News from 10 November 2000

[randi]

As a previous news post hinted, I was considering adding skybox support. I added it today, and it seems to be working quite well.

What is a skybox?

A skybox is a box that is drawn where the sky is supposed to be; at least that's what it is in its simplest form. Quake 2 and Half-Life are both games that use simple skyboxes—they use six 256x256 textures pasted on the inside of a cube. When they draw the sky, they are actually drawing the inside of the cube. Unreal uses a much cooler skybox technique (and is the method I've implemented)—the level designer creates a skybox by creating a separate section of the level that the player can only enter by using a noclip cheat. To draw the sky, the engine positions the player's view at some fixed point inside the area the designer created, and draws whatever's there.

Here are two simple screenshots showing off the skyboxes. For the first one, I cut out the mountains from doom.wad's SKY1 and created a cloud flat with PhotoShop. The mountains form a box, and the clouds are on the ceiling above the mountains. (The clouds are even scrolling, to make it look like the wind is moving them!) The second is a silly example just to illustrate that a skybox does not need to even resemble a sky. For this one, I simply cut out part of E1M1 and used it as the sky.

[Nice Clouds and Mountains]
[Not a Sky, But It's Still a Sky Box]