Halfedge

class m3sh.hds.Halfedge(origin, target)

Halfedge base class.

Halfedges store references to their vertices, the successor, predecessor, and twin halfedge as well as the incident face – the face to its left. A closed loop of halfedges defines a face and its orientation. Successor and predecessor refer to the next and previous halfedge in such a loop.

Parameters:

• origin (Vertex) – Origin vertex of the halfedge.

• target (Vertex) – Target vertex of the halfedge.

Note

As halfedges are stored in a dictionary and not in a list, they do not have a canonical index value but a key that is formed by the pair of origin and target vertex.

Attributes

boundary	Topological state.
collapsible	Topological state.
deleted	Internal state.
face	Incident face.
flags	Halfedge flags.
flippable	Topological state.
midpoint	Halfedge midpoint.
next	Successor halfedge.
origin	Halfedge origin vertex.
pair	Opposite halfedge.
prev	Predecessor halfedge.
target	Halfedge target vertex.
vector	Halfedge direction vector.

Special methods

__contains__(vertex)	Incidence test.
__getitem__(index)	Vertex access.
__iter__()	Vertex iterator.