cadex::ModelData_Edge Class Reference

Defines an edge. More...

Inheritance diagram for cadex::ModelData_Edge:

## Public Member Functions | |

ModelData_Edge (const ModelData_Curve &theCurve) | |

Constructor. More... | |

ModelData_Edge (const ModelData_Curve &theCurve, double theFirstParameter, double theLastParameter) | |

Constructor. More... | |

ModelData_Edge (const ModelData_Curve &theCurve, const ModelData_Vertex &theFirstVertex, const ModelData_Vertex &theLastVertex) | |

Constructor. More... | |

ModelData_Edge (const TopoDS_Edge &) | |

operator const TopoDS_Edge & () const | |

Cast operator. | |

operator TopoDS_Edge & () | |

Cast operator. | |

ModelData_Vertex | StartVertex () const |

Returns a start vertex. More... | |

ModelData_Vertex | EndVertex () const |

Returns a start vertex. More... | |

ModelData_Curve | Curve (double &theFirstParameter, double &theLastParameter) const |

Returns edge 3D curve and its limits. More... | |

ModelData_Curve2d | PCurve (const ModelData_Face &theFace, double &theFirstParameter, double &theLastParameter) const |

Returns edge p-curve on a face and its limits. More... | |

double | Tolerance () const |

Returns edge tolerance. More... | |

bool | IsDegenerated () const |

Returns true if an edge is degenerated. More... | |

bool | IsSeam (const ModelData_Face &theFace) const |

Returns true for a seam-edge. | |

Public Member Functions inherited from cadex::ModelData_Shape | |

ModelData_Shape () | |

Constructor. | |

ModelData_Shape (const ModelData_Shape &theOther) | |

Constructor. | |

ModelData_Shape (ModelData_Shape &&theOther) | |

Move constructor. | |

~ModelData_Shape () | |

Destructor. | |

ModelData_Shape & | operator= (const ModelData_Shape &theOther) |

Assignment operator. | |

ModelData_Shape & | operator= (ModelData_Shape &&theOther) |

Move assignment operator. | |

operator const TopoDS_Shape & () const | |

Casts this object to TopoDS_Shape. More... | |

ModelData_ShapeType | Type () const |

Returns a shape type. More... | |

ModelData_ShapeOrientation | Orientation () const |

Returns orientation flag. More... | |

ModelData_Shape | Reversed () const |

Returns a shape that shares the same geometry and subshape graph but has opposite orientation. More... | |

ModelData_Shape | Oriented (ModelData_ShapeOrientation theOrientation) const |

Returns a shape that shares the same geometry and subshape graph and has specified orientation. More... | |

void | Nullify () |

Nullifies the object. More... | |

bool | IsNull () const |

Returns true if the object has not been initialized yet. | |

operator bool () const | |

Returns true if the object is not null. More... | |

bool | IsEqual (const ModelData_Shape &theOther) const |

Returns true if the shape shares the same geometry and subshape graph, and has equal orientation. More... | |

bool | IsSame (const ModelData_Shape &theOther) const |

Returns true if the shape shares the same geometry and subshape graph. More... | |

internal::ModelData_ShapeImpl * | Impl () const |

Returns internal implementation object. | |

## Static Public Member Functions | |

static const ModelData_Edge & | Cast (const ModelData_Shape &theShape) |

static ModelData_Edge & | Cast (ModelData_Shape &theShape) |

## Additional Inherited Members | |

Protected Member Functions inherited from cadex::ModelData_Shape | |

ModelData_Shape (const TopoDS_Shape &theOther, bool) | |

Constructor. | |

ModelData_Shape (internal::ModelData_ShapeImpl *theImpl) | |

Constructor. | |

Protected Attributes inherited from cadex::ModelData_Shape | |

internal::Base_Handle | myImpl |

Internal implementation object. | |

Defines an edge.

The following image depicts an example of an edge:

An edge resides on a curve (returned by Curve()) and is bounded by two vertices returned by StartVertex() and EndVertex(). StartVertex() corresponds to smaller parameter along the curve and EndVertex() - to greater parameter (regardless of own edge orientation). Vertices must always be explicitly defined.

If an edge has forward Orientation() then it is considered to align with the underlying curve. If Orientation() is reversed, then the edge is considered to have an opposite orientation comparing to its underlying curve.

If an edge is owned by a face (via its wire) then this edge must also have a p-curve (parametric curve) defined in a parametric domain of the face surface. If an edge is shared by two faces in a shell then it must have pcurve on each parent face. P-curves are oriented in the same direction as 3D curve. P-curve(s) must be within a tolerance value (returned by Tolerance()) from the 3D curve, i.e. the tolerance can be considered as a radius of a pipe along the 3D curve, in which p-curves (reconstructed on surfaces) must reside.

When importing models from external files or creating from scratch CAD Exchanger also tries to ensure two more strict requirements:

- "same range": all curve representations (3D curve and all p-curves) have the same definition parametric range (e.g. [a, b]);
- "same parameter": for any parameter
*t*from range [a, b] a 3D point computed from 3D curve must be within an edge tolerance from a 3D point computed from p-curve and corresponding surface, i.e. |C(t) - S(p(t))| <= tolerance.

Edge tolerance should not exceed vertices tolerances.

An edge is called *degenerated* if it corresponds to a degenerated curve, e.g. a sphere pole, a cone apex or a B-Spline singularity point. In this case it does not have a 3D curve and only has a pcurve. For instance in the case of a sphere 'north' pole the pcurve is V-isoline V=PI/2.

IsDegenerated() returns true for a degenerated edge.

An edge is called *seam-edge* if it corresponds to a curve on a periodical suface that has two pcurve representations in the surface parametric domain. Examples include a curve corresponding to U-isolines of a cylindrical surface with U=0 and U=2*PI.

Although, such seam-edges typically have pcurves corresponding to surface boundary iso-lines (e.g. one corresponding to surface UMin and another to UMax), this is not always the case. Some seam-edges may have pcurves corresponding to arbitrary pairs of isolines shifted by surface period (e.g. one is V* and another V* + V_period). Some seam-edges may have even a pair of free-form pcurves, one shifted by surface period from another. This often happens when importing a file generated by CAD systems/kernels which do not explicitly support seam-edges.

A seam edge occured twice in its parent wire - with forward and reversed orientations. Edge orientation defines which pcurve will be returned by PCurve(). IsSeam() returns true for the seam-edge.

**Examples:**- brepmodeling/main.cxx, and modelexplorer/main.cxx.

cadex::ModelData_Edge::ModelData_Edge | ( | const ModelData_Curve & | theCurve | ) |

Constructor.

Creates an edge on entire curve's definition range:

The curve must have bounded definition range (see ModelData_Curve::Domain()).

cadex::ModelData_Edge::ModelData_Edge | ( | const ModelData_Curve & | theCurve, |

double | theFirstParameter, |
||

double | theLastParameter |
||

) |

Constructor.

Creates an edge from a curve and explicitly specified parametric range:

The parameters must be within curve's definition range (see ModelData_Curve::Domain()) unless it is periodic. *theLastParameter* must be greater than *theFirstParameter* by at least 1e-9.

cadex::ModelData_Edge::ModelData_Edge | ( | const ModelData_Curve & | theCurve, |

const ModelData_Vertex & | theFirstVertex, |
||

const ModelData_Vertex & | theLastVertex |
||

) |

Constructor.

Creates an edge from a curve and explicitly specified bounding vertices:

The vertices must lie on the curve within their tolerances and within curve's definition range (see ModelData_Curve::Domain()) unless it is periodic.

ModelData_Curve cadex::ModelData_Edge::Curve | ( | double & | theFirstParameter, |

double & | theLastParameter |
||

) | const |

Returns edge 3D curve and its limits.

Returns null curve for a degenerated edge (see IsDegenerated()).

**Examples:**- modelexplorer/main.cxx.

ModelData_Vertex cadex::ModelData_Edge::EndVertex | ( | ) | const |

Returns a start vertex.

End vertex corresponds to a point on a curve with greater parameter (regardless of edge orientation).

bool cadex::ModelData_Edge::IsDegenerated | ( | ) | const |

Returns true if an edge is degenerated.

A degenerated edge has no 3D curve.

**Examples:**- modelexplorer/main.cxx.

ModelData_Curve2d cadex::ModelData_Edge::PCurve | ( | const ModelData_Face & | theFace, |

double & | theFirstParameter, |
||

double & | theLastParameter |
||

) | const |

Returns edge p-curve on a face and its limits.

For a seam-edge (IsSeam() returns true), selects p-curve depending on *this* edge orientation. For a seam-edge both p-curves have the same definition range.

ModelData_Vertex cadex::ModelData_Edge::StartVertex | ( | ) | const |

Returns a start vertex.

Start vertex corresponds to a point on a curve with smaller parameter (regardless of edge orientation).

double cadex::ModelData_Edge::Tolerance | ( | ) | const |

Returns edge tolerance.

- See also
- ModelData_Vertex::Tolerance().