According to Sony’s R&D manager, Dr. Richard Marks, while researching different and new methods of motion control for videogame interaction, the team at Sony pursued technology similar to Microsoft’s ‘hands-free’ Project Natal, but ultimately ended up going down the path that lead to the current iteration of the PlayStation Move (which uses a physical hand-held device) as it allowed the publisher’s game teams to deliver more “robust” experiences.

Speaking on the Engadget Show, Dr. Marks said:

We tried a lot of different 3D cameras. I love the 3D camera technology; personally, I like the technology part of it. We worked closely with our game teams at what it would enable, and it enabled making the things we already did with EyeToy more robust, but it didn’t really enable as many new experiences as what we were hoping it would enable, so it made the things we were already able to do a little bit more robust - which is good - but it adds a lot of cost and it didn’t enable some of the other experiences we wanted to achieve.”

Source: Engadget Show via PlayStation Lifestyle