Like clockwork, Activision pushes out a new Call of Duty game every year, even going so far as to pretty much claim the first half of November as its launch window. The company has been releasing new versions of the game by shifting settings, evolving plotlines, and making new characters, all while keeping its much-beloved multiplayer mode. Earlier iterations of the game focused on World War II, while the last few games have wandered between modern-day conflicts, WWII, and the 1960s.

We went through the PC versions of Modern Warfare, World at War, Modern Warfare 2, and Black Ops to see how the graphics have evolved. For the most part, the developers have kept the changes to a minimum--and with good reason. It would be difficult to heavily modify the game's engine while sticking to a yearly release schedule and popping out versions that work well on every modern console, as well as the PC.

Exteriors

The locales change drastically within any given Call of Duty game, and they change even more so when we pop from title to title. This makes any sort of direct comparison impossible. Overall, we noticed that the lighting and shadowing system for buildings is still static. This stems from the use of either fixed lighting or prerendered shadows. The result generates effective visuals without the need for lots of GPU power.

Black Ops Modern Warfare 2 World at War Modern Warfare Black Ops Modern Warfare 2 World at War Modern Warfare

Faces

The Call of Duty series focuses a great deal on character faces. When we look at people when they speak, everything else becomes secondary. With all your attention focused on the head, shortcomings of less-detailed clothing become irrelevant. Black Ops has highly detailed facial animation, although the series is still plagued by the occasional flickering facial shadow, which certainly doesn't help maintain realism.

Black Ops Modern Warfare 2 World at War Modern Warfare Black Ops Modern Warfare 2 World at War Modern Warfare

Interiors

While we certainly didn't get to examine every room in all the games, it seems like Black Ops increases the amount of detail that can be stuffed inside of four walls.

Black Ops Modern Warfare 2 World at War Modern Warfare

Black Ops Modern Warfare 2 World at War Modern Warfare

Foliage

Given Treyarch and Infinity Ward's penchant for speed, we didn't expect much to change when it came to the grass, bushes, and trees. Increasing the quality of foliage becomes more taxing than it's worth in a series like Call of Duty.

Black Ops Modern Warfare 2 World at War Modern Warfare

Black Ops Modern Warfare 2 World at War Modern Warfare

Settings

The settings page for the PC versions of these games gets simpler and simpler with each new version. A few years back, you might have needed to turn off depth of field or specular maps, but newer GPUs don't bat an eye at those settings within Call of Duty.

Black Ops Modern Warfare 2 World at War Modern Warfare

Sky

While all these sky-related screenshots look different, they share one common thread: they're all static. Look upward in any of these games, and you'll notice that the sky isn't animated. Many games use day-and-night cycles paired with active weather systems to give a more realistic look. Treyarch and Infinity Ward opted to save precious computational horsepower in order to keep frame rates high. The result may not have moving clouds, but it's still quite nice to look at.

Black Ops Modern Warfare 2 World at War Modern Warfare

AK47

Compared to the Modern Warfare gun model, the two recent versions of the game have more in the way of minor details like serial numbers, scuff marks, and the like.

Black Ops Modern Warfare 2 Modern Warfare

Hallways and Walls

Many of the walls and hallways feature gritty, bumpy bricks, splashes of blood, and location-appropriate signage. The overall detail and the use of physical objects seem to have been fairly static over the years.

Black Ops Modern Warfare 2 World at War Modern Warfare Black Ops Modern Warfare 2 World at War Modern Warfare

The Call of Duty series keeps moving the bar higher on the graphical front, but the developers are clearly focused on maintaining speed at the expense of graphics, and with just cause. In areas like facial animation and facial texturing, the entire series holds up well and leaps forward with each iteration. But when you look at random objects, textures, clothing, lighting, and shadows, the developers have to make tradeoffs. Perhaps when the next generation of consoles comes about, we'll see the series flex its graphical muscle a bit more.