“…They are traditionally modeled either as linear combinations of analytic functions or as signed distance grids, which are flexible but memory expensive [55]. Even though the problem of the memory complexity for the grid-based methods is approached by [27,43,57,66,67], they have been outperformed by the recent learning-based continuous representations [2,3,10,12,19,30,39,40,42,45,46,56,62,64]. Furthermore, to improve scalability and representation power, the idea of using local features has been explored in [7,11,41,46,51,52,62].…”