Sam Parker Hardware Editor	Now Playing: Warcraft III Beta,Warlords Battlecry II, Morrowind Most Wanted: Warcraft III Final, Master of Orion III, Unreal Tournament 2003

More Than Pretty Pictures

We all know that screenshots don't perfectly represent how a game looks. A still image can't capture half of what makes or breaks a game's graphics: motion. Even so, game graphics aren't just about moving pictures either; otherwise we'd still be in love with the full-motion video and prerendered 2D environments of mid-'90s adventure games. While certainly different games deserve different approaches to graphics, I've recently seen some new 3D technology that I think will really open the doors to more action-packed, believable motion in games, and not surprisingly it's based on better integration of physics and animation. There's no reason to think games will be able to do real-time animation anytime soon that will look better than animation that's hand-crafted by an artist. But great physics modeling is one way to make games look that much more believable.

It's easy to find examples of games that look nearly photo-realistic at first look but reveal many noticeable inconsistencies that break a nit-picking player's sense of immersion. Game developers can now produce 3D games using superhigh polygon counts and highly detailed textures, but it's much harder to get movement right. From boxing games where the punches don't really connect with the opponent to first-person shooters with enemies that always react the same way to bullet hits, photo-realism in today's games is limited by disconnected and repetitive animations and a general lack of interactivity with environments. These are some of the reasons John Carmack gave us for id's less realistic approach to the next Doom game when we interviewed him at last summer's QuakeCon.

Resident Evil's approach to prerendered environments allows for great lighting effects, but there are some flaws to the composite 2D/3D engine.

Slapping higher levels of detail onto old games doesn't necessarily make for a better game. Just look at the new remake of Resident Evil for the GameCube: It's pretty, but the core game is unchanged from the 1996 version. As good as detailed 3D models look against prerendered backgrounds, when graphics try to look that photo-realistic, every unrealistic detail sticks out like a sore thumb, from problems with characters clipping through fallen monsters to fixed camera angles that are occasionally unwieldy.

The game industry's answer to the limitations of prerendered graphics has been the move to 3D. So why does skillful 2D art often still look so good? From the backgrounds in Resident Evil to the impressive art in PC strategy games like Commandos 2 and Disciples II, 2D art still has its place, because it can often be made to look sharper, more artistic, and more smoothly animated. Additionally, blends of 2D and 3D can often make games less hardware intensive or allow for key gameplay elements, like having thousands of units in a battle in Shogun: Total War. But while 2D art looks great initially, the amount of graphical variety in 2D games depends on how much time artists spend creating different animations.

Going 3D has a number of advantages, including the ability to create a world system that isn't all predefined by a game's developers. The rocket jump in Quake or Warthog jumping in Halo are examples of how players can figure out how to do stuff with a game's physics engine that were never imagined by the developers. Still, only a few recent games (like Hitman) have had physics work on the individual limbs of character models to make them die more interestingly. And none have looked anywhere near as good as what we saw in the Unreal engine demos at GDC. Epic Games showed for the first time how it had integrated the Karma physics engine directly into the Unreal engine to allow for better vehicle physics as well as "ragdoll" character physics.

In addition to having new physics features, new Unreal engine games, like UT 2003, can handle huge environments.

With the Karma engine support, Unreal engine games can now have characters that fall limp as they die, smoothly bending limbs, head, and torso on a joint-by-joint basis to match collisions with the environment. At one point in the demo, a character fell from a tower, hitting objects on the way down, and the body reacted with each impact. We also saw a body smoothly roll down a flight of stairs and even saw two different bodies get their limbs mixed up as they rolled one over the other. One of the strengths of the system is that the Karma physics engine models the freedom of motion that joints should have, putting the constraints we'd expect on how a body can move.

One Karma demo shows a kickboxer practicing on a heavy bag that swings with each hit.

As it stands, the Unreal engine can do ragdoll physics when characters die and there's no friction on joints, so limbs move very limply. But a conversation with the designers of Karma at UK-based Math Engine has me convinced that this is only the beginning. Getting characters to react to a bullet or punch, then have an animated response, isn't as simple as the ragdoll example, because the physics system could put the character in any number of systems, but animation needs a narrow range of starting positions to transition smoothly. One solution would be to add constraints to how far a body can move from an impact before restarting its regular animation, and that's what Math Engine is working to do to better integrate physics and animation.

What has me excited about the new physics engine is the possibility of unleashing a burst of automatic fire on an enemy and seeing it react to each bullet hit before crumpling to the ground. Further down the road I'd like to see boxing games that actually model the contact between boxers and that knock an opponent back depending on the force of a blow. It's all made possible by applying some simple formulas to a 3D world. The beauty of physics is how well simple models represent reality. But to take all this into account, games will get more complex. Hopefully, with third-party engines, this sort of thing can become common without every game programmer having to create it all from scratch.