   How to create a long distance algorithm
  If I need to make an openworld 3rd person game, for instance like gt4 how would I go about writing an (long distance) algorithm say like twenty sp miles or more area.   
  That is a huge topic.Look in to spatial hierarchy algorithms, levels of detail, spatial occlusion and visibility, and dynamic streaming of assets with proxies.  Determine what areas of your spatial grid are 'visible' and stream them in, using proxies as needed. That should get you started.   