Mass Effect 2 - Planets

When I came to Bioware, my first task was to figure out the planet system. We needed a system that would allow for hundreds of planets, without having a massive texture footprint. I came up with a few base classes of planets, and used a color gradient masked by a height field. After that it was fairly easy to get a lot of variety by altering shader parameters. I used a program called FilterForge to get the height and normal maps.