CGSociety

The Games People Play

CGSociety :: Production Focus
21 December 2010, by Renee Dunlop

The original TRON was the first film to use computer graphics in a display of chunky pixels and tongue-in-cheek references to technology. But in the 28 years since TRON hit the silver screen technology has grown, and in 'TRON world', it has grown completely out of control.

Stellar FX studio Digital Domain (DD) was charged with wrangling that world under director Joe Kosinski and VFX Supervisor Eric Barba. Legacy’s world has only two human inhabitants, Kevin and Sam Flynn, while everything and everyone else is digital. This world was designed by Kevin Flynn (played again by Jeff Bridges) and his cast of program characters. However Clu, Kevin Flynn’s digital self, has become a dangerous and deadly opponent, creating havoc in Kevin Flynn’s perfect world. The film is rife with beheadings, Disney style, as programs are destroyed and de-rez into millions of little voxels that the programs and the entire world are made of. That is why it can still be a Disney movie- it’s just a visual beheading until you realize it’s simply a collection of virtual cubes falling apart, perhaps foreshadowing what Disney films will become now that they have departed from fairytales.

THE NEW WORLD
Many of the artistic decisions for Legacy as far as the foundation and look of the film were handled before serious production began. Many of the visual queues from the original TRON like the glow lines were kept to tie the two films together. Some of the film looks like something you might see sitting in your own home, while other elements have a look no one has ever seen before. These artistic decisions were first seen in a teaser trailer completed in 2008.

And of course, TRON: Legacy is also in stereo during the entire time the viewer is in TRON world, roughly 85% of the film, and that does not address the digital work that was required. Once you enter TRON world there is always at least a set extension to full CG scenes involved, and a total of 1,500 shots were completed over a two year period.

The graphic feel of the world is still intact with bright lights and colors against a dark background, but the objects and the environment of this advanced digital civilization have far more detail, a by product of the advances in technology since Flynn first entered TRON world. Add to that, this new TRON world includes a heavy atmosphere with rolling clouds and simulated thunder that hints at the virtual aspect and helps build the ominous warnings of things to come.

STEREO
The film was planned and shot fully in stereo 3D from day one, with Barba and Animation Supervisor Steve Preeg in a strong creative partnership with director Kosinski. Principle photography ending in July 2009. The stereo was designed so that the audience looks into the world as if gazing into the monitor rather than being filled with in-your-face stereo gags. “Since Avatar,” said Barba, “I think this is the only film that kind of follows that category where it’s a great use of stereo because it’s a computer world we’ve never seen before and doesn’t necessarily follow any rules.”

Stereo was worked out in the previs step, and because of the tight shooting schedule and preproduction schedules, DD ended up doing previs while Kosinski was shooting in Vancouver. Since this was DD’s first foray into a full stereo project there was a bit of a learning curve involved.

Previs doesn’t always require the artists to create a scene that is 100% perfect, and often the artists will cheat by moving assets around to get the best composition. However in stereo, those assets need to be correct in XYZ space, which is much more demanding. DD would strive to make everything to work flat first, and once they were happy with those results they would take it to stereo. If it was an all CG shot, that was relatively easy to do because the stereo is figured out ahead of time, but with plate photography, a plate could be left or right eye dominant which occasionally required small fixes in details such as proper alignment between the two eyes.

Brightness also required some adjustments. When shooting with a twin camera setup, one camera shoots through a mirror and the other shoots across a mirror. The results end up with different polarizations. For example, say the left eye is the fixed eye, and the right eye is the stereo eye, and the specular highlights and reflections are dimmer than in the fixed eye. When you view this on the screen in stereo it can be quite painful, so DD strived to make the viewing experience as comfortable as possible.

CONCEPT TO MODELS
VFX Supervisor Eric Barba, Oscar winner for his groundbreaking work on 'The Curious Case of Benjamin Button' leaned on that experience to create Clu, a 35-year old version of Jeff Bridges today. DD had a head casting of Bridges from when he was younger, and captures of Bridges at his current age, capturing multiple expressions and various face shapes which were used ultimately as more of a guide for the animators, allowing them to get the timing of any particular performance. Using that as a timing guide, the animators would reanimate the actors face.

In some cases the art department provided 3D asset models that DD modified for the film, and 2D illustrations that worked as a guide to the world of Legacy. Barba praised production designer Darrin Gilbert who commissioned some of the most talented designers he could find, many of whom had never worked in film. One of those was Legacy’s light cycle designer Daniel Simon who has an illustrated book and has worked in car design for most of his career. He stood on the shoulders of Visual Futurist Syd Mead who designed the light cycles for the first TRON, updating the designs while maintaining a familiarity from the original iconic light cycles, and adding the additional light jets and light cars.

The light cycles, and in fact all the vehicles in Legacy can be considered a personal weapon on the grid. The riders carry a baton that is programmed to turn into the different vehicles. The riders throw the baton in front of them and it turns, for example, into a light cycle that the rider blends into, becoming one single unit. In the first TRON, the light cycle riders were originally designed to be exposed but melded into the cycle body, but with the limited real world technology of that time the design just couldn’t be rendered. Therefore that design had to be altered to be more conventional with a canopy on top. But by the time Legacy was in production, real world technology has advanced so that the riders can become part of the cycle, embracing that aspect of Mead’s original idea but refined through Simon’s style.

Simon was faced with a technology learning curve, since his work in NURBS needed to be combined with the characters created in polys. There was also the issue of verifying measurements. Were they in meters or feet, building style, and XYZ orientation from one program to another. He also had to keep in mind details such as though the cycles are a substantial size, the car, or 'light runner', needed to appear larger and more powerful to accommodate a rescue scene against a light cycle that couldn’t appear too menacing by comparison.

TEXTURES
Initially, the assumption was that this was a perfect digitally generated world and the textures would reflect that perfection. However, Kosinski felt this was a world that was heavily used and always in some sort of gladiator battle, so dirt and scratches were added.

The director was very clear that he wanted TRON world to look physical, as if a camera was in the world shooting the action.

The high quality craftsmanship on some of these set pieces helped set the standard. Set pieces are often a rough construction that is suitable for filming but on Legacy they were built with extreme attention to detail. The set pieces were well put together and looked functional, and made to look CG perfect but had the imperfections of something that was physically made.

PIXEL LIGHT
The classic look of TRON has the characters sporting suits with glow lines, and it was the use of glow lines that helped separate the characters from their dark surroundings in Legacy. During the filming of Legacy, the real world costumes were designed to actually light up. Barba made use of that during principle photography. “All the suits the actors wore were pretty sophisticated and hugely expensive costumes. They had battery packs and lit up on screen.” DD was able to use the actors costumes during post production “to get the colors right and add little flickers” and the lighting team was able to request more where it was needed.

Due to the dark environment the light cycle riders were getting little environmental lighting, and most of that was from the light inside the helmets. Since the real world actors were practically lit primarily to compliment their body postures and acting during the scene, the faces needed beauty lighting that had to be cheated for the most flattering look that often didn’t actually match the light direction of their environment. A lit rig was used to light the faces of the actors in the scenes affected by this and had to be composited in later. Another way Barba resolved the lack of environmental lighting was when they were traveling on the grid. Barba wanted the cycles to be traveling in and out of bands of light caused by the gridlines on the glass environment. The CG suits were getting the rolling light, but there was nothing on the live action faces. To fix this, DD added a secondary pass over a CG head, then in compositing, they gently layered that in to increase the impression of interaction between the cycle riders and their environment.

And speaking of the glass environment, reflections and refractions on the disk game courts and during the light cycle sequences was particularly difficult, namely through finding an appropriate balance of reflections and refractions that would define the glass environment without becoming overly distracting. This was a particular concern for the light cycle sequences that took place on three floors of horizontally laid glass. While on the top layer, the cycles would read fairly clearly but when they were on the middle layer too many refractions made the scene impossible to read. It was a delicate dance to find the right balance of reflections and refractions coupled with readability and render times.

In one of the more spectacular displays of eye candy, each light cycle and jet has a light trail that emits from the back of the vehicle. This wall hardens into an indestructible glass wall. The players use this strategically throughout the game to try and kill the other combatants just as they did in the first TRON when one cycle would make a sudden 90 degree turn and the competitor who couldn’t turn to avoid the wall would crash into it, resulting in their digital death. The doomed riders’ cycle and the light wall explodes into a fiery display, giving the viewer a lot of eye candy.

Frankly, the entire film is eye candy and DD has outdone itself again. I strongly suggest you pack your digital insulin because this is one sweet film.

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Writer: Renee Dunlop