for example, a scene where the ground and the sky are all stars is easy to do with skybox and a transparent ground texture, but let's say i want to put a planet model in the scene of big enough size that i can feasibly fly down to the surface of the planet from space and have the appearance of the planet and the action of flying down to it, actually seem like you'd expect were you to do such a thing in a real space going vessel. i guess what i'm asking is, is there anyway to program seamless paging into sandbox?
here's an example of what i mean from the infinity engine
http://www.youtube.com/watch?v=DCzDKj3hjOE
the other thing... i need to make really deep and big water, like an ocean type environment. but when i attempt to make the water big and deep, it breaks off at a certain point and won't allow any further water depth. i assume this is also an example of the limitations of non-paging? if not, then i must be doing something wrong. appreciate any help

i noticed when i am in edit mode and fly up in the sky above the textured ground, that i can only fly up so far before i run into an invisible ceiling as it were.. is there a way to set it so the "ceiling" is higher?