The bulk of the R&D and pipeline revamping revolved around volumetric dynamics. "Skyline is the first movie for Hydraulix where we did everything in scene reference, photometric, linear color space," Strause explains. "Even when we started, we didn't have that pipeline working. The big thing for us was that it started with the acquisition. We worked with Red and this was the first project where we were able to go straight to EXR [file format]. And we saw huge efficiencies even though we had to retrain the whole compositing department. The stars lined up so that our Inferno and Flame and Red were all in sync at about the same time. We were able to switch the pipeline over and even the DI was done in photometric linear, which was awesome.

"We were floating point all the way through for the way the images were stored. And the flexibility and latitude and freedom we got were fantastic. Everyone in the company started thinking more in photographic terms. That was cool because it's the best way to work: one color space to rule them all. It's been messy over the past few years with every digital camera outputting a pseudo log format that's different from each other. No one seems to have figured out a very elegant solution for controlling color science from acquisition to film out, including the DI facilities. There are so many horror stories for big budget movies, regardless of the camera, and this is one where we were able to stay in linear all the way through. The DCT master we made was just a straight output right out of that. It was also the first time we did a DI in-house, so having control from start to finish was nerve wracking but very gratifying in the end.

"We are very much Maya and mental ray-driven, including a proprietary mental ray shader and lighting system based on HDRI images. This was updated and the whole pipeline was streamlined to basically allow three guys to light 1,000 shots. We have boujou for camera tracking and quite a bit of Fume FX and Krakatoa in conjunction with some of our own tools that were integrated into Maya Fluids, which made a surprising amount of the volumetric effects. And then there was a lot of RealFlow to make the Tanker drool. So every shot of the Tanker is a fluid sim and that's 300 shots.

"The stuff that caused everyone the biggest heart attack is a sequence when one of the motherships crashes and rebuilds itself. These ships are about a mile and a quarter wide, so the scale is massive and all the dirt and dust and debris as it rebuilds is huge. When we were first showing the previs in July and telling everyone that it had to get done by September, there were a couple of guys who said it was never going to happen and they quit. It was very daunting shot from a dynamics standpoint. But they got it done."

And what does Strause say about Sony's protests of conflict of interest with Hydraulx simultaneously working on the similarly themed Battle: Los Angeles (opening March 11, 2011)? "The idea of genre preclusion may sound OK on the surface, but when you get down into it, it's ridiculous," Strause offers. "I was working on <Avatar> at the same time and that happens to be about aliens, by the way. My reply to half of their complaint is: 'I'm more concerned that the core of Battle LA is based on a scene in AVP-R.' I've already directed a scene where there's literally a fire fight on the streets of an American city where a platoon gets wiped out by aliens. We've done that already. So to try and tell me that I can't do something with aliens in it doesn't make sense."

Bill Desowitz is senior editor of AWN & VFXWorld.