
Originally Posted by
Jetsetlemming
The playable area of the terrain is cut; this section is moved to the origin (0,0) of the map grid, and multiplied by 16x. In its place in the skybox, a sky_camera entity is placed. Now, when the level is run, the skybox area and the play area will match up seemlessly, and it will appear as if the environment goes on for miles.

The final result:

An issue I had forgotten about displayed here is textures- Technically, both skybox and play area textures are set to the same resolution (and are, in fact, the exact same texture), but due to the automatic x16 rescaling of the skybox zone, the skybox textures do not match up. This is, in most cases, solved by creating a wall or other barrier preventing the player from viewing the exact border, and increasing the texture resolution on the closest visible surfaces by x2 or x4.
Except for that relatively minor, and easily correctable issue, the sky is complete- now the actual gameplay area can be constructed.
As I was walking down the stair,
I met a man who wasn't there.
He wasn't there again today.
I wish, I wish he'd go away.