This is a similar approach to the active border traversal that is described in[21], with the addition that the search is limited to stay within a given region and discards all nodes that do not at least partially lie within this region.
This is a similar approach to the active border traversalthat is described in[21], with the addition that the search is limited tostay within a given region and discards all nodes that do not at leastpartially lie within this region.