cadex.ModelData.Face Class Reference

Defines a topological face. More...

Inheritance diagram for cadex.ModelData.Face:

Public Member Functions
	Face (global::System.IntPtr cPtr, bool cMemoryOwn)
	Face (cadex.Geom.Surface theSurface, bool theMakeWire)
	Creates a face on entire surface's definition domain:
	Face (cadex.Geom.Surface theSurface)
	Face (cadex.Geom.Surface theSurface, cadex.ModelData.Wire theWire)
	Creates a face from a surface and explicitly defined wire:
	Face (cadex.Geom.Surface theSurface, double theUMin, double theUMax, double theVMin, double theVMax)
	Creates a face from a surface and its parametric definition domain:
void	ParametricDomain (out double theUMin, out double theUMax, out double theVMin, out double theVMax)
bool	Append (cadex.ModelData.Wire theWire)
	There must be single outer wire and zero, one or more inner wires (i.e.
bool	Append (cadex.Collections.WireList theWires)
	There must be single outer wire and zero, one or more inner wires (i.e.
cadex.Geom.Surface	Surface ()
	Returns underlying surface.
cadex.ModelData.Wire	OuterWire ()
	Returns outer wire.
cadex.ModelData.IndexedTriangleSet	Triangulation ()
	An empty object may be returned.
Public Member Functions inherited from cadex.ModelData.Shape
	Shape (global::System.IntPtr cPtr, bool cMemoryOwn)
override int	GetHashCode ()
cadex.ModelData.ShapeType	Type ()
	Returns a shape type. For a null object returns Undefined.
cadex.ModelData.ShapeOrientation	Orientation ()
	Returns orientation flag.
cadex.ModelData.Shape	Reversed ()
	Returns a shape that shares the same geometry and subshape graph but has opposite orientation.
cadex.ModelData.Shape	Oriented (cadex.ModelData.ShapeOrientation theOrientation)
	Returns a shape that shares the same geometry and subshape graph and has specified orientation.
bool	IsEqual (cadex.ModelData.Shape theOther)
	Returns true if the shape shares the same geometry and subshape graph, and has equal orientation.
bool	IsSame (cadex.ModelData.Shape theOther)
	Returns true if the shape shares the same geometry and subshape graph.
void	SetName (cadex.UTF16String theName)
	Sets the name.
cadex.UTF16String	Name ()
	Returns the name.
void	AddAssociatedPMI (cadex.PMI.Element theElement)
	Adds the PMI element.
void	AddAssociatedPMI (cadex.Collections.PMIElementList theElements)
	Adds the PMI elements.
cadex.Collections.PMIElementList	AssociatedPMI ()
	Returns the PMI elements.
override bool	Equals (System.Object o)
Public Member Functions inherited from cadex.BaseObject
	BaseObject (global::System.IntPtr cPtr, bool cMemoryOwn)
void	Dispose ()
bool	IsNull ()
ulong	Id ()
	Return unique identifier of public object.
bool	IsEqual (cadex.BaseObject theObj)
override int	GetHashCode ()
override bool	Equals (System.Object o)

Static Public Member Functions
static cadex.ModelData.Face	Cast (cadex.ModelData.Shape theShape)
	Casts theShape to a face.
static new bool	CompareType (cadex.BaseObject theObject)
	Check the type of object. Returns true if the specified object is this class type.
Static Public Member Functions inherited from cadex.ModelData.Shape
static bool	CompareType (cadex.BaseObject theObject)
	Check the type of object. Returns true if the specified object is this class type.
static cadex.ModelData.Shape	Cast (cadex.BaseObject theBase)

Protected Member Functions
override void	Dispose (bool disposing)
Protected Member Functions inherited from cadex.ModelData.Shape
override void	Dispose (bool disposing)

Detailed Description

Defines a topological face.

The following image depicts an example of a face:

Face

Face resides on a geometrical surface (returned by Surface()) and is bounded by one or several wires. A face must always have at least one explicit outer wire even if it corresponds to a naturally bounded surface (e.g. torus or a sphere).

Orientation() defines whether face normal matches the normal of the underlying surface, or is opposite to it.

Face Boundaries

Face wires must always be closed, both in 3D and in 2D (i.e. parametric space of the underlying surface). Therefore a face lying on a periodical surface on its full period must have an explicit seam-edge (an edge corresponding to surface boundaries).

A face outer wire can be distinguished using the OuterWire() method.

Face wires must be oriented such that they define a closed portion of material. If to look in the direction opposite to a surface normal, p-curves of an outer wire (taking into account edge orientations) must be oriented counter-clockwise, and p-curve of inner wires (if present) - clockwise. This ensures that the face has a finite area.

The following image depicts an example of face with two wires and p-curves in parametric space of the face surface. P-curves of edges with forward orientation are displayed in green, p-curves of edges with reversed orientation are displayed in red:

Face with two wires

P-curves in surface parametric space

Note

Own face orientation must be ignored when defining correct contour orientation (unlike, for instance, ACIS or Parasolid kernels which do take face orientation into account).

The following code snippet demonstrates how to iterate over face edges p-curves:

ModelData::Face aFace;
 
// always use forward orientation when analyzing pcurves orientation
ModelData::Face aFwdFace = ModelData::Face::Cast (aFace.Oriented (ModelData::ShapeOrientation::Forward));
ModelData::Wire anOuterWire = aFwdFace.OuterWire();
 
ModelData::ShapeIterator i (aFwdFace);
while (i.HasNext()) {
    const ModelData::Shape& aWire = i.Next(); // wire
    assert (aWire.Type() == ModelData::ShapeType::Wire);
 
    if (aWire.IsSame (anOuterWire)) {
        // we are exploring an outer wire
    } else {
        // we are exploring a hole
    }
 
    ModelData::ShapeIterator j (aWire);
    while (j.HasNext()) {
        const ModelData::Shape& aShape = j.Next(); // edge
        const ModelData::Edge&  anEdge = ModelData::Edge::Cast (aShape);
 
        double        aF, aL;
        Geom::Curve2d aPCurve = anEdge.PCurve (aFwdFace, aF, aL);
 
        if (anEdge.Orientation() == ModelData::ShapeOrientation::Forward) {
            // face material is on the left from the pcurve
        } else {
            // face material is on the right from the pcurve
        }
    }
}

2D Bounding Box

Face p-curves define a closed contour (or a set of contours in the case of face with holes) in surface parametric space. A 2D bounding box in this surface parametric space can be returned using the Measurements.ComputeBoundingBox() method (its overload accepting ModelData.Face). The following images demonstrate a face lying on a cylindrical surface and its 2D contour and bounding box:

Face on cylindrical surface

2D bounding box

The following example demonstrates how to retrieve this bounding box. Note aHeight below would designate a 3D length of this cylindrical face and if it occupied entire U-range of the cylindrical surface (Geom.CylindricalSurface) then it would correspond to a cylinder's height:

ModelData::Face aFace;
ModelData::Box aBox;
Measurements::ComputeBoundingBox(aFace, Geom::Transformation(), aBox);
double aHeight = aBox.YRange(); // cylindrical surface is parametrized by length in V-range

Examples

exploring/brep_geometry/Program.cs, exploring/brep_geometry/main.cxx, exploring/brep_topology/Program.cs, exploring/brep_topology/main.cxx, meshing/mesh_generation/Program.cs, and meshing/mesh_generation/main.cxx.

Constructor & Destructor Documentation

Face() [1/3]

cadex.ModelData.Face.Face ( cadex.Geom.Surface theSurface, bool theMakeWire )

inline

Creates a face on entire surface's definition domain:

Constructing face from surface

The surface must have bounded definition domain (see ModelData.Surface.Domain()). This is the case for instance for Geom.BSplineSurface.

theMakeWire specifies whether the wire must be automatically constructed and added to the face. Constructor.

Face() [2/3]

cadex.ModelData.Face.Face ( cadex.Geom.Surface theSurface, cadex.ModelData.Wire theWire )

inline

Creates a face from a surface and explicitly defined wire:

Constructing face from surface and wire

The wire's edge must lie on a surface (within proximity of their tolerances). Constructor.

Face() [3/3]

cadex.ModelData.Face.Face ( cadex.Geom.Surface theSurface, double theUMin, double theUMax, double theVMin, double theVMax )

inline

Creates a face from a surface and its parametric definition domain:

Input surface

Surface definition domain

The parameters must be within surface's definition domain (see ModelData_Surface.Domain()) unless it is periodic. theUMax must be greater than theUMin by at least 1e-9. Constructor.

Member Function Documentation

Append() [1/2]

bool cadex.ModelData.Face.Append ( cadex.Collections.WireList theWires )

inline

There must be single outer wire and zero, one or more inner wires (i.e.

holes). It is strongly recommended (although not required) that the first wire being added is an outer wire.

Returns false if one of the theWires is null and true otherwise. Adds a wires to the face.

Append() [2/2]

bool cadex.ModelData.Face.Append ( cadex.ModelData.Wire theWire )

inline

There must be single outer wire and zero, one or more inner wires (i.e.

holes). It is strongly recommended (although not required) that the first wire being added is an outer wire.

Returns false if theWire is null and true otherwise. Adds a wire to the face.

Cast()

static cadex.ModelData.Face cadex.ModelData.Face.Cast ( cadex.ModelData.Shape theShape )

inlinestatic

Casts theShape to a face.

If theShape is not a face then behavior is undefined (assert will be thrown in debug mode). Cast operator.

Examples

exploring/brep_geometry/Program.cs, exploring/brep_topology/Program.cs, and meshing/mesh_generation/Program.cs.

CompareType()

static new bool cadex.ModelData.Face.CompareType ( cadex.BaseObject theObject )

inlinestatic

Check the type of object. Returns true if the specified object is this class type.

Dispose()

override void cadex.ModelData.Face.Dispose ( bool disposing )

inlineprotectedvirtual

Reimplemented from cadex.BaseObject.

OuterWire()

cadex.ModelData.Wire cadex.ModelData.Face.OuterWire ( )

inline

Returns outer wire.

Surface()

cadex.Geom.Surface cadex.ModelData.Face.Surface ( )

inline

Returns underlying surface.

Examples

exploring/brep_geometry/Program.cs, exploring/brep_geometry/main.cxx, exploring/brep_topology/Program.cs, and exploring/brep_topology/main.cxx.

Triangulation()

cadex.ModelData.IndexedTriangleSet cadex.ModelData.Face.Triangulation ( )

inline

An empty object may be returned.

Returns triangulation of the face.

Examples

meshing/mesh_generation/Program.cs, and meshing/mesh_generation/main.cxx.