I recall watching my grandfather work for hours on end silversmithing, using both hands to manipulate 3d objects with gestures both coarse and fine.
All of these demos tend to forget to take a few minutes to look at how artisans who actually use their hands with real life 3d objects avoid fatigue. They don't stretch their arms out towards a screen. People have spent endless hours manipulating stuff using both hands since the first time we slapped a couple of flint rocks together, but after a single lifetime of manipulating a computer mouse we can't conceive of working all day using 10 fingers lol. I believe the ancient technique to avoid fatigue is called "propping the elbows." We have a "manipulation space" where we can comfortably perform gestures in 3d space for hours on end, it is where the averaged normal of one's chest and face intersect, and is often where we find one's magazine, cellphone, vinyl toy under inspection, or lunch. The major concern for future computing may not be fatigue but competition for use of this limited and precious volume. ;) > leap thing may look cool.. for first coupe minutes.. let me see you holding > your hands up in the air for longer than 15 minutes alone.. not to mention > couple hours... > completely useless waste of time and money if you ask me
