The Differences of the Graphics Engine in Both Games are "Huge", According to Sledgehammer.
Since Call of Duty 2's release back in 2005, all the entries in the Call of Duty franchise has been using the same Infinity Ward engine. Despite the fact that there has been numerous modifications and upgrades to the engine, many people are concerned that the look and feel of the games is rather "dated" when compared to the current circulating game engines. Modern Warfare 3's co-developer company's general manager, Glen Schofield of Sledgehammer, states you should think differently about MW3, stating that the engine in MW3 is more like a porsche according to an article in Incgamers.com
"I'll tell you one thing...I've worked on a lot of engines over my lifetime and spent a lot of time putting graphics in to them and this thing is [like a] Porsche. And what I mean by that is that it's stream-lined, everything in it is perfectly freaking clean. You can tell it's been worked on for years. It's easy to upgrade."
Schofield continued on stating on how Modern Warfare 3's engine will provide great improvements when compared to the other games in the series:
"We worked with engines before that are like spaghetti...you can't work on a part and put it back in without messing with everything else...[Modern Warfare 3 will]have a bigger footprint and on top of that, higher fidelity, more textures and a lot more detail.If you put Modern Warfare 2 next toModern Warfare 3 you would see a huge difference...there is so much that we've added, so when someone says 'cut and paste', I don't even want to talk to them because they don't know. They just don't know. They have no idea."
Schofield's statement was pretty bold and brash for a developer. He must have a lot of confidence to state to his critics that they have "no idea". However, this is an industry that is very complex and very strenuous in many different aspects. Some outsiders probably don't understand how fragile a game can be, especially on its graphics engine.