“Stereoscopic 3D Copy & Paste.” (made by Swiss engineers Joren van Baar and Wan-Yen Lo)Tools that let you define various objects and planes on a stereoscopic image, similar to how you might grab a shape with the magic wand tool(Photshop), and then duplicate it and move that shape around on both parts of the 3D photo….See Details.
The software handles re-creating shadows, and automatically tackling occlusion. Results aren’t perfect, particularly if you’re trying to change perspective or partially occlude an object behind something that’s transparent, it certainly trumps trying to do it by hand.