Ascension: Sky Boxes

I wrote this blog for Ascension- originally posted Tuesday, July 1, 2008 @ 9:00 pm

Greetings and salutations! My last blog was devoted to Battle Front concept art and our core element in letting our environments act as story tellers. This entry is about Sky boxes: what are they, and how do we get them to work in our game.

So first, many of you might be asking what a Sky box is. Many games make use of these to give the illusion that the game level exists beyond what the player can interact with. Laymans terms, the Sky box is the background you see when you play the game. Technically, it is a 6 sided box that surrounds the entire game level. By placing the player at the center of this box the player perceives an extension of the 3d world.
You can also think of it in these terms: You’re standing on a mountain looking out at another mountain range… First take a picture facing (1) north, then (2) east, (3) south, and (4) west, and line up your edges so that they match between pictures. This accounts for 4 sides to your Sky box, to complete it you’ll also need to take a photo (5) above and (6) below you. You might ask how to stitch these all together properly, or how would you make it appear not so “square-like” from the inside.
This is done using our modeling and texturing programs. By creating a special distortion on our cameras, you can “bend” the seams of your environment. Take a look at this Sky box texture. Each of these six squares makes up one side of the sky box. Their seams match up perfectly, but distort the edges. This is best seen when looking at the planet. At perfect center, this planet appears spherical in game. Outside of the Sky Box, it would appear like the image below.

Hope you enjoyed this entry, till next time!