At E3 2002, Ion Storm showed off some of the impressive technology behind the new game, notably the dynamic lighting. The studio licensed the Unreal engine and Havok's physics system but decided to rewrite the graphics engine to support Doom III-like lighting and normal maps, which are textures that create shadows on the characters and environments as if they were made up of many more polygons. With the normal maps, if you look at one of the 3000-poly characters in full bright light, you might not see many wrinkles in its clothes or the relief of its ears, but under low, directional lighting conditions there will be appropriate shadows that highlight such details. As we've seen before, the physics and lighting work together to create some cool effects, like being able to shoot lights on chains to make them move and cast dynamic shadows. Every light in the game is dynamic, which does push up the game's hardware requirements quite a bit. But producer Harvey Smith said that it's worth it because it takes the gameplay to another level. And while Doom III is the only other game announced for 2003 with such a lighting system, it should be the norm a couple of years down the road.