Compute edges of a tri-mesh. Can compute all edges, or only a subset, given by the face indices in the mesh.
face.edges(surface_mesh, face_indices = "all")integer matrix of size (n, 2) where n is the number of edges. The indices (source and target vertex) in each row are **not** sorted, and the edges are **not** unique. I.e., each undirected edge `u, v` (with the exception of edges on the mesh border) will occur twice in the result: once as `u, v` and once as `v, u`.
surface mesh, as loaded by subject.surface or read.fs.surface.
integer vector, the face indices. Can also be the character string 'all' to use all faces.
Other surface mesh functions:
label.border(),
mesh.vertex.included.faces(),
mesh.vertex.neighbors(),
subject.surface(),
vis.path.along.verts()