hpp::fcl::details::GJK Struct Reference

class for GJK algorithm More...

#include <hpp/fcl/narrowphase/gjk.h>

Collaboration diagram for hpp::fcl::details::GJK:

Classes
struct	Simplex
struct	SimplexV

Public Types
enum	Status {   Valid,   Inside,   Failed }
typedef unsigned char	vertex_id_t

Public Member Functions
	GJK (unsigned int max_iterations_, FCL_REAL tolerance_)
void	initialize ()
Status	evaluate (const MinkowskiDiff &shape, const Vec3f &guess)
	GJK algorithm, given the initial value guess. More...
void	getSupport (const Vec3f &d, bool dIsNormalized, SimplexV &sv) const
	apply the support function along a direction, the result is return in sv More...
bool	encloseOrigin ()
	whether the simplex enclose the origin More...
Simplex *	getSimplex () const
	get the underlying simplex using in GJK, can be used for cache in next iteration More...
bool	hasClosestPoints ()
	Tells whether the closest points are available. More...
bool	hasPenetrationInformation (const MinkowskiDiff &shape)
	Tells whether the penetration information. More...
bool	getClosestPoints (const MinkowskiDiff &shape, Vec3f &w0, Vec3f &w1)
	Get the closest points on each object. More...
Vec3f	getGuessFromSimplex () const
	get the guess from current simplex More...
void	setDistanceEarlyBreak (const FCL_REAL &dup)
	Distance threshold for early break. More...

Public Attributes
MinkowskiDiff const *	shape
Vec3f	ray
FCL_REAL	distance
	The distance computed by GJK. More...
Simplex	simplices [2]

Detailed Description

class for GJK algorithm

Note

The computations are performed in the frame of the first shape.

Member Typedef Documentation

vertex_id_t

typedef unsigned char hpp::fcl::details::GJK::vertex_id_t

Member Enumeration Documentation

Status

enum hpp::fcl::details::GJK::Status

Enumerator
Valid
Inside
Failed

Constructor & Destructor Documentation

GJK()

hpp::fcl::details::GJK::GJK ( unsigned int  max_iterations_, FCL_REAL  tolerance_  )

inline

References initialize().

Member Function Documentation

encloseOrigin()

bool hpp::fcl::details::GJK::encloseOrigin

(

)

whether the simplex enclose the origin

evaluate()

Status hpp::fcl::details::GJK::evaluate	(	const MinkowskiDiff &	shape,
		const Vec3f &	guess
	)

GJK algorithm, given the initial value guess.

Referenced by hpp::fcl::GJKSolver::shapeDistance(), hpp::fcl::GJKSolver::shapeIntersect(), and hpp::fcl::GJKSolver::shapeTriangleInteraction().

getClosestPoints()

bool hpp::fcl::details::GJK::getClosestPoints	(	const MinkowskiDiff &	shape,
		Vec3f &	w0,
		Vec3f &	w1
	)

Get the closest points on each object.

Returns

true on success

Referenced by hpp::fcl::GJKSolver::shapeDistance(), hpp::fcl::GJKSolver::shapeIntersect(), and hpp::fcl::GJKSolver::shapeTriangleInteraction().

getGuessFromSimplex()

Vec3f hpp::fcl::details::GJK::getGuessFromSimplex

(

)

const

get the guess from current simplex

Referenced by hpp::fcl::GJKSolver::shapeDistance(), hpp::fcl::GJKSolver::shapeIntersect(), and hpp::fcl::GJKSolver::shapeTriangleInteraction().

getSimplex()

Simplex* hpp::fcl::details::GJK::getSimplex ( ) const

inline

get the underlying simplex using in GJK, can be used for cache in next iteration

getSupport()

void hpp::fcl::details::GJK::getSupport ( const Vec3f &  d, bool  dIsNormalized, SimplexV &  sv  ) const

inline

apply the support function along a direction, the result is return in sv

References hpp::fcl::details::MinkowskiDiff::support(), hpp::fcl::details::GJK::SimplexV::w, hpp::fcl::details::GJK::SimplexV::w0, and hpp::fcl::details::GJK::SimplexV::w1.

hasClosestPoints()

bool hpp::fcl::details::GJK::hasClosestPoints ( )

inline

Tells whether the closest points are available.

hasPenetrationInformation()

bool hpp::fcl::details::GJK::hasPenetrationInformation ( const MinkowskiDiff &  shape )

inline

Tells whether the penetration information.

In such case, most indepth points and penetration depth can be retrieved from GJK. Calling EPA has an undefined behaviour.

References hpp::fcl::details::MinkowskiDiff::inflation.

Referenced by hpp::fcl::GJKSolver::shapeDistance(), hpp::fcl::GJKSolver::shapeIntersect(), and hpp::fcl::GJKSolver::shapeTriangleInteraction().

initialize()

void hpp::fcl::details::GJK::initialize

(

)

setDistanceEarlyBreak()

void hpp::fcl::details::GJK::setDistanceEarlyBreak ( const FCL_REAL &  dup )

inline

Distance threshold for early break.

GJK stops when it proved the distance is more than this threshold.

Note

The closest points will be erroneous in this case. If you want the closest points, set this to infinity (the default).

Member Data Documentation

distance

FCL_REAL hpp::fcl::details::GJK::distance

The distance computed by GJK.

The possible values are

• \( d = - R - 1 \) when a collision is detected and GJK cannot compute penetration informations.
• \( - R \le d \le 0 \) when a collision is detected and GJK can compute penetration informations.
• \( 0 < d \le d_{ub} \) when there is no collision and GJK can compute the closest points.
• \( d_{ub} < d \) when there is no collision and GJK cannot compute the closest points.

where \( d \) is the GJK::distance, \( R \) is the sum of the shape MinkowskiDiff::inflation and \( d_{ub} \) is the GJK::distance_upper_bound.

Referenced by hpp::fcl::GJKSolver::shapeDistance(), hpp::fcl::GJKSolver::shapeIntersect(), and hpp::fcl::GJKSolver::shapeTriangleInteraction().

ray

Vec3f hpp::fcl::details::GJK::ray

shape

MinkowskiDiff const* hpp::fcl::details::GJK::shape

simplices

Simplex hpp::fcl::details::GJK::simplices[2]