I am working on a first person rpg and I was thinking, to greatly increase preseived world size, without the massive issue of rendering objects at a distance, could I not prerender the far off objects and map them to my skydone, having one skyline mapping for every 64000 or so points in my game. I am aware this will cause a slight jumping at the boundries, and slight perspective distortion the further away from the sample point you get, I'm mainly wondering if anyone has heard of this being done, or perhaps someone might have the foresight to tell me why it isn't a good idea to continue looking into.

So you mean you split your 3D world into sections (points), and depending on what section you are in, display a different cube map / sphere map? What would be different in each cube map? Would buildings appear closer / further depending on what point you are at? Is the player inside a city or on the outskirts of the city?

Half life 2 does a decent job at creating their 3D skybox. They have a low res and poly count 3D skybox which they render in addition to the original 3D scene which doesn't seem to be a massive issue. Depending on the distance the player is from the building in the 3D skybox, you could just increase/decrease the resolution of the buildings. I doubt rending a bunch of rectangular prisms (8 vertices, 6 faces) with a low resolution texture can be that graphically intensive when many modern games have player models with thousands of faces to render.

I would say that there are already elegant solutions to 3D skyboxs, so read up on a couple engines which use large worlds (maybe other 3D mmo games?).

Note that I am not that educated with 3D, but I am curious to how this would work compared to the typical methods.

You are right there, rendering of a few dozen rectangular prisms wouldn't be hard, it also would be better to use billboard sprites for super far off objects if I was going to do that - however the main difference for this that I am going for would be persay you where on a cliff side - and there was an island 2 miles away. Now that is much too far to render everything, so a lot of games wouldn't render it - and would add fog to cover up that the scene ends. However this isn't realalistic because fog doesn't exist everywhere. Also far off mountains can appear smooth and ovbiously made of a lowed polygon mesh. I will be using decreased polygon meshes as normal games do as well, however they also have a lot of issues with things like trees on a mountainside, and other high detail items. I intend on my skydome having a sky layer, a cloud layer, a sun/moon layer, and a skyline layer. Time is not an issue for me for I am making the game I want to play - not trying to get rich.