alt Hacker NewsPVS does not require a hierarchical representation. You can use any representation you want. In fact the one in the article itself is not hiearchical.
PVS does not require a hierarchical representation. You can use any representation you want. In fact the one in the article itself is not hiearchical.
In practice many useful representation can be built only in a hierarchical way. Unless you want to force artist/map makers to split their maps in regions manually.