Making a high quality cubemap/sky?

[Oblivion2500]

@jwatte;173251

If you just want six textures:
You could turn off compression.
You could use one grayscale alpha texture (which may compress better) and a separate colorization texture.
You could use a custom shader that measures brightness and then calculates color, to avoid compression problems.

However, I’ve also seen artists have very good success with sky boxes that are made of geometry – separate polygons for various “objects” in the sky. This lets you use more, smaller textures for a visually higher-resolution result.

Can you provide a example? I want to make a good choice of which method is the best. I wish Epic Games showed how they made their own cubemaps from scratch. They have some really good looking ones for Unreal Tournament 4.

EDIT:
Actually after looking at CTF-FacingWorlds WIP for Unreal Tournament (UT4) materials and static meshes. I actually like the method of sky boxes that are made of geometry better than the cubemap method better. It seems that Epic Games likes that method better as well.