Whenever I see something new and unique in regards to technology I'm surprised. Google's Project Soli is pretty slick and it definitely is one of those things that should make any technology minded person get a little excited - or at least thinking about the potential for the technology. Watch the video below - it is very well done. I'm pretty sure all of the gestures are mimed but they give proof of concept.
Whenever I see something like this I immediately think about Apple. Why? Well every i device has gestures in them - the track pad of their macbook computers, the ipad, iphone, ipod and now the iwatch; all have gestures that complete actions - so when I see something new like this it think about those devices.
There is a problem with gestures - they have to be taught and the more natural they are the better and more natural their usage. So if learning the gestures was the first and biggest hurdle, the next would be how fast they are to do (like the actual time it takes to make a gesture) - if they are faster than another input device then they will be a win... if they take longer to do than the conventional way - then not so much of a win. Finally, is it better than what you are replacing? Humans love buttons. Don't believe me, just give a keyboard to a baby. We like tools we can touch and feel - but buttons take up space and aren't necessarily pretty - so I definitely believe there is opportunity with devices that are small and don't have room for buttons or other interaction points.
I'm very interested in this use of Radar technology. This is really interesting since it provides an input that isn't vision tracked. Vision tracking can be very limited by the environment - if it is too dark, or too light - if something is too far, or too close. Also you are dealing with a 2d object - which typically requires additional cameras to process a 3rd axis - which of course is expensive because it requires more cameras and more processing - So radar is great because it is perfect for monitoring all three axis - and it can be done with one radar - not multiple radars. I like this and I think it may be perfect for some types of devices.