by another ChFrameMoving T. More...

void	ConcatenatePostTransformation (const ChFrameMoving< double > &T)
	Apply a transformation (rotation and translation) represented by another ChFrameMoving T in local coordinate. More...

ChVector< double >	PointSpeedLocalToParent (const ChVector< double > &localpos) const
	Given the position of a point in local frame coords, and assuming it is sticky to frame, return the speed in parent coords.

ChVector< double >	PointSpeedLocalToParent (const ChVector< double > &localpos, const ChVector< double > &localspeed) const
	Given the position localpos of a point in the local reference frame, assuming that the point moves in the local reference frame with localspeed, return the speed in the parent reference frame.

ChVector< double >	PointAccelerationLocalToParent (const ChVector< double > &localpos) const
	Given the position of a point in local frame coords, and assuming it is sticky to frame, return the acceleration in parent coords. More...

ChVector< double >	PointAccelerationLocalToParent (const ChVector< double > &localpos, const ChVector< double > &localspeed, const ChVector< double > &localacc) const
	Given the position of a point in local frame coords, and assuming it has a frame-relative speed localspeed and frame-relative acceleration localacc, return the acceleration in parent coords.

ChVector< double >	PointSpeedParentToLocal (const ChVector< double > &parentpos, const ChVector< double > &parentspeed) const
	Given the position of a point in parent frame coords, and assuming it has an absolute speed parentspeed, return the speed in local coords.

ChVector< double >	PointAccelerationParentToLocal (const ChVector< double > &parentpos, const ChVector< double > &parentspeed, const ChVector< double > &parentacc) const
	Given the position of a point in parent frame coords, and assuming it has an absolute speed parentspeed and absolute acceleration parentacc, return the acceleration in local coords.

void	TransformLocalToParent (const ChFrameMoving< double > &local, ChFrameMoving< double > &parent) const
	This function transforms a frame from 'this' local coordinate system to parent frame coordinate system, and also transforms the speed and acceleration of the frame. More...

void	TransformParentToLocal (const ChFrameMoving< double > &parent, ChFrameMoving< double > &local) const
	This function transforms a frame from the parent coordinate system to 'this' local frame coordinate system. More...

bool	Equals (const ChFrameMoving< double > &other) const
	Returns true if coordsys is identical to other coordsys.

bool	Equals (const ChFrameMoving< double > &other, double tol) const
	Returns true if coordsys is equal to other coordsys, within a tolerance 'tol'.

virtual void	Invert () override
	The transformation (also for speeds, accelerations) is inverted in place. More...

ChFrameMoving< double >	GetInverse () const

Public Member Functions inherited from chrono::ChFrame< double >
	ChFrame (const ChVector< double > &mv=ChVector< double >(0, 0, 0), const ChQuaternion< double > &mq=ChQuaternion< double >(1, 0, 0, 0))
	Default constructor, or construct from pos and rot (as a quaternion)

	ChFrame (const ChVector< double > &mv, const ChMatrix33< double > &ma)
	Construct from pos and rotation (as a 3x3 matrix)

	ChFrame (const ChCoordsys< double > &mc)
	Construct from a coordsys.

	ChFrame (const ChVector< double > &mv, const double alpha, const ChVector< double > &mu)
	Construct from position mv and rotation of angle alpha around unit vector mu.

	ChFrame (const ChFrame< double > &other)
	Copy constructor, build from another frame.

ChFrame< double > &	operator= (const ChFrame< double > &other)
	Assignment operator: copy from another frame.

bool	operator== (const ChFrame< double > &other) const
	Returns true for identical frames.

bool	operator!= (const ChFrame< double > &other) const
	Returns true for different frames.

ChFrame< double >	operator>> (const ChFrame< double > &Fb) const
	The '>>' operator transforms a coordinate system, so transformations can be represented with this syntax: new_frame = old_frame >> tr_frame; For a sequence of transformations, i.e. More...

ChFrame< double >	operator* (const ChFrame< double > &Fb) const
	The '>>' operator transforms a vector, so transformations can be represented with this syntax: new_v = old_v >> tr_frame; For a sequence of transformations, i.e. More...

ChVector< double >	operator* (const ChVector< double > &V) const
	The '' operator transforms a vector, so transformations can be represented with this syntax: new_v = tr_frame old_v; For a sequence of transformations, i.e. More...

ChVector< double >	operator/ (const ChVector< double > &V) const
	The '/' is like the '*' operator (see), but uses the inverse transformation for A, in A/b. More...

ChFrame< double > &	operator>>= (const ChFrame< double > &T)
	Performs pre-multiplication of this frame by another frame, for example: A>>=T means A'=T*A ; or A'=A >> T.

ChFrame< double > &	operator>>= (const ChVector< double > &D)
	Performs pre-multiplication of this frame by a vector D, to 'move' by a displacement D:

ChFrame< double > &	operator>>= (const ChQuaternion< double > &R)
	Performs pre-multiplication of this frame by a quaternion R, to 'rotate' it by R:

ChFrame< double > &	operator>>= (const ChCoordsys< double > &F)
	Performs pre-multiplication of this frame by a ChCoordsys F, to transform it:

ChFrame< double > &	operator%= (const ChFrame< double > &T)
	Performs pre-multiplication of this frame by another frame, for example: A%=T means A'=T*A ; or A'=A >> T Note: DEPRECATED, use >>= instead.

ChFrame< double > &	operator*= (const ChFrame< double > &T)
	Performs post-multiplication of this frame by another frame, for example: A=T means A'=AT ; or A'=T >> A.

ChCoordsys< double > &	GetCoord ()
	Return both current rotation and translation as a coordsystem object, with vector and quaternion.

const ChCoordsys< double > &	GetCoord () const

ChVector< double > &	GetPos ()
	Return the current translation as a 3d vector.

const ChVector< double > &	GetPos () const

ChQuaternion< double > &	GetRot ()
	Return the current rotation as a quaternion.

const ChQuaternion< double > &	GetRot () const

ChMatrix33< double > &	GetA ()
	Return the current rotation as a 3x3 matrix.

const ChMatrix33< double > &	GetA () const

ChVector< double >	GetRotAxis ()
	Get axis of finite rotation, in parent space.

double	GetRotAngle ()
	Get angle of rotation about axis of finite rotation.

void	SetCoord (const ChCoordsys< double > &mcoord)
	Impose both translation and rotation as a single ChCoordsys. More...

void	SetCoord (const ChVector< double > &mv, const ChQuaternion< double > &mq)
	Impose both translation and rotation. More...

void	SetRot (const ChQuaternion< double > &mrot)
	Impose the rotation as a quaternion. More...

void	SetRot (const ChMatrix33< double > &mA)
	Impose the rotation as a 3x3 matrix. More...

void	SetPos (const ChVector< double > &mpos)
	Impose the translation.

void	ConcatenatePreTransformation (const ChFrame< double > &T)
	Apply a transformation (rotation and translation) represented by another ChFrame T. More...

void	ConcatenatePostTransformation (const ChFrame< double > &T)
	Apply a transformation (rotation and translation) represented by another ChFrame T in local coordinate. More...

void	Move (const ChVector< double > &V)
	An easy way to move the frame by the amount specified by vector V, (assuming V expressed in parent coordinates)

void	Move (const ChCoordsys< double > &VR)
	Apply both translation and rotation, assuming both expressed in parent coordinates, as a vector for translation and quaternion for rotation,.

ChVector< double >	TransformLocalToParent (const ChVector< double > &local) const
	This function transforms a point from the local frame coordinate system to the parent coordinate system. More...

void	TransformLocalToParent (const ChFrame< double > &local, ChFrame< double > &parent) const
	This function transforms a frame from 'this' local coordinate system to parent frame coordinate system. More...

ChVector< double >	TransformPointLocalToParent (const ChVector< double > &local) const

ChVector< double >	TransformParentToLocal (const ChVector< double > &parent) const
	This function transforms a point from the parent coordinate system to local frame coordinate system. More...

void	TransformParentToLocal (const ChFrame< double > &parent, ChFrame< double > &local) const
	This function transforms a frame from the parent coordinate system to 'this' local frame coordinate system. More...

ChVector< double >	TransformPointParentToLocal (const ChVector< double > &parent) const

ChVector< double >	TransformDirectionParentToLocal (const ChVector< double > &mdirection) const
	This function transforms a direction from 'this' local coordinate system to parent frame coordinate system. More...

ChVector< double >	TransformDirectionLocalToParent (const ChVector< double > &mdirection) const
	This function transforms a direction from the parent frame coordinate system to 'this' local coordinate system. More...

bool	Equals (const ChFrame< double > &other) const
	Returns true if coordsys is identical to other coordsys.

bool	Equals (const ChFrame< double > &other, double tol) const
	Returns true if coordsys is equal to other coordsys, within a tolerance 'tol'.

void	Normalize ()
	Normalize the rotation, so that quaternion has unit length.

virtual void	SetIdentity ()
	Sets to no translation and no rotation.

ChFrame< double >	GetInverse () const

Public Member Functions inherited from chrono::ChLoadableUVW
virtual bool	IsTetrahedronIntegrationNeeded ()
	If true, use quadrature over u,v,w in [0..1] range as tetrahedron volumetric coords (with z=1-u-v-w) otherwise use default quadrature over u,v,w in [-1..+1] as box isoparametric coords.

virtual bool	IsTrianglePrismIntegrationNeeded ()
	If true, use quadrature over u,v in [0..1] range as triangle natural coords (with z=1-u-v), and use linear quadrature over w in [-1..+1], otherwise use default quadrature over u,v,w in [-1..+1] as box isoparametric coords.

Protected Attributes
std::shared_ptr< collision::ChCollisionModel >	collision_model
	pointer to the collision model

unsigned int	body_id
	body-specific identifier, used for indexing (internal use only)

unsigned int	body_gid
	body-specific identifier, used for global indexing (internal use only)

std::vector< std::shared_ptr< ChMarker > >	marklist
	list of markers

std::vector< std::shared_ptr< ChForce > >	forcelist
	list of forces

ChVector	gyro
	gyroscopic torque, i.e. Qm = Wvel x (XInertia*Wvel)

ChVector	Xforce
	force acting on body, applied to COM (in absolute coords)

ChVector	Xtorque
	torque acting on body (in body local coords)

ChVector	Force_acc
	force accumulator, applied to COM (in absolute coords)

ChVector	Torque_acc
	torque accumulator (in body local coords)

float	density
	used when doing the 'recompute mass' operation.

ChVariablesBodyOwnMass	variables
	interface to solver (store inertia and coordinates)

float	max_speed
	limit on linear speed

float	max_wvel
	limit on angular velocity

float	sleep_time

float	sleep_minspeed

float	sleep_minwvel

float	sleep_starttime

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

Friends
class	ChSystem

class	ChSystemMulticore

class	ChSystemMulticoreNSC

class	ChAssembly

class	ChConveyor

Additional Inherited Members
Public Attributes inherited from chrono::ChFrameMoving< double >
ChCoordsys< double >	coord_dt
	Rotation and position speed, as vector+quaternion.

ChCoordsys< double >	coord_dtdt
	Rotation and position acceleration, as vector+quaternion.

Public Attributes inherited from chrono::ChFrame< double >
ChCoordsys< double >	coord
	Rotation and position, as vector+quaternion.

ChMatrix33< double >	Amatrix
	3x3 orthogonal rotation matrix

Member Function Documentation

◆ Accumulate_force()

void chrono::ChBody::Accumulate_force	(	const ChVector<> &	force,
		const ChVector<> &	appl_point,
		bool	local
	)

Add an applied force to the body's accumulator (as an increment).

It is the caller's responsibility to clear the force and torque accumulators at each integration step. If local = true, the provided applied force is assumed to be expressed in body coordinates. If local = false, the provided applied force is assumed to be expressed in absolute coordinates.

Parameters

force	applied force
appl_point	application point
local	force and point expressed in body local frame?

◆ Accumulate_torque()

void chrono::ChBody::Accumulate_torque	(	const ChVector<> &	torque,
		bool	local
	)

Add an applied torque to the body's accumulator (as an increment).

It is the caller's responsibility to clear the force and torque accumulators at each integration step. If local = true, the provided applied torque is assumed to be expressed in body coordinates. If local = false, the provided applied torque is assumed to be expressed in absolute coordinates.

Parameters

torque	applied torque
local	torque expressed in body local frame?

◆ ArchiveIN()

void chrono::ChBody::ArchiveIN ( ChArchiveIn & marchive )

overridevirtual

Method to allow deserialization of transient data from archives.

Method to allow de serialization of transient data from archives.

Reimplemented from chrono::ChBodyFrame.

Reimplemented in chrono::ChBodyAuxRef.

◆ ClampSpeed()

void chrono::ChBody::ClampSpeed ( )

Clamp the body speed to the provided limits.

When this function is called, the speed of the body is clamped to the range specified by max_speed and max_wvel. Remember to put the body in the SetLimitSpeed(true) mode.

◆ ComputeGyro()

void chrono::ChBody::ComputeGyro ( )

Computes the gyroscopic torque.

In fact, in sake of highest speed, the gyroscopic torque isn't automatically updated each time a SetCoord() or SetCoord_dt() etc. is called, but only if necessary, for each UpdateState().

◆ ComputeNF()

void chrono::ChBody::ComputeNF	(	const double	U,
		const double	V,
		const double	W,
		ChVectorDynamic<> &	Qi,
		double &	detJ,
		const ChVectorDynamic<> &	F,
		ChVectorDynamic<> *	state_x,
		ChVectorDynamic<> *	state_w
	)

overridevirtual

Evaluate Q=N'*F, for Q generalized lagrangian load, where N is some type of matrix evaluated at point P(U,V,W) assumed in absolute coordinates, and F is a load assumed in absolute coordinates.

det[J] is unused.

Parameters

U	x coordinate of application point in absolute space
V	y coordinate of application point in absolute space
W	z coordinate of application point in absolute space
Qi	Return result of N'*F here, maybe with offset block_offset
detJ	Return det[J] here
F	Input F vector, size is 6, it is {Force,Torque} in absolute coords.
state_x	if != 0, update state (pos. part) to this, then evaluate Q
state_w	if != 0, update state (speed part) to this, then evaluate Q

Implements chrono::ChLoadableUVW.

◆ Get_accumulated_force()

const ChVector& chrono::ChBody::Get_accumulated_force ( ) const

inline

Return the current value of the accumulator force.

Note that this is a resultant force as applied to the COM and expressed in the absolute frame.

◆ Get_accumulated_torque()

const ChVector& chrono::ChBody::Get_accumulated_torque ( ) const

inline

Return the current value of the accumulator torque.

Note that this is a resultant torque expressed in the body local frame.

◆ GetAppliedForce()

ChVector chrono::ChBody::GetAppliedForce ( )

Return the resultant applied force on the body.

This resultant force includes all external applied loads acting on this body (from gravity, loads, springs, etc). However, this does not include any constraint forces. In particular, contact forces are not included if using the NSC formulation, but are included when using the SMC formulation.

◆ GetAppliedTorque()

ChVector chrono::ChBody::GetAppliedTorque ( )

Return the resultant applied torque on the body.

This resultant torque includes all external applied loads acting on this body (from gravity, loads, springs, etc). However, this does not include any constraint forces. In particular, contact torques are not included if using the NSC formulation, but are included when using the SMC formulation.

◆ GetCollisionModel()

std::shared_ptr<collision::ChCollisionModel> chrono::ChBody::GetCollisionModel ( )

inline

Access the collision model for the collision engine.

To get a non-null pointer, remember to SetCollide(true), before.

◆ GetForceList()

const std::vector<std::shared_ptr<ChForce> >& chrono::ChBody::GetForceList ( ) const

inline

Gets the list of children forces.

NOTE: to modify this list, use the appropriate Remove.. and Add.. functions.

◆ GetFrame_COG_to_abs()

virtual const ChFrameMoving& chrono::ChBody::GetFrame_COG_to_abs ( ) const

inlinevirtual

Get the rigid body coordinate system that represents the GOG (Center of Gravity).

The mass and inertia tensor are defined respect to this coordinate system, that is also assumed the default main coordinates of the body. By default, doing mybody.GetPos() etc. is like mybody.GetFrame_COG_abs().GetPos() etc.

◆ GetFrame_REF_to_abs()

virtual const ChFrameMoving& chrono::ChBody::GetFrame_REF_to_abs ( ) const

inlinevirtual

Get the rigid body coordinate system that is used for defining the collision shapes and the ChMarker objects.

For the base ChBody, this is always the same reference of the COG.

Reimplemented in chrono::ChBodyAuxRef.

◆ GetInertia()

const ChMatrix33& chrono::ChBody::GetInertia ( ) const

inline

Get the inertia tensor, expressed in the local coordinate system.

The return 3x3 symmetric matrix contains the following values:

 [ int{y^2+z^2}dm    -int{xy}dm    -int{xz}dm    ]
 [                  int{x^2+z^2}   -int{yz}dm    ]
 [                                int{x^2+y^2}dm ]

◆ GetInertiaXX()

ChVector chrono::ChBody::GetInertiaXX ( ) const

Get the diagonal part of the inertia tensor (Ixx, Iyy, Izz values).

The return 3x1 vector contains the following values:

[  int{y^2+z^2}dm   int{x^2+z^2}   int{x^2+y^2}dm ]

◆ GetInertiaXY()

ChVector chrono::ChBody::GetInertiaXY ( ) const

Get the extra-diagonal part of the inertia tensor (Ixy, Ixz, Iyz values).

The return 3x1 vector contains the following values:

[ -int{xy}dm   -int{xz}dm   -int{yz}dm ]

◆ GetMarkerList()

const std::vector<std::shared_ptr<ChMarker> >& chrono::ChBody::GetMarkerList ( ) const

inline

Gets the list of children markers.

NOTE: to modify this list, use the appropriate Remove.. and Add.. functions.

◆ IsActive()

bool chrono::ChBody::IsActive ( )

Return true if the body is active; i.e.

it is neither fixed to ground nor is it in "sleep" mode. Return false otherwise.

◆ RemoveAllForces()

void chrono::ChBody::RemoveAllForces ( )

Remove all markers at once.

Faster than doing multiple RemoveForce() Don't care about deletion: it is automatic, only when needed.

◆ RemoveAllMarkers()

void chrono::ChBody::RemoveAllMarkers ( )

Remove all markers at once.

Faster than doing multiple RemoveForce() Don't care about deletion: it is automatic, only when needed.

◆ SetBodyFixed()

void chrono::ChBody::SetBodyFixed ( bool state )

Sets the 'fixed' state of the body.

If true, it does not move respect to the absolute world, despite constraints, forces, etc.

◆ SetCollide()

void chrono::ChBody::SetCollide ( bool state )

Enable/disable the collision for this rigid body.

before anim starts, if you added an external object that implements onAddCollisionGeometries(), ex. in a plug-in for a CAD)

◆ SetDensity()

void chrono::ChBody::SetDensity ( float mdensity )

inline

The density of the rigid body, as [mass]/[unit volume].

Used just if the inertia tensor and mass are automatically recomputed from the geometry (in case a CAD plugin for example provides the surfaces.)

◆ SetInertia()

void chrono::ChBody::SetInertia ( const ChMatrix33<> & newXInertia )

Set the inertia tensor of the body.

The provided 3x3 matrix should be symmetric and contain the inertia tensor, expressed in the local coordinate system:

              [ int{y^2+z^2}dm    -int{xy}dm    -int{xz}dm    ]
newXInertia = [                  int{x^2+z^2}   -int{yz}dm    ]
              [                                int{x^2+y^2}dm ]

◆ SetInertiaXX()

void chrono::ChBody::SetInertiaXX ( const ChVector<> & iner )

Set the diagonal part of the inertia tensor (Ixx, Iyy, Izz values).

The provided 3x1 vector should contain the moments of inertia, expressed in the local coordinate frame:

iner = [  int{y^2+z^2}dm   int{x^2+z^2}   int{x^2+y^2}dm ]

◆ SetInertiaXY()

void chrono::ChBody::SetInertiaXY ( const ChVector<> & iner )

Set the off-diagonal part of the inertia tensor (Ixy, Ixz, Iyz values).

The provided 3x1 vector should contain the products of inertia, expressed in the local coordinate frame:

iner = [ -int{xy}dm   -int{xz}dm   -int{yz}dm ]

◆ SetLimitSpeed()

void chrono::ChBody::SetLimitSpeed ( bool state )

Enable the maximum linear speed limit (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.

◆ SetMass()

void chrono::ChBody::SetMass ( double newmass )

inline

Set the body mass.

Try not to mix bodies with too high/too low values of mass, for numerical stability.

◆ SetMaxSpeed()

void chrono::ChBody::SetMaxSpeed ( float m_max_speed )

inline

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()

void chrono::ChBody::SetMaxWvel ( float m_max_wvel )

inline

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);

◆ SetNoGyroTorque()

void chrono::ChBody::SetNoGyroTorque ( bool state )

Deactivate the gyroscopic torque (quadratic term).

This is useful in virtual reality and real-time simulations, where objects that spin too fast with non-uniform inertia tensors (ex thin cylinders) might cause the integration to diverge quickly. The realism is limited, but the simulation is more stable.

◆ SetUseSleeping()

void chrono::ChBody::SetUseSleeping ( bool state )

Enable/disable option for setting bodies to "sleep".

If use sleeping = true, bodies which stay in same place for long enough time will be deactivated, for optimization. The realism is limited, but the simulation is faster.

◆ TrySleeping()

bool chrono::ChBody::TrySleeping ( )

Test if a body could go in sleeping state if requirements are satisfied.

Return true if state could be changed from no sleep to sleep.

◆ Variables()

virtual ChVariables& chrono::ChBody::Variables ( )

inlineoverridevirtual

Return a reference to the encapsulated ChVariablesBody, representing states (pos, speed, or accel.) and forces.

The ChVariablesBodyOwnMass is the interface to the system solver.

Implements chrono::ChBodyFrame.

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

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

Description

Public Member Functions

Protected Attributes

Friends

Additional Inherited Members

Member Function Documentation

◆ Accumulate_force()

◆ Accumulate_torque()

◆ ArchiveIN()

◆ ClampSpeed()

◆ ComputeGyro()

◆ ComputeNF()

◆ Get_accumulated_force()

◆ Get_accumulated_torque()

◆ GetAppliedForce()

◆ GetAppliedTorque()

◆ GetCollisionModel()

◆ GetForceList()

◆ GetFrame_COG_to_abs()

◆ GetFrame_REF_to_abs()

◆ GetInertia()

◆ GetInertiaXX()

◆ GetInertiaXY()

◆ GetMarkerList()

◆ IsActive()

◆ RemoveAllForces()

◆ RemoveAllMarkers()

◆ SetBodyFixed()

◆ SetCollide()

◆ SetDensity()

◆ SetInertia()

◆ SetInertiaXX()

◆ SetInertiaXY()

◆ SetLimitSpeed()

◆ SetMass()

◆ SetMaxSpeed()

◆ SetMaxWvel()

◆ SetNoGyroTorque()

◆ SetUseSleeping()

◆ TrySleeping()

◆ Variables()