MbEdge Edge

The MbEdge class is declared in the topology.h file.

The MbEdge edge is a derived class of the MbTopologyItem topological object and represents a curve with an assigned direction. The direction of the MbCurve3D curve is strictly linked to the direction of increase of its parameter. Unlike a curve, an edge can be directed both in the direction of increasing the parameter and in the direction of decreasing the curve parameter. An edge always starts and ends at some MbVertex vertex.

The edge data structure contains a pointer to the curve MbCurve3D curve, a flag indicating coincidence of the edge direction with the curve direction sameSense, a pointer to the start vertex MbVertex begVertex, and a pointer to the end vertex MbVertex endVertex. Fig. 1 shows an edge.

Fig. 1

Pointers to the curve and vertices cannot be null. The flag indicating coincidence of the edge direction with the curve direction is set to true if the edge coincides with the curve, and to false if the edge is directed opposite to the curve. If an edge starts and ends at the same vertex, then such an edge is closed. Pointers to the start and end vertex of a closed edge are equal.

The edge can be named and can have attributes. The name can be used to identify the edge, and attributes can carry additional information about the edge, such as color, display style, origin, and so on.

The edge is used for wireframe modeling.