How have they made a 3D film from a 2D original?

[Bert]

The Lion King has just been released in 3D. Since the original was made in 1994, and I suppose with no view to re-releasing it 17 years in the future in 3D, how has it been done? With computers, obviously, but how? In a simple explanation, each frame would need to be duplicated from a slightly different point of view - about 7 cm to the left (or right) of the original. If they still have the original cells, I suppose they could move the ones that are nearer to the camera, relative to the ones of the distant background. Maybe that's how they did it. But I'd like an expert to say.

[BrainsTracy]

I'm not an expert on animation but I'd say your original suggestion is correct. From each frame create 2 new ones slightly offeset and re merge back.

[Buenchico]

There's a video here that explains the process far better than just words could do:
http://geeknizer.com/...ting-2d-movies-to-3d/

Chris

[Bert]

Thanks, Buenchico. I can see that working for real-life films where objects have depth. But an animated cartoons consists of flat images, so I don't see how a computer can make a 3D image out of them.
But, gee-whizz, it's complicated enough with a real-life film. Has anybody asked themselves if it was worth the effort? I haven't watched a 3D film, but I get the impression that most people think 3D adds very little to a film.