SoJointUniversal Class Reference
[libipsa classes, Joint Classes]

Defines an universal joint which has two orthogonally intersecting axis. More...

#include <SoJointUniversal.h>

Inheritance diagram for SoJointUniversal:

Collaboration diagram for SoJointUniversal:

List of all members.

Public Member Functions

virtual void setParams ()

virtual void setTorque (dReal torque1=0.0f, dReal torque2=0.0f, dReal torque3=0.0f)

SoJointUniversal (const SbString &BodyOne="", const SbString &BodyTwo="", const SbString &nodeName="")

Static Public Member Functions

static void initClass ()

Public Attributes

SoSFFloat Bounce

SoSFFloat Bounce2

SoSFFloat CFM

SoSFFloat CFM2

SoSFFloat FudgeFactor

SoSFFloat FudgeFactor2

SoSFFloat HiStop

SoSFFloat HiStop2

SoSFFloat LoStop

SoSFFloat LoStop2

SoSFFloat MaxForce

SoSFFloat MaxForce2

SoSFVec3f soAnchor

SoSFVec3f soAxis1

SoSFVec3f soAxis2

SoSFVec2f soTorque

SoSFFloat StopCFM

SoSFFloat StopCFM2

SoSFFloat StopERP

SoSFFloat StopERP2

SoSFFloat Velocity

SoSFFloat Velocity2

Protected Member Functions

virtual void createOdeJoint (const dWorldID soWorldId)

virtual SoNode * createVisualisation ()

virtual void updateOdeJointProperties (const SbMatrix &modelMatrix)

Protected Attributes

float initMaxForce [2]

float initVelocity [2]

Private Member Functions

SO_KIT_HEADER (SoJointUniversal)

Detailed Description

Defines an universal joint which has two orthogonally intersecting axis.

A universal joint is like a ball and socket joint that constrains an extra degree of rotational freedom.
Given axis 1 on body 1, and axis 2 on body 2 that is perpendicular to axis 1,
it keeps them perpendicular. In other words, rotation of the two bodies about the direction perpendicular to the two axes will be equal.

In the picture, the two bodies are joined together by a cross.
Axis 1 is attached to body 1, and axis 2 is attached to body 2. The cross keeps these axes at 90 degrees,
so if you grab body 1 and twist it, body 2 will twist as well.

A Universal joint is equivalent to a hinge-2 joint where the hinge-2's axes are perpendicular to each other,
and with a perfectly rigid connection in place of the suspension.

An universal joint

Definition at line 34 of file SoJointUniversal.h.

Constructor & Destructor Documentation

SoJointUniversal::SoJointUniversal	(	const SbString &	BodyOne = `""`,
		const SbString &	BodyTwo = `""`,
		const SbString &	nodeName = `""`
	)

The parameterized constructor of SoJointUniversal.

Parameters:

	BodyOne	name of the first body to connect with (default = "")
	BodyTwo	name of the second body to connect with (default = "")
	nodeName	name of the node in the Inventor scenegraph

Definition at line 204 of file SoJointUniversal.cpp.

References Bounce, Bounce2, CFM, CFM2, FudgeFactor, FudgeFactor2, HiStop, HiStop2, SoJoint::INIT_CFM, SoJoint::INIT_ERP, LoStop, LoStop2, MaxForce, MaxForce2, soAnchor, soAxis1, soAxis2, soTorque, StopCFM, StopCFM2, StopERP, StopERP2, SoJoint::updateOdeParametersTrigger, Velocity, and Velocity2.

Member Function Documentation

void SoJointUniversal::createOdeJoint ( const dWorldID soWorldId ) [protected, virtual]

This method creates a universal joint using the soWorldId and stores initial values.

Parameters:

soWorldId

the ODE world ID used for creating the joint

Reimplemented from SoJoint.

Definition at line 278 of file SoJointUniversal.cpp.

References initMaxForce, initVelocity, MaxForce, MaxForce2, SoJoint::soJointGroupId, SoJoint::soJointId, Velocity, and Velocity2.

SoNode * SoJointUniversal::createVisualisation ( ) [protected, virtual]

This method must be overridden by any subclass of SoJoint to return a visualisation matching the joint type.

Reimplemented from SoJoint.

Definition at line 321 of file SoJointUniversal.cpp.

References SoJoint::GenerateCylinderAlignmentRotation(), soAnchor, soAxis1, and soAxis2.

void SoJointUniversal::initClass ( ) [static]

Initialises the class and it's type id variables.

Reimplemented from SoJoint.

Definition at line 192 of file SoJointUniversal.cpp.

void SoJointUniversal::setParams ( ) [virtual]

This method must be overridden by any subclass of SoJoint to set the ODE parameters of the object.

Reimplemented from SoJoint.

Definition at line 366 of file SoJointUniversal.cpp.

References Bounce, Bounce2, CFM, CFM2, FudgeFactor, FudgeFactor2, HiStop, HiStop2, LoStop, LoStop2, MaxForce, MaxForce2, SoJoint::soJointId, StopCFM, StopCFM2, StopERP, StopERP2, Velocity, and Velocity2.

void SoJointUniversal::setTorque	(	dReal	torque1 = `0.0f`,
		dReal	torque2 = `0.0f`,
		dReal	torque3 = `0.0f`
	)			`[virtual]`

This method uses torque1 and torque2 to set torques on the universal joint.

Parameters:

	torque1	applied to axis1
	torque2	applied to axis2
	torque3	UNUSED

Reimplemented from SoJoint.

Definition at line 267 of file SoJointUniversal.cpp.

References SoJoint::soJointId.

SoJointUniversal::SO_KIT_HEADER ( SoJointUniversal ) [private]

void SoJointUniversal::updateOdeJointProperties ( const SbMatrix & modelMatrix ) [protected, virtual]

This method updates the anchor and the axis of the universal joint using the modelMatrix as reference.

Parameters:

modelMatrix

model matrix taken from Coin

Reimplemented from SoJoint.

Definition at line 296 of file SoJointUniversal.cpp.

References initMaxForce, initVelocity, MaxForce, MaxForce2, soAnchor, soAxis1, soAxis2, SoJoint::soJointId, Velocity, and Velocity2.

Member Data Documentation

SoJointUniversal::Bounce

The bouncyness of the stops of axis 1 (default = 0.0). This is a restitution parameter in the range 0..1. 0 means the stops are not bouncy at all, 1 means maximum bouncyness.

Definition at line 57 of file SoJointUniversal.h.

Referenced by setParams(), and SoJointUniversal().

SoJointUniversal::Bounce2

The bouncyness of the stops of axis 2 (default = 0.0). This is a restitution parameter in the range 0..1. 0 means the stops are not bouncy at all, 1 means maximum bouncyness.

Definition at line 67 of file SoJointUniversal.h.

Referenced by setParams(), and SoJointUniversal().

SoJointUniversal::CFM

The constraint force mixing (CFM) value used for axis 1 when not at a stop (default = SoJoint::INIT_CFM).

Definition at line 58 of file SoJointUniversal.h.

Referenced by setParams(), and SoJointUniversal().

SoJointUniversal::CFM2

The constraint force mixing (CFM) value used for axis 2 when not at a stop (default = SoJoint::INIT_CFM).

Definition at line 68 of file SoJointUniversal.h.

Referenced by setParams(), and SoJointUniversal().

SoJointUniversal::FudgeFactor

(default = 1.0)
The current (ODE) joint stop/motor implementation has a small problem: when the joint is at one stop and the motor is set to move it away from the stop, too much force may be applied for one time step, causing a ``jumping'' motion. This fudge factor is used to scale this excess force. It should have a value between zero and one (the default value). If the jumping motion is too visible in a joint, the value can be reduced. Making this value too small can prevent the motor from being able to move the joint away from a stop.

Definition at line 56 of file SoJointUniversal.h.

Referenced by setParams(), and SoJointUniversal().

SoJointUniversal::FudgeFactor2

(default = 1.0)
The current (ODE) joint stop/motor implementation has a small problem: when the joint is at one stop and the motor is set to move it away from the stop, too much force may be applied for one time step, causing a ``jumping'' motion. This fudge factor is used to scale this excess force. It should have a value between zero and one (the default value). If the jumping motion is too visible in a joint, the value can be reduced. Making this value too small can prevent the motor from being able to move the joint away from a stop.

Definition at line 66 of file SoJointUniversal.h.

Referenced by setParams(), and SoJointUniversal().

SoJointUniversal::HiStop

High stop for the angle of axis 1 (default = dInfinity). Setting this to dInfinity turns off the high stop. For rotational joints, this stop must be less than pi to be effective.

Warning:: If SoJointUniversal::HiStop is less than SoJointUniversal::LowStop then both stops will be ineffective.

Definition at line 53 of file SoJointUniversal.h.

Referenced by setParams(), and SoJointUniversal().

SoJointUniversal::HiStop2

High stop for the angle of axis 2 (default = dInfinity). Setting this to dInfinity turns off the high stop. For rotational joints, this stop must be less than pi to be effective.

Warning:: If SoJointUniversal::HiStop is less than SoJointUniversal::LowStop then both stops will be ineffective.

Definition at line 63 of file SoJointUniversal.h.

Referenced by setParams(), and SoJointUniversal().

float SoJointUniversal::initMaxForce[2] [protected]

Definition at line 78 of file SoJointUniversal.h.

Referenced by createOdeJoint(), and updateOdeJointProperties().

float SoJointUniversal::initVelocity[2] [protected]

Definition at line 77 of file SoJointUniversal.h.

Referenced by createOdeJoint(), and updateOdeJointProperties().

SoJointUniversal::LoStop

Low stop for the angle of axis 1 (default = -dInfinity). Setting this to -dInfinity turns off the low stop. For rotational joints, this stop must be greater than - pi to be effective.

Definition at line 52 of file SoJointUniversal.h.

Referenced by setParams(), and SoJointUniversal().

SoJointUniversal::LoStop2

Low stop for the angle of axis 2 (default = -dInfinity). Setting this to -dInfinity turns off the low stop. For rotational joints, this stop must be greater than - pi to be effective.

Definition at line 62 of file SoJointUniversal.h.

Referenced by setParams(), and SoJointUniversal().

SoJointUniversal::MaxForce

The maximum force or torque that the motor of axis 1 will use to achieve the desired velocity (default = 0.0). This must always be greater than or equal to zero. Setting this to zero turns off the motor.

Definition at line 55 of file SoJointUniversal.h.

Referenced by createOdeJoint(), setParams(), SoJointUniversal(), and updateOdeJointProperties().

SoJointUniversal::MaxForce2

The maximum force or torque that the motor of axis 2 will use to achieve the desired velocity (default = 0.0). This must always be greater than or equal to zero. Setting this to zero turns off the motor.

Definition at line 65 of file SoJointUniversal.h.

Referenced by createOdeJoint(), setParams(), SoJointUniversal(), and updateOdeJointProperties().

SoJointUniversal::soAnchor

The anchor for the universal joint (default = {0.0f, 0.0f, 0.0f}).

Definition at line 47 of file SoJointUniversal.h.

Referenced by createVisualisation(), SoJointUniversal(), and updateOdeJointProperties().

SoJointUniversal::soAxis1

The first axis for the universal joint (default = {0.0f, 0.0f, 0.0f}).

Definition at line 48 of file SoJointUniversal.h.

Referenced by createVisualisation(), SoJointUniversal(), and updateOdeJointProperties().

SoJointUniversal::soAxis2

The second axis for the universal joint (default = {0.0f, 0.0f, 0.0f}).

Definition at line 49 of file SoJointUniversal.h.

Referenced by createVisualisation(), SoJointUniversal(), and updateOdeJointProperties().

SoJointUniversal::soTorque

The torque for the universal joint (default = {0.0f, 0.0f}).

Definition at line 50 of file SoJointUniversal.h.

Referenced by SoJointUniversal().

SoJointUniversal::StopCFM

The constraint force mixing (CFM) value used by the stops of axis 1 (default = SoJoint::INIT_CFM). Together with the ERP value this can be used to get spongy or soft stops.

Warning:: Note that this is intended for unpowered joints, it does not really work as expected when a powered joint reaches its limit.

Definition at line 60 of file SoJointUniversal.h.

Referenced by setParams(), and SoJointUniversal().

SoJointUniversal::StopCFM2

The constraint force mixing (CFM) value used by the stops of axis 2 (default = SoJoint::INIT_CFM). Together with the ERP value this can be used to get spongy or soft stops.

Warning:: Note that this is intended for unpowered joints, it does not really work as expected when a powered joint reaches its limit.

Definition at line 70 of file SoJointUniversal.h.

Referenced by setParams(), and SoJointUniversal().

SoJointUniversal::StopERP

The error reduction parameter (ERP) used by the stops of axis 1 (default = SoJoint::INIT_ERP).

Definition at line 59 of file SoJointUniversal.h.

Referenced by setParams(), and SoJointUniversal().

SoJointUniversal::StopERP2

The error reduction parameter (ERP) used by the stops of axis 2 (default = SoJoint::INIT_ERP).

Definition at line 69 of file SoJointUniversal.h.

Referenced by setParams(), and SoJointUniversal().

SoJointUniversal::Velocity

Desired angular or linear velocity of the motor of axis 1 (default = 0.0).

Definition at line 54 of file SoJointUniversal.h.

Referenced by createOdeJoint(), setParams(), SoJointUniversal(), and updateOdeJointProperties().

SoJointUniversal::Velocity2

Desired angular or linear velocity of the motor of axis 2 (default = 0.0).

Definition at line 64 of file SoJointUniversal.h.

Referenced by createOdeJoint(), setParams(), SoJointUniversal(), and updateOdeJointProperties().

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

include/IPSA/SoJointUniversal.h
source/SoJointUniversal.cpp


Public Member Functions
virtual void	setParams ()
virtual void	setTorque (dReal torque1=0.0f, dReal torque2=0.0f, dReal torque3=0.0f)
	SoJointUniversal (const SbString &BodyOne="", const SbString &BodyTwo="", const SbString &nodeName="")
Static Public Member Functions
static void	initClass ()
Public Attributes
SoSFFloat	Bounce
SoSFFloat	Bounce2
SoSFFloat	CFM
SoSFFloat	CFM2
SoSFFloat	FudgeFactor
SoSFFloat	FudgeFactor2
SoSFFloat	HiStop
SoSFFloat	HiStop2
SoSFFloat	LoStop
SoSFFloat	LoStop2
SoSFFloat	MaxForce
SoSFFloat	MaxForce2
SoSFVec3f	soAnchor
SoSFVec3f	soAxis1
SoSFVec3f	soAxis2
SoSFVec2f	soTorque
SoSFFloat	StopCFM
SoSFFloat	StopCFM2
SoSFFloat	StopERP
SoSFFloat	StopERP2
SoSFFloat	Velocity
SoSFFloat	Velocity2
Protected Member Functions
virtual void	createOdeJoint (const dWorldID soWorldId)
virtual SoNode *	createVisualisation ()
virtual void	updateOdeJointProperties (const SbMatrix &modelMatrix)
Protected Attributes
float	initMaxForce [2]
float	initVelocity [2]
Private Member Functions
	SO_KIT_HEADER (SoJointUniversal)

SoJointUniversal Class Reference [libipsa classes, Joint Classes]

Public Member Functions

Static Public Member Functions

Public Attributes

Protected Member Functions

Protected Attributes

Private Member Functions

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation

SoJointUniversal Class Reference
[libipsa classes, Joint Classes]