shot, which involved shooting police cars and a SWAT van driving around the industrial docklands outside the soundstage, was filmed on in Toronto. Principal photography took place over 25 days at Toronto's Cinespace Film Studios from to . The film was initially given 21 days to be shot. The nerve gas house scenes were shot in an abandoned warehouse in Toronto and the actors who played the Jigsaw victims there worked sixteen hours each day. At the time of filming, in addition to having an on-set tutor for two hours, Erik Knudsen caught the flu, so he filmed his part while sick, which he mused that actually worked due to his character's apparent poisoning throughout the film. The ending was filmed on May 25 and 26. The music and sound was recorded in July and Saw II was locked on . It was completely finished by . Visual effects were performed by C.O.R.E. Digital Pictures and post-production services were provided by Deluxe. Trap designs David Hackl, the film's production designer, took three weeks to construct 27 sets on a single sound stage. The puppet Billy, used in the series to give instructions to Jigsaw's victims, was originally created by Wan out of paper towel rolls and papier-mâché. Given the larger budget for the sequel, Billy was upgraded with remote-controlled eyes and a servo-driven mouth. In one trap, "The Needle Room", Smith's character Amanda is thrown into a pit of needles to find a key. In order for this to be done safely, four people, over a period of four days, removed the needle tips from syringes and replaced them with fiber optic tips. They modified a total of 120,000 fake needles. However, this number was insufficient, and the pit had to be filled with styrofoam and other materials to make it appear to have more needles. The needles that were apparently stuck into Smith were actually blunted syringes stuck into padding under her clothing. For certain shots, a fake arm was used. Bousman came up with an idea whereby a character's hands would get stuck in some sort of vessel, and this resulted in the "Hand Trap". It proved to be a challenge, but after much discussion, Hackl, property master Jim Murray and art director Michele Brady came up with a suitable design. They arranged a glass box suspended by chains from the ceiling which contained a hypodermic needle with