The decision to use VFX as an adjunct to live action is never taken lightly. But how else do you 'show' the Times Square of the period? What we had available when we shot this sequence was 30 people, 10 cars, a length of pavement, a lit awning and a ton of greenscreen.
Look frames had already been established with Baz and CM and Animal Logic constructed a 3d version of the same. The extra people in the background were a mix of additional bluescreen sprites and CG people.
In an odd way 3d production processes are rather similar to traditional film making. The digital sets are designed and look frames are established, we build, texture, colour and light the 3d models and then we use them in production. As a result we used the same design and production methodology and also concept art and artists.
Side note one: The reason we jump from bluescreens to greenscreens is simple. I always use bluescreen for stage and greens outdoor. But by the time we got to this scene I already had 1.7km of screens hanging and we simply ran out of bluescreens for this studio work.
Side note two: For accuracy in making this film we engaged a lovely gentleman called Bob Singleton from the Greater Astoria Historical Society. He could tell us the building style, street furnishings, lamp posts, colour palette, bunting, awnings, etc, right the way from Long Island through to New York itself.