Faking a crowd

The casting process for AHRS was rarely logical- we tended to assign characters to faraway friends and family, so whenever someone was kind enough to visit Ann Arbor we would take them out for a hectic, marathon day of filming. We tried to run through the entire script, making sure we hit every scene with that actor present. However, our planning rarely made sure that the OTHER people from each scene were visiting at the same time.

A common problem for us, then, was how to deal with scenes that called for more than three characters at any single time (i.e. pretty much every scene in a squad-based war movie). Our writing process rarely made concessions to reality, and once we had something in a script we tried to figure out how we could get some approximation of it on film. The solution that we used for previous projects- crosscuts between actors who never met each other- will still show up in AHRS out of necessity, but it’s *cough cough* unconvincing at best.

Digital compositing software gives us some additional opportunities. One obvious option is the classic chroma key: filming actors separately, then removing the background to place them in the same shot. I'm doing this in several scenes with the character Torque, since Dave was awesome enough to make a blue screen studio in his garage, and we handled most of his scenes in Kalamazoo. This provides more flexibility in putting shots together, but the believability of the final result is dependent on subtle cues that require color correction, grain matching, etc. Frankly, I’m not experienced enough to create scenes that look natural.

If some of the characters are just nameless extras, an easier option is to stick the camera on a tripod and divide the field of view into distinct regions, then populate each area with the three or four people we had on hand. All that's required in post is to put a mask around each group and adjust the clip timing so the different sets of characters appear side by side. The final product doesn’t depend on my compositing skills, since all the actors are filmed in the same physical space under the same conditions. As long as you’re willing to forgive all the dopplegangers pointing guns at each other, then it's a very easy effect.

One example that you’ll see in the first chapter is a confrontation with a big crowd of armed dudes springing an ambush. The dozen or so combatants required about ten minutes of Becky, Mike and myself walking around a field, changing outfits and popping up from behind weeds.

In retrospect, the camera was far enough away that changing outfits each time was unnecessary; we’re kinda just little black blobs using my 2003 Sony Handycam (no HD issues here). But because no editing was required beyond masking the individual regions, we’re little black blobs that match our surroundings.

Note that in the final shot the most unnatural element is the “wreckage” I tried to stick in for plot reasons, so you might not even think about whether those dozen guys with guns are really there. Like I said, my compositing sucks.