This has baffled me as to what film producers do to film a movie or an episode based on an entire city.
Examples of this is as seen in the movie Day after tommorrow where a tsunami hits the city itself, and the city is caught on camera from above being submerged.
In White House Down, this is another prime example because the White house itself is in the city of Washington DC. How did they manage to film something like this in a settlement that looks just like the city itself?
In Charmed(series), this is another one because demons roam the streets and the surroundings is a city. The film producers use proportion of the city. I do believe the opening scene of the large proportion of the city was just shot in either a plane or a helicopter that flew around the place.
Divergent (and the other movies in the same story) is also filmed in the *Chicago City Experiment (basically the city of Chicago) and the people inside it.
How do film producers film movies based on entire or a proportion of towns and cities?