An virtual class for simulation with constraints. More...

#include <ConstraintSimulator.h>

Inheritance diagram for Moby::ConstraintSimulator:

Public Member Functions
	ConstraintSimulator ()
	Default constructor.

virtual void	load_from_xml (boost::shared_ptr< const XMLTree > node, std::map< std::string, BasePtr > &id_map)
	Implements Base::load_from_xml()

virtual void	save_to_xml (XMLTreePtr node, std::list< boost::shared_ptr< const Base > > &shared_objects) const
	Implements Base::save_to_xml()

boost::shared_ptr < ContactParameters >	get_contact_parameters (CollisionGeometryPtr geom1, CollisionGeometryPtr geom2) const
	Gets the contact data between a pair of geometries (if any) More...

const std::vector < PairwiseDistInfo > &	get_pairwise_distances () const

std::vector < UnilateralConstraint > &	get_compliant_constraints ()
	Gets the (sorted) compliant constraint data.

std::vector < UnilateralConstraint > &	get_rigid_constraints ()
	Gets the (sorted) rigid constraint data.

boost::shared_ptr < CollisionDetection >	get_collision_detection () const
	Gets the collision detection mechanism.

Public Member Functions inherited from Moby::Simulator
	Simulator ()
	Sets up the simulator. More...

virtual double	step (double step_size)
	Steps the Simulator forward in time without contact. More...

ControlledBodyPtr	find_dynamic_body (const std::string &name) const
	Finds the dynamic body in the simulator, if any. More...

void	add_dynamic_body (ControlledBodyPtr body)
	Adds a dynamic body to the simulator. More...

void	remove_dynamic_body (ControlledBodyPtr body)
	Removes a dynamic body from the simulator.

void	update_visualization ()
	Updates all visualization under the simulator.

const std::vector < ControlledBodyPtr > &	get_dynamic_bodies () const
	Gets the list of dynamic bodies in the simulator. More...

void	add_transient_vdata (osg::Node *vdata)
	Adds transient visualization data to the simulator.

osg::Node *	get_persistent_vdata () const
	Gets the persistent visualization data.

osg::Node *	get_transient_vdata () const
	Gets the transient (one-step) visualization data.

template<class ForwardIterator >
double	integrate (double dt, ForwardIterator begin, ForwardIterator end)
	Integrates both position and velocity of rigid _bodies. More...

Public Member Functions inherited from Moby::Base
	Base (const Base *b)

Public Attributes
ConstraintStabilization	cstab
	The constraint stabilization mechanism.

std::set< Ravelin::sorted_pair < CollisionGeometryPtr > >	unchecked_pairs
	Determines whether two geometries are not checked.

std::vector< std::pair < ControlledBodyPtr, Ravelin::VectorNd > >	_x0
	Vectors set and passed to collision detection.

std::vector< std::pair < ControlledBodyPtr, Ravelin::VectorNd > >	_x1

boost::shared_ptr < ContactParameters >(*	get_contact_parameters_callback_fn )(CollisionGeometryPtr g1, CollisionGeometryPtr g2)
	Callback function for getting contact parameters.

void(*	post_mini_step_callback_fn )(ConstraintSimulator *s)
	Callback function after a mini-step is completed.

void(*	constraint_callback_fn )(std::vector< UnilateralConstraint > &, boost::shared_ptr< void >)
	The callback function (called when constraints have been determined) More...

void(*	constraint_post_callback_fn )(const std::vector< UnilateralConstraint > &, boost::shared_ptr< void >)
	The callback function (called after forces/impulses are applied)

boost::shared_ptr< void >	constraint_callback_data
	Data passed to unilateral constraint callback.

boost::shared_ptr< void >	constraint_post_callback_data
	Data passed to post-constraint callback.

std::map< Ravelin::sorted_pair < BasePtr >, boost::shared_ptr < ContactParameters > >	contact_params
	Mapping from objects to contact parameters.

bool	render_contact_points
	If set to 'true' simulator will process contact points for rendering.

Public Attributes inherited from Moby::Simulator
double	current_time
	The current simulation time.

boost::shared_ptr< Dissipation >	dissipator
	The dissipation mechanism for larger time steps.

void(*	post_step_callback_fn )(Simulator *s)
	Callback function after a step is completed.

double	dynamics_time
	User time spent by dynamics on the last step.

std::vector< JointPtr >	implicit_joints
	Set of implicit joints maintained in the simulation (does not include implicit joints belonging to RCArticulatedBody objects)

Public Attributes inherited from Moby::Base
boost::shared_ptr< void >	userdata
	Any relevant userdata.

std::string	id
	The unique ID for this object.

Protected Member Functions
void	calc_impacting_unilateral_constraint_forces (double dt)
	Handles constraints.

void	find_unilateral_constraints ()
	Finds the set of unilateral constraints.

void	calc_compliant_unilateral_constraint_forces ()
	Computes compliant contact forces.

void	preprocess_constraint (UnilateralConstraint &e)
	Performs necessary preprocessing on an constraint.

void	determine_geometries ()
	Sets up the list of collision geometries.

void	broad_phase (double dt)
	Does broad phase collision detection, identifying which pairs of geometries may come into contact over time step of dt.

void	calc_pairwise_distances ()
	Computes pairwise distances of geometries at their current poses, using broad phase results to determine which pairs should be checked. More...

void	visualize_contact (UnilateralConstraint &constraint)
	Draws a ray directed from a contact point along the contact normal.

double	calc_CA_step ()

double	calc_next_CA_Euler_step (double contact_dist_thresh) const

Protected Member Functions inherited from Moby::Simulator
void	apply_impulse (boost::shared_ptr< Ravelin::DynamicBodyd > db, const Ravelin::SharedVectorNd &gj)
	Applies a generalized impulse to a dynamic body. More...

void	solve (const std::vector< boost::shared_ptr< Ravelin::DynamicBodyd > > &island, const std::vector< JointPtr > &island_joints, const Ravelin::VectorNd &v, const Ravelin::VectorNd &f, double dt, Ravelin::VectorNd &a, Ravelin::VectorNd &lambda) const

virtual double	check_pairwise_constraint_violations (double t)

void	find_islands (std::vector< std::vector< boost::shared_ptr< Ravelin::DynamicBodyd > > > &islands)
	Finds islands.

unsigned	num_generalized_coordinates (const std::vector< boost::shared_ptr< Ravelin::DynamicBodyd > > &island) const
	Gets the number of generalized coordinates in an island.

void	calc_fwd_dyn (double dt)
	Calculates forward dynamics for bodies (does not consider unilateral constraints)

void	precalc_fwd_dyn ()
	Prepares to calculate forward dynamics for bodies.

template<class ForwardIterator >
double	integrate (double step_size, ForwardIterator begin, ForwardIterator end)
	Integrates both position and velocity of rigid _bodies. More...

double	integrate (double step_size)
	Integrates all dynamic bodies.

Protected Attributes
ImpactConstraintHandler	_impact_constraint_handler
	Object for handling impact constraints.

PenaltyConstraintHandler	_penalty_constraint_handler
	Object for handling penalty constraints.

std::vector< UnilateralConstraint >	_rigid_constraints
	The vector of rigid constraints.

std::vector< UnilateralConstraint >	_compliant_constraints
	The vector of compliant constraints.

std::vector< PairwiseDistInfo >	_pairwise_distances
	Pairwise distances at bodies' current configurations.

Ravelin::VectorNd	_workV
	Work vector.

boost::shared_ptr < CollisionDetection >	_coldet
	The collision detection mechanism.

std::vector< CollisionGeometryPtr >	_geometries
	The geometries in the simulator.

std::vector< std::pair < CollisionGeometryPtr, CollisionGeometryPtr > >	_pairs_to_check
	Geometric pairs that should be checked for unilateral constraints (according to broad phase collision detection)

Protected Attributes inherited from Moby::Simulator
osg::Group *	_persistent_vdata

osg::Group *	_transient_vdata

std::vector< ControlledBodyPtr >	_bodies
	The set of bodies in the simulation.

Ravelin::VectorNd	_current_dx
	The derivative at the current time.

Friends
class	CollisionDetection

class	ConstraintStabilization

Additional Inherited Members
Static Public Member Functions inherited from Moby::Base
template<class T >
static boost::shared_ptr< T >	clone (boost::shared_ptr< T > x)
	Static method for cloning a shared pointer.

Detailed Description

An virtual class for simulation with constraints.

Member Function Documentation

void ConstraintSimulator::calc_pairwise_distances ( )

protected

Computes pairwise distances of geometries at their current poses, using broad phase results to determine which pairs should be checked.

Parameters

pairwise_distances on return, contains the pairwise distances

shared_ptr< ContactParameters > ConstraintSimulator::get_contact_parameters	(	CollisionGeometryPtr	geom1,
		CollisionGeometryPtr	geom2
	)		const

Gets the contact data between a pair of geometries (if any)

This method looks for contact data not only between the pair of geometries, but also the rigid bodies that the geometries belong to, and any articulated bodies as well. The search proceeds in the following manner:

two collision geometries
one collision geometry, one rigid body
two rigid bodies
one collision geometry, one articulated body
one rigid body, one articulated body
two articulated bodies

The search order allows for multiple granularities; for example, a collision can easily be specified between two geometries of two of a robot's links (i.e., representing different surfaces on the links), between two links, or between two robots.

Parameters

g1	the first collision geometry
g2	the second collision geometry

Returns: a pointer to the contact data, if any, found

Member Data Documentation

void(* Moby::ConstraintSimulator::constraint_callback_fn)(std::vector< UnilateralConstraint > &, boost::shared_ptr< void >)

The callback function (called when constraints have been determined)

The callback function can remove constraints from the list, which will disable their processing (however, doing so may prevent the simulation from making progress, as the simulator attempts to disallow violations.

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

/home/drum/Moby/include/Moby/ConstraintSimulator.h
/home/drum/Moby/src/ConstraintSimulator.cpp

Public Member Functions

Public Attributes

Protected Member Functions

Protected Attributes

Friends

Additional Inherited Members

Detailed Description

Member Function Documentation

Member Data Documentation