title: Algorithm to find path in continuous space
body: <p>I have a big map with ( 20000 x 20000 ) and I have occasionally obstacles with shape of polygon ( from 4 to 20 edges ). How to find path between two points, which algorithm is appropriate to use for this to be reasonably quick ?
  ( At the moment I am splitting map to cells and using A* algorithm to find path but smoothness is not good because it is passing from center of one cell to another and for more distant start / end pair is slow ).
  Which algorithm can you suggest, no need implementation just suggestion.  </p>