When Neil Burger's Faustian thriller, Limitless, was in post, it was in dire need of vfx assistance. Apparently the visual motifs weren't working. And they were vital in conveying the hyper real state of writer Eddie (Bradley Cooper) becoming brilliant as a result of the mind-altering drug, NZT.

So Dan Schrecker and Look Effects (Black Swan) came to the rescue. Turns out that Schrecker wanted to do the vfx from the beginning, but it didn't work out when a previous incarnation with Shia LaBeouf fell through after the star broke his hand on the Transformers sequel. Later, when the film finally got made, another vendor was signed. But director Burger was not pleased with the work.

"It was fun for us as a rescue mission and to help conceptualize some of these key sequences in post, which doesn't get to happen that often," recounts the visual effects supervisor. It's a character-driven film but it needs these visual effects pieces to help tell the story that's going on.

"Neil is a sharp guy who knows what he's looking for and he gave us a lot of references. But we came in late in the game and it was walking that line of: 'We can make this work with what you shot, but for some of this other stuff, we can't because the footage just isn't there.' In some cases, we did get to design from the ground up: take his reference, shoot some tests, show him different ideas and then reshoot it and put it together."

There are less than 50 vfx shots, but, as Schrecker suggests, they help visualize Eddie's roller coaster ride on NZT. "They designed and shot stuff but they didn't get it right," Schrecker admits. "For instance, when Eddie first takes the drug, the whole environment [on a stairwell] unwraps from close-up into a full 360 panorama. They shot this initially with three fish-eye lenses on a single rig so they could see three different directions at the same time. But everything was distorted through the fish-eye and there was a blind spot in the middle so there was no information and you couldn't stitch it together. So we had to go back in and figure out how to fill in the missing pieces and stitch it together."

Since the stairwell set was no longer around, Look reshot on greenscreen, tweaked the existing footage and wrapped it around a matte painting.

Then there were surreal effects to depict Eddie's out of body highs and lows. First, when he's alone in his room and writing his novel in only four days, and, later, when he zips back and forth throughout Manhattan in a state of total disorientation.

"Neil wanted to show the inspiration of writing and have this idea that these letters and words and phrases would fall from the ceiling," Schrecker continues. "Again, he had some reference from interactive exhibits that someone had put together, which was an augmented reality where letters were falling and landing on real people standing in front of a camera. So we riffed on that and we essentially built a rig with strings of phrases where we controlled the speed of the string. We tracked it and did some roto. It was much more like waves or sheets of words falling around Eddie. It was a CG job done by the same artist who did the wings on The Black Swan, Shawn Lipowski.