Creating Custom Skies

From Multiverse

This article explains skyboxes. For a detailed tutorial on skyboxes, see Creating Skyboxes with Terragen.

A sky is a texture which is rendered behind everything else to give the illusion of a sky. Often skies are created as a SkyBox, which is a set of 6 images that form a cube.

Example sky images

Here is an example sky image set from the Multiverse Tools.. Notice how there is a separate image for each side of the sky cube.

Left skybox image	Right skybox image	Front skybox image	Back skybox image
Top skybox image

How skybox images are displayed

Notice how the images in the example above each represent a different face of the cube (as viewed from the inside). In order to create a skybox, you need to make sure that when placed side by side, the images blend together, otherwise you will see seams at the cube edges and destroy the illusion of a sky.

Getting the right image layout can be a bit frustrating, so to help out I've created a set of test sky images you might use. They are each labled with their representative file names (front, left, back, right, top), plus each image side has a number. Here is what they look like...

Left skybox image	Right skybox image	Front skybox image	Back skybox image
Top skybox image

Note that each face is named, and that numbers on each side help you figure out what face is next to which.

To further help see how they all line up with each other, here is a picture showing the face edge associations. Note that the different side images have been rotated, and for each individual sky image, side 1 is always on top. Sides 2 and 4 of adjacient faces also connect, as indicated by the arrows.