Base class for a physics engine. More...

#include <physics/physics.hh>

Inherited by BulletPhysics, DARTPhysics, ODEPhysics, and SimbodyPhysics.

Public Member Functions
	PhysicsEngine (WorldPtr _world)
	Default constructor. More...

virtual	~PhysicsEngine ()
	Destructor. More...

virtual CollisionPtr	CreateCollision (const std::string &_shapeType, LinkPtr _link)=0
	Create a collision. More...

CollisionPtr	CreateCollision (const std::string &_shapeType, const std::string &_linkName)
	Create a collision. More...

virtual JointPtr	CreateJoint (const std::string &_type, ModelPtr _parent=ModelPtr())=0
	Create a new joint. More...

virtual LinkPtr	CreateLink (ModelPtr _parent)=0
	Create a new body. More...

virtual ModelPtr	CreateModel (BasePtr _base)
	Create a new model. More...

virtual ShapePtr	CreateShape (const std::string &_shapeType, CollisionPtr _collision)=0
	Create a physics::Shape object. More...

virtual void	DebugPrint () const =0
	Debug print out of the physic engine state. More...

virtual void	Fini ()
	Finilize the physics engine. More...

virtual bool	GetAutoDisableFlag ()
	: Remove this function, and replace it with a more generic property map More...

ContactManager *	GetContactManager () const
	Get a pointer to the contact manger. More...

double	GetMaxStepSize () const
	Get max step size. More...

virtual boost::any	GetParam (const std::string &_key) const
	Get an parameter of the physics engine. More...

virtual bool	GetParam (const std::string &_key, boost::any &_value) const
	Get a parameter from the physics engine with a boolean to indicate success or failure. More...

boost::recursive_mutex *	GetPhysicsUpdateMutex () const
	returns a pointer to the PhysicsEngine::physicsUpdateMutex. More...

double	GetRealTimeUpdateRate () const
	Get real time update rate. More...

sdf::ElementPtr	GetSDF () const
	Get a pointer to the SDF element for this physics engine. More...

double	GetTargetRealTimeFactor () const
	Get target real time factor. More...

virtual std::string	GetType () const =0
	Return the physics engine type (ode\|bullet\|dart\|simbody). More...

double	GetUpdatePeriod ()
	Get the simulation update period. More...

virtual void	Init ()=0
	Initialize the physics engine. More...

virtual void	InitForThread ()=0
	Init the engine for threads. More...

virtual void	Load (sdf::ElementPtr _sdf)
	Load the physics engine. More...

virtual void	Reset ()
	Rest the physics engine. More...

virtual void	SetAutoDisableFlag (bool _autoDisable)
	: Remove this function, and replace it with a more generic property map More...

virtual void	SetGravity (const ignition::math::Vector3d &_gravity)=0
	Set the gravity vector. More...

virtual void	SetMaxContacts (unsigned int _maxContacts)
	: Remove this function, and replace it with a more generic property map More...

void	SetMaxStepSize (double _stepSize)
	Set max step size. More...

virtual bool	SetParam (const std::string &_key, const boost::any &_value)
	Set a parameter of the physics engine. More...

void	SetRealTimeUpdateRate (double _rate)
	Set real time update rate. More...

virtual void	SetSeed (uint32_t _seed)=0
	Set the random number seed for the physics engine. More...

void	SetTargetRealTimeFactor (double _factor)
	Set target real time factor. More...

virtual void	UpdateCollision ()=0
	Update the physics engine collision. More...

virtual void	UpdatePhysics ()
	Update the physics engine. More...

WorldPtr	World () const
	Get a pointer to the world. More...

Protected Member Functions
virtual void	OnPhysicsMsg (ConstPhysicsPtr &_msg)
	virtual callback for gztopic "~/physics". More...

virtual void	OnRequest (ConstRequestPtr &_msg)
	virtual callback for gztopic "~/request". More...

Protected Attributes
ContactManager *	contactManager
	Class that handles all contacts generated by the physics engine. More...

double	maxStepSize
	Real time update rate. More...

transport::NodePtr	node
	Node for communication. More...

ignition::transport::Node	nodeIgn
	Ignition node for communication. More...

transport::SubscriberPtr	physicsSub
	Subscribe to the physics topic. More...

boost::recursive_mutex *	physicsUpdateMutex
	Mutex to protect the update cycle. More...

double	realTimeUpdateRate
	Real time update rate. More...

transport::SubscriberPtr	requestSub
	Subscribe to the request topic. More...

transport::PublisherPtr	responsePub
	Response publisher. More...

ignition::transport::Node::Publisher	responsePubIgn
	Response publisher. More...

sdf::ElementPtr	sdf
	Our SDF values. More...

double	targetRealTimeFactor
	Target real time factor. More...

WorldPtr	world
	Pointer to the world. More...

Detailed Description

Base class for a physics engine.

Constructor & Destructor Documentation

PhysicsEngine ( WorldPtr _world )

explicit

Default constructor.

Parameters

[in] _world Pointer to the world.

virtual ~PhysicsEngine ( )

virtual

Destructor.

Member Function Documentation

virtual CollisionPtr CreateCollision	(	const std::string &	_shapeType,
		LinkPtr	_link
	)

pure virtual

Create a collision.

Parameters

[in]	_shapeType	Type of collision to create.
[in]	_link	Parent link.

Implemented in ODEPhysics, DARTPhysics, BulletPhysics, and SimbodyPhysics.

CollisionPtr CreateCollision	(	const std::string &	_shapeType,
		const std::string &	_linkName
	)

Create a collision.

Parameters

[in]	_shapeType	Type of collision to create.
[in]	_linkName	Name of the parent link.

virtual JointPtr CreateJoint	(	const std::string &	_type,
		ModelPtr	_parent = `ModelPtr()`
	)

pure virtual

Create a new joint.

Parameters

[in]	_type	Type of joint to create.
[in]	_parent	Model parent.

Implemented in ODEPhysics, DARTPhysics, BulletPhysics, and SimbodyPhysics.

virtual LinkPtr CreateLink ( ModelPtr _parent )

pure virtual

Create a new body.

Parameters

[in] _parent Parent model for the link.

Implemented in ODEPhysics, DARTPhysics, BulletPhysics, and SimbodyPhysics.

virtual ModelPtr CreateModel ( BasePtr _base )

virtual

Create a new model.

Parameters

[in] _base Boost shared pointer to a new model.

Reimplemented in DARTPhysics, and SimbodyPhysics.

virtual ShapePtr CreateShape	(	const std::string &	_shapeType,
		CollisionPtr	_collision
	)

pure virtual

Create a physics::Shape object.

Parameters

[in]	_shapeType	Type of shape to create.
[in]	_collision	Collision parent.

Implemented in ODEPhysics, DARTPhysics, BulletPhysics, and SimbodyPhysics.

virtual void DebugPrint ( ) const

pure virtual

Debug print out of the physic engine state.

Implemented in ODEPhysics, BulletPhysics, DARTPhysics, and SimbodyPhysics.

virtual void Fini ( )

virtual

Finilize the physics engine.

Reimplemented in ODEPhysics, BulletPhysics, DARTPhysics, and SimbodyPhysics.

virtual bool GetAutoDisableFlag ( )

inlinevirtual

: Remove this function, and replace it with a more generic property map

access functions to set ODE parameters..

Returns: Auto disable flag.

ContactManager* GetContactManager ( ) const

Get a pointer to the contact manger.

Returns: Pointer to the contact manager.

double GetMaxStepSize ( ) const

Get max step size.

Returns: Max step size.

virtual boost::any GetParam ( const std::string & _key ) const

virtual

Get an parameter of the physics engine.

Parameters

[in] _attr String key

See Also: SetParam

Returns: The value of the parameter

Reimplemented in SimbodyPhysics, ODEPhysics, BulletPhysics, and DARTPhysics.

virtual bool GetParam	(	const std::string &	_key,
		boost::any &	_value
	)		const

virtual

Get a parameter from the physics engine with a boolean to indicate success or failure.

Parameters

[in]	_key	Key of the accessed param
[out]	_value	Value of the accessed param

Returns: True if the parameter was successfully retrieved

Reimplemented in SimbodyPhysics, ODEPhysics, BulletPhysics, and DARTPhysics.

boost::recursive_mutex* GetPhysicsUpdateMutex ( ) const

inline

returns a pointer to the PhysicsEngine::physicsUpdateMutex.

Returns: Pointer to the physics mutex.

References PhysicsEngine::physicsUpdateMutex.

double GetRealTimeUpdateRate ( ) const

Get real time update rate.

Returns: Update rate

sdf::ElementPtr GetSDF ( ) const

Get a pointer to the SDF element for this physics engine.

Returns: Pointer to the physics SDF element.

double GetTargetRealTimeFactor ( ) const

Get target real time factor.

Returns: Target real time factor

virtual std::string GetType ( ) const

pure virtual

Return the physics engine type (ode|bullet|dart|simbody).

Returns: Type of the physics engine.

Implemented in ODEPhysics, BulletPhysics, DARTPhysics, and SimbodyPhysics.

double GetUpdatePeriod ( )

Get the simulation update period.

Returns: Simulation update period.

virtual void Init ( )

pure virtual

Initialize the physics engine.

Implemented in ODEPhysics, BulletPhysics, DARTPhysics, and SimbodyPhysics.

virtual void InitForThread ( )

pure virtual

Init the engine for threads.

Implemented in ODEPhysics, DARTPhysics, BulletPhysics, and SimbodyPhysics.

virtual void Load ( sdf::ElementPtr _sdf )

virtual

Load the physics engine.

Parameters

[in] _sdf Pointer to the SDF parameters.

Reimplemented in ODEPhysics, BulletPhysics, DARTPhysics, and SimbodyPhysics.

virtual void OnPhysicsMsg ( ConstPhysicsPtr & _msg )

protectedvirtual

virtual callback for gztopic "~/physics".

Parameters

[in] _msg Physics message.

Reimplemented in ODEPhysics, SimbodyPhysics, DARTPhysics, and BulletPhysics.

virtual void OnRequest ( ConstRequestPtr & _msg )

protectedvirtual

virtual callback for gztopic "~/request".

Parameters

[in] _msg Request message.

Reimplemented in ODEPhysics, SimbodyPhysics, DARTPhysics, and BulletPhysics.

virtual void Reset ( )

inlinevirtual

Rest the physics engine.

Reimplemented in ODEPhysics, DARTPhysics, BulletPhysics, and SimbodyPhysics.

virtual void SetAutoDisableFlag ( bool _autoDisable )

virtual

: Remove this function, and replace it with a more generic property map

Access functions to set ODE parameters.

Parameters

[in] _autoDisable True to enable auto disabling of bodies.

virtual void SetGravity ( const ignition::math::Vector3d & _gravity )

pure virtual

Set the gravity vector.

Parameters

[in] _gravity New gravity vector.

Implemented in BulletPhysics, ODEPhysics, DARTPhysics, and SimbodyPhysics.

virtual void SetMaxContacts ( unsigned int _maxContacts )

virtual

: Remove this function, and replace it with a more generic property map

access functions to set ODE parameters

Parameters

[in] _maxContacts Maximum number of contacts.

Reimplemented in ODEPhysics.

void SetMaxStepSize ( double _stepSize )

Set max step size.

Parameters

[in] _stepSize Max step size.

virtual bool SetParam	(	const std::string &	_key,
		const boost::any &	_value
	)

virtual

Set a parameter of the physics engine.

See SetParam documentation for descriptions of duplicate parameters.

Parameters

[in]	_key	String key Below is a list of _key parameter definitions: "solver_type" (string) - returns solver used by engine, e.g. "sequential_impulse' for Bullet, "quick" for ODE "Featherstone and Lemkes" for DART and "Spatial Algebra and Elastic Foundation" for Simbody. -# "cfm" (double) - global CFM (ODE/Bullet) -# "erp" (double) - global ERP (ODE/Bullet) -# "precon_iters" (bool) - precondition iterations (experimental). (ODE) "iters" (int) - number of LCP PGS iterations. If sor_lcp_tolerance is negative, full iteration count is executed. Otherwise, PGS may stop iteration early if sor_lcp_tolerance is satisfied by the total RMS residual. "sor" (double) - relaxation parameter for Projected Gauss-Seidel (PGS) updates. (ODE/Bullet) "contact_max_correcting_vel" (double) - truncates correction impulses from ERP by this value. (ODE) "contact_surface_layer" (double) - ERP is 0 for interpenetration depths below this value. (ODE/Bullet) "max_contacts" (int) - max number of contact constraints between any pair of collision bodies. "min_step_size" (double) - minimum internal step size. (defined but not used in ode). "max_step_size" (double) - maximum physics step size when physics update step must return.
[in]	_value	The value to set to

Returns: true if SetParam is successful, false if operation fails.

Reimplemented in SimbodyPhysics, ODEPhysics, BulletPhysics, and DARTPhysics.

void SetRealTimeUpdateRate ( double _rate )

Set real time update rate.

Parameters

[in] _rate Update rate

virtual void SetSeed ( uint32_t _seed )

pure virtual

Set the random number seed for the physics engine.

Parameters

[in] _seed The random number seed.

Implemented in ODEPhysics, BulletPhysics, DARTPhysics, and SimbodyPhysics.

void SetTargetRealTimeFactor ( double _factor )

Set target real time factor.

Parameters

[in] _factor Target real time factor

virtual void UpdateCollision ( )

pure virtual

Update the physics engine collision.

This function works in tandem with PhysicsEngine::UpdatePhysics() to update the world. This function will be called even if the physics is disabled (when World::PhysicsEnabled()) returns false). Which updates are done in which of the two functions PhysicsEngine::UpdateCollision() and PhysicsEngine::UpdatePhysics() is to some extent left to the implementing physics engine. The intention is that PhysicsEngine::UpdateCollision() will update the collision states of the world, including contact information, and PhysicsEngine::UpdatePhysics() will update the dynamics of the world, i.e. advance the world and react to the collision state. However for some physics engines, both is done in one step, or providing the contact information separately in UpdateCollision() would mean double work, as it can't be avoided to be done again in PhysicsEngine::UpdatePhysics() - in this case it is better that PhysicsEngine::UpdateCollision does not actually update collision and contact information, and instead leaves it to UpdatePhysics(). There should be one exception however when it still does make this update: If World::PhysicsEnabled() returns false, and therefore PhysicsEngine::UpdatePhysics() will not be called in the update step, then PhysicsEngine::UpdateCollision will need to ensure that collision and contact information will still be updated.