| | X-Factor A few years back, the big buzzword in console gaming was "3-D." Every new system, game, and marketing sell-sheet was plastered with catchphrases like "realistic 3-D worlds!" and "amazing 3-D action!" A few years later and it's almost impossible to find a game that doesn't employ fluid, jaw-dropping, real-time rendering. Aside from some fancy lighting techniques and texturing tricks, we've been playing in the same polygonal worlds for what seems like ages.
And then physics came along and turned video games upside-down—literally.
Half-Life® 2, the sequel to the award-winning 1998 Windows PC Game of the Year, is the latest Xbox® game to showcase this most recent craze in gameplay. Rather than place gamers in a static, lifeless world, the designers have littered the environments with objects that act and react in realistic—and sometimes unpredictable—ways. Read on to see how Valve is pushing the Havok physics engine to its limits, taking first-person shooter action to the next wild level, and why the Xbox is the only console of this generation that can handle it. 
Environments feature real-world physics. Physics Education
Physics systems in games aren't new, but they've never been more realistic, either. What are physics? In layman's terms, gameplay physics simulate object interaction inside a game world based on real-world rules. For instance, if you were to roll an empty garbage can down your street, it would pick up speed as it travels and perhaps veer off in unpredictable directions based on gravity, imperfections in the road surface, wind, and collision with other objects like rocks and sand. Try rolling that same can down the same hill a second time, and it's guaranteed to bounce, tumble, and land someplace entirely different. It's that same element of fuzzy unpredictability that makes the inclusion of physics systems in games so compelling—even though you can ballpark the results of your actions, outside interaction from NPCs, moving objects in the environment, and other influences all add that sweet element of surprise.
Since sophisticated physics engines like Havok essentially turn virtual worlds into three-dimensional playgrounds governed by Sir Isaac Newton's laws, we're seeing more and more games with emergent gameplay. In other words, unscripted events and unique experiences are commonplace in games like Half-Life 2, and it's all thanks to physics. Still not getting it?
Take this scenario: As protagonist Gordon Freeman enters the creepy streets of Ravenholm, he eyes a creature on a nearby rooftop. The enemy's A.I. makes a conscious decision—pitch a few oil-laden fuel barrels off the side of the building. As the containers hit the ground, they bounce and roll like ordinary cylinders. Run up to a barrel and push it down the hill; it'll tumble down the block until something stops it. A cluster of zombie-like entities shamble into view and collide with a barrel, where a simple shot from your pistol ignites the fuel into a slow blaze. Moments later, the container explodes, sending enemies everywhere and setting some stray tanks on fire, which in turn sets off a dangerous chain reaction of blasts next to you, causing you damage. It is dynamic moments like this that define gameplay physics, and make Half-Life 2 an experience not to be missed. 
Burn, baby, burn! Number-Crunching
There's no denying that physics, when creatively implemented, enhance the gaming experience. So why don't more console games employ middleware like Havok? The answer lies in the hardware. In simplest terms, the Xbox is the only current-generation videogame console that can handle the steep graphics and physics requirements that a game like Half-Life 2 demands. It takes a lot of computing power to keep track of every object onscreen in a first-person shooter—especially when every object has weight, mass, and other properties attached to it.
In order to keep up with the onscreen action, vast amounts of data must be processed on the fly. Such activities require lots of RAM, which the Xbox has in spades. Couple that advantage with a fast CPU and massive data-streaming capabilities, and it becomes evidently clear: Half-Life 2 wouldn't be the same on any other console. That's why it's an Xbox exclusive.
Keep checking back for more updated content on Half-Life 2 as the title nears release, including combat tips and strategy walkthrough coverage. By Franklin Beans |
