private double getHeuristic(final TerrainMap map, final Point pt1, final Point pt2) {
// return 0;
int d = Math.max(Math.abs(pt1.x - pt2.x), Math.abs(pt1.y - pt2.y));
double h = map.getTile(pt2) - map.getTile(pt1);
return d * Math.exp(h / d);
}
