<em>AVP-R</em>: The Strause Brothers Strike Back

Film sets can be combative places, with department heads butting heads over any number of disputes. But in the case of Aliens vs. Predator: Requiem (opening Christmas Day from Twentieth Century Fox) -- the second film to pit the popular sci-fi franchises against each other -- directors Colin and Greg Strause couldn't help but be on same page as their visual effects supervisors because they were the visual effects supervisors.

Colin Strause, who, along with brother Greg, heads up the vfx house Hydraulx, says having no such boundaries on their first feature-film-directing gig was a liberating experience. "I would literally go from the edit bay and then sit down on a Maya machine and start building shaders for the movie," says Colin. "So I still love doing both."

Colin Strause says he and his brother used to make Super 8 movies when they were children. Their desire to be a part of the movies was kick started by Terminator 2, which Colin says inspired them to move out to Los Angeles and break into showbiz. "For directing, it was kind of like, 'Yeah, it's going to be cool,' but it was a pie in the sky kind of dream," Colin admits.

After failing to land their dream jobs at ILM, the Strauses started doing vfx work on The X-Files in 1995. They jumped into features in 1996 and have since founded Hydraulx and worked on more than 40 films, including The Nutty Professor, Volcano, Titanic, The Day After Tomorrow [1], Poseidon [2] and 300 [3].

The duo began directing music videos in 2000, followed in 2001 with commercials and a pair of sponsored short films, Mute and 16mm Mystery. But Colin says it was the good will he and his brother had built with Fox, in particular, that landed them the job.

"We've a had a really good relationship with Fox, to the point where in meetings the co-chair of the studio would talk about Hydraulx as being the company they would want to do certain sequences. It gave us good awareness with all the same people that we'd have to be dealing with as directors," he adds.

Colin says they made an unsuccessful pitch for the first Alien vs. Predator film, then pitched a movie called Wolfenstein that Fox almost bought. "When the script came up for this movie, they though 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," Colin offers.

The brothers' vfx experience allowed them to shoot the film and execute the work in the most efficient way possible. "One of the biggest issues with movies right now that we see as an effects company is the amount of money that isn't as efficiently spent as it could be," Colin suggests. "There are people who use motion control when they shouldn't, so instead of getting 20 setups a day they only get three and then they don't even use the mo-co data."

Hired on in late spring of 2006, the brothers had limited prep time before shooting began in the fall. "We didn't have a lot of time to sit around go. 'I don't know, what do you think of this?" Colin says. "It was like fucking war every day, but it was the funnest thing we've ever done."

[4]

Outside of the crash sequence, all the others scenes in the film contained live-action elements for the visual effects artists to work with. [4]

Going into the shoot, the brothers endeavored to make both principal photography and the visual effects work as efficient as possible, tapping into their expert knowledge to do as much as possible in camera and resort to CGI, only when and where it was necessary. "Other than the exterior spaceship shots, there are no pure CG shots," says Colin. "The lighters and the modelers had something real in every shot that they could actually reference. It was kind of a big thing for keeping the whole movie grounded." That meant using practical costumes for both Alien and Predator -- though some adjustments were made. For example, the Aliens' tails as done in previous movies required puppeteers and wire removal, so those plus the Aliens' mouth strikers were done with CG this time out.

An unexpected side effect was the extent to which rabid fans of the Alien and Predator films would go to get information on the film, Colin says. "These are the guys who will go see the movie six times in the theaters and it's pretty wild about how aggressive they are about getting information," Colin says. "We even had a couple kids break into one of our trailers and steal some of our stunt Aliens and actually were trying to sell them on eBay while we were filming."

Shot on a tight 52-day schedule in Vancouver, the film posed several vfx challenges, including digital characters, matching the look of the original films and set pieces that include a nuclear explosion and the crash of the predators' ship.

One example was the cloaking effect used by the Predators. "We wanted to make sure it didn't look too digital," recalls Colin. The original had plenty of imperfections such as gate weave that they tried to preserve. "All these little inaccuracies, it makes it more of an analog effect."

A nuclear explosion sequence required fluid simulations for the explosion and the shockwave, as well as dynamic structures were destroyed in the blast, all of which was done using Maya fluids and BA Volume Shader.

The Predator ship and its crash were two of the largest sequences in the film. First was the interior of the ship, unseen in previous films, which had to impress and look functional at the same time. "We decided because of how crazy big it was going to be it wasn't going to be cost effective to build a set, so we did full digital interiors for all the shots," Colin adds.

The crash of the ship was another huge sequence, showing the vessel crash into the ledge on a mountain and setting off a huge shockwave of its own. Colin compares it to the crash shots in Transformers [5], but with a much larger ship.

Most unusual was the use of the Maya hair simulator to build a forest of trees that devastated by the crash. A procedural tree building system added branches that could break off and start bouncing around, while the hair sim created the flow of falling trees. "That was a really tricky shot because there are so many trees getting plowed over by the big ship, so quickly, that we probably spent a good four five months getting that whole system worked out," Colin says.

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Part of the challenge, as with any film, is getting everyone on the same page. And when you're working with guys like this, it makes it even more challenging. [6]

The structure of the production enabled the Strauses to centralize production of the film out of Hydraulx, bringing the editorial from previs and cutting as well as the DI processes in house.

"Editorial groups become like little castles," Colin insists of most films. "It's hard to get everyone on the same page." On this film, however, "everyone is under one roof, so it made it so much cleaner and simpler. There's no excuse for editorial and visual effects not getting along perfectly."

Colin estimates Hydraulx did 460 of the estimated 500 vfx shots in the film and CIS doing the remainder, most of which involved ordinary tasks such as wire removal. Efilm did the DI. The vfx crew maxed out for a couple of months at about 110 people -- almost the entire staff of Hydraulx -- and averaged about 70.

The film came in under budget, "which doesn't seem to happen too often around here," Colin says. "It actually freed up money so the studio would let us expand the movie and do the Predator home world and bunch of other cool sequences."

Amazingly, the shop kept itself busy with other shows while making Alien vs. Predator: Requiem, with the Strauses supervising work on the likes of 300, Shooter and Fantastic Four: Rise of the Silver Surfer [7]. They accomplished this by relying on their up-and-coming in-house supervisors and a custom data system dubbed Mavis and Lucy that allowed the brothers to track, view and approve dailies from the set during breaks in shooting.

Another seemingly simple change that had a major impact was the installation of a Barco projector at Hydraulx's Santa Monica headquarters that allowed the shots conformed in Smoke to be viewed in realtime, uncompressed at 2K resolutions. "That's really changed how we do our effects shots now," admits Colin. "You put your shot up there, it has to be tight."

It also helps the vfx work stand up better over time, with IMAX presentations and home HD formats becoming increasingly common. "Some (films), they look great on film, and then they do the HD transfer and it's got matte boxes around it and stuff," Colin complains. "(It has) really changed our pipeline quite a bit and really got everyone to make sure everything's buttoned down better."

Thomas J. McLean is a freelance journalist whose articles have appeared in Variety, Below the Line, Animation Magazine and Publishers Weekly. He writes a comicbook blog for Variety.com called Bags and Boards, and is the author of Mutant Cinema: The X-Men Trilogy from Comics to Screen, forthcoming from Sequart.com Books.