vpWorld Class Reference

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#include <vpWorld.h>

List of all members.

Public Member Functions
void	AddBody (vpBody *)
void	AddWorld (vpWorld *)
void	SetGlobalFrame (const SE3 &)
const SE3 &	GetGlobalFrame (void) const
void	Initialize (void)
virtual void	StepAhead (void)
void	SetTimeStep (scalar)
scalar	GetTimeStep (void) const
void	SetIntegrator (VP::INTEGRATOR_TYPE type)
scalar	GetBoundingSphere (Vec3 &center) const
void	SetGravity (const Vec3 &)
const Vec3 &	GetGravity (void) const
void	EnableCollision (bool=true)
void	IgnoreCollision (vpBody *B0, vpBody *B1)
scalar	GetSimulationTime (void) const
scalar	GetKineticEnergy (void) const
scalar	GetPotentialEnergy (void) const
scalar	GetTotalEnergy (void) const
int	GetNumBody (void) const
int	GetNumGeometry (void) const
const vpBody *	GetBody (int) const
const vpBody *	GetBodyByName (const string &name) const
void	BackupState (void)
void	RollbackState (void)
void	UpdateFrame (void)
int	GetNumMaterial (void) const
const vpMaterial *	GetMaterial (int) const
const vpMaterial *	GetMaterialByName (const string &name) const
int	GetNumJoint (void) const
const vpJoint *	GetJoint (int) const
const vpJoint *	GetJointByName (const string &name) const
void	Clear (void)
Friends
ostream &	operator<< (ostream &, const vpWorld &)
istream &	operator>> (istream &, vpWorld &)

---

Detailed Description

vpWorld is a class to model your virtual world goverened by physics law.

Examples:

pendulum.cpp.

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Member Function Documentation

void vpWorld::AddBody

(

vpBody *

)

add a body to the world

Examples:

pendulum.cpp.

void vpWorld::AddWorld

(

vpWorld *

)

add a world

World's parameters such as a time step and the gravity will not be updated with newly added world'parameters. Only the body and joints will be added.

VP_INLINE void vpWorld::SetGlobalFrame

(

const SE3 &

T

)

set a global frame

All the coordinate frame is represented by this global frame. Should be followed by vpWorld::Initialize.

VP_INLINE const SE3 & vpWorld::GetGlobalFrame

(

void

)

const

set a global frame

void vpWorld::Initialize

(

void

)

initialize the world. Before simulation, the world should be initialized.

Examples:

pendulum.cpp.

virtual void vpWorld::StepAhead

(

void

)

[virtual]

simulate the world during a specified time step.

See also:

SetTimeStep()

Examples:

pendulum.cpp.

VP_INLINE void vpWorld::SetTimeStep

(

scalar

t

)

set simulation time step used in integrating dynamics equations. Default time step is 0.001. For stable simulation, smaller time step is preferred. However how small the time step can depend on your model.

VP_INLINE scalar vpWorld::GetTimeStep

(

void

)

const

get a current time step.

void vpWorld::SetIntegrator

(

VP::INTEGRATOR_TYPE

type

)

choose an integration algorithm used in simulation.

Parameters:

type

VP::EULER is faster but less accurate than VP::RK4.

scalar vpWorld::GetBoundingSphere

(

Vec3 &

center

)

const

get a bounding sphere including whole world.

VP_INLINE void vpWorld::SetGravity

(

const Vec3 &

g

)

set a gravity. Default is zero gravity.

Examples:

pendulum.cpp.

VP_INLINE const Vec3 & vpWorld::GetGravity

(

void

)

const

get a gravity.

VP_INLINE void vpWorld::EnableCollision

(

bool

flag = true

)

enable or disable collision between bodies.

See also:

vpWorld::IgnoreCollision()

void vpWorld::IgnoreCollision	(	vpBody *	B0,
		vpBody *	B1
	)

declare that collision of B0 and B1 will be ignored.

VP_INLINE scalar vpWorld::GetSimulationTime

(

void

)

const

get a simulation time.

scalar vpWorld::GetKineticEnergy

(

void

)

const

get a kinetic energy.

scalar vpWorld::GetPotentialEnergy

(

void

)

const

get a potential energy.

VP_INLINE scalar vpWorld::GetTotalEnergy

(

void

)

const

get a total energy(= kinetic energy + potential energy).

VP_INLINE int vpWorld::GetNumBody

(

void

)

const

get a number of bodies in the world.

int vpWorld::GetNumGeometry

(

void

)

const

get a number of geometries in the world.

VP_INLINE const vpBody * vpWorld::GetBody

(

int

idx

)

const

get a pointer to the ith body.

See also:

vpBody::GetID

const vpBody* vpWorld::GetBodyByName

(

const string &

name

)

const

get a pointer to the body with the name

void vpWorld::BackupState

(

void

)

keep current states which are transformation matrices, velocities, joint angles, joint velocities.

See also:

vpWorld::RestoreState

void vpWorld::RollbackState

(

void

)

restore states to the values kept by BackupState()

See also:

vpWorld::KeepCurrentState

void vpWorld::UpdateFrame

(

void

)

update transformation matrices from joint angles.

It is useful when you change joint angles and want to compute corresponding transformation matrices of articulated bodies. Basically, VP does not compute transformation matrices of bodies even if you change the joint angles. The transformation matrices or relevant values will be updated after the simulation which is typically done by calling vpWorld::StepAhead().

VP_INLINE int vpWorld::GetNumMaterial

(

void

)

const

get a number of materials defined in the world

VP_INLINE const vpMaterial * vpWorld::GetMaterial

(

int

idx

)

const

get a pointer to the ith material

const vpMaterial* vpWorld::GetMaterialByName

(

const string &

name

)

const

get a pointer to the material with the name

VP_INLINE int vpWorld::GetNumJoint

(

void

)

const

get a number of joints in the world

VP_INLINE const vpJoint * vpWorld::GetJoint

(

int

idx

)

const

get a pointer to the ith joint

const vpJoint* vpWorld::GetJointByName

(

const string &

name

)

const

get a pointer to the joint with the name

void vpWorld::Clear

(

void

)

clear all the instances managed by the world

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Friends And Related Function Documentation

ostream& operator<<	(	ostream &	,
		const vpWorld &
	)			[friend]

print out current configuration of the wolrd in XML format.

istream& operator>>	(	istream &	,
		vpWorld &
	)			[friend]

read the configuration generated from output stream