@Squilliam
again: the world of 3d sensors and so called depth cameras predates the commercially known entry level options for consoles. Many cameras have been available, differing in tech and resulting in different tradeoffs for rate, resolution, field of view, z-sensitivity etc. If you say that you've been trying out different cameras and you've been playing with camera-based interfaces since say 6 or 7 years ago, why should the only options be "3dv or primesense"?
As for 3DV not bringing anything to the table of Natal's 3D: from the Eurogamer article you linked:
The two PrimeSense men are also very keen to point out that despite the Microsoft acquisition of time-of-flight camera specialists, 3DV, who'd already made several 3D-camera based gaming demos, all of the video capture and depth perception hardware within Natal comes from them, and only from them.
"PrimeSense isn't just the provider of the 3D technology in Project Natal... it's the sole provider," says Maizels proudly. "Project Natal is much more than a 3D sensing device, but PrimeSense is the only company responsible for the 3D."
...
"But Natal is much more than that. Natal is content. Natal is processing software. Natal is about other ways of interaction like voice and so on. Microsoft was able to put this vast and expensive eco-system around it to make turn a raw technology into a product. Natal is far, far wider than the PrimeSense element, but PrimeSense is the acquisition element."
Bold is mine: the guys are proud to be the eclusive partner and providers of the hardware. As they say themselves, Natal is more than that, including the processing software. So maybe this is where 3DV enters? Let me quote another link:
Moshe Lichtman, Microsoft corporate vice president and head of Israel R&D said:
“Fourteen development projects are taking place at the center today, twelve of them completely new and destined to become Microsoft products in new markets… the R&D center helped Microsoft in buying the intellectual property of 3DV Systems, and in the wake of that dozens of the company’s employees were recruited to work at the development center.”
I think this is quite clear: MS is using primesense's hardware instead of 3DV's Zcam. But they bought the intellectual property for the processing software from 3DV at least as a building block and put those people to work on the project. They might have scrapped it entirely by now, or merely and more likely swapped out the "parse the camera data into a 3D map" driver (primesense's chip will do that job instead) and kept the "build a 3d skeleton model out of the 3d map" one.
Thus I still won't buy that a small firm like 3DV was bought for patent litigation threats. If MS had developed the processing software before, they'd have filed their own patents on the software part. And as I said, any patent trying to cover the whole 3d-camera -> 3d skeletal model idea over different sensor techs would be unlikely to be enforceable given the width of the scope.
The most likely scenario is simply that MS acquired and later extended the necessary software base. It's up to you if you want to call this 3DV's work or MS R&D, because we'll probably never know where the fuzzy bounduary lies.
