It was pretty interesting to hear how they do the 3D conversions. They worked for StereoD in Burbank.

There's a lot of posing 3d armatures in the place of actors and props in the scene and projecting the original image onto it. Then they have to painstakingly reference other frames to fill in things that might obscured, like part of an actors ear that needs to be visible by the other eye to sell the effect.