According to Jay's storyboard, we have a city that needs to appear in the background.
We will just incorporate a bit of his art to represent the city. Animatics often include everything from finished-looking elements to very sketchy portions. Their job is only to convey the overall editorial content of the shot, and, for most purposes, it would be a waste of time to create a complex and detailed image of the background city.
In addition to the city, we'll also need laser bolts, as the soldier fires at the battle tank and the tank shoots back at him. Animatics artist Ryan Tudhope fixes these up to look good for the shot, including some blast flares. David Dozoretz decides to add a few trees in front of the city, and shadows from the fighters overhead as well, which are even made to appear on the soldier as he runs toward the tank. While assembling the composite layers, David notes that the guy with the gun ducked slightly toward the end of the shot. This gives David the opportunity to link something to the actor's move by adding a stock explosion at that point, as well as a virtual boulder to help protect the soldier from the blast. So our man survives the confrontation with the tank after all.
All these elements, and the CG models as well, become individual layers within the shot. These must be assembled into one image, or composited, using a popular compositing program. Compositing blends all the layered elements together in one final video image.
In this process, David must specify which layers go behind or on top of others. The city is fitted in-between the trees in the foreground and the sky in the background. The tank is layered over the urban background but under the laser bolts searing the air in front of it, and so on. In the end, even for this example animatic shot, there are about 40 layers involved!
