One of the few movies where the upgrade to 3D was really worth it was probably Gravity, a space disaster movie that came out in 2013 and wound up at the top of my list of best movies of the year. I got the Blu-ray last year and finally watched it. Just like the first time it kept me on the edge of my seat the whole time and I was blown away by how realistic everything looked. So I watched it and enjoyed it all over again and started watching the making of segments which are really amazing. For the space stuff they had two light sources, earth and sun, and as an actor moved or spun the lights would have to go around the actor since they couldn’t really spin Sandra Bullock and George Clooney that much. So they got robots like they use for making cars and would have one robot hold the camera, one the sun light, and one the earth light and the actor wouldn’t have to move that much. In the scenes that take place in space, really the only thing that was real was the actor’s face. Everything else was pretty much CGI. On scenes inside space ships they had sets (but still did a great job of mimicking weightlessness, which I won’t go into).
So first they did the whole movie on computer in 3D using software called Previs (for previsualization) to get everything in the right place and set up camera angles, kind of like computerized storyboards. Then they gave the director a computer/camera that he could move around and see the 3D model as if he had a camera and he could “film” whatever he wanted in virtual reality by capturing where his camera was and which way it was pointing. So he went to an empty room and spent a month filming all the shots of the previs 3D virtual world. Then they took all of that and programmed the robots to replicate that around the actors with exactly the same coordinates and motion so they could just drop in the face of the actor and their faces would have the correct lighting (which was the whole point).
However the earth and sun robots couldn’t move fast enough around the actor, so they created a lightbox which was a room with LED screens on all four walls, the floor, and ceiling (really would have been better to have a spherical room, but whatever) and they would show the sun and earth and even all the space ship stuff on the LED screens which would light up the actors face correctly at all times, even though the LED screens were pretty coarse. They have done computer-controlled cameras and lighting before, but nobody had done the lightbox thing before. One of the lighting guys went to a concert and saw a LED screen and saw how it lit up the band differently depending on what was on the screen and realized it was what they were looking for.
Another thing they had to keep track of was night and day as time went by in the movie, knowing they would orbit the earth twice during the length of the movie: two daytimes, two nighttimes, two sunsets, two sunrises. And they wanted to the earth to have realistic imagery, so they had to track what part of earth they were over at every minute of the movie. They got a globe and taped a red string along the orbital path (which they modified from a real one so they weren’t over the ocean all the time) and then added movie events as points along the string to keep everything straight. They still had the globe in the piece I watched about it.
I remember reading how groundbreaking the filming of the movie was and reading that they didn’t even know how to film the movie when they started and wound up using technology that didn’t exist at the start to pull it off, but I didn’t know any of the details. Already a really good movie, Gravity also has some of the best extras.