Alain Bielik talks with the visual effects artists behind Aeon Flux to find out how they handled turning the superhuman animated adventures of the title character into a live-action feature.
Utopian societies have always been a popular theme in science-fiction movies. Inevitably, the plot introduces characters living a perfect life in a perfect world, until one rogue individual uncovers the hidden truth behind this dream society. Major feature films based on this theme include THX 1138 (1971), Logans Run (1976), Demolition Man (1993) and The Island (2005). Paramounts Aeon Flux (opening Dec. 2) follows the same plot pattern, with a few twists of its own. It is the year 2415. A deadly disease has wiped out the majority of earths population, except for one walled city, Bregna. In this protected environment, the population lives a perfect life, completely isolated from the outside world. Some individuals, though, believe this perfect society is hiding a perfect lie. One of them is Aeon Flux (Charlize Theron), a top assassin for the rebellion against Bregnas rulers. During the course of a mission, she unveils the hidden side of Bregna
As always in a movie depicting our future world, the major challenge is to visualize it in a convincing and innovative way. For Aeon Flux, director Karyn Kusama chose to portray Bregna as an organic world, one that is less hardware-driven. She based the look of the city on the clear, unbroken lines of the Bauhaus architectural style. Indeed, a large part of the movie was shot on location in Berlin, Germany, in and outside many landmark Bauhaus-style buildings. Having found real locations to serve as a suitable backdrop for many scenes allowed Kusama to limit visual effects to a reasonable shot count.
Initially, the entire project was awarded to Digital Domain where David Prescott and Jonathan Egstad supervised over 260 shots. Interestingly for a futuristic movie, it features very few environmental effect shots, Prescott said. What we did was to extend the real locations with matte-paintings, or incorporate real buildings into 3D environments. This included the sequence in which Aeon and Sithandra (Sophie Okonedo) break into a government complex. The plates were shot at an animal shelter in Berlin and this building later formed the basis of the environment. Using Maya, we built on top of it, added a giant compound in the background and many structures in the foreground. The images were then rendered out in RenderMan with some elements rendered in Houdinis Mantra. The various layers were composited in Nuke with compositing supervisor Sonja Burchard overseeing the project.
The government complex is surrounded by a no mans land equipped with unique security systems. These included grass that, upon contact, becomes as sharp as a razor blade. This unusual device was part of the organic approach implemented by Kusama and production designer Andrew McAlpine for all Bregnas technology. Everything had to be based on organic material, rather than on hardware, which led to unique designs throughout the movie. The sharp grass effect was created first by animating CG grass in Houdini, and then, by compositing it into plate elements of the real stone garden location. The elements were then combined with CG extensions and matte-paintings.
The sequence also included a shot in which the characters approach the entrance to the government complex, a crane move reveals another major CG environment. For this shot that was added late in postproduction, Theron and Okonedo were filmed on a greenscreen stage entering a doorway. We didnt have any location plate beyond the foreground greenscreen element for this environment, Prescott continues. Using photographic reference material that we had shot in Berlin, we were able to reconstruct the building and then, extend it with CG additions and extra features that were designed from scratch.
Interior scenes of the movie also feature many CG extensions, most especially when Aeon enters the Relical, a flying monument with a hidden secret. A small section of the Relical interior was built as a live-action set. The rest was a CG environment that was built in Maya for the set itself, and in Houdini and NUKE for the holographic projections. Another challenging CG environment was built for the sequence in which Aeon attacks a ground-based surveillance facility. She discovers live surveillance images of the Bregna people projected into a pool of water, another illustration of Bregnas organic approach to technology. Aside from Charlize and the surveillance source imagery, the entire room is computer-generated, Prescott recounts. In the movie, the images are formed in the pool by drops of water that carry the visual information. It meant we had to create the surface of the water, the puddle and the drops, and all this had to be synchronized with different footage appearing at every drop. The most difficult aspect of the sequence was to make it look like the images were part of the water, and not some sort of monitors submerged in the pool. Most of the CG animation was created in Houdini.
Hand in Hand
Assisting Aeon in her mission is Sithandra, a medically-enhanced girl who has hands for feet. Two different techniques were used to create it. On wide shots, a stunt double was photographed wearing prosthetic hands (created by Kevin Yagher) on top of her real feet, and her heels were later painted out. For tighter shots on the character, we shot Sophie wearing skin-colored stunt shoes equipped with markers, Prescott explains. She also wore a circular prosthetic scar to represent the junction between her legs and her hands. We used that line as the replacement mark: everything below it was replaced by CG animation. We first tracked her feet and match-moved the CG hands, so that they followed every move of the legs. CG supervisor Darren Hendler then used proprietary shaders using sub-surface scattering to render the hands.
Ultimately, the major challenge with the fands effect was more artistic than technical. The anatomy of a foot and a hand are so completely different that we struggled real hard to figure out how a hand should land on the ground, and trying to get the anatomy of a hand to fit within a foot space, Prescott explains. It ended up being a lot trickier than we had originally thought! We had shot reference footage of a stuntman in Berlin who could do incredible things walking on his hands. We asked him to do actions that corresponded to various scenes in the movie, and later studied that motion to incorporate the same kind of dynamics in the animation. Several close-ups on the fands were created by filming the stuntman with his arms covered with prosthetics to make them look like legs; others required a fully CG approach.
Right from the beginning, Digital Domain knew a digital version of Charlize Theron would be needed for stunt work that couldnt possibly be performed live, but they werent sure for how many shots. To this purpose, the actress was digitized and photographed in high resolution. In order to capture a maximum of information, a cast of her face was also produced, which was later scanned to complement the scan of the real face. This enabled CG Aeon look development lead Francisco Cortina to build a highly detailed replica of Theron that could be used in any kind of shots, such as in the scene where Aeon jumps on top of the Relical. In several shots throughout the movie, Digital Domain only used the CG head and composited it over a stuntwomans head.
Power of 10
Parallel to Digital Domains effort, the production commissioned The Orphanage to produce 37 shots. Visual effects supervisor Jonathan Rothbart and CG supervisor Shadi Almassizadeh created a monorail train that was made to look like it was manufactured out of bones and resin. We first looked at reference to find out what bones that big would look like, Almassizadeh remarks. So, we researched huge dinosaur bones. By comparing the head of a t-rex to the concept of the monorail, we created a tangible reference. The next step was creating the correct shader that accounted for the porous bone material. We observed that the t-rex head had some transmission of light through it, which made the shaded parts of the bone more luminant than they would have been if they were made out of stone. All the shader work was done in 3ds Max and rendered in Brazil. Using the Brazil Advance Material, we added a sub-surface scattering solution to the shader to achieve the transmission effect.
The company also created the city of Bregna in two spectacular powers of 10 shots that reveal its jungle surroundings. We didnt have enough time to build out an entire city in full 3D, Almassizadeh continues. So, we decided to use multiple matte paintings nested inside each other. We also assigned multiple technical directors to work with our matte painters to provide them with the 3D geometry in which the paintings were projected onto.
Crafting a CG Crash
Late in post-production, the ending was completely modified to include the crash of the Relical, which led to 28 last minute visual effects shots being assigned to Hydraulx. The Relical was a polygon model provided by production, recalls visual effects supervisor Greg Strause. The primary animation of the Relical and any items it collided with was all key framed no rigid body dynamics were used. We used this technique in Day After Tomorrow for the scene where a large piece of ice breaks off the ice shelf. In our experience, talented animators can get great results faster and in a more precise way than by relying on simulations. In this case, it proved to be the fastest way to get the results that worked best for the locked cut we were working towards. For the secondary animation of the Relical reacting to collisions, we used Syflex cloth simulations. Since the fabric tear was pre-modeled into the geometry, we had to use a pinning rig to keep it closed until the collision ripped it open. The animators simply had to key frame the pins releasing, and the tear would open and ripple via a Syflex cloth simulation.
The city itself was built from a digital asset provided by the production. However, the file did not provide the level of detail necessary for shots in which the buildings needed to appear up close in camera. So, a team of modelers created new datasets of high-resolution polygonal architecture. In order to optimize render times, the backside of the buildings was deleted and lower resolution models were used for background structures.
Throughout the sequence, Aeon is a digital character. Production sent us a highly detailed Maya file of Aeon, but the UVs were incomplete, and we had to start the texturing process from scratch, Strause recalls. We used high resolution stills that were provided by production, and projected them onto the model in several steps. The final texture was touched up in 3D paint in Maya and Photoshop. Then, our proprietary rigging techniques were applied to the model, and CG supervisor Chris Wells turned it over to our character department. The animation was all key-framed, but we had to tackle the issue that Aeon was grabbing on to a piece of cloth for several of our shots. This required simulating the cloth first, and then using this as a basis for Aeons performance. The layers were finally composited in Inferno.
We had two significant challenges on this sequence, recalls Strause. One was time we only had six weeks for the entire sequence, start to finish. The other was the scope we had to create a complete 3D city from scratch, rig and texture the 3D model of Aeon, tune the blocking of the sequence and then prep physical specs for a miniature elements shoot (realized by New Deal Studios). Considering all this, were very pleased with how everything turned out.
Alain Bielik is the founder and special effects editor of renowned effects magazine S.F.X, published in France since 1991. He also contributes to various French publications and occasionally to Cinefex. He recently organized a major special effects exhibition at the Musée International de la Miniature in Lyon, France.