Open CASCADE Technology  6.9.1
Public Member Functions | Protected Attributes
ShapeAnalysis_Surface Class Reference

Complements standard tool Geom_Surface by providing additional functionality for detection surface singularities, checking spatial surface closure and computing projections of 3D points onto a surface. More...

#include <ShapeAnalysis_Surface.hxx>

Inheritance diagram for ShapeAnalysis_Surface:
Inheritance graph
[legend]

Public Member Functions

 ShapeAnalysis_Surface (const Handle< Geom_Surface > &S)
 Creates an analyzer object on the basis of existing surface. More...
 
void Init (const Handle< Geom_Surface > &S)
 Loads existing surface. More...
 
void Init (const Handle< ShapeAnalysis_Surface > &other)
 Reads all the data from another Surface, without recomputing. More...
 
void SetDomain (const Standard_Real U1, const Standard_Real U2, const Standard_Real V1, const Standard_Real V2)
 
const Handle< Geom_Surface > & Surface () const
 Returns a surface being analyzed. More...
 
const Handle< GeomAdaptor_HSurface > & Adaptor3d ()
 Returns the Adaptor. Creates it if not yet done. More...
 
const Handle< GeomAdaptor_HSurface > & TrueAdaptor3d () const
 Returns the Adaptor (may be Null if method Adaptor() was not called) More...
 
Standard_Real Gap () const
 Returns 3D distance found by one of the following methods. IsDegenerated, DegeneratedValues, ProjectDegenerated (distance between 3D point and found or last (if not found) singularity), IsUClosed, IsVClosed (minimum value of precision to consider the surface to be closed), ValueOfUV (distance between 3D point and found solution). More...
 
gp_Pnt Value (const Standard_Real u, const Standard_Real v)
 Returns a 3D point specified by parameters in surface parametrical space. More...
 
gp_Pnt Value (const gp_Pnt2d &p2d)
 Returns a 3d point specified by a point in surface parametrical space. More...
 
Standard_Boolean HasSingularities (const Standard_Real preci)
 Returns True if the surface has singularities for the given precision (i.e. if there are surface singularities with sizes not greater than precision). More...
 
Standard_Integer NbSingularities (const Standard_Real preci)
 Returns the number of singularities for the given precision (i.e. number of surface singularities with sizes not greater than precision). More...
 
Standard_Boolean Singularity (const Standard_Integer num, Standard_Real &preci, gp_Pnt &P3d, gp_Pnt2d &firstP2d, gp_Pnt2d &lastP2d, Standard_Real &firstpar, Standard_Real &lastpar, Standard_Boolean &uisodeg)
 Returns the characteristics of the singularity specified by its rank number <num>. That means, that it is not neccessary for <num> to be in the range [1, NbSingularities] but must be not greater than possible (see ComputeSingularities). The returned characteristics are: preci: the smallest precision with which the iso-line is considered as degenerated, P3d: 3D point of singularity (middle point of the surface iso-line), firstP2d and lastP2d: first and last 2D points of the iso-line in parametrical surface, firstpar and lastpar: first and last parameters of the iso-line in parametrical surface, uisodeg: if the degenerated iso-line is U-iso (True) or V-iso (False). Returns False if <num> is out of range, else returns True. More...
 
Standard_Boolean IsDegenerated (const gp_Pnt &P3d, const Standard_Real preci)
 Returns True if there is at least one surface boundary which is considered as degenerated with <preci> and distance between P3d and corresponding singular point is less than <preci> More...
 
Standard_Boolean DegeneratedValues (const gp_Pnt &P3d, const Standard_Real preci, gp_Pnt2d &firstP2d, gp_Pnt2d &lastP2d, Standard_Real &firstpar, Standard_Real &lastpar, const Standard_Boolean forward=Standard_True)
 Returns True if there is at least one surface iso-line which is considered as degenerated with <preci> and distance between P3d and corresponding singular point is less than <preci> (like IsDegenerated). Returns characteristics of the first found boundary matching those criteria. More...
 
Standard_Boolean ProjectDegenerated (const gp_Pnt &P3d, const Standard_Real preci, const gp_Pnt2d &neighbour, gp_Pnt2d &result)
 Projects a point <P3d> on a singularity by computing one of the coordinates of preliminary computed <result>. More...
 
Standard_Boolean ProjectDegenerated (const Standard_Integer nbrPnt, const TColgp_Array1OfPnt &points, TColgp_Array1OfPnt2d &pnt2d, const Standard_Real preci, const Standard_Boolean direct)
 Checks points at the beginning (direct is True) or end (direct is False) of array <points> to lie in singularity of surface, and if yes, adjusts the indeterminate 2d coordinate of these points by nearest point which is not in singularity. Returns True if some points were adjusted. More...
 
Standard_Boolean IsDegenerated (const gp_Pnt2d &p2d1, const gp_Pnt2d &p2d2, const Standard_Real tol, const Standard_Real ratio)
 Returns True if straight pcurve going from point p2d1 to p2d2 is degenerate, i.e. lies in the singularity of the surface. NOTE: it uses another method of detecting singularity than used by ComputeSingularities() et al.! For that, maximums of distances between points p2d1, p2d2 and 0.5*(p2d1+p2d2) and between corresponding 3d points are computed. The pcurve (p2d1, p2d2) is considered as degenerate if: More...
 
void Bounds (Standard_Real &ufirst, Standard_Real &ulast, Standard_Real &vfirst, Standard_Real &vlast) const
 Returns the bounds of the surface (from Bounds from Surface, but buffered) More...
 
void ComputeBoundIsos ()
 Computes bound isos (protected against exceptions) More...
 
Handle< Geom_CurveUIso (const Standard_Real U)
 Returns a U-Iso. Null if not possible or failed Remark : bound isos are buffered. More...
 
Handle< Geom_CurveVIso (const Standard_Real V)
 Returns a V-Iso. Null if not possible or failed Remark : bound isos are buffered. More...
 
Standard_Boolean IsUClosed (const Standard_Real preci=-1)
 Tells if the Surface is spatially closed in U with given precision. If <preci> < 0 then Precision::Confusion is used. If Geom_Surface says that the surface is U-closed, this method also says this. Otherwise additional analysis is performed, comparing given precision with the following distances: More...
 
Standard_Boolean IsVClosed (const Standard_Real preci=-1)
 Tells if the Surface is spatially closed in V with given precision. If <preci> < 0 then Precision::Confusion is used. If Geom_Surface says that the surface is V-closed, this method also says this. Otherwise additional analysis is performed, comparing given precision with the following distances: More...
 
gp_Pnt2d ValueOfUV (const gp_Pnt &P3D, const Standard_Real preci)
 Computes the parameters in the surface parametrical space of 3D point. The result is parameters of the point projected onto the surface. This method enhances functionality provided by the standard tool GeomAPI_ProjectPointOnSurface by treatment of cases when the projected point is near to the surface boundaries and when this standard tool fails. More...
 
gp_Pnt2d NextValueOfUV (const gp_Pnt2d &p2dPrev, const gp_Pnt &P3D, const Standard_Real preci, const Standard_Real maxpreci=-1.0)
 Projects a point P3D on the surface. Does the same thing as ValueOfUV but tries to optimize computations by taking into account previous point <p2dPrev>: makes a step by UV and tries Newton algorithm. If <maxpreci> >0. and distance between solution and P3D is greater than <maxpreci>, that solution is considered as bad, and ValueOfUV() is used. If not succeded, calls ValueOfUV() More...
 
Standard_Real UVFromIso (const gp_Pnt &P3D, const Standard_Real preci, Standard_Real &U, Standard_Real &V)
 Tries a refinement of an already computed couple (U,V) by using projecting 3D point on iso-lines: More...
 
Standard_Real UCloseVal () const
 Returns minimum value to consider the surface as U-closed. More...
 
Standard_Real VCloseVal () const
 Returns minimum value to consider the surface as V-closed. More...
 
const Bnd_BoxGetBoxUF ()
 
const Bnd_BoxGetBoxUL ()
 
const Bnd_BoxGetBoxVF ()
 
const Bnd_BoxGetBoxVL ()
 
- Public Member Functions inherited from MMgt_TShared
virtual void Delete () const
 Memory deallocator for transient classes. More...
 
- Public Member Functions inherited from Standard_Transient
 Standard_Transient ()
 Empty constructor. More...
 
 Standard_Transient (const Standard_Transient &)
 Copy constructor – does nothing. More...
 
Standard_Transientoperator= (const Standard_Transient &)
 Assignment operator, needed to avoid copying reference counter. More...
 
virtual ~Standard_Transient ()
 Destructor must be virtual. More...
 
virtual const Handle_Standard_Type & DynamicType () const
 Returns a type information object about this object. More...
 
Standard_Boolean IsInstance (const Handle_Standard_Type &theType) const
 Returns a true value if this is an instance of Type. More...
 
Standard_Boolean IsInstance (const Standard_CString theTypeName) const
 Returns a true value if this is an instance of TypeName. More...
 
Standard_Boolean IsKind (const Handle_Standard_Type &theType) const
 Returns true if this is an instance of Type or an instance of any class that inherits from Type. Note that multiple inheritance is not supported by OCCT RTTI mechanism. More...
 
Standard_Boolean IsKind (const Standard_CString theTypeName) const
 Returns true if this is an instance of TypeName or an instance of any class that inherits from TypeName. Note that multiple inheritance is not supported by OCCT RTTI mechanism. More...
 
virtual Handle_Standard_Transient This () const
 Returns a Handle which references this object. Must never be called to objects created in stack. More...
 
Standard_Integer GetRefCount () const
 Get the reference counter of this object. More...
 

Protected Attributes

Handle< Geom_SurfacemySurf
 
Handle< GeomAdaptor_HSurfacemyAdSur
 
Extrema_ExtPS myExtPS
 
GeomAdaptor_Surface myExtSrf
 
Standard_Boolean myExtOK
 
Standard_Integer myNbDeg
 
Standard_Real myPreci [4]
 
gp_Pnt myP3d [4]
 
gp_Pnt2d myFirstP2d [4]
 
gp_Pnt2d myLastP2d [4]
 
Standard_Real myFirstPar [4]
 
Standard_Real myLastPar [4]
 
Standard_Boolean myUIsoDeg [4]
 
Standard_Boolean myIsos
 
Standard_Real myUF
 
Standard_Real myUL
 
Standard_Real myVF
 
Standard_Real myVL
 
Handle< Geom_CurvemyIsoUF
 
Handle< Geom_CurvemyIsoUL
 
Handle< Geom_CurvemyIsoVF
 
Handle< Geom_CurvemyIsoVL
 
Standard_Boolean myIsoBoxes
 
Bnd_Box myBndUF
 
Bnd_Box myBndUL
 
Bnd_Box myBndVF
 
Bnd_Box myBndVL
 
Standard_Real myGap
 
Standard_Real myUDelt
 
Standard_Real myVDelt
 
Standard_Real myUCloseVal
 
Standard_Real myVCloseVal
 

Detailed Description

Complements standard tool Geom_Surface by providing additional functionality for detection surface singularities, checking spatial surface closure and computing projections of 3D points onto a surface.

This tool is optimised: computes most information only once

Constructor & Destructor Documentation

ShapeAnalysis_Surface::ShapeAnalysis_Surface ( const Handle< Geom_Surface > &  S)

Creates an analyzer object on the basis of existing surface.

Member Function Documentation

const Handle< GeomAdaptor_HSurface >& ShapeAnalysis_Surface::Adaptor3d ( )

Returns the Adaptor. Creates it if not yet done.

void ShapeAnalysis_Surface::Bounds ( Standard_Real ufirst,
Standard_Real ulast,
Standard_Real vfirst,
Standard_Real vlast 
) const

Returns the bounds of the surface (from Bounds from Surface, but buffered)

void ShapeAnalysis_Surface::ComputeBoundIsos ( )

Computes bound isos (protected against exceptions)

Standard_Boolean ShapeAnalysis_Surface::DegeneratedValues ( const gp_Pnt P3d,
const Standard_Real  preci,
gp_Pnt2d firstP2d,
gp_Pnt2d lastP2d,
Standard_Real firstpar,
Standard_Real lastpar,
const Standard_Boolean  forward = Standard_True 
)

Returns True if there is at least one surface iso-line which is considered as degenerated with <preci> and distance between P3d and corresponding singular point is less than <preci> (like IsDegenerated). Returns characteristics of the first found boundary matching those criteria.

Standard_Real ShapeAnalysis_Surface::Gap ( ) const

Returns 3D distance found by one of the following methods. IsDegenerated, DegeneratedValues, ProjectDegenerated (distance between 3D point and found or last (if not found) singularity), IsUClosed, IsVClosed (minimum value of precision to consider the surface to be closed), ValueOfUV (distance between 3D point and found solution).

const Bnd_Box& ShapeAnalysis_Surface::GetBoxUF ( )
const Bnd_Box& ShapeAnalysis_Surface::GetBoxUL ( )
const Bnd_Box& ShapeAnalysis_Surface::GetBoxVF ( )
const Bnd_Box& ShapeAnalysis_Surface::GetBoxVL ( )
Standard_Boolean ShapeAnalysis_Surface::HasSingularities ( const Standard_Real  preci)

Returns True if the surface has singularities for the given precision (i.e. if there are surface singularities with sizes not greater than precision).

void ShapeAnalysis_Surface::Init ( const Handle< Geom_Surface > &  S)

Loads existing surface.

void ShapeAnalysis_Surface::Init ( const Handle< ShapeAnalysis_Surface > &  other)

Reads all the data from another Surface, without recomputing.

Standard_Boolean ShapeAnalysis_Surface::IsDegenerated ( const gp_Pnt P3d,
const Standard_Real  preci 
)

Returns True if there is at least one surface boundary which is considered as degenerated with <preci> and distance between P3d and corresponding singular point is less than <preci>

Standard_Boolean ShapeAnalysis_Surface::IsDegenerated ( const gp_Pnt2d p2d1,
const gp_Pnt2d p2d2,
const Standard_Real  tol,
const Standard_Real  ratio 
)

Returns True if straight pcurve going from point p2d1 to p2d2 is degenerate, i.e. lies in the singularity of the surface. NOTE: it uses another method of detecting singularity than used by ComputeSingularities() et al.! For that, maximums of distances between points p2d1, p2d2 and 0.5*(p2d1+p2d2) and between corresponding 3d points are computed. The pcurve (p2d1, p2d2) is considered as degenerate if:

  • max distance in 3d is less than <tol>
  • max distance in 2d is at least <ratio> times greather than the Resolution computed from max distance in 3d (max3d < tol && max2d > ratio * Resolution(max3d)) NOTE: <ratio> should be >1 (e.g. 10)
Standard_Boolean ShapeAnalysis_Surface::IsUClosed ( const Standard_Real  preci = -1)

Tells if the Surface is spatially closed in U with given precision. If <preci> < 0 then Precision::Confusion is used. If Geom_Surface says that the surface is U-closed, this method also says this. Otherwise additional analysis is performed, comparing given precision with the following distances:

  • periodic B-Splines are closed,
  • polinomial B-Spline with boundary multiplicities degree+1 and Bezier - maximum distance between poles,
  • rational B-Spline or one with boundary multiplicities not degree+1 - maximum distance computed at knots and their middles,
  • surface of extrusion - distance between ends of basis curve,
  • other (RectangularTrimmed and Offset) - maximum distance computed at 100 equi-distanted points.
Standard_Boolean ShapeAnalysis_Surface::IsVClosed ( const Standard_Real  preci = -1)

Tells if the Surface is spatially closed in V with given precision. If <preci> < 0 then Precision::Confusion is used. If Geom_Surface says that the surface is V-closed, this method also says this. Otherwise additional analysis is performed, comparing given precision with the following distances:

  • periodic B-Splines are closed,
  • polinomial B-Spline with boundary multiplicities degree+1 and Bezier - maximum distance between poles,
  • rational B-Spline or one with boundary multiplicities not degree+1 - maximum distance computed at knots and their middles,
  • surface of revolution - distance between ends of basis curve,
  • other (RectangularTrimmed and Offset) - maximum distance computed at 100 equi-distanted points.
Standard_Integer ShapeAnalysis_Surface::NbSingularities ( const Standard_Real  preci)

Returns the number of singularities for the given precision (i.e. number of surface singularities with sizes not greater than precision).

gp_Pnt2d ShapeAnalysis_Surface::NextValueOfUV ( const gp_Pnt2d p2dPrev,
const gp_Pnt P3D,
const Standard_Real  preci,
const Standard_Real  maxpreci = -1.0 
)

Projects a point P3D on the surface. Does the same thing as ValueOfUV but tries to optimize computations by taking into account previous point <p2dPrev>: makes a step by UV and tries Newton algorithm. If <maxpreci> >0. and distance between solution and P3D is greater than <maxpreci>, that solution is considered as bad, and ValueOfUV() is used. If not succeded, calls ValueOfUV()

Standard_Boolean ShapeAnalysis_Surface::ProjectDegenerated ( const gp_Pnt P3d,
const Standard_Real  preci,
const gp_Pnt2d neighbour,
gp_Pnt2d result 
)

Projects a point <P3d> on a singularity by computing one of the coordinates of preliminary computed <result>.

Finds the iso-line which is considered as degenerated with <preci> and a. distance between P3d and corresponding singular point is less than <preci> (like IsDegenerated) or b. difference between already computed <result>'s coordinate and iso-coordinate of the boundary is less than 2D resolution (computed from <preci> by Geom_Adaptor). Then sets not yet computed <result>'s coordinate taking it from <neighbour> and returns True.

Standard_Boolean ShapeAnalysis_Surface::ProjectDegenerated ( const Standard_Integer  nbrPnt,
const TColgp_Array1OfPnt points,
TColgp_Array1OfPnt2d pnt2d,
const Standard_Real  preci,
const Standard_Boolean  direct 
)

Checks points at the beginning (direct is True) or end (direct is False) of array <points> to lie in singularity of surface, and if yes, adjusts the indeterminate 2d coordinate of these points by nearest point which is not in singularity. Returns True if some points were adjusted.

void ShapeAnalysis_Surface::SetDomain ( const Standard_Real  U1,
const Standard_Real  U2,
const Standard_Real  V1,
const Standard_Real  V2 
)
Standard_Boolean ShapeAnalysis_Surface::Singularity ( const Standard_Integer  num,
Standard_Real preci,
gp_Pnt P3d,
gp_Pnt2d firstP2d,
gp_Pnt2d lastP2d,
Standard_Real firstpar,
Standard_Real lastpar,
Standard_Boolean uisodeg 
)

Returns the characteristics of the singularity specified by its rank number <num>. That means, that it is not neccessary for <num> to be in the range [1, NbSingularities] but must be not greater than possible (see ComputeSingularities). The returned characteristics are: preci: the smallest precision with which the iso-line is considered as degenerated, P3d: 3D point of singularity (middle point of the surface iso-line), firstP2d and lastP2d: first and last 2D points of the iso-line in parametrical surface, firstpar and lastpar: first and last parameters of the iso-line in parametrical surface, uisodeg: if the degenerated iso-line is U-iso (True) or V-iso (False). Returns False if <num> is out of range, else returns True.

const Handle< Geom_Surface >& ShapeAnalysis_Surface::Surface ( ) const

Returns a surface being analyzed.

const Handle< GeomAdaptor_HSurface >& ShapeAnalysis_Surface::TrueAdaptor3d ( ) const

Returns the Adaptor (may be Null if method Adaptor() was not called)

Standard_Real ShapeAnalysis_Surface::UCloseVal ( ) const

Returns minimum value to consider the surface as U-closed.

Handle< Geom_Curve > ShapeAnalysis_Surface::UIso ( const Standard_Real  U)

Returns a U-Iso. Null if not possible or failed Remark : bound isos are buffered.

Standard_Real ShapeAnalysis_Surface::UVFromIso ( const gp_Pnt P3D,
const Standard_Real  preci,
Standard_Real U,
Standard_Real V 
)

Tries a refinement of an already computed couple (U,V) by using projecting 3D point on iso-lines:

  1. boundaries of the surface,
  2. iso-lines passing through (U,V)
  3. iteratively received iso-lines passing through new U and new V (number of iterations is limited by 5 in each direction) Returns the best resulting distance between P3D and Value(U,V) in the case of success. Else, returns a very great value
gp_Pnt ShapeAnalysis_Surface::Value ( const Standard_Real  u,
const Standard_Real  v 
)

Returns a 3D point specified by parameters in surface parametrical space.

gp_Pnt ShapeAnalysis_Surface::Value ( const gp_Pnt2d p2d)

Returns a 3d point specified by a point in surface parametrical space.

gp_Pnt2d ShapeAnalysis_Surface::ValueOfUV ( const gp_Pnt P3D,
const Standard_Real  preci 
)

Computes the parameters in the surface parametrical space of 3D point. The result is parameters of the point projected onto the surface. This method enhances functionality provided by the standard tool GeomAPI_ProjectPointOnSurface by treatment of cases when the projected point is near to the surface boundaries and when this standard tool fails.

Standard_Real ShapeAnalysis_Surface::VCloseVal ( ) const

Returns minimum value to consider the surface as V-closed.

Handle< Geom_Curve > ShapeAnalysis_Surface::VIso ( const Standard_Real  V)

Returns a V-Iso. Null if not possible or failed Remark : bound isos are buffered.

Field Documentation

Handle< GeomAdaptor_HSurface > ShapeAnalysis_Surface::myAdSur
protected
Bnd_Box ShapeAnalysis_Surface::myBndUF
protected
Bnd_Box ShapeAnalysis_Surface::myBndUL
protected
Bnd_Box ShapeAnalysis_Surface::myBndVF
protected
Bnd_Box ShapeAnalysis_Surface::myBndVL
protected
Standard_Boolean ShapeAnalysis_Surface::myExtOK
protected
Extrema_ExtPS ShapeAnalysis_Surface::myExtPS
protected
GeomAdaptor_Surface ShapeAnalysis_Surface::myExtSrf
protected
gp_Pnt2d ShapeAnalysis_Surface::myFirstP2d[4]
protected
Standard_Real ShapeAnalysis_Surface::myFirstPar[4]
protected
Standard_Real ShapeAnalysis_Surface::myGap
protected
Standard_Boolean ShapeAnalysis_Surface::myIsoBoxes
protected
Standard_Boolean ShapeAnalysis_Surface::myIsos
protected
Handle< Geom_Curve > ShapeAnalysis_Surface::myIsoUF
protected
Handle< Geom_Curve > ShapeAnalysis_Surface::myIsoUL
protected
Handle< Geom_Curve > ShapeAnalysis_Surface::myIsoVF
protected
Handle< Geom_Curve > ShapeAnalysis_Surface::myIsoVL
protected
gp_Pnt2d ShapeAnalysis_Surface::myLastP2d[4]
protected
Standard_Real ShapeAnalysis_Surface::myLastPar[4]
protected
Standard_Integer ShapeAnalysis_Surface::myNbDeg
protected
gp_Pnt ShapeAnalysis_Surface::myP3d[4]
protected
Standard_Real ShapeAnalysis_Surface::myPreci[4]
protected
Handle< Geom_Surface > ShapeAnalysis_Surface::mySurf
protected
Standard_Real ShapeAnalysis_Surface::myUCloseVal
protected
Standard_Real ShapeAnalysis_Surface::myUDelt
protected
Standard_Real ShapeAnalysis_Surface::myUF
protected
Standard_Boolean ShapeAnalysis_Surface::myUIsoDeg[4]
protected
Standard_Real ShapeAnalysis_Surface::myUL
protected
Standard_Real ShapeAnalysis_Surface::myVCloseVal
protected
Standard_Real ShapeAnalysis_Surface::myVDelt
protected
Standard_Real ShapeAnalysis_Surface::myVF
protected
Standard_Real ShapeAnalysis_Surface::myVL
protected

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