business. After an unsuccessful attempt to find employment at Industrial Light & Magic, the brothers worked on The X-Files film and founded their own special effects company, Hydraulx. The company produced special effects for films such as Volcano, The Day After Tomorrow, Poseidon and 300 and the brothers began a career directing commercials and music videos. Colin believes Hydraulx secured a strong relationship with 20th Century Fox, which owns the Alien and Predator franchises. The brothers unsuccessfully pitched an idea for the first Alien vs. Predator film and Fox almost bought a film titled Wolfenstein suggested by the brothers, "When the script came up for this movie, they thought we'd be perfect for it because it's an ambitious movie for the budget that they had and they knew that having our visual effects background was going to be a huge thing." The brothers were hired to direct the sequel to Alien vs. Predator in late spring 2006 and had limited time to start filming in the fall. The film's original title was Alien vs. Predator: Survival of the Fittest, but was later dropped. Filming on Aliens vs. Predator: Requiem begun on September 23, 2006, in Vancouver, British Columbia for a 52-day schedule. During filming breaks, the brothers supervised visual effects work on 300, Shooter and Fantastic Four: Rise of the Silver Surfer by using in-house supervisors and a system called Mavis and Lucy, which let the brothers track, view and approve dailies. Colin estimates Hydraulx produced 460 of the 500 visual effects shots including the nuclear explosion which was created using Maya fluids and BA Volume Shader. The interior of the Predator ship was created using CGI, as the brothers felt it would be more cost effective than building a set. The visual effects team peaked at 110 people for several months and averaged 70, almost all of the entire Hydraulx staff. Using their knowledge in visual effects and making use of principal photography, the brothers tried to film as much as they could on camera without resorting to CGI, Colin said "other than the exterior spaceship shots, there are no pure CG shots." CGI was used for the Alien tails and inner jaws, whereas they required puppeteers and wire removal on previous films. The main visual effects of the film included set design, a nuclear explosion, the Predator's ship crashing and the Predator cloak, about which Colin stated: "We