Open CASCADE Technology  6.8.0
Public Member Functions
BRepAlgoAPI_Section Class Reference

Computes the intersection of two shapes or geometries. Geometries can be surfaces of planes. Geometries are converted to faces When a geometry has been converted to topology the created shape can be found using the methods Shape1 and Shape2 inherited from the class BooleanOperation. The result (Shape() method) is a compound containing edges built on intersection curves. By default, the section is performed immediatly in class constructors, with default values : More...

#include <BRepAlgoAPI_Section.hxx>

Inheritance diagram for BRepAlgoAPI_Section:
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Public Member Functions

 BRepAlgoAPI_Section (const TopoDS_Shape &S1, const TopoDS_Shape &S2, const BOPAlgo_PaveFiller &aDSF, const Standard_Boolean PerformNow=Standard_True)
 
virtual ~BRepAlgoAPI_Section ()
 
 BRepAlgoAPI_Section (const TopoDS_Shape &Sh1, const TopoDS_Shape &Sh2, const Standard_Boolean PerformNow=Standard_True)
 see upper More...
 
 BRepAlgoAPI_Section (const TopoDS_Shape &Sh, const gp_Pln &Pl, const Standard_Boolean PerformNow=Standard_True)
 see upper More...
 
 BRepAlgoAPI_Section (const TopoDS_Shape &Sh, const Handle< Geom_Surface > &Sf, const Standard_Boolean PerformNow=Standard_True)
 see upper More...
 
 BRepAlgoAPI_Section (const Handle< Geom_Surface > &Sf, const TopoDS_Shape &Sh, const Standard_Boolean PerformNow=Standard_True)
 see upper More...
 
 BRepAlgoAPI_Section (const Handle< Geom_Surface > &Sf1, const Handle< Geom_Surface > &Sf2, const Standard_Boolean PerformNow=Standard_True)
 This and the above classes construct a framework for computing the section lines of: More...
 
void Init1 (const TopoDS_Shape &S1)
 initialize first part More...
 
void Init1 (const gp_Pln &Pl)
 initialize first part More...
 
void Init1 (const Handle< Geom_Surface > &Sf)
 initialize first part More...
 
void Init2 (const TopoDS_Shape &S2)
 initialize second part More...
 
void Init2 (const gp_Pln &Pl)
 initialize second part More...
 
void Init2 (const Handle< Geom_Surface > &Sf)
 Reinitializes the first and the second parts on which this algorithm is going to perform the intersection computation. This is done with either: the surface Sf, the plane Pl or the shape Sh. You use the function Build to construct the result. More...
 
void Approximation (const Standard_Boolean B)
 Defines an option for computation of further intersections. This computation will be performed by the function Build in this framework. By default, the underlying 3D geometry attached to each elementary edge of the result of a computed intersection is: More...
 
void ComputePCurveOn1 (const Standard_Boolean B)
 Indicates if the Pcurve must be (or not) performed on first part. More...
 
void ComputePCurveOn2 (const Standard_Boolean B)
 Define options for the computation of further intersections, which will be performed by the function Build in this framework. By default, no parametric 2D curve (pcurve) is defined for the elementary edges of the result. If ComputePCurve1 equals true, further computations performed in this framework with the function Build will attach an additional pcurve in the parametric space of the first shape to the constructed edges. If ComputePCurve2 equals true, the additional pcurve will be attached to the constructed edges in the parametric space of the second shape. These two functions may be used together. More...
 
void Build ()
 Performs the computation of section lines between two parts defined at the time of construction of this framework or reinitialized with the Init1 and Init2 functions. The constructed shape will be returned by the function Shape. This is a compound object composed of edges. These intersection edges may be built: More...
 
Standard_Boolean HasAncestorFaceOn1 (const TopoDS_Shape &E, TopoDS_Shape &F) const
 get the face of the first part giving section edge <E>. Returns True on the 3 following conditions : 1/ <E> is an edge returned by the Shape() method. 2/ First part of section performed is a shape. 3/ <E> is built on a intersection curve (i.e <E> is not the result of common edges) When False, F remains untouched. More...
 
Standard_Boolean HasAncestorFaceOn2 (const TopoDS_Shape &E, TopoDS_Shape &F) const
 Identifies the ancestor faces of the intersection edge E resulting from the last computation performed in this framework, that is, the faces of the two original shapes on which the edge E lies: More...
 
- Public Member Functions inherited from BRepAlgoAPI_BooleanOperation
void SetOperation (const BOPAlgo_Operation anOp)
 Sets the type of Boolean operation to perform It can be BOPAlgo_SECTION BOPAlgo_COMMON BOPAlgo_FUSE BOPAlgo_CUT BOPAlgo_CUT21. More...
 
const TopoDS_ShapeShape1 () const
 Returns the first shape involved in this Boolean operation. More...
 
const TopoDS_ShapeShape2 () const
 Returns the second shape involved in this Boolean operation. More...
 
BOPAlgo_Operation Operation () const
 Returns the type of Boolean Operation that has been performed. More...
 
Standard_Boolean FuseEdges () const
 Returns the flag of edge refining. More...
 
void RefineEdges ()
 Fuse C1 edges. More...
 
Standard_Boolean BuilderCanWork () const
 
Standard_Integer ErrorStatus () const
 Returns the error status of operation. 0 - Ok 1 - The Object is created but Nothing is Done 2 - Null source shapes is not allowed 3 - Check types of the arguments 4 - Can not allocate memory for the DSFiller 5 - The Builder can not work with such types of arguments 6 - Unknown operation is not allowed 7 - Can not allocate memory for the Builder

100 - See the Builder's ErrorStatus

More...
 
virtual const
TopTools_ListOfShape
Modified (const TopoDS_Shape &aS)
 Returns the list of shapes modified from the shape <S>. More...
 
virtual Standard_Boolean IsDeleted (const TopoDS_Shape &aS)
 Returns true if the shape S has been deleted. The result shape of the operation does not contain the shape S. More...
 
virtual const
TopTools_ListOfShape
Generated (const TopoDS_Shape &S)
 Returns the list of shapes generated from the shape <S>. For use in BRepNaming. More...
 
virtual Standard_Boolean HasModified () const
 Returns true if there is at least one modified shape. For use in BRepNaming. More...
 
virtual Standard_Boolean HasGenerated () const
 Returns true if there is at least one generated shape. For use in BRepNaming. More...
 
virtual Standard_Boolean HasDeleted () const
 Returns true if there is at least one deleted shape. For use in BRepNaming. More...
 
void Destroy ()
 
virtual ~BRepAlgoAPI_BooleanOperation ()
 
const TopTools_ListOfShapeSectionEdges ()
 Returns a list of section edges. The edges represent the result of intersection between arguments of Boolean Operation. They are computed during operation execution. More...
 
- Public Member Functions inherited from BRepBuilderAPI_MakeShape
virtual void Delete ()
 
virtual ~BRepBuilderAPI_MakeShape ()
 
const TopoDS_ShapeShape () const
 Returns a shape built by the shape construction algorithm. Raises exception StdFail_NotDone if the shape was not built. More...
 
 operator TopoDS_Shape () const
 
- Public Member Functions inherited from BRepBuilderAPI_Command
virtual ~BRepBuilderAPI_Command ()
 
virtual Standard_Boolean IsDone () const
 
void Check () const
 Raises NotDone if done is false. More...
 

Additional Inherited Members

- Protected Member Functions inherited from BRepAlgoAPI_BooleanOperation
 BRepAlgoAPI_BooleanOperation (const TopoDS_Shape &S1, const TopoDS_Shape &S2, const BOPAlgo_Operation anOperation)
 Prepares the operations for S1 and S2. More...
 
 BRepAlgoAPI_BooleanOperation (const TopoDS_Shape &S1, const TopoDS_Shape &S2, const BOPAlgo_PaveFiller &aDSF, const BOPAlgo_Operation anOperation)
 Prepares the operations for S1 and S2. More...
 
Standard_Boolean PrepareFiller ()
 
- Protected Member Functions inherited from BRepBuilderAPI_MakeShape
 BRepBuilderAPI_MakeShape ()
 
- Protected Member Functions inherited from BRepBuilderAPI_Command
 BRepBuilderAPI_Command ()
 Set done to False. More...
 
void Done ()
 Set done to true. More...
 
void NotDone ()
 Set done to false. More...
 
- Protected Attributes inherited from BRepAlgoAPI_BooleanOperation
TopoDS_Shape myS1
 
TopoDS_Shape myS2
 
Standard_Boolean myBuilderCanWork
 
BOPAlgo_Operation myOperation
 
Standard_Integer myErrorStatus
 
BOPAlgo_PPaveFiller myDSFiller
 
BOPAlgo_PBuilder myBuilder
 
- Protected Attributes inherited from BRepBuilderAPI_MakeShape
TopoDS_Shape myShape
 
TopTools_ListOfShape myGenerated
 

Detailed Description

Computes the intersection of two shapes or geometries. Geometries can be surfaces of planes. Geometries are converted to faces When a geometry has been converted to topology the created shape can be found using the methods Shape1 and Shape2 inherited from the class BooleanOperation. The result (Shape() method) is a compound containing edges built on intersection curves. By default, the section is performed immediatly in class constructors, with default values :

Constructor & Destructor Documentation

BRepAlgoAPI_Section::BRepAlgoAPI_Section ( const TopoDS_Shape S1,
const TopoDS_Shape S2,
const BOPAlgo_PaveFiller aDSF,
const Standard_Boolean  PerformNow = Standard_True 
)
virtual BRepAlgoAPI_Section::~BRepAlgoAPI_Section ( )
inlinevirtual
BRepAlgoAPI_Section::BRepAlgoAPI_Section ( const TopoDS_Shape Sh1,
const TopoDS_Shape Sh2,
const Standard_Boolean  PerformNow = Standard_True 
)

see upper

BRepAlgoAPI_Section::BRepAlgoAPI_Section ( const TopoDS_Shape Sh,
const gp_Pln Pl,
const Standard_Boolean  PerformNow = Standard_True 
)

see upper

BRepAlgoAPI_Section::BRepAlgoAPI_Section ( const TopoDS_Shape Sh,
const Handle< Geom_Surface > &  Sf,
const Standard_Boolean  PerformNow = Standard_True 
)

see upper

BRepAlgoAPI_Section::BRepAlgoAPI_Section ( const Handle< Geom_Surface > &  Sf,
const TopoDS_Shape Sh,
const Standard_Boolean  PerformNow = Standard_True 
)

see upper

BRepAlgoAPI_Section::BRepAlgoAPI_Section ( const Handle< Geom_Surface > &  Sf1,
const Handle< Geom_Surface > &  Sf2,
const Standard_Boolean  PerformNow = Standard_True 
)

This and the above classes construct a framework for computing the section lines of:

  • two shapes Sh1 and Sh2, or
  • shape Sh and plane Pl, or
  • shape Sh and surface Sf, or
  • surface Sf and shape Sh, or
  • two surfaces Sf1 and Sf2, and builds a result if PerformNow equals true, its default value. If PerformNow equals false, the intersection will be computed later by the function Build. The constructed shape will be returned by the function Shape. This is a compound object composed of edges. These intersection edges may be built:
  • on new intersection lines, or
  • on coincident portions of edges in the two intersected shapes. These intersection edges are independent: they are not chained or grouped in wires. If no intersection edge exists, the result is an empty compound object. Note that other objects than TopoDS_Shape shapes involved in these syntaxes are converted into faces or shells before performing the computation of the intersection. A shape resulting from this conversion can be retrieved with the function Shape1 or Shape2. Parametric 2D curves on intersection edges No parametric 2D curve (pcurve) is defined for each elementary edge of the result. To attach such parametric curves to the constructed edges you may use a constructor with the PerformNow flag equal to false; then you use:
  • the function ComputePCurveOn1 to ask for the additional computation of a pcurve in the parametric space of the first shape,
  • the function ComputePCurveOn2 to ask for the additional computation of a pcurve in the parametric space of the second shape, in the end,
  • the function Build to construct the result. Approximation of intersection edges The underlying 3D geometry attached to each elementary edge of the result is:
  • analytic where possible, provided the corresponding geometry corresponds to a type of analytic curve defined in the Geom package; for example, the intersection of a cylindrical shape with a plane gives an ellipse or a circle;
  • or elsewhere, given as a succession of points grouped together in a BSpline curve of degree 1. If you prefer to have an attached 3D geometry which is a BSpline approximation of the computed set of points on computed elementary intersection edges whose underlying geometry is not analytic, you may use a constructor with the PerformNow flag equal to false. Then you use:
  • the function Approximation to ask for this computation option, and
  • the function Build to construct the result.
  • Note that as a result, approximations will only be computed on edges built on new intersection lines.
  • Example You may also combine these computation options. In the following example:
  • each elementary edge of the computed intersection, built on a new intersection line, which does not correspond to an analytic Geom curve, will be approximated by a BSpline curve whose degree is not greater than 8.
  • each elementary edge built on a new intersection line, will have:
  • a pcurve in the parametric space of the intersected face of shape S1,
  • no pcurve in the parametric space of the intersected face of shape S2. // TopoDS_Shape S1 = ... , S2 = ... ; Standard_Boolean PerformNow = Standard_False; BRepAlgoAPI_Section S ( S1, S2, PerformNow ); S.ComputePCurveOn1 (Standard_True); S.Approximation (Standard_True); S.Build(); TopoDS_Shape R = S.Shape();

Member Function Documentation

void BRepAlgoAPI_Section::Approximation ( const Standard_Boolean  B)

Defines an option for computation of further intersections. This computation will be performed by the function Build in this framework. By default, the underlying 3D geometry attached to each elementary edge of the result of a computed intersection is:

  • analytic where possible, provided the corresponding geometry corresponds to a type of analytic curve defined in the Geom package; for example the intersection of a cylindrical shape with a plane gives an ellipse or a circle;
  • or elsewhere, given as a succession of points grouped together in a BSpline curve of degree 1. If Approx equals true, when further computations are performed in this framework with the function Build, these edges will have an attached 3D geometry which is a BSpline approximation of the computed set of points. Note that as a result, approximations will be computed on edges built only on new intersection lines.
void BRepAlgoAPI_Section::Build ( )
virtual

Performs the computation of section lines between two parts defined at the time of construction of this framework or reinitialized with the Init1 and Init2 functions. The constructed shape will be returned by the function Shape. This is a compound object composed of edges. These intersection edges may be built:

  • on new intersection lines, or
  • on coincident portions of edges in the two intersected shapes. These intersection edges are independent: they are not chained or grouped into wires. If no intersection edge exists, the result is an empty compound object. The shapes involved in the construction of section lines can be retrieved with the function Shape1 or Shape2. Note that other objects than TopoDS_Shape shapes given as arguments at the construction time of this framework, or to the Init1 or Init2 function, are converted into faces or shells before performing the computation of the intersection. Parametric 2D curves on intersection edges No parametric 2D curve (pcurve) is defined for the elementary edges of the result. To attach parametric curves like this to the constructed edges you have to use:
  • the function ComputePCurveOn1 to ask for the additional computation of a pcurve in the parametric space of the first shape,
  • the function ComputePCurveOn2 to ask for the additional computation of a pcurve in the parametric space of the second shape. This must be done before calling this function. Approximation of intersection edges The underlying 3D geometry attached to each elementary edge of the result is:
  • analytic (where possible) provided the corresponding geometry corresponds to a type of analytic curve defined in the Geom package; for example, the intersection of a cylindrical shape with a plane gives an ellipse or a circle; or
  • elsewhere, given as a succession of points grouped together in a BSpline curve of degree 1. If, on computed elementary intersection edges whose underlying geometry is not analytic, you prefer to have an attached 3D geometry which is a Bspline approximation of the computed set of points, you have to use the function Approximation to ask for this computation option before calling this function. You may also have combined these computation options: look at the example given above to illustrate the use of the constructors.

Reimplemented from BRepAlgoAPI_BooleanOperation.

void BRepAlgoAPI_Section::ComputePCurveOn1 ( const Standard_Boolean  B)

Indicates if the Pcurve must be (or not) performed on first part.

void BRepAlgoAPI_Section::ComputePCurveOn2 ( const Standard_Boolean  B)

Define options for the computation of further intersections, which will be performed by the function Build in this framework. By default, no parametric 2D curve (pcurve) is defined for the elementary edges of the result. If ComputePCurve1 equals true, further computations performed in this framework with the function Build will attach an additional pcurve in the parametric space of the first shape to the constructed edges. If ComputePCurve2 equals true, the additional pcurve will be attached to the constructed edges in the parametric space of the second shape. These two functions may be used together.

Standard_Boolean BRepAlgoAPI_Section::HasAncestorFaceOn1 ( const TopoDS_Shape E,
TopoDS_Shape F 
) const

get the face of the first part giving section edge <E>. Returns True on the 3 following conditions : 1/ <E> is an edge returned by the Shape() method. 2/ First part of section performed is a shape. 3/ <E> is built on a intersection curve (i.e <E> is not the result of common edges) When False, F remains untouched.

Standard_Boolean BRepAlgoAPI_Section::HasAncestorFaceOn2 ( const TopoDS_Shape E,
TopoDS_Shape F 
) const

Identifies the ancestor faces of the intersection edge E resulting from the last computation performed in this framework, that is, the faces of the two original shapes on which the edge E lies:

  • HasAncestorFaceOn1 gives the ancestor face in the first shape, and
  • HasAncestorFaceOn2 gives the ancestor face in the second shape. These functions return true if an ancestor face F is found, or false if not. An ancestor face is identifiable for the edge E if the following conditions are satisfied:
  • the first part on which this algorithm performed its last computation is a shape, that is, it was not given as a surface or a plane at the time of construction of this algorithm or at a later time by the Init1 function,
  • E is one of the elementary edges built by the last computation of this section algorithm. To use these functions properly, you have to test the returned Boolean value before using the ancestor face: F is significant only if the returned Boolean value equals true.
void BRepAlgoAPI_Section::Init1 ( const TopoDS_Shape S1)

initialize first part

void BRepAlgoAPI_Section::Init1 ( const gp_Pln Pl)

initialize first part

void BRepAlgoAPI_Section::Init1 ( const Handle< Geom_Surface > &  Sf)

initialize first part

void BRepAlgoAPI_Section::Init2 ( const TopoDS_Shape S2)

initialize second part

void BRepAlgoAPI_Section::Init2 ( const gp_Pln Pl)

initialize second part

void BRepAlgoAPI_Section::Init2 ( const Handle< Geom_Surface > &  Sf)

Reinitializes the first and the second parts on which this algorithm is going to perform the intersection computation. This is done with either: the surface Sf, the plane Pl or the shape Sh. You use the function Build to construct the result.


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