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How’d They Do That? 10 Secrets of ‘Gravity’ Exposed at AMPAS Event Honoring the Film’s Tech Wizards

How'd They Do That? 10 Secrets of 'Gravity' Exposed at AMPAS Event Honoring the Film's Tech Wizards

Even if you think you know how the Oscar-winning space odyssey “Gravity” was made, you don’t. That is, unless you’re Alfonso Cuaron or another member of the cast and crew. There aren’t enough special features, docs, interviews, or behind the scenes information available for anyone outside the creators to fully grasp the monumental efforts that went into making last year’s critical and commercial smash appear as simple as it did. 

Seven Oscars really weren’t enough for “Gravity.” 

The Academy of Motion Pictures Arts & Sciences held a special event Monday night in Hollywood to honor the film’s stunning technical achievements with editor Mark Sanger, visual effects supervisor Tim Webber — both of whom won Oscars in February — and animation supervisor Max Solomon. Hosted by Academy Governor Bill Kroyer, “Deconstructing Gravity” took an in-depth look at the production methods employed to make the space odyssey come to life. Here are the highlights of the incredibly informative event, as best as can be explained by a layman:

Remember when Sandra Bullock spun head over heels, over and over into the black depths of space? She never moved.

“We were hoping we would move the actors more,” Webber said, while chronicling the elaborate and lengthy production process, or simply how they made the movie at all. After explaining the restrictions put in place by the advanced lighting set-ups (see photos), Webber and his team came to the conclusion they couldn’t move the actors that much at all. There wasn’t enough space for the actors to move and for the camera to move, so they simulated most of it. One of the methods “was not to move the actor, or at least not to move them so much, but to move the camera instead. For instance, when Sandra is spinning, we would move the camera around her as if she was spinning. Or, more often than not, we would partially move her and partially move the camera. We had to sort of abstract all the motion that was in the pre-vis and create new motion of her and the camera that weren’t actually related to her original motion or the camera’s original motion, but the combination of the two would produce the same result.”

They made the movie three times (at least).

Wondering what “pre-vis” means in the last statement? Pre-vis is shorthand for pre-visualizations used by the “Gravity” filmmakers to map out the film before shooting any of it. They showed animated videos they created in order to know when and where things should happen on screen, and these videos were used then used for production and then used again for editing. They would check dailies against the pre-vis to make sure they lined up, and then Sanger would edit something together using the dailies for the VFX team to work on — but whenever adjustments needed to made based on new input (Webber provided an example of Bullock’s character freaking out when she first undressed in the original version, only to scrap it after seeing how unnatural it looked once shot), each part had to be redone from the pre-vis, to the shooting, to the edits. While three versions of the film existed in the pre-vis, the dailies, and the final cut, hundreds more are out there from the pieces discarded along the way.

Car assembly robots were reconfigured to move lighting and cameras as needed.

An early challenge for filmmakers was determining how to create the constant camera movement replicating the baseless world of space. “One of the earliest steps in solving the problem was getting involved with robots, car assembly robots,” Webber said. “Chris DeFaria, the executive at Warner Bros., had read an article in “Wired” magazine about a company called AutoFuss in San Francisco that had put a camera on a car assembly robot, and we went to see them and we did some tests with them. We worked with them to develop a robot to add parts of it that didn’t exist […] the tracks you can see the robot is on […] the ability to change the speed […] and we put a traditional camera head on the end. And we ended up with a very sophisticated motion control. One of the key things, I mean, it gave us faster and more flexible camera moves, but another really important part was it allowed us to move the lighting as well. It wasn’t just the cameras it was moving.

The light box.

As you can see in the photo on the left (and above), the “Gravity” team used what they called “a light box” to reflect light on the actors as it would be reflected in space. Because things were moving so quickly, they constructed panels holding more than 2 million LED lights to surround Bullock in what came to be known as “Sandy’s cage.”

“Essentially, the robots were quite cumbersome for moving the lights, so we needed to find a way that a) was more flexible than the robots, and b) less cumbersome, and the best way of doing that was not to physically move anything, but to, essentially, dim and brighten lots and lots of different lights at the same time. Dimming and brightening lights to simulate movement has been done for car shots and pour man’s process stage type work, and other people have done similar stuff. Paul Debevec had done something similar with his light stage, but we needed something really quite sophisticated, quite all-enveloping that could go behind anything that had been done before, really.” 

“At some point, Cheevo [sp] was at a rock concert and saw these massive screens at the back of the stage and realized that the panels used on that screen were bright enough to light what we needed. So we then ended up designing this light box with panels.”

Remember when Bullock took off her astronaut suit? There was no suit.

“You can see she’s starting to take the suit off,” Webber said. “We couldn’t do that in the light box for various reasons to with the mechanics of where the space suit would go and the techniques of the lighting and stuff. So we had to make an invisible drawing to a completely different rig. We had to work out how she could be taking these clothes off, which would actually fall to the ground when she took them off. They wouldn’t behave as if they were in zero gravity. Also, in order to get her to be moving and twisting and turning this way, she would be attached to a rig that would get in the way of her from taking all these clothes off. We would look at the pre-vis and work it out literally beat by beat. We would say, “This little bit we can solve this way, and this little bit we can solve that way.” 

After a lengthy discussion about more of the scene’s difficult aspects, they screened the clip of her “womb scene,” as it was referred to, and you could see part of the suit taking up enough of the frame to hide one part of the removal and her headset being pushed out of frame above her. They also screened behind the scenes footage of Bullock removing what little she actually wore on set — no space pants ever existed in real life. 

Astronaut Cady Coleman saw “Gravity” as a powerful message to young women.

Astronaut Cady Coleman, who worked with Sandra Bullock on many aspects of creating her character, including how to move like she was in space, provided a heartfelt introduction to kick off the evening. “It was significant to me that “Gravity” had a female hero,” Coleman said. “I think it’s invaluable for the next generations to see themselves as tough, resilient characters like Ryan Stone. The makers of “Gravity” sent a powerful message and it is so important that girls can be and need to be part of the technological solutions for our planet. Can you imagine millions of girls around the planet thinking they can do anything? It’s awesome.”

Remember those beautiful long, uncut sequences? They used hundreds of edits.

Perhaps the most shocking element of the entire night came when Sanger stood up to illustrate how the editing of “Gravity” wasn’t nearly as simple as stitching together a few dozen lengthy scenes. Sangor showed a few screengrabs of his editing timeline, and they were packed to the gills with cut after cut. Plenty of sound levels came into play as well, but there were at least nine different tracks layered on top of one another with more edits than appeared possible inserted in each one. 

“To give you another example of what a strange and unique production this was, I was on the film 14 months before we started shooting. The reason for that was we had to put together an edit. Initially, we were just flushing out ideas, and we were taking the storyboards and cutting the storyboards together with some dialogue and just trying to get an idea of how the sequences and scenes would go together. Before we knew it, we were taking the storyboarded scenes and giving them to the animators who would then put together a very rough pre-vis, to try to tell the story better than with the board. At this stage, we had dialogue in there. I was playing George Clooney’s character and my assistant was playing Sandra Bullock’s character, and we were editing dialogue. […] We had to be careful to keep up with each other because we were all working at the same time. We were blocking the movie in advance of the shoot. […] The shots were so complex, everybody in pre-production needed to use the cut as the basis for calculating the logistics behind the shoot.”

“70 percent of the movie is made up of 17 shots.”

As illustrated above, it wasn’t that there was less editing going on in “Gravity.” There was a different kind of editing. Webbert tried to explain further. “Just to give everyone an idea, typical movies these days have 2,000 shots in them. This one had about 350. The opening shot is nearly 30 minutes long, and 70 percent of the movie is made up of 17 shots. It’s not just one opening shot. It’s a lot of long shots.”

“Gravity” may be the most collaborative motion picture ever assembled.

“We would work on a bit of pre-vis with Alfonso, and he’d come up with a new idea or we’d try something out that was working really well and that would feed into the script,” Webber told Indiewire in a pre-show interview. “Then he’d talk to Sandra about what this new bit was and she’d have an idea and then George would. That would come back into pre-vis and you’d have ideas working on the script and that would then go into pre-vis. Meanwhile, we were developing the techniques for making the movie, and all this was going on in parallel. It wasn’t the case of the script was done and then the pre-vis was done and then the actors have their input. It was kind of all working along in parallel, and I think that’s an interesting aspect. It definitely doesn’t normally happen to the extent it did on this movie.” 

“It was definitely more collaborative,” he continued. “Because everything was so different about the movie, it meant that people couldn’t fall into their usual way of working together through different departments. People couldn’t just fall into their usual routines. We all had to work together to figure out how we were going to do it.”

Originally, Alfonso Cuaron planned on shooting the film in six weeks using wires and green screen.

That, obviously, did not work out.

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