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: More...

#include <BRepOffsetAPI_MakeOffsetShape.hxx>

Inheritance diagram for BRepOffsetAPI_MakeOffsetShape:

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Public Member Functions
	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)
	Constructs a shape parallel to the shape S, where. More...

virtual const BRepOffset_MakeOffset &	MakeOffset () const

virtual void	Build ()
	Builds the resulting shape (redefined from MakeShape). More...

virtual const TopTools_ListOfShape &	Generated (const TopoDS_Shape &S)
	Returns the list of shapes generated from the shape <S>. More...

const TopTools_ListOfShape &	GeneratedEdge (const TopoDS_Shape &S)
	Returns the list of edges generated from the shape <S>. More...

GeomAbs_JoinType	GetJoinType () const
	Returns offset join type. More...

Public Member Functions inherited from BRepBuilderAPI_MakeShape
virtual void	Delete ()

virtual	~BRepBuilderAPI_MakeShape ()

virtual const TopoDS_Shape &	Shape () 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

virtual const TopTools_ListOfShape &	Modified (const TopoDS_Shape &S)
	Returns the list of shapes modified from the shape <S>. More...

virtual Standard_Boolean	IsDeleted (const TopoDS_Shape &S)
	Returns true if the shape S has been deleted. More...

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...

Protected Attributes
BRepOffset_MakeOffset	myOffsetShape

Protected Attributes inherited from BRepBuilderAPI_MakeShape
TopoDS_Shape	myShape

TopTools_ListOfShape	myGenerated

Additional Inherited Members
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...

Detailed Description

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.

Constructor & Destructor Documentation

BRepOffsetAPI_MakeOffsetShape::BRepOffsetAPI_MakeOffsetShape ( )

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`
	)

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

All the faces of the shape S should be based on the surfaces with continuity at least C1.
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".
The algorithm may fail if the shape S contains vertices where more than 3 edges converge.
Since 3d-offset algorithm involves intersection of surfaces, it is under limitations of surface intersection algorithm.
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.