<em>G.I. Joe</em>: Rising to a New Level of Techno VFX

 

Check out trailers and clips [2] from G.I. Joe: The Rising of Cobra at AWNtv!

According to Boyd Shermis (Poseidon [3]), G.I. Joe: The Rise of Cobra is more than your typical summer tentpole: it takes advanced technology to a higher level of spectacle and mayhem.

"There are a handful of things about the film, at least for me, that are unique and provided personal challenge," the overall visual effects supervisor suggests. "One was the Typhoon aircraft, which is the bladeless helicopter that uses vertical takeoff and landing technology. One of the things we wanted to do, in addition to giving it that advanced technology aspect, was to give it some flight characteristics that would make you feel like it's an advanced tactical fighter. Not like a spaceship, but something that would obey the laws of physics. So, one of my fun challenges was defining the animation style for this craft to make it do some really tricky stuff with gravity."

A more crucial challenge for Shermis, however, was designing and executing an elaborate chase through Paris, in which the Joes use special accelerator suits to help thwart the metal-eating Nanomites from disintegrating The Eiffel Tower and all of Paris along with it. In fact, the previs for the sequence not only helped greenlight the Stephen Sommers-directed movie, but also offered the explosive centerpiece.

"Stephen Sommers said, 'I've got this idea where these guys wear exo-skeletal suits and they have a chase here in the streets of Paris trying to knock down The Eiffel Tower.' And that was literally about all the direction I got and I had the opportunity to create something from scratch and design an entire sequence and then execute the whole thing almost entirely the way it was done.

"So we took a lot of this advanced technology and applied it in a cinematic way that gave us a very elaborate and choreographed chase through Paris. There was the challenge of animating human characters and making them feel and act human while also accelerating them. So you had to walk that fine line by having them run 40 miles an hour and not looking stupid. That 10-minute roller coaster ride is just out there."

Shermis turned to Digital Domain, which handled the accelerator suit, the recreation of The Eiffel Tower and the CG cars and the destruction that occurs during the heart-pounding sequence.

"So we were given the task of recreating, I would say, the centerpiece of the movie," explains Bryan Grill, Digital Domain's visual effects supervisor. "It was definitely a mish mash of very big practical effects and a lot of CG augmentation and then full CG shots. It ran the gamut from removing pipe bombs, which would lift cars up, to completely having CG cars get blown up and thrown across the sky. We shot mostly at the Downey soundstage and then went to Prague [at the Czech Republic's Barrandov Studios] for two-and-a-half months. It was pretty intense. We call it raining cars, while the Joes are in their accelerator suits trying to jump through all of these obstacles in their way. It's kind of like a mine field in Paris."

As for the accelerator suit, Shane Mahan was in charge of building the actual suit. He made four to six and they all had different types of damage or no damage at all, depending on the requirements. They were form fitted for both Marlan Wayans and Channing Tatum and their stunt guys. "And, basically, anything from the belly button up was the practical suit, and everything else was our CG recreation of the suit," Grill adds. "We knew we had to match it exactly but also used motion capture early on to get Marlan and Channing jumping, running and walking. We wanted to make sure during the chase scene that you could get a sense of who was who at all times.

"The animation team (supervised by Bernd Angerer) worked really hard to preserve who the characters were and used the parkour running style as a basis for the acceleration effect. It's all about grounding. For our sequences, we tried to make it real world and not look too unbelievable. They had to have balance, they had to land correctly."

 

It all culminates with the collapse of The Eiffel Tower. "We had to match it and make it look as believable as possible. And I think we have the most detailed model of the Eiffel Tower every built, so if you know anybody who wants it, we would love to rent it out. The most difficult thing about this sequence, in addition to The Eiffel Tower being eaten, was dealing with the falling pieces as its being disintegrated by the Nanomites. It was a case of rigid body dynamics, but the Nanomites would also eat around certain areas and leave island structures in the middle. We had to write the code so that procedurally when it detected no more connections for a piece of metal, it would know to drop. Then we got into the whole failure of the structure issue when The Eiffel Tower loses a leg. This includes vibration when a structure can't feel it all the way to collapsing and crashing into the Seine River. We looked at reference of buildings falling, but not steel structures. We contacting an engineering firm and figured out where the failure of The Tower would occur once the legs are gone."

Both Digital Domain and Prime Focus [5] VFX (formerly Frantic Films VFX) shared work on the Nanomites. However, Digital Domain wanted to drive the look "because we didn't want to be chasing our tales, and it just so happened that we were able to solidify the look with our sequence and keep moving forward," adds Grill. "We each used our own proprietary softwares for the Nanomites: we used Storm and they used Krakatoa. And, surprisingly, we both achieved a complementary look and it was hard to tell the difference."

 

Prime Focus handled the climactic attempt to thwart the Nanomites from destroying Washington, D.C. and the White House. "I challenged the guys at Prime Focus to render aerial skies and ultimately landscapes to virtualize the Potomac and Washington, D.C.," says Shermis. What they did is fantastic. They came up with a methodology -- they basically designed their own software and rendering tools -- to create aerial skyscapes, which, as far as I'm concerned, are the best I've ever seen in an aerial chase like that."

Prime Focus, which started out contributing previs, wound up creating roughly 70 out of a total of 124 visual effects shots for the finale's aerial sequence. Says Chris Bond, senior visual effects supervisor and president of Prime Focus VFX, "This sequence was particularly challenging because we weren't relying on any aerial photography, which would be nearly impossible to shoot at these speeds, but instead created nearly everything digitally -- the plane, sky, clouds and the destructive Nanomites that eat away the plane."

In addition to developing a custom toolset to generate 3D cloud and sky environments, Prime Focus built a Nanomite animation pipeline and a hybrid matte painting, environment and 3D animation pipeline. The company also dedicated extensive R&D to improving its in-house scene collaboration system that allowed its LA and Vancouver offices to work seamlessly together.

"We created a system whereby no single shot lives as a whole, but rather as a collection of project, sequence or shot assets," adds Chris Harvey, visual effects supervisor for Prime Focus VFX in Vancouver. "Assets could range from models, shaders, animations, scripts, light rigs and anything in-between. These assets would then be assembled on the fly based on the specific requirements. This facilitated a number of important aspects to our pipeline - artists would always have the latest approved assets regardless of their global location, and we could make changes en masse and have them propagate through various levels of the show, shot, sequence and even across the entire project."

 

In addition to providing previs for the aerial sequence, Prime Focus artists, with supervision from Bond and Harvey, built a Nanomite animation pipeline using Krakatoa, along with Autodesk 3ds Max, to render out the billions upon billions of particles that make up the Nanomite cloud. Functioning as an intelligent swarm, the Nanomites are able to track their movements to avoid retracing their steps, leaving no metal untouched until whatever they're consuming crumbles and collapses. To produce this complex destruction, Prime Focus created a series of particle systems, shader networks, and procedural level set tools that would all talk to and affect each other. This created a true geometric volume with thickness and surface properties that would be eaten, rather than paper-thin transparency texture maps.

 

Meanwhile, CIS Hollywood completed 263 shots. "Some of the sequences we worked on for the movie were Scarlett's Invisibility Suit, flaming NeoVipers in the Training Pit, The Landing Platform, the Elevator Platform, G.I. Joe Submarine Landing (with polar bear from MPC), interiors and exteriors around the Cobra base in the polar ice caps, the G.I. Joe Training pit, the Molepods, some day and night desert shots, pulse weapons effects and Baroness' and Stormshadow's escape via jetpack from the G.I. Joe base," explains Joe Henke, digital effects supervisor.

"The Landing Platform was probably our most challenging shot. We had to create a giant subterranean hangar populated with soldiers and vehicles that gets established as the camera descends with a Howler. The cut length ended up at a little over 700 frames. This shot had to set the tone that the G.I. Joe base was incomprehensibly huge and alive with technology and training. We started with the production's concept art and dressed the environment with CG versions of elevators, rock walls, control towers, repair hangars, vehicles, props, dust, shaft of light and soldiers with different uniforms. We also used live-action elements such as steam, sparks and dust. Midground soldiers were extras shot on greenscreen and placed on cards in the 3D environment. Lastly, the doorway of our CG Howler had to line up with a greenscreen shot of a practical Howler doorway from which Duke, Ripcord and the Joes exit.

 

"Another challenging sequence took place inside the Cobra base underneath the polar ice caps. The actors were shot in a set against greenscreen that resembled the mouth of an ice cave. The interior of the ice cave was a Cobra hangar with Typhoons and a Nightraven that Ripcord eventually pilots. We used a panoramic matte painting for the background of the interior and built the midground platforms, vehicles and props in 3D to accommodate the different camera angles for the sequence. The exterior of the Ice Cave started as a panoramic matte painting to which we added gusts of CG snow and wind.

"We developed most of our CG Elements in Maya, with some help from Houdini and 3ds Max. CG Fire elements for the flaming Neoviper shots were created in FumeFX, a 3ds Max plug-in. CG Water elements were created in RealFlow and surfaced in our proprietary mesher. Rendering was done in RenderMan with several custom shaders for metal, skin, hair, fire, fluids and volumetric lighting. We also did some additional rendering with V-Ray. Shots were composited in Shake. Boyd shot several 360-degree HDR panoramas of the training pit that gave us accurate lighting for CG elements inside the training pit -- particularly the CG Baroness, Stormshadow, Neovipers, Jetpack, Molepods and set extensions.

"Most of our CG assets were characters for shots involving stunts or crowds. A lot of shots began with us tracking a CG character to its live-action counterpart for the invisibility suit, adding CG fire, or transitioning to a digital double for a particular stunt. We built digital doubles for the Baroness, Stormshadow, Scarlett, NeoViper, as well as several Joes with varying hats, gloves, vests, and weapons. For the characters we started with a point cloud and reflectance maps from a 3D scanner. We would mesh the scan for use as a 3D template for the modelers. For the Baroness we developed a RenderMan shader that calculated light absorption and scattering for CG hair -- this gave our hair renders a more natural sheen, volume and color."

The movie provided the opportunity for CIS Hollywood to push its CG pipeline for characters, environments, vehicles, water, fragments, fire, smoke, dust and ice. "Each major sequence brought a new set of challenges that drew upon every artist in the facility. There were huge technical challenges, but at the end of the day the ultimate criteria for each shot was pure entertainment value. Everything had to be cool, big and loud, be it a huge CG environment, a digital double or a flaming tire."

Another unique opportunity, according to Shermis, was coming up with the ultimate underwater submarine battle. "You have two big underwater submarines that are highly maneuverable and they somewhat bend the laws of underwater physics in terms of how far you could see and how quickly you could maneuver. But we otherwise tried to replicate the feeling of doing a submarine battle underwater."

This was designed and executed by London-based MPC (led by Greg Butler, the visual effects supervisor), which was tasked with going way beyond Thunderball or any more recent underwater adventure, for that matter. MPC’s CG team built the fully underwater station environment using Maya and rendered using a mixture of RenderMan and mental ray depending on the sequence content. The usual CG challenges of creating fluids applied, with much testing to create a believable environment.

The R&D team focused on solving the various underwater CG challenges. The team investigated the physics of the underwater environment and how this affects color refraction and visibility fall off using reference sourced from arctic underwater photography. The result was a specific color curve operation for shaders, which helped to manage to color fall off in the depths by shifting colors to blue across a curve. This also gave efficient light volume for rays. The R&D crew also focused on the underwater explosions, which required research into underwater explosion and implosion techniques essentially requiring a zero gravity situation.

"I refer to it as Star Wars underwater," Shermis concludes. "Again, it was another tricky balance between real world and [the fantastical.]"

Bill Desowitz is senior editor of AWN and VFXWorld.