My wild hypothesis is that as you go from 2D to 3D navigation, the cognitive load increases to a level which is much more than a normal human can handle. (Simil

My wild hypothesis is that as you go from 2D to 3D navigation, the cognitive load increases to a level which is much more than a normal human can handle. (Similar to 2D matching being polynomial time and 3D matching being NP-Complete). It will be interesting to see some vision research which shows that human navigation (vision) uses some kind of matching (http://en.wikipedia.org/wiki/Matching http://en.wikipedia.org/wiki/Matching).