the stay puft marshmallow man was puppeted by a motion capture actor, and reitman used a vcam — a kind of virtual camera — to record the action from a variety of angles that would have been pretty expensive to do in the real new york. he could shoot from street level, he could get up to building height, he could shoot from cranes, he could do drone shots. there's a great example of a happy accident during the shoot, where jason stepped backwards into a building and actually really liked the shot through the window, so we ended up doing some shots through a building window, down onto a street. and those buildings weren't built from scratch. see, unreal engine comes with 20 square kilometres of ready—made city to work from, complete with autonomous inhabitants. there's a system within the city where traffic is driving and coordinating junctions and avoiding other vehicles in a completely kind of organic way. we made some enhancements to that. very specifically, we had the challenge of driving the ecto through some busy streets and needing vehicles to pull out of the way of an emergen