Cloning an audience
Theater matte shot for Se Habla Español
Director: Gabriel Del Rio
Problem: The plot of the movie hinges on the fact that the lead character has stage fright. At the end of the movie he is forced onto stage in front of a large audience at a film festival.
Just the Facts: I happened to be visiting the set the day they were shooting the stage fright scenes in a medium sized theater in Washington D.C. and despite having invited over a hundred people to come and be extras, the production only ended up with about 20 people and that included the crew. Key grip Joe O'Ferrell who I had done some visual FX work for on his first movie Franky's Heaven suggested to Gabriel that we might be able to clone the audience.
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How it was done: I was invited to direct the visual effect. The first thing we did was to lock down the camera (which was on a tripod on the stage facing the audience). It is always easier and much, much cheaper to do Visual FX when the camera has been locked down, and by locked down I mean, it doesn't move, doesn't pan, doesn't zoom, doesn't dolly, doesn't get refocused, it needs to stay perfectly, absolutely still. Even the slightest jiggle could add hours to the effect production. I am always surprised when I tell directors and cameramen that, and they still move the camera. "I didn't think you meant I couldn't move it this way..." Once you move that camera you have added several hundred percent to the cost of the shot.
With the Canon XL 1 camera locked down and recording we moved the extras from one group of seats to another, being careful to redistribute the audience and try and change the appearance of extras who stood out from the crowd. Sometimes we had them put on a jacket, a hat or a sweater, trade with a neighbor, whatever we could think of. If you look at the stills long enough you can pick out the duplicates (after all we only had twenty people trying to like like two hundred). But in the context of the 10 second shot in the darkened theater it was not noticeable. We also did the shot with the house lights on as it is easier to darken the scene in post and there were times in the movie that the lights were on, were going off, and when a projector was running. All of that was done in post. Another thing to be careful of is to not put two people in the same place at the same time. and to make sure you fill in all the empty seats. That can actually get kind of complicated because with everyone moving around you lose track of where people just were. I had drawn a quick grid of the theater that I was using to keep track and it worked even though we were winging it. A digital camera would have been helpful as a reference. We obviously did not want to touch the Video camera .
It only took about 20 minutes to shoot all the shots we needed to fill the entire theater. Then came the fun part.
I grabbed clips of the audience in various seats, I think there might have been ten shots. and they were all layered in After Effects (maybe version 5.0 at the time). Starting from the front rows as the top layer and working back in the rows and down in the layers, I used the mask tools to draw an outline around the last group of people in each shot which revealed the shot underneath and so on until all of the rows had been revealed. In some cases the mattes had to be animated as heads moved but we had requested that the extras in the back row of each shot not move their heads too much.
As it happened I had been working on a matte shot of a theater for my own project so it was decided to incorporate it into the audience shot. My original matte shot had been designed as a crane move from the roof through the attic, past the balcony and down to the main seating area. For this shot we would only need a crane move from the lower floor up to the balcony.
The artwork for this matte was started in Lightwave as a 3D model of an older theater from the forties or fifties and I did a lot of online research using the images search in Google to find interiors from classic theaters. The design was a combination of several that I found. I didn't want to go to all the additional work of mapping textures onto the 3D objects and animating them in lightwave so I just rendered out the basic structure. Since in the end we were going to be doing a 2D move in AfterEffects (now I would use the 2 and a half D feature that AfterEffects has) the different layers of the theater were rendered from a perspective that could be panned and would be convincing. If you study old layouts and backgrounds from Disney movies you will notice how the perspective changes are built into the artwork so as you pan the artwork below the camera it appears that the perspective is changing. Perspective is a huge part of most artwork especially matte paintings so it is good to have a through knowledge of it.
Once the renders were made, textures were added to the different parts which were kept on separate layers in Photoshop. The wooden beams of the attic were textured from some digital photos I took of beams in an old barn. The balcony and lower floors were taken from scans of artwork or photos.
After the artwork was completed I went back to Lightwave and rendered a small animation of the crane move on the 3D model. This was also brought into AfterEffects as a reference for the movement of the perspective which I tried to match using the 2D layers from photoshop. The footage that had been created from the live video shoot was matched onto the seating in the Lightwave/photoshop theater with the crowd being cloned for the balcony area as well. In the final shot the camera starts on the front row and rises to view the crowd in the balcony. By varying the timing of the layers in AfterEffects I was able to make the perspective shift work fairly well.
In AfterEffects you are able to work on a very large canvas and move your camera around on it. (or move it under the camera is another way of thinking about it.) It can be confusing to work with at first, but it works a lot like the old style of animation and the multi-plane camera so it always made sense to me. If you pan a background it looks like the camera is moving. If you scale something down it looks like you are moving away from something and if you scale it up it looks like you are moving towards something. Of course you don't really want to scale your artwork up past 100% (well maybe you can get away with 110-120%) so what you have to do is make your artwork very large then scale it down in AE then scale it back to 100% when you want to zoom. Yeah I know this is confusing, think of it this way. You want to drive to Baltimore for steamed crabs, you have a state map which when unfolded blows all over the car, so you end up folding it to the section that covers Baltimore. Well the folded section is like your frame for the finished zoom. This is what your camera sees. We haven't changed the size of the map we are just looking at a smaller section of it.
I hope you have learned a few things from this article. I use the cloning technique all the time. It was used last summer to clone Civil War soldiers for The Battle of Chantilly (directed by Bert Morgan) and the zoom into artwork technique was just used in the HD movie Prayer Life to show a zoom from outer space to a chicken farm in China.
