Home | News | Reviews | Previews | Hardware

CoD's New Engine
Company: Activision
Product: Call of Duty: Ghosts
We recently got a chance to check out some of the technology behind Activision's latest Call of Duty game as it will be seen on the PlayStation 4 and the next Xbox console.

Given the sheer power provided by the new wave of consoles, Infinity Ward decided to take this opportunity to completely redesign the engine that drives Call of Duty: Ghosts, and from what we've seen, you can expect some pretty impressive visuals. Infinity Ward said that they worked with several people in the Hollywood visual effects world to understand the cutting edge of CG in films and worked hard to incorporate a lot of the tips and tricks they learned with those collaborations into their new game engine.

While the new engine gives the game the ability to push out more polygons and even more particle effects, there are two specific technologies added that really make the game shine. Both involve being able to dynamically add polygons to the world as the game sees fit.

Displacement mapping is an alternative to bump mapping (a buzz word a console-generation or so ago). Where that technique made objects appear to have a less smooth object than they actually did, displacement mapping actually adds the necessary triangles to the object in order to truly give it the shape it is trying to model. What this means is that instead of walking up to a rocky wall and seeing that most of the apparent jaggedness and depth was actually a result of a good texture artist, that rock wall can have the complex surface it needs in order to really sell the world.

If I understand displacement technology right, this gives the developers and artists an interesting bit of freedom. Instead of having to actually build a complex object full of geometric detail, the world can be filled with fairly flat models. The detail comes in the map that is applied to the model in-game, and from what we saw, it can be tuned up or down as the game decides what is necessary. It wasn't clear to me if this was the case, but what I can see happening is that the game engine decides based on how close you are to the object, just how much detail it needs to add. For instance, if you are a good distance from that rocky wall mentioned earlier, the game could decide that you don't really need to see a lot of the extra geometry until you get closer and are inspecting the wall. Not only should this make the development of the environments easier to develop, but it should make for a less complicated rendering process since the models that need fewer polygons will have fewer, and the game engine really only has to work hard on the important models close to the player.

The other bit of game engine magic that Infinity Ward was keen to show us involves a technique called Sub-D. This system also uses the new game engine's ability to add polygons on the fly, but its goal is to make the models smoother. The best example of this was when the developers showed the character looking through his scope. Without Sub-D turned on, you would see the standard jagged-edged "circular" tube, but with this feature in play, the game adds more polygons and sub-divides the existing geometry to make smoother curves. The result is what appears to be a perfectly circular object just like you would expect to see on a real gun.

Curious about how well CoD: Ghosts will look on the current generation of consoles? Infinity Ward talked about the fact that they actually work at a much higher resolution than can even be used in the upcoming console specs. From there, they tune down various aspects of the levels and characters so that it can run well on the target platform. The Infinity Ward spokesman assured us that Ghosts will still be their best looking product on the current systems.

It's clear that Infinity Ward is putting a lot of effort into the engine's ability to add more complex geometry to the game on the fly, and from what we were shown, it does a lot to add some serious realism to Call of Duty: Ghosts. This, coupled with a new lighting engine and still keeping the game at a solid 60 fps, means that we should be expecting a lot, not only from Ghosts, but from the next-generation of hardware and software in general.

Not everything we learned was about the engine, though. We did get some interesting tidbits about the game's story. For one, the developers at Infinity Ward have decided to completely break away from the Modern Warfare story, so while this game is called Ghosts, it is not a reference to the previous games' character of the same name. Instead, you play with a small squad of fighters made of the elite of the elite. Some cataclysmic event has happened and the U.S.A. is no longer a superpower. You and your squadmates, including a highly trained dog, are out-numbered, out-gunned and out-teched. You are not the highest thing on the food chain anymore and you will have to work hard to achieve your objectives.

One of more stunning parts of our time with the game involved an underwater sequence where you and your squad use scuba gear to navigate a sea bottom in order to get to some enemy ships. This environment was filled with underwater life that seems to react to your movements as you progress through the level. This particular mission culminated in attacking some of the enemy ships and the destruction that is wrought from that attack. As ships sink, your cover is blown away and sand floods the screen making it hard to see, and it all feels like a really believable scene.

While the demonstrations of Sub-D and displacement mappings really showed exactly what the technology does, it was this mission that really sold the feel of the game as a whole and just how strong the new engine is.

-J.R. Nip, GameVortex Communications
AKA Chris Meyer
Related Links: