Jack Bauer always saves the day on 24, and this seventh season of the popular political thriller TV series has been no different. Jack is faced with finding a way to prevent the U.S. from being devastated by a host of missiles weaponized with biological pathogens, housed at the Starkwood warehouse complex and controlled by the villainous Jonas Hodges. As the April 7th (12:00 am to 1:00 am, Episode 717) episode ended last week, the evil Hodges showed President Taylor images of the missiles, lined up and ready to go if she doesn’t call off the air strike against Starkwood. When Taylor backs down, it seems inevitable that the missiles will be fired, wreaking death and havoc.

Instead, during last night’s episode (April 14, 1:00 am to 2:00 am, Episode 718), the good guys won again, at least for the moment, when the missiles are destroyed in a huge fireball explosion just seconds after they’re activated. Hollywood-based visual effects facility LOOK Effects created both that very realistic explosion as well as the scenes of the missiles in Episodes 717 and 718, for a total of 19 multi-layered shots.

“The missile room was something that was too big of a build to do practically on a TV budget,” said 24 producer Paul Gadd. “We knew we needed to see the missiles since they’re the big threat that’s been building up over the weeks. The studio agreed that [creating them with VFX] was money well spent.”

Gadd found LOOK Effects from word of mouth. “[Producer] David Jeffrey from Bones has been telling me for a long time that they’re great guys who do good work, so I thought, let’s give them a shot,” he said.

LOOK Effects partner/visual effects supervisor Henrik Fett reports that the company has developed a reputation for set extensions, or what they call ‘location-based effects,’ for everything from Pushing Daisies to The Spirit. “They said that they couldn’t film a rocket launch site, and that it needed to be dramatic and eye-catching since the whole season was building up to this moment,” says Fett. “We knew it was eight rockets, and that it had to coincide with the practical stuff they’d already shot, as well as modifying that.”

(Watch the video below to see the progression of the visual effects.)

In addition to Fett, the core LOOK Effects team included visual effects executive producer Don Voorhies, visual effects producer Melinka Thompson-Godoy and digital supervisor Brad Kalinoski. The first challenge was to come up with ideas for what the missiles and silo would look like.

“We had multiple brainstorming sessions,” says Fett. “We looked at different rockets and silos. We wanted to develop something that was realistic enough but also fit in with their existing locations. To take the designs already created by 24 production designer Joseph Hodges but also take it to the next level while keeping it real and making it dramatic.”

At one point, says Fett, they showed an example of the Peacemaker rocket, but it was rejected for being too real. “They helped us create a couple of different looks,” says Gadd. “There was a whole reality discussion that came in. Rockets shouldn’t have fins on them, but they looked a little tougher with fins, so we kept them. The LOOK Effects team helped us try to figure out what we needed by looking at several different options.”

The physical set featured a greenscreen window through which we see the missiles. “We knew the hero shot was a pull-out of the missile silo to an over-the-shoulder shot of the missile control room staff,” says Fett. “They’d already shot the control room and we were working with the greenscreen and the camera data.”

LOOK Effects lead digital compositor/matte painter Christian Cardona-with the help of 3D supervisor Michael Capton, 3D artists Shawn Lipowski and Antonello Stornelli and digital compositors Adam Avitabile and Michael Collins-created 3D animatics by combining digital matte paintings and real world textures projected onto 3D planes. “What was 3D were the platforms and the missiles,” says Fett. “The 3D department was building these simultaneously with the creation of the animatics. [The 3D] was a moving target. Every time we came back from a meeting, the 3D department would have to tweak what they’d done.”

Based on a range of iterations, they narrowed down the room’s mood and atmosphere and details such as the catwalk between the rockets. Textures were a mix of stock footage and footage from LOOK Effects’ own library of assets shot over the years. For example, when the rockets lift off, LOOK Effects used some smoke elements from stock footage of actual rockets taking off. “We also have an extensive smoke and fire library,” says Fett. “We use real footage, not CG elements, wherever possible. Using as many real elements in the effects is what sets them apart.”

Gadd agrees. “The toughest thing with these kinds of shots when you’re creating environments completely from CG is to get them to look real,” he says. “It did help that the elements were practical. Our production designer took a lot of photos to create the environments he did, and LOOK Effects has a library as well, which helped immensely in making it look real.”

LOOK Effects has a particularly rich archive of real explosions. “We’ve shot those ourselves over the years,” he says. “Any time you have a show that allows you to shoot explosions, you do it and build your library. Every so often, we’ll go out and do an insert shoot ourselves, and run the gamut with fire, explosions, any kind of natural dynamics.” Of course those elements are just the basis of what is actually used in any production. “Colors, contrast, speed, interactivity are all changed,” says Fett.

But the devil is in the details, Gadd notes. “When you put the missiles in, first they’re not shiny enough,” he says. “Then they’re too shiny. Then the color isn’t red enough, then it’s too pink. Trying to get everything to look right in the room and have the camera moves match the style of 24-and it’s all about the handheld and the snap-zoom-is what’s tough.”

Fett notes that the reliance on photographed elements for effects shots is a primary focus. “We’re filmmakers at heart, not CG artists,” he says. “As a facility we know CG animation. We made our name in film compositing. Having done that for so many years, we’ve made a decision that we’ll always choose real over CG.” The exterior shot of the warehouse, for example, is comprised of stock and specifically shot warehouse elements. The elements that are created in 3D CG rely on Autodesk Maya.

To keep it real, LOOK Effects also shoots HDRI photography for all the lighting passes. “We use high-resolution digital stills and then set different exposures and compile it to an HDR image that allows us to dial through the different exposure settings,” says Fett. “It gives a really nice depth for the lighting.” The camera moves are computer-generated, he adds. “The big pull-out, from the shot of the missiles to the over-the-shoulder in the control room, was done in Maya.” Compositing is done with Shake. “We do like Shake because it allows our artists to express themselves,” says Thompson-Godoy. “It helps with the workflow.”

With regard to workflow, LOOK Effects relies on Shotgun, a scalable, flexible, and open web-based information system for digital production studio that the company has tailored to its needs. “All the producers and coordinators use Shotgun, which allows us to track all the shots, the data and metadata, the compositing data and access material from any workstation,” says Fett, who says LOOK Effects is also now Mac-based. “When an artist picks up a new render, Quicktimes are generated of the latest version and emails are sent to the supervisor to review the new shot. It’s an HTML-based interface, and you can put your comments and the artist will automatically see it.”

All of this came into play for creating the missiles and the explosive scenes in last night’s episode. On the eve before the episode aired, producer Gadd seemed quite confident with what he’d gotten. “This is a big episode for us,” he said. “We’ll tune in and see all the fine work that LOOK Effects did.”