<em>District 9</em>: Bringing Back '80s Sci-Fi

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The facial design was redone at the last minute to get more emotion from the eyes, so Image Engine utilized interlocking plates. All images courtesy of TriStar Pictures.

When it came time for Neill Blomkamp [2] to assemble the visual effects team for his first feature, District 9, his distinctive mash up of '80s militaristic sci-fi (adapted from his short, Alive in Joburg [3]), he was counting on Weta Digital. But with Avatar [4] consuming Peter Jackson's CG arm, the Vancouver resident turned to newcomer Image Engine to tackle the aliens and The Embassy (his former company) to create the exo-suit worn by the beleaguered protagonist (Sharlto Copley), who transforms into a "prawn" and must learn to embrace his new identity. Even so, Weta Digital found time to help out in the end, and Zoic contributed some minor yet explosive shots as well.

"We had never done realistic digital characters on screen, let alone with a scope of 300 tough shots," explains Image Engine's Peter Muyzers, on-set visual effects plate supervisor & digital production manager. "So at the outset, Neill didn't know very much about Image Engine. But Neill is such a supporter of Vancouver. When Weta Digital couldn't do the whole movie, he saw it as an opportunity for a Vancouver company to step in. We started talking about the project with Neill and his assistants and by taking advantage of the BC tax incentives, they had a larger budget -- that was key. We worked at keeping the look of the aliens as simple as possible. There's not a lot of fur on them, there's little physical interaction. There's no water or major steam effects. Neill knows what he wants. He used Weta Workshop to design the aliens. We made use of hundreds of illustrations."

As for the design of the aliens that inhabit Johannesburg as wandering drones in search of direction, they look like a cross between an insect exo-skeleton and a crustacean. For Image Engine, Dan Kaufman served as visual effects supervisor, Steven Nichols was animation supervisor and James Stewart was creature supervisor.

"We wanted to make sure the shoulder range was there so the plates wouldn't collide," Muyzers continues."We went and modeled them [in Maya] and wanted Neill to further enhance in CG. At the same time, we could test our rigs for full range of motion and get the desired performance out of the aliens. He was very particular early on about the look: he wanted it to look like a lobster shell with iridescence, sometimes a beetle. So he gave us great reference that he loved in a nature book about bugs and insects. We translated that reference and research into CG."

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The Embassy's challenge with the exo-suit was integrating it well, having the moving parts interlock seamlessly and dealing with dirt, bullet hits and fragments falling off. [5]

Interestingly, after they were ready for the shots, Blomkamp decided at the last instant that he didn't like the eyes were all wrong: they were too insect-like and wouldn't elicit the empathy that he was after.

"So at a very late stage we did a completely new face design and our creature supervisor, James Stewart, basically started sculpting something from a block of clay right then and there. And he built three small head sculpts in a couple of hours. And Neill picked one and we built it in CG. And that's the Christopher Jones you see in the movie." And through a series of digital interlocking plates, the eyes conveyed more emotion.

Meanwhile, The Embassy, having previously worked on Iron Man [6] was busy with the exo-suit worn by Copley in his final defense. "The first Mach 1 Iron Man suit is an exo-suit in the same way, but this was a lot different for us and the sequence is much larger," recounts Embassy President Winston Helgason, who served as visual effects supervisor with Bob Habros.

"We got a rough model from Weta on the suit. It's a pretty detailed rig because there are so many moving pieces on it, interlocking bits of metal that open up when he gets inside and it closes up inside him. And it's really complex in the way it moves. You have to avoid intersections all over the place, and that's one of the difficult things you face with a robot. And then we spent a great deal of time texturing it in."

The Embassy team relied heavily on Luxology's modo [7] because of its advanced UV mapping tools, 3D painting and texturing capabilities. modo's versatility was instrumental in doing look development for the exo-suit. "Because modo's renderer is so fast, we could quickly set up shaders and occlusion maps," adds artist Simon van de Lagemaat. "This was very helpful in simulating the dusty conditions on various parts of the exo-suit. We built some simple shaders and test-rendered it before moving it over to Autodesk Softimage XSI. It's great to go into the shading and rendering phase with a good idea of what something's going to look like."

As The Embassy's main modeling application, he says that modo integrates seamlessly into a pipeline that includes Autodesk Softimage, mental images' mental ray, Pixologic's ZBrush and Apple's Shake.

"I spent all of last July shooting the exo-suit sequence," Helgason adds. "We did HDRI recording the lighting on the set and tracking seven cameras to make sure the exo-suit was going to be integrated well because he's kicking up dirt all the time and a big thing also was the compositing of bullet hits on the exo-suit. This was originally going to be around 40 shots but that completely changed when it got back to editing and Neill and Peter requested more, so it became 100 shots that we turned around in three-and-a-half months.

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modo was invaluable in the modeling of the exo-suit, while, in the background, Weta Digital's work on the mothership included modeling and dirt sim challenges. [8]

"Throughout the sequence, from a CG side, he's getting dirtier and more and more damaged with pieces falling off, so the model was constantly being redone. But then from a compositing side, there was a ton of bullet hits that were really hard to get to look right. We had a lot of practice with Iron Man, so we're getting good at that."

As for Weta Digital, Matt Aitken [9] (King Kong, Lord of the Rings) supervised the exterior shots of the alien mother ship and drop ship. "We did the previs and modeling for the exo-suit, which The Embassy took on. At the end, there were some shots that Image Engine couldn't squeeze in, so we did get involved after all. We did about 100 shots. We worked on some really nice sequences, including when the drop ship comes out from underneath the shack and takes off and immediately gets shot down by a missile. And then being tractor beamed up. And any close-ups of the mother ship.

"It was quite a complicated dirt simulation getting that sense of the ground being sliced by the mother ship and crashing. Neill gave us some footage from Iraq of a roadside bomb that doesn't get buried too deep. It just causes this giant mound to rise up, so it became a multi-pass simulation. We drove it with keyframe animation to start off with so that we could shape it and time it. We had to play to the drop ship below but then we ran some in-house dirt simulation tools that we developed. It's a case of running the cracks until that looks good and then baking that and taking that back into the simulation software and running the finer dirt particles and getting [the right] interaction. Drop ship breaks free of the dirt. We structured the event so that it didn't look like a lot of dust swirling around. We wanted it to have some detail in the form and shape.

"The mother ship was a complex modeling and texturing task. We picked up a model that Image Engine had produced and we built that. We did one interior matte painting shot of the hull where the humans find all these huddled mass of aliens. We created that environment and Image Engine did the aliens."

Bill Desowitz is senior editor of AWN and VFXWorld.