From 2D sprites to 3D models and textures for AAA titles, these are the tools for game art used by the pros.
Here's a quick tutorial to Blender. Show how to use Gradien Texture to model the earth with slices. The instructions are simple, easy to understand, and can be applied in many cases. Hope it is useful ...
As you scroll through the site, you can see an explanation of ShareTextures. ShareTextures has three categories: Atlases (natural materials that combine multiple textures into one), Textures, and ...