TRIMESHEDGEFACES Compute index of faces adjacent to each edge of a triangular mesh.

   EF = trimeshEdgeFaces(FACES)
   EF = trimeshEdgeFaces(VERTICES, FACES)
   EF = trimeshEdgeFaces(VERTICES, EDGES, FACES)
   Compute index array of faces adjacent to each edge of a mesh.
   FACES is a NF-by-3 array containing vertex indices of each face. The
   result EF is a NE-by-2 array containing the indices of the two faces
   incident to each edge. If an edge belongs to only one face, the other
   face index is ZERO.

   The list of edges (as array of source and target vertex indices) can be
   obtained from the function 'meshEdges'.

   Note: faces are listed in increasing order for each edge, and no
   information is kept about relative orientation of edge and face.

   Example
     % compute incidence list of each edge of an octahedron. For example,
     % first edge is incident to faces 1 and 5. Second edge is incident to
     % faces 4 and 8, and so on.
     [v, f] = createOctahedron;
     ef = trimeshEdgeFaces(v, f)
     ef =
          1     5
          4     8
          4     1
          5     8
          2     6
          1     2
          6     5
          3     7
          2     3
          7     6
          3     4
          7     8

   See also
   meshes3d, meshEdgeFaces, trimeshMeanBreadth, meshEdges

Package: matgeom