Finally, the scenes of Ancient Rome were shot over a period of nineteen weeks in Fort Ricasoli, Malta. In Malta, a replica of about one-third of Rome's Colosseum was built, to a height of 52 feet (15.8 meters), mostly from plaster and plywood (the other two-thirds and remaining height were added digitally). The replica took several months to build and cost an estimated $1 million. The reverse side of the complex supplied a rich assortment of Ancient Roman street furniture, colonnades, gates, statuary, and marketplaces for other filming requirements. The complex was serviced by tented "costume villages" that had changing rooms, storage, armorers, and other facilities. The rest of the Colosseum was created in computer-generated imagery using set-design blueprints and textures referenced from live action, and rendered in three layers to provide lighting flexibility for compositing in Flame and Inferno software. British post-production company The Mill was responsible for much of the computer-generated imagery effects that were added after filming. The company was responsible for such tricks as compositing real tigers filmed on bluescreen into the fight sequences, and adding smoke trails and extending the flight paths of the opening scene's salvo of flaming arrows to get around regulations on how far they could be shot during filming. They also used 2,000 live actors to create a computer-generated crowd of 35,000 virtual actors that had to look believable and react to fight scenes. The Mill accomplished this by shooting live actors at different angles giving various performances, and then mapping them onto cards, with motion-capture tools used to track their movements for three-dimensional compositing. The Mill created over 90 visual effects shots, comprising approximately nine minutes of the film's running time. An unexpected post-production job was caused by the death of Oliver Reed of a heart attack during the filming in Malta, before all his scenes had been shot. The Mill created a digital body double for the remaining scenes involving his character Proximo by photographing a live-action body double in the shadows and by mapping a three-dimensional computer-generated imagery mask of Reed's face to the remaining scenes during production at an estimated cost of $3.2 million for two minutes of additional footage. Visual effects supervisor John Nelson reflected on the decision to include the additional footage: "What we did was small compared to our other tasks on the film. What Oliver did was much greater. He gave an inspiring, moving performance. All we did was help him finish it."