Erica Naone, the assistant editor of Technology Review interviewed Spore’s executive producer, Lucy Bradshaw, about the how they used procedural generation on Spore’s game play.
TR: One goal of the Creature Creator was to make it relatively easy to use, while also giving people a lot of range in what they could create. How did you pull that off?
LB: The Creature Creator’s interface is probably the single item that we spent the most time on. To make it something that feels as simple as shaping clay, allowing players to easily add parts, stretch them, or rescale them, we taught the computer to respond to what the player was doing. If the creature is facing the player, it will manipulate the limbs differently than if the creature is to the side. We created methodology like symmetry, so that if you’re dragging on a leg and you put it to the side of the creature, it’s going to have two of them.
TR: Because so much of the behavior of these creatures is procedurally generated once the game is running, my understanding is that the files for the creatures themselves turn out to be much smaller than for a 3-D model, for example.
LB: What you’re doing with your Creature Creator is creating a recipe for a creature. Because the computer builds the creatures up procedurally, the file that stores [the creatures] gets reduced down to about 8 K. We’re talking about kilobytes, not megabytes or gigabytes [as you might expect for most 3-D models].
I love the way that Maxis has handled the data for the creatures by storing them into PNG files. It seems a lot simplier to deal with and you can publish them to the net in no time, making fast and easy distrubition.