Computer Graphics World

October 2008 24 ■ ■ ■ ■ Gaming scripts that walked paint brushes across the creatures. Hecker likens the approach to writing simplifi ed programming language. Once Hecker and Quigley got the par- ticle-paint aspect working, they discovered that the particles couldn't make proper de- terminations about the skeleton in terms of the torso's location or other issues. Goffi n enhanced the system so that the scripting language would enable the particles to ac- cess the creature's morphology and know, for instance, what kind of parts are near one of the hand meshes so it can start fl ar- ing out at the end of a limb versus the mid- dle of the torso. e animation system uses this creature morphology as well. Creatures are made to move in ways that express what Hecker calls "the verbs of the game"—from picking fruit and fi ghting, to running around and dancing. e tricky part is that these movements have to work on creatures that players create, which means the animators don't get the benefi t of having a fi xed character in a game with James Bond, Lara Croft, or other known models. "All the parts are marked up semanti- cally," Hecker explains, "which is a new thing in animation that gives us tremen- dous power because the computer can [make certain determinations] about the animation data and map it onto diff erent creatures." is process is also known as retargeting. Meanwhile, inverse kinematics technology enables the creature bodies to move like human skeletons. Hecker says Spore Creature Creator, a stand-alone product released in June that focuses solely on the game's creature-mak- ing capability, enables the public to see "a concrete example of the various decisions we made and how much control we give people over the paint system." For example, users can paint their name on the creature they've created but cannot paint directly on the creature in 3D. While Pixologic's ZBrush or Maya's 3D paint program are far more fl exible than Spore's paint-editing feature, they require about six months of training. So the trick was making the in- game tool powerful while remaining acces- sible to those who lack the artistic expertise of an industry professional. Barely a month after Creature Creator's release, users had contributed 2.7 million creatures to the Spore database. To put this into perspective, the number of known species of plants, animals, and algae on the planet earth is approximately 1.58 million. "It took a lot longer than [a few months] to get that many on earth," Hecker says with a chuckle. In a serious tone, he predicts that the fi gure could top three million by the product's release date. at would far ex- ceed the expectations of Wright, who when dreaming up the idea for Spore, decided to fuse his fascination with science and inter- est in architecture and design. From a programming standpoint, the AI system that Spore used is a derivative of what Halo game developer Bungie Studios has published. And Hecker says he is grateful that game developers are so open to shar- ing information. e motivation involves a hunger to learn from mistakes and incorpo- rate those lessons into product updates, as well as a relentless commitment to quality assurance that's ingrained in the industry's culture. Hecker expects even more informa- tion sharing to occur in the future thanks in part to the Internet, trade shows such as Game Developers Conference (GDC), and books about game programming. "It doesn't matter that they work for a totally diff erent company," Hecker explains, "because games are entertainment products, and we don't necessarily compete unless you're like Rock Band and Guitar Hero, go- ing after the exact same audience at the exact same time. But most games aren't like that. If Halo had better AI because of something Spore did, it doesn't hurt Spore in any way, and then they can share with us next time at GDC or on Internet message boards." Creature Creator Creature Creator—which, as the title sug- gests, allows people to create their own creature (free on the Spore.com Web site, though there's also a $10 version with more parts)—has been enthusiastically embraced by both casual and hard-core players. "We made it accessible so that even if you are not a computer game person, it is just kind of magic to play with," Hecker says. e magic moment usually takes hold once users watch their creation come alive from a tide-pool amoeba, which forms a torso that eventu- ally sprouts an arm or leg, and eventually the creature speaks, dances, punches, and does other things to display a range of emotion. "One thing I hadn't thought about before I came here was this concept of using player creativity as a design tool in games," Hecker says. For Spore, that means using an editor, infl uencing player choices about what to place into their own world or universe, and erecting walls around the outside of a level so that the character can't jump out. Given the unique nature of Spore, Heck- er was anxious about whether adrenaline junkies who are accustomed to sweating it out on the Halo game series or Grand eft Game players are content creators, evolving their model from an amoeba (above) to an advanced life form. Particle-paint scripts assess the creature's morphology during modeling and animation.

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