   Octree - Units move, update node in octree
  Creating an octree that grows whenever the number of models in a node reaches a certain number.  This is outlined in XNA 3.0 Game Programming Recipes and well all over the internet and google.  Yet I cannot find a good answer to one simple catch:  What happens when units move and need to be re distributed into the octree.  It seems if you have objects moving frequently and the octree is small/tight then you will be spending a ton of time re-arranging the models in the cube.  Is there a decent solution here or is this really not a problem to worry about?   
  I believe the prefered method is to use a "loose octree." It has a particular property that the level of insertion can be determined by the size of the object being inserted. Creating what i believe to be O(1) insert time. This is what you're looking for for a frequently changing tree.   ;Quote:What happens when units move and need to be re distributed into the octree. Element is removed, tree is rebalanced, then element is reinserted elsewhere.   ;  @Bzroom - Perfect, google has turned up some results on Loose Octree's.  I will begin reading the theory behind it to see if it shall fit the scenerio.@Loufoque - Yes that is the basic way to handle it but since insertion into the tree is not a quick opertion.  Removal and re-insertion provides a lot of overhead.  However until I read about "loose octree" I have no other solution than this.Thanks dudes.   ;  How many remove/inserts do you need to do?I usually do this:for each dynamic object,   check if still inside parent node if not, changeNode.Depending on how large the nodes objects usually change node at most once per second. 