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.