If you have played SimCity Societies, you’d notice that the game uses XML files to create it’s content.  Well, it seems Spore will be using the same process.  This will keep the file sizes for Spore relatively small, and the game will read them then expand it to a much bigger file.

You can find an interview with N’Gai Croal and Spore Developer Todd Jones over at Newsweek which takes you in-depth on how XML will work.  Thanks to Space Oddity’s Blog for this information.

Can you explain, in layman’s terms, how various types of user-generated content in Spore–creatures, buildings, vehicles, space ships, music, etc.–are translated into small files that can be easily shared among various players?

User-generated content in Spore is shared among our players in small files that are generally less than 20KB in size. However, the final game-ready form of that content can be 1MB or bigger! This is possible because the game-ready content is algorithmically generated based on the information in the small files.

Each of the small files is a recipe that describes how assets that come with the game can be combined to make something new. The assets are things like hands, mouths, wheels, textures, or even animations. When the game creates a game-ready piece of content, the instructions in the recipe are followed and final geometry, textures, animations, and sounds are created as a result. We call this “baking'” because conceptually we take raw materials that come with the game, combine them, run them through a number of optimization processes and after a while, something interesting pops out the other end.

For example, when a player is creating a creature in the creature editor, they take actions that can be boiled down to statements like “elongate the spine by 10 percent,” “bend the spine upward,” “put legs on the creature,” “bend the knees outward,” “paint the skin of the creature in purple scales, with little warts all over.” The recipes that are shared between players consists of these kind of statements. When we need to view a creature in the game, we assemble the skin of the creature per the recipe, stitch on the parts, pose the creature, go through the process of painting the creature’s skin, and so forth. Each of these steps are usually done on-the-fly, in the background, as the player is playing. After a few seconds, the final content is ready and the game can display it in the world. This is different from most other games in that most games have the final assets on the DVD and display them directly in the game, with little modification. The fact that we build them on-demand allows for a much wider range of content in the game than is usual.

Read The XML-ization of Videogames, Part II: A Chat With Spore Senior Development Director Eric Todd