ReadWriteBuilders is a series of interviews with developers, designers and other architects of the programmable future.

Torsten Reil, a neuroscientist by training, was an unlikely videogame entrepreneur. Then he founded a company, NaturalMotion, whose Clumsy Ninja blossomed into an unlikely mobile gaming success. Then fast-shrinking social-game house Zynga bought NaturalMotion for a half-billion dollars, suddenly casting Reil in the unlikely role of potential savior.

What were the odds?

Zynga, the notorious creator of FarmVille, Words With Friends and a spate of gambling games for mobile and Facebook, owes its boom-and-bust trajectory more to its remarkable understanding of how to get people hooked on things than its largely unoriginal, ad-glutted products.

NaturalMotion, by contrast, may not ring a bell—but you’re probably more familiar with the company than you think. Ever seen a Grand Theft Auto V character throw a punch or leap out of a flaming hotrod? That’s NaturalMotion doing what it does best: quietly powering lifelike animation sequences, generating them in real time—and making it look easy.

When technology is convincing enough, when graphics move and feel like things would in the real world, you don’t stop to marvel at it. In those cases, you’re too busy playing the game.

Many games touched by Reil work just like that. As the CEO and co-founder of NaturalMotion, Reil built motion graphics engines that power some of the most immersive video games ever made. As fluid as those gameplay experiences feel for the player, someone along the way had to figure out the complicated physics of, for example, a cowboy getting shot off a horse that's running at 25 mph.

That’s the unsung job of NaturalMotion’s graphics middleware, Euphoria. It's a kind of artificial intelligence that simulates animated movement in real time; it can determine precisely how the cowboy’s limbs will splay out and, presumably, where his hat would land, when he's shot off his horse. The same logic (literally) applies for the NaturalMotion's popular mobile games, from CSR Racing to its more recent charmer, Clumsy Ninja.

I chatted with Reil a few weeks ago about NaturalMotion’s journey from powering hit games to crafting its own, and how Reil’s vision and technology could open a chapter of innovation in mobile game development—something Zynga isn’t exactly known for. Our discussion predated the Zynga acquisition.

On Making Magic

ReadWrite: I know that you have a background in research, specifically neuroscience. How did NaturalMotion spring out of that?

Torsten Reil: I was working with the Zoology Department [at Oxford] trying to do realtime simulations of different creatures that would essentially learn how to walk. I created a simulation of their body and their muscles and of the motor nervous system. And we actually managed to get, essentially, stick figures to walk more or less naturally. That’s how the company started and also hence the name NaturalMotion.

RW: Before NaturalMotion started making games, you all licensed your motion simulation technology to some pretty cool projects. What were the early days like?

TR: [Our] technology was used essentially as virtual stunt men in movies like Lord of the Rings or Troy or 10,000 B.C. And then after a while we realized that it would be amazing to use this technology in realtime, in games. We were approached by Rockstar Games and ended up working very closely with them, developing our technology called Euphoria.

Euphoria drives, for example, the character interactions in Grand Theft Auto IV or most recently Grand Theft Auto V as well as games like Red Dead Redemption or Max Payne 3. So we originally started out doing that. And for us, the big promise of [those projects] was that it is possible to essentially create magic using technology.

So that was how we started. We then realized, not a long time ago actually, that the iPhone was becoming fast enough to run our technology in realtime. We believed there was a big opportunity to create games on mobile devices that were different from the games that were around at the time.

The Anti-Zynga

RW: NaturalMotion has a lot going on. What unifies all of those moving parts?

TR: What we do is create games that are different from other people's games. We don't believe in taking from other people's games or copying people. We believe in doing original content and making it feel magic using technology.

A lot of people compete for the same audience with very similar games. We feel that that is not a way to create a sustainable business. You have to innovate, you have to essentially own a genre and do it in a different way so that the audience wants to download the game. So essentially, the product becomes the distribution strategy—not the other way around.

I'm personally very excited about using simulation more in general ... whether it's for generating movements, natural processes like water, landscapes ... essentially starting to simulate the world rather than trying to emulate it by making it look like [itself].

Simulate, Don’t Animate

RW: How is simulation different than how most graphics animation works?

TR: Usually the way characters are animated in games is that [the game] play[s] back animation that you've pre-produced. And what we've tried to do is actually simulate [animation] in realtime so that the character can be different and surprising every time you interact with them.

[On mobile], a lot of people have been working on 2D games, essentially taking Facebook games onto mobile, like zookeeping games for example, and a lot of the games end up quite similar.

We thought that there was a huge opportunity to create much richer, much more believable games, using our technology and really high end graphics. And the reason we thought that that would work on mobile devices is because of similar trends in animated movies: animated movies went from Snow White in the '30s then obviously to Toy Story, Toy Story 3 or Monsters Inc., more recently.

And Pixar used technology really well to create believable experiences and we knew that the mass market audience loved it. We thought the iPhone and mobile [users] were actually quite similar to the cinema-going audience [and] there was a big opportunity to wow that audience as well....

[NaturalMotion's] breakthrough came with a game called My Horse, which was a horse simulation—completely out of the blue for everyone, including ourselves. I was never really particularly into horses.

RW: And then you made the (big) leap from a horse sim to CSR Racing, a polished game in a well-established genre.

TR: [CSR Racing] gave me the confidence that we could build a games company on this premise—and that is to disrupt genres, to innovate and to create a really believable and rich experience for the audience.

The Secret Recipe

RW: Obviously, mobile and console gaming are very different modes of play. What makes you so excited about mobile?

TR: One things we've noticed, particularly with Clumsy Ninja, is that touch makes a huge difference... when you touch the ninja and he gives you the thumbs up—it feels like it's real.

RW: Why did you decide to make casual games with Euphoria’s sophisticated technology? In some ways, Clumsy Ninja is the quintessential casual game.

TR: I like the idea of trying to take [something like Euphoria]—which is pretty complex underneath and uses a lot of computing power— and make it so accessible that literally kids could play with it. It's kind of the way we like it. Ideally it just feels new and fresh and a bit like magic—but they shouldn't really care that there are pretty complex physics and AI simulations running in the background.

RW: What is going on under the hood exactly?

TR: We focus a lot on building a character skeleton that is a physical simulation. If you think about how your arm moves ... it can only bend so far. At some point you can't bend any further. And the way that resistance works is actually really specific.

Tuning all of those parameters for all the different joint types turns out to be essential for creating believable motion. One of the things that's particularly tricky with anything humanoid, like Clumsy Ninja or characters in GTA for example, is that if you don't get it right, it will feel really weird to the audience.

So we spend a lot of time tuning some of the basic biomechanics of the body, but then on top of that obviously we have all of these artificial intelligence controllers ... that all talk to each other. For example, the ninja might be trying to protect his body because you're throwing a melon at him, but at the same time he might also need to balance on a beam. Our controllers work in such a way that the artificial intelligence will prioritize all of the different tasks by itself, and it will do it in a pretty clever way.

And on top of that, we let the ninja “see." [The character] can see everything in the environment and any type of object that's coming toward him. He’ll try and calculate roughly when the object will hit him and the try and take evasive action. The whole set of things that are all running at the same time hopefully get orchestrated in a way that just looks like you're watching a performance. But it took us about 12 years to get there.

Lead image of Torsten Reil, a clumsy ninja and the Zynga logo by Madeleine Weiss for ReadWrite