The main body of work for The Senate’s 170+ shots on Captain America: First Avenger (supervised by the company's Richard Higham) involved the Kruger Chase Sequence, a major action sequence near the beginning of the film, where Steve Rogers, having just taken the "Super Soldier Serum" that will transform him into Captain America, gives chase to Heinz Kruger, a man bent on stealing the serum for his own dastardly ends.
The chase takes place through the bustling streets of 1940s Brooklyn. As Kruger escapes by stolen car, Steve is able to give chase by foot, thanks to his newly enhanced physical attributes. Very much a classic car chase, the pair weave in and out of traffic and dodge pedestrians, culminating in Steve leaping onto the roof of the car and hanging on for dear life, before forcing Kruger to crash the vehicle down by the Brooklyn Docks.
The Senate's primary task was to transform the shoot location - modern day Manchester and Liverpool, England - into the setting of the sequence - 1940s Brooklyn, New York. Production had managed to find a few blocks of Manchester which, once dressed by the art department and filled with period cars, were incredibly convincing as wartime New York. However, a few Manchester blocks were clearly not going to suffice for a sprawling car chase. Extending the existing set was required to create the illusion of driving around a vast area of the city, varying the street views to avoid repetition, and adding life to the distant streets by way of extra people and cars, to enrich the sequence.
The Senate's involvement began early, remaining on set during the shoot and documenting with meticulous stills photography any textures, buildings, cars or artwork that could prove useful for the street extension work that was to follow. As well as on set photography, we also gathered hundreds of images of actual New York streets, as well as any London buildings that could also pass for 1940s Brooklyn.
Once filming was complete and the first cut of the sequence was available, the chase was carefully mapped, ensuring that it would be geographically correct and consistent with the street views. From this, the street extensions were broken down into roughly 20 different views. Using the collated photographic elements a master digital matte paintings was created for each of the views. These views were then manipulated to suit each new angle that was seen of that particular street.
The completed matte paintings were then handed over to the 3D department, who projected the images onto simple geometry. Where necessary, extra dimension was added to the geometry to boost the three dimensional quality of the backgrounds, increasing a sense of parallax and perspective shift that would otherwise be missing from a flat matte painting. Extra dimension was also added with the use of 3D models of fire escapes and electricity wires, threading their way down the streets. Fully CG cars were also built and animated, in order to populate the extended streets, as well as using additional pedestrian elements. To give the sequence a greater sense of scale and location, a CG model of Brooklyn Bridge was also built, complete with animating traffic. This can largely be seen towards the end of the sequence, as the pair head down toward the docks.
In order to protect their lead actor as he raced about the Manchester streets during filming, production had Chris Evans wear a pair of flesh-colored rubber shoes. The Senate's other main task for the sequence was to replace these rubber shoes with realistic CG human feet. Unfortunately, it was not simply a case of tracking a pair of CG feet to the shoes, as shoes do not move in the same intricate fashion as human feet. In order to achieve all the subtle nuances seen in real human movement, the CG feet were made to be fully anatomically correct, complete with wiggling toes, flexing muscles and skin that could stretch, fold and react when making contact with the ground. A team of animators then meticulously recreated every movement that would be naturally seen had the actor actually been running through the streets barefoot. Another, smaller sequence tended to by The Senate was the United Services Organization Sequence. The United Services Organization - or USO - is a party whose primary function is to entertain, raise moral and provide some comforts of home to military personnel. Bob Hope, Marilyn Monroe and Marlene Dietrich are some of the most famous members, who, during WWII, toured Europe and put on shows for soldiers when they had some reprieve from the front lines.
Steve Rogers, having taken the serum, becomes super but through a series of circumstances becomes the only one of his kind. The Army program that created him is now dead and they do not know what to do with him. Steve is then recruited by the government to become part of a USO show as "Captain America" to raise morale, and money for war bonds. Obviously he doesn't stay an entertainer for long but this is how his name, outfit and the fact that he uses a shield are established.
For this sequence, The Senate's task was to take the limited number of military extras that Captain America addresses from a stage, and turn them into a vast crowd. Using multiple passes provided by production of the 80 or so extras in different positions, the crowds were carefully blended to form a small army of several hundred individuals. Careful attention was needed for the areas where the different passes met, dotting about individual soldiers to ensure there was no obvious division between the different groups of spectators.
Meanwhile, Method Studios completed 28 shots (supervised by Sean Faden), including the sequence where Captain America is jumping out of the Stark airplane behind enemy lines. This involved all of the plane interior shots - adding backgrounds outside the windows - and the exterior shots of the plane which needed to be changed from day to night and augmented with explosions, clouds, tracers and some matte painting adjustments. For the opening exterior shot, Oliver Pron created a more pronounced Alps ridgeline for the plane to approach to help it cut better with the subsequent interior shots.
The interior shots required multilayer greenscreen comps out the windows, which consisted of CG clouds, CG flak explosions and tracers, background plates shot on location in the Swiss Alps, as well as reflection reconstruction for the plane windows. For the exterior shots, Method turned the day plates to a night look, adding CG clouds, CG flak explosions and tracers, and rendered a CG moonlit plane to be mixed in with the practical. In addition, interactive flak lighting, “Stark Industry” logos, and interior window lights were added to the plane.
The most complex shot involved a digital double for Captain America jumping from the plane and deploying his parachute while flak explosions and tracers filled the sky. Method received a scan of Chris Evans in a body suit, and Method Lead Modeller, Masa Narita proceeded to model and texture his full jump suit and parachute gear. Animator Aaron Schultz animated the character as well as the parachute as a combination of hand animation and Ncloth within Maya.
CG flak explosions, tracers, and clouds were generated in Houdini and rendered through Mantra, while Captain America, the parachute, and all interactive light for the plane shots were rendered through Vray out of Maya. Compositing was a combination of Nuke and Flame, with the majority of interior shots going Nuke to take advantage of sharing similar setups across shots.