Block decomposition techniques in the generation of adaptive grids

We consider the problem of the generation of adaptive grids, where, for a given domain Ω, we have to compute a partition that depends on a given map f providing the desired local mesh size. We propose a numerical method for the solution of this problem in the case of planar quadrilateral grids. In particular, a block decomposition method is proposed, by which Ω is first decomposed in several blocks depending on the shape of the domain and on the size map f, and then the whole grid is obtained as the union of the quadrilateral grids on each block. The algorithm concludes with a smoothing step that depends on the size map f. We present some simple numerical examples to test the proposed method.