Muffie Meyer, producer/director: Alexander Hamilton spent most of his adult life in New York City, but no place still exists that looks like New York in the 18th century. So we decided to recreate a New York City street using computer generated effects.
Here's the raw footage that we shot.
This is the same shot after we added special effects.
What we realized was that the most important element was the kind of 18th century cobblestones that would have been on the streets, which were very hard to find. It's not those flat brick things that you see in many cities. They're lumpy. And not many of those kinds of cobblestone streets still exist. But we did manage to find a few places that had them, and we ended up choosing one in Alexandria, Virginia.
Voice on set: Action!
Meyer: We took our basic shot with a cobblestone street, a horse, a carriage, and a dozen or so people in costume.
New York in the 18th century was busy and crowded. We didn't have enough money for a huge cast of extras, so we filmed eight or ten people in front of a green screen.
The green screen makes it easy to separate the people from the background, and put them wherever you want.
We shot each of them a number of times, each time doing a different activity, so that when they were placed in the shot, it would look like a crowd.
Even though some of the Alexandria houses actually were 18th century, it just didn't look like a New York City street. New York City's architecture in the 18th century was very motley looking. There were three-story brick buildings next to squat wooden buildings. There were very few trees. And it looked like it was built higgledy-piggledy. That's the look we wanted to go after.
So in order to replace the Alexandria buildings with New York City-style buildings, we went around to places like Newport, Philadelphia, and Annapolis, taking stills of buildings that looked like the ones in the drawings and paintings.
There were two kinds of typical New York buildings that were particularly hard to find. One was a kind of gambrel roof, barn-like building that we ended up finding in Newport, Rhode Island. And the other was the kind of Dutch-style building with a stepped roof that was very common at the time. We eventually had to hire a photographer in Holland, because that kind of building doesn't exist anymore in the United States.
The next step was to get rid of all the stuff we didn't want: the original houses, the end of the street with all the traffic going by, et cetera.
The shot that we took is a crane shot: that is, the camera started about 18 feet off the ground, and then swooped down and forward into the street. So the question was: how do you keep the perspective of that moving shot, but replace the three-dimensional buildings with two-dimensional photographs?
Chris Healer, The Molecule: The issue is that you are trying to add 3D elements to a shot, and the shot has a moving camera. So how do you view those 3D elements and render them so that everything registers together?
Meyer: Chris Healer and his team at The Molecule created the visual effects for the film. What he did was, he made a 3D grid that matches and tracks the camera motion.
Healer: (demonstrating on computer) What we have is the tracked camera, and the tracking points, and if I look through this camera -- this thing right here is the camera -- now, if I look through this camera, you'll start to see that the points actually line up. So as I get closer and closer to it, you can see these start to line up. All of a sudden, everything registers together. So, if I scroll through, you can see that, as the camera moves, the points move with it, and they all feel together. Now, everything has been parameterized into a 3D world.
The objective was to add certain elements and take other elements away.
Meyer: The amazing thing is, Chris can take flat photos and turn them into three-dimensional buildings -- buildings that you can see from various perspectives. First, he makes little grid models based on the photographs, kind of little building blocks.
Healer: We started with this picture, just a regular old digital photograph. So if you notice, up here, you can't actually see this top piece of the roof. You can't see that one segment or the back two segments. So...
This photograph is then projected in 3D onto a model, which is just a simple model, it's just basically a simple barn. And so you can't see, you know, up here, the texture doesn't exist, because in the original photograph, that segment was missing. So... It means that in the final shot I actually had to fake this chunk right here. I knew that it was going to be off in the distance somewhere. So I just grafted a piece of this roof, and flipped it, and rotated it, and stuck it in.
In the actual shot, it's actually flipped horizontally, and then rotated and placed a little ways down the street. So this being our final shot, now you can see -- here's our barn.
The placing of the figures is what takes up most of the complexity. Here's one of our guys, with his matte. They get keyed and then color corrected, and a shadow added of some kind. So this guy right here, that's him composited into the scene so you can see that. Here he's just raw, with a matte, he's got kind of a rough shadow. And here, we've added a tree shadow on top, color corrected, and made the hot spots on his face roughly match the hot spots in the other areas of the scene. And then added a little bit of grain, and made the darks match.
I mean, really, the shadow -- the shadow and the contrast between the light and the dark side are what glue something into a scene.
Meyer: I really wanted pigs for our shot, because they roamed the streets of New York. They were the 18th century garbage collectors. So we hired a couple of heirloom pigs and shot them against green screen.
Healer: When you're building the scene, and you're putting in layers, it's almost 100% chance that a layer is going to be the wrong size when you put it in there. You have to scale it, and get it to sit in the right space.
Meyer: Here's the pig before Chris brought it down to scale. And here it is after.
Healer: So... I have my houses, which are all 3D, just stacked one by one on top of each other, going all the way down the street. And after I add all the pieces together, I have a whole street. This gets added to our alpha channel, and you end up with this. This is our houses, plus the raw footage with the matte cut, there's a little bit of water back here, and there's no sky yet. Now if you add people to the mix, and you add our sky, and then a little more color correction, and we end up with our final shot.
Meyer: This is obviously a completely artificial process, but it's kind of a metaphor for what one has to do when making historical films before photography. You take the few elements that still exist, real buildings scattered around the East coast, or real words, and combine them, to give a sense of what Hamilton and his world were really like.
Exclusive Corporate Funding is provided by: