Chain Class Reference

The class representing the whole mechanism. May contain multiple characters. More...

#include <chain.h>

Inheritance diagram for Chain:

List of all members.

Classes
struct	scale_object
	XML utility functions. More...
Public Member Functions
void	add_scale_object (const scale_object &_s)
int	AddJoint (Joint *target, Joint *p)
	Add a new joint target as a child of joint p.
int	AddJoint (Joint *target, const char *parent_name, const char *charname=0)
	Add a new joint target as a child of joint with name parent_name.
Joint *	AddJoint (JointData *joint_data, const char *charname=0)
	Create and add a joint using JointData structure.
Joint *	AddRoot (const char *name=0, const fVec3 &grav=fVec3(0.0, 0.0, 9.8))
	Add the (unique) root joint.
int	AddRoot (Joint *r)
	Add the (unique) root joint.
void	ApplyGeomScale (SceneGraph *sg)
int	BeginCreateChain (int append=false)
	Indicates begining of creating a kinematic chain.
void	CalcAcceleration ()
void	CalcPosition ()
	Forward kinematics.
void	CalcVelocity ()
	Chain ()
virtual void	Clear ()
	Remove all joints and clear all parameters.
void	clear_scale_object_list ()
int	ClearExtForce ()
	Clear the external forces/torques.
int	ClearJointForce ()
	Clear the joint forces/torques.
double	ComJacobian (fMat &J, fVec3 &com, const char *chname=0)
	Computes the com Jacobian.
int	Connect (Joint *virtual_joint, Joint *parent_joint)
	Connect two links by adding a new virtual joint.
int	CreateParallel (int num_char, const char *prmname, const char *charname, const fVec3 &init_pos=0.0, const fMat33 &init_att=1.0, const fVec3 &pos_offset=0.0, const fMat33 &att_offset=1.0, int init_num=0)
	Automatically generate multiple identical chains.
int	CreateSerial (int num_joint, const JointData &joint_data, const char *charname=0, Joint *parent_joint=0)
	Automatically generate a serial chain.
int	Disconnect (Joint *j)
	Disconnect the loop at the specified virtual joint.
int	EndCreateChain (SceneGraph *sg=NULL)
	End editing a chain.
Joint *	FindCharacterRoot (const char *charname)
	Find the root joint of the character with name charname.
Joint *	FindJoint (const char *jname, const char *charname=0)
	Find a joint from name.
Joint *	FindJoint (int _id)
	Find a joint with ID _id.
int	GetJointAcc (fVec &accs)
int	GetJointForce (fVec &forces)
	Obtain the joint forces/torques.
int	GetJointList (Joint **&joints)
	Obtain a list of pointers to all joints.
int	GetJointNameList (char **&jnames)
	Obtain a list of joint names.
int	GetJointValue (fVec &values)
	Obtain the joint values/velocities/accelerations.
int	GetJointVel (fVec &vels)
int	Integrate (double timestep)
	Performs Euler integration with timestep timestep [s].
int	IntegrateAdaptive (double &timestep, int step, double min_timestep=DEFAULT_MIN_TIMESTEP, double max_integ_error=DEFAULT_MAX_INTEG_ERROR)
	Performs Euler integration with adaptive timestep.
int	IntegrateRK4 (double timestep, int step)
	Performs 4-th order Runge-Kutta integration.
int	IntegrateRK4Value (double timestep, int step)
int	IntegrateRK4Velocity (double timestep, int step)
int	IntegrateValue (double timestep)
	Integrate value/velocity only.
int	IntegrateVelocity (double timestep)
void	InvDyn (fVec &tau)
	Inverse dynamics.
int	Load (const char *fname, const char *charname=0)
	Load the chain from a file in original (*.prm) format.
int	LoadXML (const char *fname, const char *charname=0)
	Load the chain from an XML file.
int	NumDOF ()
	Total degrees of freedom.
int	NumJoint ()
	Total number of joints.
int	NumValue ()
	Dimension of the joint value vector (using Euler parameter representation for orientation).
int	RemoveJoint (Joint *j)
	disconnect joint j from its parent
Joint *	Root ()
int	Save (const char *fname, const char *charname=0) const
	Save the chain data to a file in original (*.prm) format.
int	Save (ostream &ost, const char *charname=0) const
int	SaveStatus (fVec &value, fVec &vel, fVec &acc)
	Save current joint values, velocities, and accelerations.
int	SaveXML (const char *fname, const char *charname=0) const
	Save the chain data to a file in XML format.
int	SaveXML (ostream &ost, const char *charname=0) const
int	set_abs_position_orientation (Joint *jnt, const fVec3 &abs_pos, const fMat33 &abs_att)
int	SetAllTorqueGiven (int _tg)
	Change torque/motion control property of all joints.
int	SetCharacterTorqueGiven (const char *charname, int _tg)
	Change torque/motion control property of a character.
int	SetJointAcc (const fVec &accs)
int	SetJointForce (const fVec &forces)
	Set all joint forces/torques.
int	SetJointValue (const fVec &values)
	Set all joint values.
int	SetJointVel (const fVec &vels)
	Set all joint velocities/accelerations.
int	SetStatus (const fVec &value, const fVec &vel, const fVec &acc)
	Set current joint values, velocities, and accelerations.
int	SetTorqueGiven (Joint *_joint, int _tg)
	Change torque/motion control property of a joint.
double	TotalCOM (fVec3 &com, const char *chname=0)
	Center of mass of the chain.
virtual	~Chain ()
Protected Member Functions
void	_apply_scale (Joint *jnt, double scale)
void	apply_geom_scale (SceneGraph *sg, Joint *cur)
virtual void	apply_scale ()
void	apply_scale (const scale_object &_s)
void	apply_scale_sub (Joint *cur, double scale)
void	apply_scale_top (Joint *top, double scale)
void	calc_abs_positions (Joint *cur, SceneGraph *sg)
void	calc_rel_positions (Joint *cur, SceneGraph *sg)
virtual int	clear_data ()
	Clear arrays only; don't delete joints.
virtual int	init (SceneGraph *sg)
	Initialize the parameters.
void	init_scale (SceneGraph *sg)
void	init_scale_sub (Node *node)
void	reset_scale ()
void	reset_scale_sub (Joint *jnt)
void	set_all_torque_given (Joint *cur, int _tg)
void	set_relative_positions (SceneGraph *sg)
Protected Attributes
double **	all_value
	Pointers to the integration variables.
double **	all_value_dot
double **	all_vel
double **	all_vel_dot
int	do_connect
	true after Connect() was called; application (or subclass) must reset the flag
int	in_create_chain
	true if between BeginCreateChain() and EndCreateChain().
double *	init_value
double *	init_vel
double *	j_acc_p [4]
double *	j_value_dot [4]
	for 4-th order Runge-Kutta
int	n_dof
int	n_joint
int	n_thrust
	total DOF of the joints with t_given = false
int	n_value
Joint *	root
	Chain information.
std::list< scale_object >	scale_object_list
Friends
class	Joint

---

Detailed Description

The class representing the whole mechanism. May contain multiple characters.

Definition at line 144 of file chain.h.

---

Constructor & Destructor Documentation

Chain::Chain

(

)

Definition at line 46 of file chain.cpp.

Chain::~Chain

(

)

[virtual]

Definition at line 65 of file chain.cpp.

---

Member Function Documentation

void Chain::_apply_scale	(	Joint *	jnt,
		double	scale
	)		[protected]

void Chain::add_scale_object

(

const scale_object &

_s

)

int Chain::AddJoint	(	Joint *	target,
		Joint *	p
	)

Add a new joint target as a child of joint p.

Add a new joint target as a child of joint p.

Parameters:

[in]	target	the pointer to the new joint
[in]	p	the pointer to the parent joint

Returns:

0 if success and -1 otherwise

Definition at line 117 of file edit.cpp.

int Chain::AddJoint	(	Joint *	target,
		const char *	parent_name,
		const char *	charname = 0
	)

Add a new joint target as a child of joint with name parent_name.

Add a new joint target as a child of joint p.

Parameters:

[in]	target	the pointer to the new joint
[in]	parent_name	name of the parent joint
[in]	charname	character name of the parent joint

Returns:

0 if success and -1 otherwise

Definition at line 105 of file edit.cpp.

Joint * Chain::AddJoint	(	JointData *	joint_data,
		const char *	charname = 0
	)

Create and add a joint using JointData structure.

Create and add a joint using JointData structure.

Parameters:

[in]	joint_data	pointer to the JointData structure
[in]	charname	character name

Returns:

the pointer to the new joint, NULL if failed

Definition at line 164 of file edit.cpp.

Joint * Chain::AddRoot	(	const char *	name = 0,
		const fVec3 &	grav = fVec3(0.0, 0.0, 9.8)
	)

Add the (unique) root joint.

Creates a new joint and add as the (unique) root joint.

Parameters:

[in]	name	name of the root joint
[in]	grav	gravity vector

Returns:

the pointer to the root joint; fails after the first call unless BeginCreateChain(false) is called.

Definition at line 60 of file edit.cpp.

int Chain::AddRoot

(

Joint *

r

)

Add the (unique) root joint.

Add the (unique) root joint from a Joint object.

Parameters:

[in]

r

the pointer to the joint object

Returns:

0 if success and -1 otherwise

Definition at line 87 of file edit.cpp.

void Chain::apply_geom_scale	(	SceneGraph *	sg,
		Joint *	cur
	)		[protected]

Definition at line 120 of file init.cpp.

virtual void Chain::apply_scale

(

)

[protected, virtual]

void Chain::apply_scale

(

const scale_object &

_s

)

[protected]

void Chain::apply_scale_sub	(	Joint *	cur,
		double	scale
	)		[protected]

void Chain::apply_scale_top	(	Joint *	top,
		double	scale
	)		[protected]

void Chain::ApplyGeomScale

(

SceneGraph *

sg

)

Definition at line 115 of file init.cpp.

int Chain::BeginCreateChain

(

int

append = false

)

Indicates begining of creating a kinematic chain.

Indicates begining of creating a kinematic chain. Must be called before editing the chain.

Parameters:

[in]

append

If false (default), clean up the current chain and build from scratch. Otherwise append new joints to the current chain.

Definition at line 19 of file edit.cpp.

void Chain::calc_abs_positions	(	Joint *	cur,
		SceneGraph *	sg
	)		[protected]

Definition at line 251 of file edit.cpp.

void Chain::calc_rel_positions	(	Joint *	cur,
		SceneGraph *	sg
	)		[protected]

Definition at line 279 of file edit.cpp.

void Chain::CalcAcceleration

(

)

Definition at line 75 of file fk.cpp.

void Chain::CalcPosition

(

)

Forward kinematics.

Definition at line 16 of file fk.cpp.

void Chain::CalcVelocity

(

)

Definition at line 41 of file fk.cpp.

void Chain::Clear

(

)

[virtual]

Remove all joints and clear all parameters.

Reimplemented in pSim.

Definition at line 87 of file chain.cpp.

int Chain::clear_data

(

)

[protected, virtual]

Clear arrays only; don't delete joints.

Reimplemented in pSim.

Definition at line 127 of file vary.cpp.

void Chain::clear_scale_object_list

(

)

int Chain::ClearExtForce

(

)

Clear the external forces/torques.

Definition at line 928 of file joint.cpp.

int Chain::ClearJointForce

(

)

Clear the joint forces/torques.

Definition at line 912 of file joint.cpp.

double Chain::ComJacobian	(	fMat &	J,
		fVec3 &	com,
		const char *	chname = 0
	)

Computes the com Jacobian.

Computes the com Jacobian.

Parameters:

[out]	J	com Jacobian
[out]	com	com
[in]	chname	name of the character to compute com Jacobian; all joints if omitted

Returns:

the total mass

Definition at line 18 of file jacobi.cpp.

int Chain::Connect	(	Joint *	virtual_joint,
		Joint *	parent_joint
	)

Connect two links by adding a new virtual joint.

Definition at line 95 of file vary.cpp.

int Chain::CreateParallel	(	int	num_char,
		const char *	prmname,
		const char *	charname,
		const fVec3 &	init_pos = 0.0,
		const fMat33 &	init_att = 1.0,
		const fVec3 &	pos_offset = 0.0,
		const fMat33 &	att_offset = 1.0,
		int	init_num = 0
	)

Automatically generate multiple identical chains.

Generate num_char chains with identical structure in a prm file.

Parameters:

[in]	num_char	number of chains to generate
[in]	prmname	prm file name
[in]	charname	character name (the actual name includes the number starting from init_num)
[in]	init_pos	the position offset of the first chain
[in]	init_att	the orientation offset of the first chain
[in]	pos_offset	the position offset of each chain from the previous
[in]	att_offset	the orientation offset of each chain from the previous
[in]	init_num	the number of the first chain

int Chain::CreateSerial	(	int	num_joint,
		const JointData &	joint_data,
		const char *	charname = 0,
		Joint *	parent_joint = 0
	)

Automatically generate a serial chain.

Generate a serial chain with num_joint joints.

Parameters:

[in]	num_joint	number of joints
[in]	joint_data	JointData structure to be used as the template for the joints; each joint will named as joint_data.name + number
[in]	charname	character name (optional)
[in]	parent_joint	pointer to the root of the serial chain (optional); the global root if omitted or NULL

int Chain::Disconnect

(

Joint *

j

)

Disconnect the loop at the specified virtual joint.

Definition at line 111 of file vary.cpp.

int Chain::EndCreateChain

(

SceneGraph *

sg = NULL

)

End editing a chain.

End editing a chain; performs initialization process.

Parameters:

[in]

sg

the pointer to the SceneGraph to be used for setting the initial configuration.

Definition at line 225 of file edit.cpp.

Joint * Chain::FindCharacterRoot

(

const char *

charname

)

Find the root joint of the character with name charname.

Definition at line 429 of file chain.cpp.

Joint * Chain::FindJoint	(	const char *	jname,
		const char *	charname = 0
	)

Find a joint from name.

Find a joint from name. If charname is not null, find a joint whose basename is jname and character name is charname. Otherwise, find a joint whose name is jname.

Parameters:

[in]	jname	joint name
[in]	charname	character name

Returns:

the pointer to the joint, NULL if not found

Definition at line 391 of file chain.cpp.

Joint * Chain::FindJoint

(

int

_id

)

Find a joint with ID _id.

Definition at line 415 of file chain.cpp.

int Chain::GetJointAcc

(

fVec &

accs

)

Definition at line 214 of file joint.cpp.

int Chain::GetJointForce

(

fVec &

forces

)

Obtain the joint forces/torques.

Definition at line 866 of file joint.cpp.

int Chain::GetJointList

(

Joint **&

joints

)

Obtain a list of pointers to all joints.

Obtain a list of pointers to all joints.

Returns:

number of joints

Definition at line 365 of file chain.cpp.

int Chain::GetJointNameList

(

char **&

jnames

)

Obtain a list of joint names.

Obtain a list of joint names.

Returns:

number of joints

Definition at line 338 of file chain.cpp.

int Chain::GetJointValue

(

fVec &

values

)

Obtain the joint values/velocities/accelerations.

Definition at line 124 of file joint.cpp.

int Chain::GetJointVel

(

fVec &

vels

)

Definition at line 172 of file joint.cpp.

int Chain::init

(

SceneGraph *

sg

)

[protected, virtual]

Initialize the parameters.

Reimplemented in pSim, and IK.

Definition at line 22 of file init.cpp.

void Chain::init_scale

(

SceneGraph *

sg

)

[protected]

Definition at line 92 of file init.cpp.

void Chain::init_scale_sub

(

Node *

node

)

[protected]

Definition at line 97 of file init.cpp.

int Chain::Integrate

(

double

timestep

)

Performs Euler integration with timestep timestep [s].

Definition at line 110 of file integ.cpp.

int Chain::IntegrateAdaptive	(	double &	timestep,
		int	step,
		double	min_timestep = DEFAULT_MIN_TIMESTEP,
		double	max_integ_error = DEFAULT_MAX_INTEG_ERROR
	)

Performs Euler integration with adaptive timestep.

Performs Euler integration with adaptive timestep. Requires two acceleration computations per step.

Parameters:

[in,out]	timestep	inputs maximum timestep and overwritten by the actual timestep
[in]	step	step in the integration (0/1)
[in]	min_timestep	minimum timestep
[in]	max_integ_error	maximum error

estimate the integration error by comparing x1 and x2, where (1) x1 = x(t) + xdot(t)dt (2) x(t+dt/2) = x(t) + xdot(t)dt/2, x2 = x(t+dt/2) + xdot(t+dt/2)dt/2 the actual timestep will be equal to or smaller than the timestep parameter, which will be overwritten by the actual timestep

Definition at line 24 of file integ.cpp.

int Chain::IntegrateRK4	(	double	timestep,
		int	step
	)

Performs 4-th order Runge-Kutta integration.

Performs 4-th order Runge-Kutta integration.

Parameters:

[in]	timestep	integration time step [s]
[in]	step	step in the integration (0/1/2/3)

Definition at line 214 of file integ.cpp.

int Chain::IntegrateRK4Value	(	double	timestep,
		int	step
	)

Definition at line 126 of file integ.cpp.

int Chain::IntegrateRK4Velocity	(	double	timestep,
		int	step
	)

Definition at line 170 of file integ.cpp.

int Chain::IntegrateValue

(

double

timestep

)

Integrate value/velocity only.

Integrate value/velocity only. (for test) See Guendelman et al., SIGGRAPH2003

Definition at line 86 of file integ.cpp.

int Chain::IntegrateVelocity

(

double

timestep

)

Definition at line 98 of file integ.cpp.

void Chain::InvDyn

(

fVec &

tau

)

Inverse dynamics.

Inverse dynamics

Parameters:

[out]

tau

joint forces/torques

Definition at line 16 of file id.cpp.

int Chain::Load	(	const char *	fname,
		const char *	charname = 0
	)

Load the chain from a file in original (*.prm) format.

Load the chain from a file in original (*.prm) format.

Parameters:

[in]	fname	file name
[in]	charname	character name; each joint is named as "basename:charname"

Returns:

0 if success and -1 otherwise

Definition at line 26 of file load.cpp.

int Chain::LoadXML	(	const char *	fname,
		const char *	charname = 0
	)

Load the chain from an XML file.

int Chain::NumDOF

(

)

[inline]

Total degrees of freedom.

Definition at line 343 of file chain.h.

int Chain::NumJoint

(

)

[inline]

Total number of joints.

Definition at line 347 of file chain.h.

int Chain::NumValue

(

)

[inline]

Dimension of the joint value vector (using Euler parameter representation for orientation).

Definition at line 351 of file chain.h.

int Chain::RemoveJoint

(

Joint *

j

)

disconnect joint j from its parent

Definition at line 32 of file edit.cpp.

void Chain::reset_scale

(

)

[protected]

void Chain::reset_scale_sub

(

Joint *

jnt

)

[protected]

Joint* Chain::Root

(

)

[inline]

Definition at line 151 of file chain.h.

int Chain::Save	(	const char *	fname,
		const char *	charname = 0
	)		const

Save the chain data to a file in original (*.prm) format.

int Chain::Save	(	ostream &	ost,
		const char *	charname = 0
	)		const

int Chain::SaveStatus	(	fVec &	value,
		fVec &	vel,
		fVec &	acc
	)

Save current joint values, velocities, and accelerations.

Definition at line 24 of file chain.cpp.

int Chain::SaveXML	(	const char *	fname,
		const char *	charname = 0
	)		const

Save the chain data to a file in XML format.

int Chain::SaveXML	(	ostream &	ost,
		const char *	charname = 0
	)		const

int Chain::set_abs_position_orientation	(	Joint *	jnt,
		const fVec3 &	abs_pos,
		const fMat33 &	abs_att
	)

Definition at line 396 of file joint.cpp.

void Chain::set_all_torque_given	(	Joint *	cur,
		int	_tg
	)		[protected]

Definition at line 74 of file vary.cpp.

void Chain::set_relative_positions

(

SceneGraph *

sg

)

[protected]

Definition at line 243 of file edit.cpp.

int Chain::SetAllTorqueGiven

(

int

_tg

)

Change torque/motion control property of all joints.

Definition at line 60 of file vary.cpp.

int Chain::SetCharacterTorqueGiven	(	const char *	charname,
		int	_tg
	)

Change torque/motion control property of a character.

vary.cpp Create:Katsu Yamane, 04.04.19 functions related to changing joint connectivity

Definition at line 17 of file vary.cpp.

int Chain::SetJointAcc

(

const fVec &

accs

)

Definition at line 497 of file joint.cpp.

int Chain::SetJointForce

(

const fVec &

forces

)

Set all joint forces/torques.

Set all joint forces/torques. The index of the first data of a joint is Joint::i_dof.

Definition at line 746 of file joint.cpp.

int Chain::SetJointValue

(

const fVec &

values

)

Set all joint values.

Set all joint values. The orientation of spherical/free joints are represented as Euler parameters. The index of the first data of a joint is Joint::i_value.

Definition at line 415 of file joint.cpp.

int Chain::SetJointVel

(

const fVec &

vels

)

Set all joint velocities/accelerations.

Set all joint velocities/accelerations. The index of the first data of a joint is Joint::i_dof.

Definition at line 456 of file joint.cpp.

int Chain::SetStatus	(	const fVec &	value,
		const fVec &	vel,
		const fVec &	acc
	)

Set current joint values, velocities, and accelerations.

Definition at line 35 of file chain.cpp.

int Chain::SetTorqueGiven	(	Joint *	_joint,
		int	_tg
	)

Change torque/motion control property of a joint.

Definition at line 34 of file vary.cpp.

double Chain::TotalCOM	(	fVec3 &	com,
		const char *	chname = 0
	)

Center of mass of the chain.

Center of mass of the chain.

Parameters:

[out]	com	center of mass
[in]	chname	name of the character to compute com; all joints if omitted

Returns:

the total mass

Definition at line 129 of file fk.cpp.

---

Friends And Related Function Documentation

friend class Joint [friend]

Definition at line 146 of file chain.h.

---

Member Data Documentation

double** Chain::all_value [protected]

Pointers to the integration variables.

Pointers to the integration variables.

	 *   all_value += timestep * all_value_dot
	 *   all_vel += timestep * all_vel_dot  

Definition at line 455 of file chain.h.

double** Chain::all_value_dot [protected]

Definition at line 456 of file chain.h.

double** Chain::all_vel [protected]

Definition at line 457 of file chain.h.

double** Chain::all_vel_dot [protected]

Definition at line 458 of file chain.h.

int Chain::do_connect [protected]

true after Connect() was called; application (or subclass) must reset the flag

Definition at line 476 of file chain.h.

int Chain::in_create_chain [protected]

true if between BeginCreateChain() and EndCreateChain().

Definition at line 473 of file chain.h.

double* Chain::init_value [protected]

Definition at line 462 of file chain.h.

double* Chain::init_vel [protected]

Definition at line 463 of file chain.h.

double* Chain::j_acc_p[4] [protected]

Definition at line 461 of file chain.h.

double* Chain::j_value_dot[4] [protected]

for 4-th order Runge-Kutta

Definition at line 460 of file chain.h.

int Chain::n_dof [protected]

Definition at line 468 of file chain.h.

int Chain::n_joint [protected]

Definition at line 469 of file chain.h.

int Chain::n_thrust [protected]

total DOF of the joints with t_given = false

Definition at line 470 of file chain.h.

int Chain::n_value [protected]

Definition at line 467 of file chain.h.

Joint* Chain::root [protected]

Chain information.

Definition at line 466 of file chain.h.

std::list<scale_object> Chain::scale_object_list [protected]

Definition at line 517 of file chain.h.

---

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

• chain.h
• chain.cpp
• edit.cpp
• fk.cpp
• id.cpp
• init.cpp
• integ.cpp
• jacobi.cpp
• joint.cpp
• load.cpp
• vary.cpp