Physics::Joint Class Reference

Wrapper for joints between bodies. More...

#include <Joint.h>

List of all members.

Public Types

enum EJointType {
  BALL = dJointTypeBall, HINGE = dJointTypeHinge, HINGE2 = dJointTypeHinge2, UNIVERSAL = dJointTypeUniversal,
  SLIDER = dJointTypeSlider, PRISMATIC_ROTOIDE = dJointTypePR, FIXED = dJointTypeFixed, CONTACT = dJointTypeContact,
  ANGULAR_MOTOR = dJointTypeAMotor, LINEAR_MOTOR = dJointTypeLMotor, PLANE2D = dJointTypePlane2D
}

Different types the joint can be. More...

enum EAnchoredTo { GLOBAL = 0, BODY1 = 1, BODY2 = 2 }

Anchor type for motor joints. More...

enum EAMotorMode { ANGULAR_MOTOR_USER = dAMotorUser, ANGULAR_MOTOR_EULER = dAMotorEuler }

Mode for angular motors. More...

Public Member Functions

Joint (World *pWorld, EJointType type)

Creates a joint of the given type, except contact joints.

Joint (World *pWorld, Contact *pContact=NULL)

Creates contact a joint, using the provided contact data.

Joint (const Joint &v)

Copies a joint but do not attach bodies and do not allocate a feedback structure.

~Joint ()

EJointType getType () const

Returns the type of the joint.

void attach (Body *pBody1, Body *pBody2)

Attaches two bodies with the joint. A NULL body is equivalent to the global frame (= "the environment"). Joining two NULL bodies is possible but has no effet on the simulation.

Body * getBody1 ()

Gets first body in joint, or NULL (= global frame).

Body * getBody2 ()

Gets second body in joint, or NULL (= global frame).

const Body * getBody1 () const

const version of getBody1().

const Body * getBody2 () const

const version of getBody2().

UINT getNumBodies () const

Return the number of bodies attached to the joint.

void setFeedback (JointFeedback *pJointFeedback)

Sets a feedback structure that will be filled with data on world step.

JointFeedback * getFeedback ()

Gets the current feetback structure.

const JointFeedback * getFeedback () const

const version of getFeedback().

virtual void accept (Visitor &v)

Intrinsic parameters

All parameters are in world coordinates.
Some parameters cannot be set on certain types of joints (ex: A position on a slider joint). Setting parameters when it should not results in an undefined behaviour ! Actually, in debug configuration, it throws an exception because joint type is checked on each call. In release, it sometimes does nothing, and sometimes tries to call a non-corresponding ODE function (this generally results in an ODE error). When joint has 2 or 3 axis, then the 1st is attached to body 1 and the last one is attached to body 2 (attached does not mean relative). Axis are internally normalized.

void setPos (const osg::Vec3 &pos)

Sets position (=anchor) of the joint.

osg::Vec3 getPosBody1 () const

Gets position of the joint on body 1 (should be the same result for body 2 if joint is perfectly matched).

osg::Vec3 getPosBody2 () const

Gets position of the joint on body 2 (should be the same result for body 1 if joint is perfectly matched).

void setAxis1 (const osg::Vec3 &axis)

Sets primary axis for the joint (attached to body 1 for 2-axis joints).

osg::Vec3 getAxis1 () const

Used for hinge, slider, universal, hinge2, prismatic rotoide.

void setAxis2 (const osg::Vec3 &axis)

Sets secondary axis for the joint (attached to body 2 for universal and hinge2).

osg::Vec3 getAxis2 () const

Used for universal, hinge2, prismatic rotoide.

void setAMotorMode (EAMotorMode mode)

Sets the mode for an AMotor.

EAMotorMode getAMotorMode () const

Gets the mode for an AMotor.

void setNumAxes (UCHAR num)

Sets the number of axes for the joint.

UCHAR getNumAxes () const

Gets the number of axes for the joint.

void setMotorAxis (UCHAR num, EAnchoredTo frame, const osg::Vec3 &axis)

Sets one of the axis for the joint.

osg::Vec3 getMotorAxis (UCHAR num) const

Gets one of the axis for the joint.

EAnchoredTo getAxisFrameAMotor (UCHAR num) const

Gets one of the axis frame for the joint.

void setAxisAngleAMotor (UCHAR num, dReal angle)

Sets one of the axis angle for the joint.

dReal getAxisAngleAMotor (UCHAR num) const

Gets one of the axis angle for the joint.

dReal getAxisAngleRateAMotor (UCHAR num) const

Gets one of the axis angle rate for the joint.

dReal getRelAngleAxis1 () const

Gets angle between two bodies on primary axis (0 is the initial angle).

dReal getRelAngleRateAxis1 () const

Derivate of the getAngleAxis1() value.

dReal getRelAngleRateAxis2 () const

Used for hinge2.

dReal getRelPosAxis1 () const

Gets relative position along axis 1 (0 is the initial position).

dReal getRelPosRateAxis1 () const

Derivate of the getRelPosAxis1() value.

General parameters

void setCFM (dReal val, UINT axis=0)

Sets CFM (when not at a stop).

dReal getCFM (UINT axis=0) const

Stop parameters

Stop parameters allow the joint to be limited in movement.
Note that zero always correspond to initial relative position (or rotation). Note that angles must be in [-pi, pi] to be effective (otherwise they are considered as infinity). If the high stop is less than the low stop, then the stop will be disabled (ineffective).

void setLoStop (dReal val, UINT axis=0)

Defines a low limit for the joint. Ex: -PI/2 can be the lowest angle for a hinge.

dReal getLoStop (UINT axis=0) const

void setHiStop (dReal val, UINT axis=0)

Defines a high limit for the joint. Ex: PI/2 can be the higest angle for a hinge.

dReal getHiStop (UINT axis=0) const

void setStopBouncyness (dReal val, UINT axis=0)

Defines the bouncyness for the limits of the joint, in [0;1].

dReal getStopBouncyness (UINT axis=0) const

void setStopERP (dReal val, UINT axis=0)

Defines the ERP for the limits of the joint.

dReal getStopERP (UINT axis=0) const

void setStopCFM (dReal val, UINT axis=0)

Sets CFM for the limit of the joint (warning : this does not work as expected for powered joints).

dReal getStopCFM (UINT axis=0) const

Motor parameters

Motor parameters allow to continuously set a given speed for the joint, provided that it does not need too much force to accomplish.

void setMotorVel (dReal val, UINT axis=0)

dReal getMotorVel (UINT axis=0) const

void setMotorMaxForce (dReal val, UINT axis=0)

dReal getMotorMaxForce (UINT axis=0) const

void setMotorFudgeFactor (dReal val, UINT axis=0)

Sets a factor for the force applied to the joint when it leaves its stop position. Used to correct the behaviour if a "jumping" motion appears.

dReal getMotorFudgeFactor (UINT axis=0) const

Utility methods

void copyParameters (const Joint &v)

Copies all parameters of a joint of the same type.

Position and orientation

Joints position and orientation are meaningful when attached to the enviroment.
These methods handle the case.

void translate (const osg::Vec3 &vec)

void rotate (const osg::Quat &quat)

void rotate (const osg::Quat &quat, const osg::Vec3 &center)

Rotates the joint around a given point.

Protected Types

typedef void(* TFuncODESetParam )(dJointID, int, dReal)

typedef dReal(* TFuncODEGetParam )(dJointID, int)

Protected Member Functions

Joint (World *pWorld, EJointType type, dJointGroupID joinGroup)

Joint (World *pWorld, Contact *pContact, dJointGroupID joinGroup)

void init (EJointType type, dContact *pContact=NULL, dJointGroupID joinGroup=NULL)

TFuncODESetParam getODESetParamFuncPt () const

Retreives the function pointer for setting ODE param.

TFuncODEGetParam getODEGetParamFuncPt () const

Retreives the function pointer for getting ODE param.

Protected Attributes

dJointID id

dWorldID worldId

Friends

class JointGroup

Detailed Description

Wrapper for joints between bodies.

Joints use current data when setting parameters ; for example, when you set a fixed joint, the current relative position of the two bodies will be stored and kept as this. Note that joint parameters can be applied on different axis (in {0,1,2}). Number of axis available depends on the joint type. For a slider, you can only set the axis 0, whereas you can set 0 and 1 for a hinge2.

Author:: Sukender

Version:: 0.2.0 Incomplete - Does not support Plane2D (Not stable in ODE 0.8), does not support all ODE joint functions. Added copy constructor and translation/rotation methods.

Todo:

Test AMotors/LMotors and complete implementation. Idea : If AMotors are only a way to set/limit velocities/stops, separate angular motors by setting them to be parameters of joints, not a joint itself.

Look for LMotors new functions in ODE next releases.

Implement Plane2D when it'll be more stable in ODE (dJointSetPlane2DXParam, dJointSetPlane2DYParam, dJointSetPlane2DAngleParam).

Implement wrappers for utility functions (chapter 7.6 / Wiki-Joints 1.6) : setting joints forces/torques directly (dJointAdd*Torque, dJointAddSliderForce)

See what are (and implement) : dJointSetBallAnchor2 (Directly set anchor for body 2 olny ?), dJointSetHingeAnchorDelta (???), dJointSetSliderAxisDelta (Set axis with offset for body 1 ???)

Definition at line 72 of file Joint.h.

Member Typedef Documentation

typedef dReal(* Physics::Joint::TFuncODEGetParam)(dJointID, int) [protected]

Definition at line 311 of file Joint.h.

typedef void(* Physics::Joint::TFuncODESetParam)(dJointID, int, dReal) [protected]

Definition at line 310 of file Joint.h.

Member Enumeration Documentation

enum Physics::Joint::EAMotorMode

Mode for angular motors.

Enumerator:

ANGULAR_MOTOR_USER
ANGULAR_MOTOR_EULER

Definition at line 102 of file Joint.h.

enum Physics::Joint::EAnchoredTo

Anchor type for motor joints.

Enumerator:

GLOBAL
BODY1
BODY2

Definition at line 95 of file Joint.h.

enum Physics::Joint::EJointType

Different types the joint can be.

Joints have degrees of freedom, written (t,r), where t is the number of axis on which translations are possible, and r are for rotations.

Enumerator:

BALL	Ball and socket joint (0,3).
HINGE	Hinge joint (0,1).
HINGE2	Two hinges in series (0,2) with the ability to function as a suspension axis (Axis 1 only).
UNIVERSAL	Two hinges in series (0,2) where axes are perpendicular to each other, and with a perfectly rigid connection in place of the suspension.
SLIDER	Slider joint (1,0).
PRISMATIC_ROTOIDE	Prismatic-rotoide (1,1). Combination of a slider and a hinge.
FIXED	Fixed joint (0,0).
CONTACT	Contact joint (2.5,3), allow to move in only one direction for an axis.
ANGULAR_MOTOR	Angular motor.
LINEAR_MOTOR	Linear motor.
PLANE2D

Definition at line 76 of file Joint.h.

Constructor & Destructor Documentation

Physics::Joint::Joint	(	World *	pWorld,
		EJointType	type
	)

Creates a joint of the given type, except contact joints.

Definition at line 37 of file Joint.cpp.

References init().

Physics::Joint::Joint	(	World *	pWorld,
		Contact *	pContact = `NULL`
	)

Creates contact a joint, using the provided contact data.

Definition at line 38 of file Joint.cpp.

References CONTACT, and init().

Physics::Joint::Joint ( const Joint & v )

Copies a joint but do not attach bodies and do not allocate a feedback structure.

Definition at line 43 of file Joint.cpp.

References CONTACT, copyParameters(), getType(), init(), and THROW_TRACED_EXCEPTION.

Physics::Joint::~Joint ( ) [inline]

Definition at line 114 of file Joint.h.

Physics::Joint::Joint	(	World *	pWorld,
		EJointType	type,
		dJointGroupID	joinGroup
	)			`[protected]`

Definition at line 40 of file Joint.cpp.

References init().

Physics::Joint::Joint	(	World *	pWorld,
		Contact *	pContact,
		dJointGroupID	joinGroup
	)			`[protected]`

Definition at line 41 of file Joint.cpp.

References CONTACT, and init().

Member Function Documentation

void Physics::Joint::accept ( Visitor & v ) [virtual]

Definition at line 498 of file Joint.cpp.

References Physics::Visitor::apply().

Referenced by C3DPhy::accept().

void Physics::Joint::attach	(	Body *	pBody1,
		Body *	pBody2
	)

Attaches two bodies with the joint. A NULL body is equivalent to the global frame (= "the environment"). Joining two NULL bodies is possible but has no effet on the simulation.

Definition at line 134 of file Joint.cpp.

References FIXED, getType(), and Physics::Body::id.

Referenced by C3DPhy::attachBodies(), and Physics::NearCallback::operator()().

void Physics::Joint::copyParameters ( const Joint & v )

Copies all parameters of a joint of the same type.

Definition at line 50 of file Joint.cpp.

References ANGULAR_MOTOR, ASSERT, BALL, CONTACT, DBG_TRY_BLOCK_END, DBG_TRY_BLOCK_START, FIXED, getAMotorMode(), getAxis1(), getAxis2(), getAxisAngleAMotor(), getAxisFrameAMotor(), getCFM(), getHiStop(), getLoStop(), getMotorAxis(), getMotorFudgeFactor(), getMotorMaxForce(), getMotorVel(), getNumAxes(), getPosBody1(), getStopBouncyness(), getStopCFM(), getStopERP(), getType(), HINGE, HINGE2, LINEAR_MOTOR, PLANE2D, PRISMATIC_ROTOIDE, setAMotorMode(), setAxis1(), setAxis2(), setAxisAngleAMotor(), setCFM(), setHiStop(), setLoStop(), setMotorAxis(), setMotorFudgeFactor(), setMotorMaxForce(), setMotorVel(), setNumAxes(), setPos(), setStopBouncyness(), setStopCFM(), setStopERP(), SLIDER, THROW_TRACED_EXCEPTION, and UNIVERSAL.

Referenced by C3DPhy::attachBodies(), and Joint().

Joint::EAMotorMode Physics::Joint::getAMotorMode ( ) const

Gets the mode for an AMotor.

Definition at line 303 of file Joint.cpp.


Public Types
enum	EJointType { BALL = dJointTypeBall, HINGE = dJointTypeHinge, HINGE2 = dJointTypeHinge2, UNIVERSAL = dJointTypeUniversal, SLIDER = dJointTypeSlider, PRISMATIC_ROTOIDE = dJointTypePR, FIXED = dJointTypeFixed, CONTACT = dJointTypeContact, ANGULAR_MOTOR = dJointTypeAMotor, LINEAR_MOTOR = dJointTypeLMotor, PLANE2D = dJointTypePlane2D }
	Different types the joint can be. More...
enum	EAnchoredTo { GLOBAL = 0, BODY1 = 1, BODY2 = 2 }
	Anchor type for motor joints. More...
enum	EAMotorMode { ANGULAR_MOTOR_USER = dAMotorUser, ANGULAR_MOTOR_EULER = dAMotorEuler }
	Mode for angular motors. More...
Public Member Functions
	Joint (World *pWorld, EJointType type)
	Creates a joint of the given type, except contact joints.
	Joint (World pWorld, Contact pContact=NULL)
	Creates contact a joint, using the provided contact data.
	Joint (const Joint &v)
	Copies a joint but do not attach bodies and do not allocate a feedback structure.
	~Joint ()
EJointType	getType () const
	Returns the type of the joint.
void	attach (Body pBody1, Body pBody2)
	Attaches two bodies with the joint. A NULL body is equivalent to the global frame (= "the environment"). Joining two NULL bodies is possible but has no effet on the simulation.
Body *	getBody1 ()
	Gets first body in joint, or NULL (= global frame).
Body *	getBody2 ()
	Gets second body in joint, or NULL (= global frame).
const Body *	getBody1 () const
	`const` version of getBody1().
const Body *	getBody2 () const
	`const` version of getBody2().
UINT	getNumBodies () const
	Return the number of bodies attached to the joint.
void	setFeedback (JointFeedback *pJointFeedback)
	Sets a feedback structure that will be filled with data on world step.
JointFeedback *	getFeedback ()
	Gets the current feetback structure.
const JointFeedback *	getFeedback () const
	`const` version of getFeedback().
virtual void	accept (Visitor &v)
Intrinsic parameters
All parameters are in world coordinates. Some parameters cannot be set on certain types of joints (ex: A position on a slider joint). Setting parameters when it should not results in an undefined behaviour ! Actually, in debug configuration, it throws an exception because joint type is checked on each call. In release, it sometimes does nothing, and sometimes tries to call a non-corresponding ODE function (this generally results in an ODE error). When joint has 2 or 3 axis, then the 1st is attached to body 1 and the last one is attached to body 2 (attached does not mean relative). Axis are internally normalized.
void	setPos (const osg::Vec3 &pos)
	Sets position (=anchor) of the joint.
osg::Vec3	getPosBody1 () const
	Gets position of the joint on body 1 (should be the same result for body 2 if joint is perfectly matched).
osg::Vec3	getPosBody2 () const
	Gets position of the joint on body 2 (should be the same result for body 1 if joint is perfectly matched).
void	setAxis1 (const osg::Vec3 &axis)
	Sets primary axis for the joint (attached to body 1 for 2-axis joints).
osg::Vec3	getAxis1 () const
	Used for hinge, slider, universal, hinge2, prismatic rotoide.
void	setAxis2 (const osg::Vec3 &axis)
	Sets secondary axis for the joint (attached to body 2 for universal and hinge2).
osg::Vec3	getAxis2 () const
	Used for universal, hinge2, prismatic rotoide.
void	setAMotorMode (EAMotorMode mode)
	Sets the mode for an AMotor.
EAMotorMode	getAMotorMode () const
	Gets the mode for an AMotor.
void	setNumAxes (UCHAR num)
	Sets the number of axes for the joint.
UCHAR	getNumAxes () const
	Gets the number of axes for the joint.
void	setMotorAxis (UCHAR num, EAnchoredTo frame, const osg::Vec3 &axis)
	Sets one of the axis for the joint.
osg::Vec3	getMotorAxis (UCHAR num) const
	Gets one of the axis for the joint.
EAnchoredTo	getAxisFrameAMotor (UCHAR num) const
	Gets one of the axis frame for the joint.
void	setAxisAngleAMotor (UCHAR num, dReal angle)
	Sets one of the axis angle for the joint.
dReal	getAxisAngleAMotor (UCHAR num) const
	Gets one of the axis angle for the joint.
dReal	getAxisAngleRateAMotor (UCHAR num) const
	Gets one of the axis angle rate for the joint.
dReal	getRelAngleAxis1 () const
	Gets angle between two bodies on primary axis (0 is the initial angle).
dReal	getRelAngleRateAxis1 () const
	Derivate of the getAngleAxis1() value.
dReal	getRelAngleRateAxis2 () const
	Used for hinge2.
dReal	getRelPosAxis1 () const
	Gets relative position along axis 1 (0 is the initial position).
dReal	getRelPosRateAxis1 () const
	Derivate of the getRelPosAxis1() value.
General parameters
void	setCFM (dReal val, UINT axis=0)
	Sets CFM (when not at a stop).
dReal	getCFM (UINT axis=0) const
Stop parameters
Stop parameters allow the joint to be limited in movement. Note that zero always correspond to initial relative position (or rotation). Note that angles must be in [-pi, pi] to be effective (otherwise they are considered as infinity). If the high stop is less than the low stop, then the stop will be disabled (ineffective).
void	setLoStop (dReal val, UINT axis=0)
	Defines a low limit for the joint. Ex: -PI/2 can be the lowest angle for a hinge.
dReal	getLoStop (UINT axis=0) const
void	setHiStop (dReal val, UINT axis=0)
	Defines a high limit for the joint. Ex: PI/2 can be the higest angle for a hinge.
dReal	getHiStop (UINT axis=0) const
void	setStopBouncyness (dReal val, UINT axis=0)
	Defines the bouncyness for the limits of the joint, in [0;1].
dReal	getStopBouncyness (UINT axis=0) const
void	setStopERP (dReal val, UINT axis=0)
	Defines the ERP for the limits of the joint.
dReal	getStopERP (UINT axis=0) const
void	setStopCFM (dReal val, UINT axis=0)
	Sets CFM for the limit of the joint (warning : this does not work as expected for powered joints).
dReal	getStopCFM (UINT axis=0) const
Motor parameters
Motor parameters allow to continuously set a given speed for the joint, provided that it does not need too much force to accomplish.
void	setMotorVel (dReal val, UINT axis=0)
dReal	getMotorVel (UINT axis=0) const
void	setMotorMaxForce (dReal val, UINT axis=0)
dReal	getMotorMaxForce (UINT axis=0) const
void	setMotorFudgeFactor (dReal val, UINT axis=0)
	Sets a factor for the force applied to the joint when it leaves its stop position. Used to correct the behaviour if a "jumping" motion appears.
dReal	getMotorFudgeFactor (UINT axis=0) const
Utility methods
void	copyParameters (const Joint &v)
	Copies all parameters of a joint of the same type.
Position and orientation
Joints position and orientation are meaningful when attached to the enviroment. These methods handle the case.
void	translate (const osg::Vec3 &vec)
void	rotate (const osg::Quat &quat)
void	rotate (const osg::Quat &quat, const osg::Vec3 &center)
	Rotates the joint around a given point.
Protected Types
typedef void(*	TFuncODESetParam )(dJointID, int, dReal)
typedef dReal(*	TFuncODEGetParam )(dJointID, int)
Protected Member Functions
	Joint (World *pWorld, EJointType type, dJointGroupID joinGroup)
	Joint (World pWorld, Contact pContact, dJointGroupID joinGroup)
void	init (EJointType type, dContact *pContact=NULL, dJointGroupID joinGroup=NULL)
TFuncODESetParam	getODESetParamFuncPt () const
	Retreives the function pointer for setting ODE param.
TFuncODEGetParam	getODEGetParamFuncPt () const
	Retreives the function pointer for getting ODE param.
Protected Attributes
dJointID	id
dWorldID	worldId
Friends
class	JointGroup

void Physics::Joint::init	(	EJointType	type,
		dContact *	pContact = `NULL`,
		dJointGroupID	joinGroup = `NULL`
	)			`[protected]`

void Physics::Joint::rotate	(	const osg::Quat &	quat,
		const osg::Vec3 &	center
	)

void Physics::Joint::setAxisAngleAMotor	(	UCHAR	num,
		dReal	angle
	)

void Physics::Joint::setCFM	(	dReal	val,
		UINT	axis = `0`
	)			`[inline]`

void Physics::Joint::setHiStop	(	dReal	val,
		UINT	axis = `0`
	)			`[inline]`

void Physics::Joint::setLoStop	(	dReal	val,
		UINT	axis = `0`
	)			`[inline]`

void Physics::Joint::setMotorAxis	(	UCHAR	num,
		Joint::EAnchoredTo	frame,
		const osg::Vec3 &	axis
	)

void Physics::Joint::setMotorFudgeFactor	(	dReal	val,
		UINT	axis = `0`
	)			`[inline]`

void Physics::Joint::setMotorMaxForce	(	dReal	val,
		UINT	axis = `0`
	)			`[inline]`

void Physics::Joint::setMotorVel	(	dReal	val,
		UINT	axis = `0`
	)			`[inline]`

void Physics::Joint::setStopBouncyness	(	dReal	val,
		UINT	axis = `0`
	)			`[inline]`

void Physics::Joint::setStopCFM	(	dReal	val,
		UINT	axis = `0`
	)			`[inline]`

void Physics::Joint::setStopERP	(	dReal	val,
		UINT	axis = `0`
	)			`[inline]`

Physics::Joint Class Reference

Public Types

Public Member Functions

Protected Types

Protected Member Functions

Protected Attributes

Friends

Detailed Description

Member Typedef Documentation

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation

Friends And Related Function Documentation

Member Data Documentation