Biomedical Engineering Reference
In-Depth Information
(a)
Before
(b)
After
Fig. 14.3
An example of a structural alteration to an environment that can be used to redirect the
user. A door is swapped to the adjacent wall in the corner of a room, which results in users exiting
in a different direction than when they entered
the doors is moved as they are looking inside strategically-placed containers (see
Fig.
14.4
b). Upon exiting the building, users will be located at the opposite end of
the gravel road from where they entered, allowing them to walk repeatedly over the
same surface to enter the next building (see Fig.
14.4
c). Thus, the gravel road could
be extended infinitely, so long as the user stops to explore each building along the
way. Of course, if users choose to continue walking straight down the road without
stopping, an intervention would be required to prevent them from exiting the physical
workspace. Feedback from demonstrations and informal testing of this environment
suggest that the physical sensation of walking on a gravel surface provides a com-
pelling illusion that makes the virtual environment seem substantially more real.
Our vision is to provide a dynamic mixed reality experience with physical props
that can be moved to a different location in the tracking space when the user is redi-
rected. Dynamically moving props would be difficult and unpredictable with redi-
rected walking techniques that use gradual, continuous rotations. However, because
change blindness redirection shifts between predictable discrete environment states,
it would be relatively simple to mark the correct locations for each prop on the floor,
and have assistants move them to the appropriate place whenever a scene change
is applied to the environment. Thus, we expect spatial manipulation techniques to
prove useful for mixed reality training scenarios that incorporate a variety of passive
haptic stimuli such as walking surfaces, furniture, and other physical props.
