function E = bp_edges(tri)
% BP_EDGES Unique bead pairs (edges) of a triangle list.
%   E = bp_edges(tri) returns an m-by-2 matrix with E(:,1) < E(:,2).
E = sort([tri(:, [1 2]); tri(:, [2 3]); tri(:, [3 1])], 2);
E = unique(E, 'rows');
end