Returns unique edges as pairs of point indices, and a count of uses of each edge.


t (numpy int array of shape (N, 3)) – the points indices defining a set of triangles


(numpy int array of shape (N, 2), numpy int array of shape (N,)) where 2D array is list-like sorted points index pairs for unique edges and 1D array contains corresponding edge usage count (usually 1 or 2)


first entry in each pair is always the lower of the two point indices; for well formed surfaces, the count should everywhere be zero or one; the function does not attempt to detect coincident points