  A variational lattice model is proposed to define an evolution of sets from a
single point (nucleation) following a criterion of "maximization" of the
perimeter. At a discrete level, the evolution has a "checkerboard" structure
and its shape is affected by the choice of the norm defining the dissipation
term. For every choice of the scales, the convergence of the discrete scheme to
a family of expanding sets with constant velocity is proved.
