Environmental Engineering Reference
In-Depth Information
Fig. 10. Results of the paths used by the users to perform the task.
option: to walk in a straight line near the marble. The black line represents the automatic path
computed by the system. Our method keeps constant speed along the path and avoids the
obstacles automatically without errors. Note that some of users chose the other side of the
table which is the longest way. These users had, in general, more difficulties in navigating, as
it can be seen from their paths sparser and more erratic.
The temperature diagram in Figure 11 represents the head deviation in the pitch angle in free
navigation mode. The figure shows that users tend to look down to see where they are going.
Users ranked the navigation method easiness in the following order: automatic, assisted,
assisted rotation and free. As expected, they found the automatic method very easy or easy
(100% of users). The assisted mode was also considered as easy and very easy by 95% of users.
However, the assisted rotation was less valued (only 80% scored it as easy or very easy). Users
reported that not being able to rotate the camera was disturbing. The sensation was the same
in all groups. The free navigation mode was found easy and very easy by 67% of users in
general, but only by 20% of non 3D-gamers, who were, however, 2D-gamers. We conclude, as
expected, that free navigation is difficult for non-gamers. Concerning the preferred navigation
mode, all groups of users chose the assisted mode, even the 60% of game players.
