The control room is completely created through the use of CGI and green screen. The set consists simply of bare desks and actors who mimic movements which are later matched which computer generated images.
Examples of CGI can be seen when one gamemaker creates a fireball in the control center and then pushes it towards Katniss.
Another gamemaker creates a hologram of a mutt on a touchscreen interface and places it in the arena near Katniss and Peeta. Both the fireball and the Mutts are created with CGI but look extremely realistic.