Greg and Colin Strause on the set of Skyline

Left to right: Scottie Thompson, Eric Balfour, Greg Strause and Colin Strause on the set of Skyline. Photo by Patrick Flannery/Rogue.

Colin and Greg Strause came to Hollywood to become visual effects artists. They did that — they've contributed VFX to a long list of movies including The Book of Eli, Avatar, 2012 and The Curious Case of Benjamin Button. They founded their own visual effects house, Hydraulx, in Santa Monica. And, in 2007, they directed AVPR: Alien vs. Predator — Requiem.The directing bug took; the brothers most recently directed and produced Skyline and have more projects on the way.

Q: What is the story behind creating Skyline? What was it like making your own movie?

A: This is our first foray into the producing world.  We developed the script, shot it, financed it, did all the post and actually had to finish it and did all 540 versions for all the territories. We did it soup to nuts.

Greg had the idea about a bright light that would attract people by the thousands. He had just finished construction on his penthouse. We'd always joked when we were on location that we would never let a film crew in our house. But our agent was telling us about the Paranormal Activity success and how the guy had shot it. We'd already bought one or two RED cameras and had amazing lenses. So we thought, why don't we shoot something here. We bounced ideas around with [screenwriters] Josh [Cordes] and Liam [O'Donnell] and came up with the alien invasion movie.

From the balcony of Greg's place, you have box seats to the end of the world. So, it has to be something epic, with big scope. They whipped up a treatment and the script came in 2 months through all the revisions. And from the inception to being in the theaters was 11 and a half months, which is really, really quick.

Q: What did you bring to producing from your VFX background?

A: Every movie is its own castle with a moat around it, with different gear. We shot the movie for under $1 million; the whole thing is under $10 million with all the deferments, which is kind of insane. We took not only our VFX background but our entire production background. One of the weird things we see in every movie now is that studios spend hundreds of thousands of dollars on some of the most amazing previsualization, and then no director follows it. That's the whole point of previs — you do it so the shoot goes fast. We did a lot of the previs and it was exactly what we shot. Occasionally we deviated, but all the key shots were what we did the previs. It should be a standard, common-sense lesson, but no one follows it.

We were our own VFX company and used one big green screen. We were able to go into the movie without a cover-your-ass mentality. Greg and I were able to make those decisions as directors and VFX supervisors. We also knew that if we spent five minutes fixing something, we'd save thousands down the line. We also edited it in house; all the editors were the existing Hydraulx staff, so there was no retraining people.

Everyone re-invents the wheel for every single feature. Since editorial was in house, we followed our normal in-house procedures. We did the DI in house as well, so there was no having to send stuff out to a DI facility. We have our own film projector and two awesome theaters set up for DI. We were able to do all the mastering.

Q: I understand you created a new workflow for post and VFX for this movie. Can you describe it?

We're one of the first movies — maybe the first — that kept the entire pipeline in Open EXR throughout the entire process. Because we were using the new MX chips on the RED, we had a crazy amount of color information and latitude. We did everything in 32-bit floating point out of Mental Ray. We comped with the newest version of Autodesk Inferno, which was a little tricky. We were on the bleeding edge there. There is a new version of Inferno that added floating-point support. At the time, it was 60 or 80 percent there, so the first few weeks we were learning the workarounds. Once we figured which nodes worked, Autodesk also gave us updates. Granted, Shake and Nuke have been floating-point for a while, but they're slow. We are up to 44 Infernos, Flames and Flares now, and we needed the speed of those machines. We want 44 artists on Infernos and Flames because we can work 10 times faster [than with Shake or Nuke]. Working in log space, we were losing info from mental ray. Now we're able to take exactly what we rendered and bring the same color depth into Inferno and comp it with the same matte.

Q: And you were able to keep the digital intermediate also in Open EXR?

A: Yes. We used DigitalVision's Nucoda system and worked in full floating point. We had no log space at all. Because we stayed in floating point, we were able to maintain the exact same color space from the original RED files that the camera spits out, all throughout the DI. That included having all the information for all the highlights. If you expose the RED correctly you have four more stops of exposure than you would with a film camera. The DI — which was done by in-house DI artist Michael Smollin — went so much faster.

Q: What did you learn from the experience that you'll bring to your next project? What is your next project?

A: We've learned that the model worked. There is actually a different way of making these movies. I wished we performed better domestically, but we still made two and a half times our original budget in our first weekend. It's fuckin' hard making a movie, even a bad movie. It's a hard thing to actually finish. We feel good at the end of it. It looks really good — it looks like a $70 million movie, but we shot it for $950,000.

The basic lesson is that we did an experiment and it worked. Now we want to take what was an experiment and find a more commercial approach. We want to turn it into a real studio business model where we do a negative pick-up with a studio or continue our pre-sale model. Black Hole is our next movie. It's more of a cool sci-fi action film with a happy ending. Black Hole is like an American James Bond where the disaster happens at the beginning. Every James Bond movie is about stopping the disaster. I want to see the disaster and then figure out how to stop it.