GProp_PEquation Class Reference

Analyzes a collection of 3D points to decide whether they are coincident, collinear, coplanar, or span 3D space, within a given tolerance. More...

#include <GProp_PEquation.hxx>

Public Types
enum class	Type {   None , Point , Line , Plane ,   Space }
	Type of geometric entity that best fits the cloud. More...

Public Member Functions
	GProp_PEquation (const NCollection_Array1< gp_Pnt > &thePnts, double theTol)
	Constructs the analysis from a set of points and a tolerance.
Type	GetType () const
	Returns the type of the fitted entity.
bool	IsPlanar () const
	Returns true if points are coplanar within tolerance.
bool	IsLinear () const
	Returns true if points are collinear within tolerance.
bool	IsPoint () const
	Returns true if points are coincident within tolerance.
bool	IsSpace () const
	Returns true if points span 3D space.
gp_Pln	Plane () const
	Returns the mean plane.
gp_Lin	Line () const
	Returns the mean line.
gp_Pnt	Point () const
	Returns the mean point.
void	Box (gp_Pnt &theP, gp_Vec &theV1, gp_Vec &theV2, gp_Vec &theV3) const
	Returns a bounding box aligned with the principal axes.
const gp_Pnt &	Barycentre () const
	Returns the centre of mass of the cloud (always valid after construction).
const gp_Vec &	PrincipalAxis (int theIndex) const
	Returns the unit principal axis at theIndex (1, 2 or 3), ordered by eigenvalue.
double	Extent (int theIndex) const
	Returns the extent (max - min projection) along principal axis theIndex (1, 2 or 3).

Detailed Description

Analyzes a collection of 3D points to decide whether they are coincident, collinear, coplanar, or span 3D space, within a given tolerance.

Uses principal-axis analysis (eigendecomposition of the inertia matrix) to determine the dimensionality of the cloud. Depending on the result type, the corresponding accessor (Point(), Line(), Plane() or Box()) returns the fitted geometric entity.

The raw PCA results (Barycentre(), PrincipalAxis(), Extent()) are always available regardless of the fitted type.

Member Enumeration Documentation

Type

enum class GProp_PEquation::Type

strong

Type of geometric entity that best fits the cloud.

Enumerator
None	Not yet computed.
Point	All points are coincident within tolerance.
Line	Points are collinear within tolerance.
Plane	Points are coplanar within tolerance.
Space	Points span 3D space.

Constructor & Destructor Documentation

GProp_PEquation()

GProp_PEquation::GProp_PEquation	(	const NCollection_Array1< gp_Pnt > &	thePnts,
		double	theTol )

Constructs the analysis from a set of points and a tolerance.

Parameters

[in]	thePnts	array of points to analyze
[in]	theTol	tolerance for dimensional collapse detection

Member Function Documentation

Barycentre()

const gp_Pnt & GProp_PEquation::Barycentre ( ) const

inline

Returns the centre of mass of the cloud (always valid after construction).

Box()

void GProp_PEquation::Box	(	gp_Pnt &	theP,
		gp_Vec &	theV1,
		gp_Vec &	theV2,
		gp_Vec &	theV3 ) const

Returns a bounding box aligned with the principal axes.

Parameters

[out]	theP	corner of the box (minimum projection on principal axes)
[out]	theV1	first box edge vector (along first principal axis)
[out]	theV2	second box edge vector (along second principal axis)
[out]	theV3	third box edge vector (along third principal axis)

Exceptions

Standard_NoSuchObject

if !IsSpace().

Extent()

double GProp_PEquation::Extent ( int theIndex ) const

inline

Returns the extent (max - min projection) along principal axis theIndex (1, 2 or 3).

GetType()

Type GProp_PEquation::GetType ( ) const

inline

Returns the type of the fitted entity.

IsLinear()

bool GProp_PEquation::IsLinear ( ) const

inline

Returns true if points are collinear within tolerance.

IsPlanar()

bool GProp_PEquation::IsPlanar ( ) const

inline

Returns true if points are coplanar within tolerance.

IsPoint()

bool GProp_PEquation::IsPoint ( ) const

inline

Returns true if points are coincident within tolerance.

IsSpace()

bool GProp_PEquation::IsSpace ( ) const

inline

Returns true if points span 3D space.

Line()

gp_Lin GProp_PEquation::Line

(

)

const

Returns the mean line.

Exceptions

Standard_NoSuchObject

if !IsLinear().

Plane()

gp_Pln GProp_PEquation::Plane

(

)

const

Returns the mean plane.

Exceptions

Standard_NoSuchObject

if !IsPlanar().

Point()

gp_Pnt GProp_PEquation::Point

(

)

const

Returns the mean point.

Exceptions

Standard_NoSuchObject

if !IsPoint().

PrincipalAxis()

const gp_Vec & GProp_PEquation::PrincipalAxis ( int theIndex ) const

inline

Returns the unit principal axis at theIndex (1, 2 or 3), ordered by eigenvalue.

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

• GProp_PEquation.hxx