In HBO's Game of Thrones (airing Sundays at 9:00 pm and concluding its first season June 19), environments are especially crucial to the VFX. In fact, there are four distinct worlds representing the different regions for this violent struggle for total power between seven medieval noble families. As a result, it's "The Sopranos set in Middle Earth," suggests David Benioff, who created the series with D.B. Weiss.

"The main challenge was to create or extend environments that would be totally believable and could have existed in a parallel medieval world," says Lucy Ainsworth-Taylor, the visual effects producer. "Therefore, although being fantasy, there was very little scope to be fantastical."

The lead vendor was London-based BlueBolt, which took on all the CG environments, CG creatures and matte paintings. Screen Scene in Dublin provided an in-house comp team and did a lot of shots involving CG swords & blades and crowd comps. Meanwhile, to meet the tight post schedule, they used a few vendors in LA: CHE, Outsource, Encore and Look FX.

Overall, Game of Thrones, which has been renewed, has around 700 shots (episode one required 180). Approximately half are fix its with easy comp, and the remainder are far more solid environmental CG shots along with some very creative comp to help the series along, according to visual effects supervisor Adam McInnes.

"The budget was tight for VFX, but not for television," Taylor continues. "It was ambitious from the start. We had to take an early call on the approach to certain shots, what was a 3D build, what was a 2D matte painting, etc. However, in advance, BlueBolt realized that if they did some simple builds on certain key environments which were only ever going to be matte paintings it would help further down the line. These simple builds allowed us to move the actual buildings around (Red Keep, The Twins) to get the layout working on the individual shots with the lighting working on the original plates. Our element shoot provided of lots of blood spurts, snow, breath, which became invaluable in post for all the VFX houses. Violence presented no problems; there appeared to be no limits to how graphic we could be in depicting the horror."

The series was shot predominantly in Northern Ireland. A lot of the interior sets were built at the Painthall, an incredibly tall warehouse on the docks of Belfast. This allowed for a large scale and height of set build. There was a nine-week shoot in Malta simultaneously, covered by VFX Supervisor Angela Barson. This is where all of the Kings Landing exteriors and The Dothraki wedding were shot. Castle Black was a large location build in a quarry just outside Belfast. The interior courtyard was practical to a certain height and required VFX top ups when they shot off the set to include either towers or, where visible, the CG ice wall.

The highlights have been the environments and the opening shot of the Wall when the riders come out on the North side. "The gate goes up and [the first shot] is a VFX composite using bluescreen footage of the rangers and the gate plus the second courtyard of Castle Black in the background," explains McInnes.