UNBROKEN: Philippe Theroux – VFX Supervisor – Hybride

Philippe Theroux started his career in the visual effects at Hybride in 1997. He has worked on all major projects of the studio such as SIN CITY, 300, THE HUNGER GAMES or AVATAR.

What are the sequences made by Hybride?
Hybride was responsible for the 1936 Berlin Olympics sequence.

What references and indications did you receive for the Olympic Games sequence?
The Internet proved once again to be helpful in finding footage of the event. We did a lot of research to find original photography and footage of the stadium, and we were particularly interested in any references that could show us how the athletes from each country were positioned while standing in the center of the stadium. Hitler’s youths formed white rows throughout the stadium that were also reproduced using our proprietary crowd tool. Officials and dignitaries’ positions on the field were also matched with CG characters.

Can you explain in details about the stadium creation?
The FG action was shot in Australia on an outdoor track. Unfortunately, the size and shape of the field didn’t exactly match the center field of the Berlin stadium. The production crew built an eight-foot-tall wall around it, representing the lower levels of the surrounding stadium. We then extended the location to replicate the 1936 Berlin stadium and track setting as faithfully as possible. The location was fairly empty, on one side there were modern bleachers that had to be removed, and on the other side there were trees in the background, but no buildings. So we cleaned up all of that, and then added the CG stadium. We did a lot of research to find original photography and footage of the stadium, and matched it. We modeled the correct architecture, textured it with the same stone used in the original stadium, and added details such as the giant clock on the pillar, the scoreboard, Hitler’s Nazi banners and Olympic flags.

How did you approach the crowd creation?
We have in-house proprietary tools to create crowds. Some of our tools worked with 3D characters and some with textures of people on cards. Both tools come with their own advantages and inconveniences. For this project we decided to go with textured characters on grids. Many of the live action shots took place on the sides of the field, so the camera is relatively close to the CG crowds. In fact, the CG crowds were close enough that we were able to read the facial expression for each individual in the crowd so we went with the “real people on cards” solution.

Can you explain in detail about the crowd creation?
First, we went trough the sequence and decided on the actions we needed for the crowds – people standing up, sitting down, applauding, waving flags, and so on. All of these actions were then incorporated into a very specific choreography that was comprised of 12 different actions. A total of 48 extras were required to create the entire crowd. They would film 12 extras at a time, sitting in a row, in front of a blue screen. The extras that were not being shot went through a costume change while waiting in order to maximize crowd variations. When they performed, the people on set would follow a video playback of the choreography that lasted a little over 4 minutes. Once the choreography was finished, the extras would rotate in their places, and the sequence was performed one more time to capture a different angle of the same action. In the end, every group of 12 performed the routine 5 times, from 5 different angles. Then they would start over, but this time with the camera placed at a lower position looking up, so that it would look like the people were sitting in the higher sections of the stadium.

We placed a grid for every seat in the stadium. Our software would then analyze the position of each grid in relation to the position of the camera, and would then chose the angle of the choreography that needed to be projected onto each grid in the stadium. This proved really helpful in the curved sections of the stadium where a single angle shooting will look totally unnatural and 2D. Using multi angle shooting, we can achieve a crowd effect that looks three-dimensional. We can also decide of a point of interest to have our crowds looking toward a specific part of the stadium when necessary. Using sliders, we can set parameters for the crowd, designating it to be 60% male, 40% female, for example, or with 20% of the characters wearing hats, and 5% waving flags. When the crowd performed a specific action such as transitioning from sitting idly to standing up cheering, we simply needed to select the corresponding section from our choreography. We can offset the timings from the original choreography displayed on each card to create random transitions. Our crowd system has a lot of other built tools, so it’s very easy to make modifications and procedurally control the behavior of the clips projected on each card. Since the crowd is made up of cards and textures, edits and renders are lightning fast.

We ended up with something like 1,444 elements, which we cleaned up and introduced into our crowd system. 3D characters were also used in places where 2D cards were not practical.

What were the main challenges on the show and how did you achieve it?
Since the filming was done outside on a racetrack the use of green screen was next to impossible. One of the biggest challenges was creating mattes for almost ever shot.

How many shots have you done?
Hybride produced a total of 50 VFX shots.

What was the size of your team?
For this production, a small group of 12 – 14 people was enough to complete the work.

A big thanks for your time.

// WANT TO KNOW MORE?

Hybride: Official website of Hybride.





© Vincent Frei – The Art of VFX – 2015

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Vincent Frei

Founder & Editor-in-Chief // VES Member // Former comp artist

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