Getting Trippy VFX for 'Looper'

VFX pro Karen Goulekas (Green Lantern, The Day After Tomorrow) found working on Looper to be refreshing in so many ways. First, just working with director Rian Johnson (Brick) on the trippy, time-traveling, sci-fi/actioner was creatively satisfying. Second, Looper is such a unique movie with a strong visual language that it needed top flight VFX to help pull it off.

However, Johnson came in with an anti-CG bias, so Goulekas made it her mission to turn him into a convert. But then Goulekas had no choice: she needed A-list VFX to create convincing work.

"I kind of understand where Rian was coming from," Goulekas says, "because there's so much bad CG that gets done out there and that's the stuff you notice unless it's a really good, in your face, CG character. But when it's done seamlessly, you don't notice it. That's why it was so important to me that we got good vendors, obviously for my own personal craft, but also in support of Rian's vision."

In the end, Johnson was pleased; he thought the VFX looked real. "He was even picking up the lingo," Goulekas adds. "'Hey, Karen, let's give it a little comping: Is that a halo I see?' Then we'd be comping dust and he'd say, 'It doesn't look like they comp'd it based on the luminance of the plate.' So I'd make a note of it and I'd line up all the shots and show Rian the changes and I'd follow up."

In fact, Looper was Goulekas' first indie experience and she got her first taste of globalization. She even got to collaborate with some old pals and new people she's admired that she didn't think she could afford at first. But they wanted to work with Johnson and were flexible with their prices and scheduling. Scanline VFX's Munich division handled the tricky telekinesis; Hydraulx did impressive decomposition of victims; and Atomic Fiction took on futuristic cityscapes.

"CG effects work included the initial telekinesis shockwave as it radiates out and knocks over a van, the big telekinesis effects of rising and swirling debris, telekinetically affected debris that breaks out of the soil and CG sugar cane set extensions," explains Scanline CG supervisor Ivo Klaus. "The main idea we received from the production was that the effects were going into the telekinesis shots to convey a sense of drama. There was to be a progression of ever faster flying debris until finally something important happens and everything slows down again until the telekinetic effect falters and stops."

As with everything else Scanline did, the prominent elements were developed first and then details were added. Manually animated debris pieces went together with Thinking Particles animations, Particle Flow animations and Flowline simulations used for some sand effects and dust. The most complex effects were the pieces of debris that would break through the soil and rise upwards. "We fractured the ground geometry to a high degree and then pushed bigger chunks from below ground against it so that some smaller pieces would rise but others would fall back down to the ground," Klaus continues. "We also created a version were we actually simulated a couple of million sand particles and pushed those upward with the fractured geometry."

Each shot pertaining to the shockwaves had to be treated individually because they were so different from each other: the top shot of the shockwave blasting outward, the shockwave rushing away from camera and flinging actress into the air, the shockwave traveling from left to right and flinging actor into the air, the shockwave seen from afar through the window of a van and finally the shockwave hitting the van.

"To make those individual shots into parts of the same shockwave we had to develop some concepts that would be carried over from shot to shot," Klaus adds. "The main body of the shockwave would consist of an atmospheric dust fluid simulation driven by controllable geometric helper objects. On the inside and surrounding the shockwave large numbers of debris would be carried along by the shockwave; debris that would be able to both shoot forward with the shockwave and upward to explain why the actors also got lifted into the air by the passing shockwave.

"When the shockwave finally hits the van, the action is experienced from inside a storm of debris raining sideways against the van. We had to find exactly the right amount and speed of flying elements to keep it from turning into one big mush hitting the van and also to keep enough elements so that the amount hitting the van could actually believably push it over. Effectively the amount of particles used was so high that we needed to split it into several particle simulations to prevent excessive simulation and caching times."

The integration of the flying debris elements into the plates took them a while to figure out. Usually CG effects need to connect with what is visible in the plate at one point. "In this case, we had many shots where our effects did not interact directly with the plate, which made it more difficult to get the feeling of full integration," Klaus explains. "The solution was to actually try and push the effects more into the plate and not making them stand out."

Meanwhile, Atomic Fiction, which completed nearly 100 shots of cities (including Shanghai) and vehicles, offers a lower-cost business model utilizing cloud computing and other measures. Atomic has been working with a company called ZYNC to utilize Amazon's EC2 cloud services. By moving rendering to the cloud instead of owning the computers, they treat rendering like a utility and only pay for what they use. This means that rendering can literally be scaled from as many cores as you need for a particular job, back down to the Macs on the artists' desks between gigs.

"We established some new ground rules for the look of things," offers Atomic co-owner and VFX supervisor Ryan Tudhope. "This included finding common elements such as graffiti, shelters/tents, antennas, and camp fires to tie our shots together and, more importantly, give Looper's cityscapes their own signature feel.”

"Rian chose to shoot the film on anamorphic 35mm, which was (mostly) a blessing. The plates are beautiful and grungy, with blue anamorphic lens stripes, lens distortion, and heavy chromatic aberration around the edges of the frame. The downside, of course, is that all these lens artifacts made the work more complicated. For example, the lenses produce an extreme warping and 'scaling' at the edge of frame during focus pulls, while the center of the image remains unaffected. In the end, we tackled each challenge by building custom scripts (in Nuke) that would re-create these artifacts on our CG elements or matte paintings and could be rolled out to the entire team."

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Bill Desowitz is former senior editor of AWN and VFXWorld, the owner of Immersed in Movies (www.billdesowitz.com), a columnist for Thompson on Hollywood at Indiewire and author of James Bond Unmasked (www.jamesbondunmasked.com), which chronicles the 50-year evolution of 007 on screen, featuring interviews with all six actors.

Bill Desowitz, former editor of VFXWorld, is currently the Crafts Editor of IndieWire.