Making Your Sky
Making a custom sky for your level is an important part of creating the perfect mood of your scene. If you are new to Source you may be a little bit confused about what goes into making your sky.
The first thing to understand is that there are two completely different aspects of your sky. One is the 3D Skybox that is the viewable extended world beyond the playable areas and the other is the 2D sky that is a giant cubemap image that is the backdrop for the scene (usually encompassing the sky, clouds, stars, sun, etc).
This series of articles explains how to build these two parts of your level in a much more convenient and optimized fashion than is done in traditional work flows. Wall Worm allows you to start your skies earlier in the design process (really from the start) and keep them as seamless environments that are easier to adjust and visualize throughout the entire process.