Double Negative's biggest challenge in Doomsday was turning Cape Town, South Africa, where the film was shot, into a dystopian future Scotland. All images © 2008 Rogue Pictures. All Rights Reserved. 

In Doomsday (opening today from Rogue Pictures), a government agent goes into a disease-ravaged, barbaric future Scotland in search of a cure. But the biggest challenge facing the visual effects crew in bringing director Neil Marshall's vision to life was turning Cape Town, South Africa, where the film was shot, into a dystopian future Scotland.

VFX Supervisor Hal Couzens says Marshall's approach to the film was to have everything based in reality and all the imagery and effects started with a photographic base. "The film has a lot to do with '80s movies like Escape from New York, The Warriors, Mad Max 2 [The Road Warrior] -- all stunt-based films," he says. "So everything that happens, while fantastical, are things that are happening in a real world 25 years in the future. Everything we designed, special effects-wise, stemmed from that."

The project grew from an initial estimate of about 110 shots to around 275, with most of the work being done by Double Negative. Supervised by Mark Michaels and produced by Clare Tinsley, the London-based shop delivered about 180 shots for Doomsday,with Diccon Alexander as the lead matte painter. While Michaels says their work on the film wasn't innovative in a technical sense, the film required a lot of set extensions that had to be pulled off under tight budget restrictions.

"A lot of the shots were in daylight and it took an extensive amount of set extensions and matte paint extensions, 2D solutions, 3D solutions, to pull it off visually and convincingly," Michaels explains.

"Everything that could have been projected as a texture was done that way rather than building the full 3D model," adds CG Supervisor Alex Pejic.

Michaels suggests the crew made frequent visits to Scotland, taking reference photos of any signature elements in the landscape that could be added into the matte paintings or other elements that would help them make the Cape Town locations used for filming look more like Glasgow. "The two cities are similar but different types of weather add different types of look to the buildings and so forth."

Using Double Negative's proprietary Stig software let Michaels' crew stitch together still photographs into a panorama that could be manipulated, while many of the matte paintings were created in Photoshop and it was all composited with Shake.

Still, the film called for some unusual and challenging scenes. In one such sequence, a flare lights up a landscape that Double Negative had to fill with cows -- the idea being that with no people left, the cow population in Scotland grew unchecked. "We just had a bunch of 2D cows that we shot on greenscreen in the fields and they just had to be placed to fill the entire hillside," Michaels continues.

Another problem came from the wall built to keep the Reaper virus inside Scotland. Marshall asked for a blue-steel look for the wall that was hard to maintain in daylight sequences. Making the wall look like it ran for miles into the distance was another problem.