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ModelingAlgorithms
TKOffset
BRepOffsetAPI


BRepOffsetAPI_MakeOffsetShape Class Reference

Describes functions to build a shell out of a shape. The
result is an unlooped shape parallel to the source shape.
A MakeOffsetShape object provides a framework for:
- defining the construction of a shell
- implementing the construction algorithm
- consulting the result.
.

#include <BRepOffsetAPI_MakeOffsetShape.hxx>

Inheritance diagram for BRepOffsetAPI_MakeOffsetShape:

Inheritance graph
[legend]

Public Member Functions

void * operator new (size_t, void *anAddress)
void * operator new (size_t size)
void operator delete (void *anAddress)
Standard_EXPORT BRepOffsetAPI_MakeOffsetShape ()
Standard_EXPORT BRepOffsetAPI_MakeOffsetShape (const TopoDS_Shape &S, const Standard_Real Offset, const Standard_Real Tol, const BRepOffset_Mode Mode=BRepOffset_Skin, const Standard_Boolean Intersection=Standard_False, const Standard_Boolean SelfInter=Standard_False, const GeomAbs_JoinType Join=GeomAbs_Arc)
 Constructs a shape parallel to the shape S, where
· S may be a face, a shell, a solid or a compound of these shape kinds;
· Offset is the offset value. The offset shape is constructed:
- outside S, if Offset is positive,
- inside S, if Offset is negative;
· Tol defines the coincidence tolerance criterion for generated shapes;
· Mode defines the construction type of parallels
applied to the free edges of shape S; currently, only one
construction type is implemented, namely the one where the free
edges do not generate parallels; this corresponds to the default
value BRepOffset_Skin;
· Intersection specifies how the algorithm must work in
order to limit the parallels to two adjacent shapes:
- if Intersection is false (default value), the intersection
is calculated with the parallels to the two adjacent shapes,
- if Intersection is true, the intersection is calculated by
taking all generated parallels into account; this computation method is
more general as it avoids some self-intersections generated in the
offset shape from features of small dimensions on shape S, however this
method has not been completely implemented and therefore is not
recommended for use;
· SelfInter tells the algorithm whether a computation
to eliminate self-intersections must be applied to the resulting
shape; however, as this functionality is not yet
implemented, it is recommended to use the default value (false);
· Join defines how to fill the holes that may appear between
parallels to the two adjacent faces. It may take values
GeomAbs_Arc or GeomAbs_Intersection:
- if Join is equal to GeomAbs_Arc, then pipes are generated
between two free edges of two adjacent parallels,
and spheres are generated on "images" of vertices;
it is the default value,
- if Join is equal to GeomAbs_Intersection, then the parallels to the
two adjacent faces are enlarged and intersected,
so that there are no free edges on parallels to faces.
Warnings
1. All the faces of the shape S should be based on the surfaces
with continuity at least C1.
2. The offset value should be sufficiently small to avoid
self-intersections in resulting shape. Otherwise these
self-intersections may appear inside an offset face if its
initial surface is not plane or sphere or cylinder, also some
non-adjacent offset faces may intersect each other. Also, some
offset surfaces may "turn inside out".
3. The algorithm may fail if the shape S contains vertices where
more than 3 edges converge.
4. Since 3d-offset algorithm involves intersection of surfaces,
it is under limitations of surface intersection algorithm.
5. A result cannot be generated if the underlying geometry of S is
BSpline with continuity C0.
Exceptions
Geom_UndefinedDerivative if the underlying
geometry of S is BSpline with continuity C0.
.
virtual Standard_EXPORT const
BRepOffset_MakeOffset
MakeOffset () const
virtual Standard_EXPORT void Build ()
 Builds the resulting shape (redefined from MakeShape).
.
virtual Standard_EXPORT const
TopTools_ListOfShape & 
Generated (const TopoDS_Shape &S)
 Returns the list of shapes generated from the
shape <s>.
.
Standard_EXPORT const TopTools_ListOfShape & GeneratedEdge (const TopoDS_Shape &S)
 Returns the list of edges generated from the shape <s>.
.
Standard_EXPORT GeomAbs_JoinType GetJoinType () const
 Returns offset join type.
.

Protected Attributes

BRepOffset_MakeOffset myOffsetShape

Constructor & Destructor Documentation

Standard_EXPORT BRepOffsetAPI_MakeOffsetShape::BRepOffsetAPI_MakeOffsetShape  ) 
 

Standard_EXPORT BRepOffsetAPI_MakeOffsetShape::BRepOffsetAPI_MakeOffsetShape const TopoDS_Shape &  S,
const Standard_Real  Offset,
const Standard_Real  Tol,
const BRepOffset_Mode  Mode = BRepOffset_Skin,
const Standard_Boolean  Intersection = Standard_False,
const Standard_Boolean  SelfInter = Standard_False,
const GeomAbs_JoinType  Join = GeomAbs_Arc
 


Member Function Documentation

virtual Standard_EXPORT void BRepOffsetAPI_MakeOffsetShape::Build  )  [virtual]
 

Reimplemented from BRepBuilderAPI_MakeShape.

Reimplemented in BRepOffsetAPI_MakeThickSolid.

virtual Standard_EXPORT const TopTools_ListOfShape& BRepOffsetAPI_MakeOffsetShape::Generated const TopoDS_Shape &  S  )  [virtual]
 

Reimplemented from BRepBuilderAPI_MakeShape.

Standard_EXPORT const TopTools_ListOfShape& BRepOffsetAPI_MakeOffsetShape::GeneratedEdge const TopoDS_Shape &  S  ) 
 

Standard_EXPORT GeomAbs_JoinType BRepOffsetAPI_MakeOffsetShape::GetJoinType  )  const
 

virtual Standard_EXPORT const BRepOffset_MakeOffset& BRepOffsetAPI_MakeOffsetShape::MakeOffset  )  const [virtual]
 

void BRepOffsetAPI_MakeOffsetShape::operator delete void *  anAddress  )  [inline]
 

Reimplemented from BRepBuilderAPI_MakeShape.

Reimplemented in BRepOffsetAPI_MakeThickSolid.

void* BRepOffsetAPI_MakeOffsetShape::operator new size_t  size  )  [inline]
 

Reimplemented from BRepBuilderAPI_MakeShape.

Reimplemented in BRepOffsetAPI_MakeThickSolid.

void* BRepOffsetAPI_MakeOffsetShape::operator new size_t  ,
void *  anAddress
[inline]
 

Reimplemented from BRepBuilderAPI_MakeShape.

Reimplemented in BRepOffsetAPI_MakeThickSolid.


Field Documentation

BRepOffset_MakeOffset BRepOffsetAPI_MakeOffsetShape::myOffsetShape [protected]
 


The documentation for this class was generated from the following file:
Generated on Mon Aug 25 13:41:27 2008 for OpenCASCADE by  doxygen 1.4.1