HashMap<Point,V> old_exact = exact;
exact = new HashMap<Point,V>();
kd = new KDTree(3);
for(V v : old_exact.values()) add(v);
HashMap<Point,V> old_exact = exact;
exact = new HashMap<Point,V>();
kd = new KDTree(3);
for(V v : old_exact.values()) add(v);