In the dream, you're in the back of a van, asleep and dreaming that you are walking down a long hotel hallway, followed by security operatives. The van, itself pursued by security forces, is run off the road and tips precariously off a bridge. In the dream within the dream, the entire hotel tumbles as the van rolls.
Then you wake up to the potential nightmare: You are working on Christopher Nolan's mind-bending "Inception" and have been charged with bringing those images to the screen, using practical — or real world — effects rather than computer-generated visual effects.
On screen, we see the hotel hallway start to disengage from the laws of nature. As actor Joseph Gordon-Levitt battles the agents pursuing him, the floor suddenly starts to shift out from under his feet, even as what had once been a corridor wall takes its place.
It's an engaging, and seamless, scene. Here, the craftspeople behind it talk about putting all the elements together.
Special effects supervisor Chris Corbould: "Any [set] built to rotate has generally been done round, very slow, very surreal. Chris had a new take on it: First of all, it was going to be more than 100 feet long and rectangular. The next thing was it wasn't going to be just someone walking along the walls, creating a weird illusion. It was a full-on fight sequence with a main actor in there."
Production designer Guy Hendrix Dyas: "Many of the sets we built defied convention. [Nolan] gave us the freedom to break rules, to build corridors up on their end, elevator shafts that were horizontal to the ground and Escher-like environments. [We built] two versions of the same corridor set, each one positioned to use gravity in a different way. One rotated and one stood 80 feet vertically. Our longest stretch of corridor, which was 120 feet, included a modular system that enabled us to add various twists and turns as needed by borrowing segments from one end and adding them to another area."
Cinematographer Wally Pfister: The combination of those two sets, he says, was particularly effective in creating the illusion of weightlessness that follows the "rotating corridor" fight. "You're looking down the horizontal hallway and we've got Joe coming down on a trolley; just when you've kind of figured out how the trick is done, you cut to the vertical hallway where you're able to suspend him on wires, and now you're able to rotate him around 360 degrees. It's an identical shot of a completely different set where gravity has shifted 90 degrees."
Pfister: "All the lighting had to be built into the set. There would be no grid or floor-standing lights since the entire set piece had to rotate." Pfister, with Dyas and chief lighting technician Cory Geryak, built special fixtures into the ceiling that looked like ordinary hotel lamps but actually housed movie lights. "The second challenge was camera placement and movement. With the help of Chris Corbould, we created a hidden track in the floor that allowed the camera to glide across the floor smoothly regardless of what was happening to the set.
"So, effectively, we got dolly shots up and down that corridor as it was rotating. That really helped sell the illusion, because if you start to suspect there's a camera fixed to the set as it's rotating, the second you start dollying up and down the hallway, you lose that concern. In addition, we employed a Technocrane so we could telescope down the hall with the set rotating around us."
The actors found out just how difficult it was to tussle in what was, essentially, a rectangular washing machine.
Stunt coordinator Tom Struthers: "In the fight between Joseph and the second security guard, Marvin [Stewart-Campbell], in the bedroom, the whole room was tumbling; it was on a gimbal. When you've got 30-foot surfaces and 14-foot-high ceilings and you're gimballing them, you can hardly keep up with 3, 31/2, 4 revolutions per minute. They couldn't handle more than 5 [rpm] in the corridor. Because if you get behind the [pace of the] arc, it will throw you 30 feet across the room."
Struthers says rehearsal for the scene, headed by assistant stunt coordinator Sy Holland, took more than two months — three weeks with Gordon-Levitt.
Holland's team, Struthers says, "worked on it 12 hours a day, sometimes six days a week, for nine weeks, just for 21/2 days' filming. Joseph trained so hard for it to get his core strength up for the wire work we had and for running around inside the corridor. There's only one shot in that whole sequence that Joseph didn't do."
Joseph Gordon-Levitt: "Creating the effect practically—rather than digitally—made the acting easy. I didn't have to pretend. The floor really was spinning out from under me."
The start of the fight is captured in one long shot tracking up and down that corridor — about 15 seconds of surreal but carefully choreographed mayhem.
Editor Lee Smith: "I loved simply being able to hold a shot as long as I did when [Gordon-Levitt] runs down and clubs the security guard. Then you notice they're suddenly landing on the side of the room, inexplicably. You don't get to do that very often in movies. So that was a treat.
"You never forget your first reaction, looking at shots like that where everyone sits there and goes, 'Wow, how did we do that?' So the tendency to sort of jazz it up with editing — you have to restrain yourself and go, 'No, that's actually an amazing shot.' You can only do that for so long; then as the fight progresses, you have to inject more energy into it by using multiple angles.
"Basically, though, to slow the editing down, you have to be seeing something amazing, especially if you're in a fight sequence. This was one of those 'big idea' sequences, and it deserved its place in the movie and as much time as I gave it."