Thanks i3di, that sounds very interesting. However I think my requirements are little different to most. Most games that require large terrains only show a relatively small amount of the terrain at once, so they can load in the current and neighbouring terrain chunks and that's all fine, but in my case I need the ability to zoom completely out so that I can see the entire terrain at once.
Does your World Max assume that you will only be viewing a small piece of your terrain at once, or can it use LOD to show more of the terrain (At lower levels of detail) as you zoom out?
Thanks
Ben