With the exception of the security gate, guard office, a couple of the trees, a bit of roadway, the foreground grass and the pursuing agents, everything in the background is matte painted in,including the foreground curb that extrudes into the scene. We had very little processor space available, due to other projects in the house, and the model was very detailed, 67,000 polygons worth.
To simplify and speed up the render. I had all textures painted as orthographic projections of surfaces as seen from the camera's point of view, and had removed all the geometry from the model except for basic surface planes. All of the lighting is painted into the texture maps. I painted some of the White House, such as the portico, and did touch up on the other surfaces where needed for blending. I also painted most of the landscape and the front fence and barriers. Most of the White House and other buildings were painted by David Bailey. As you can see, the cheat works and cut down rendering time dramatically.