<s>
TrackIR	B-Operating_System
is	O
an	O
optical	B-Application
motion	I-Application
tracking	I-Application
controller	O
for	O
Microsoft	B-Application
Windows	I-Application
created	O
by	O
NaturalPoint	O
Inc	O
..	O
TrackIR	B-Operating_System
tracks	O
head	O
motions	O
with	O
up	O
to	O
six	O
degrees	O
of	O
freedom	O
(	O
6DOF	O
)	O
allowing	O
handsfree	O
view	O
control	O
for	O
improved	O
game	O
immersion	O
and	O
situational	O
awareness	O
.	O
</s>
<s>
Head	O
position	O
and	O
orientation	O
are	O
measured	O
by	O
a	O
purpose-built	O
video	O
camera	O
,	O
mounted	O
on	O
top	O
of	O
the	O
user	O
's	O
monitor	B-Device
,	O
which	O
observes	O
infrared	O
(	O
IR	O
)	O
light	O
reflected	O
or	O
emitted	O
by	O
markers	O
on	O
a	O
rigid	O
model	O
worn	O
by	O
the	O
user	O
.	O
</s>
<s>
TrackIR	B-Operating_System
software	O
is	O
used	O
to	O
control	O
the	O
camera	O
,	O
as	O
well	O
as	O
adjust	O
tracking	O
sensitivity	O
.	O
</s>
<s>
Head	O
movements	O
can	O
be	O
scaled	O
,	O
allowing	O
a	O
virtual	O
movement	O
of	O
180	O
degrees	O
to	O
occur	O
,	O
whilst	O
the	O
user	O
still	O
looks	O
at	O
the	O
monitor	B-Device
.	O
</s>
<s>
TrackIR	B-Operating_System
was	O
initially	O
designed	O
as	O
an	O
assistive	O
technology	O
device	O
for	O
Windows	O
cursor	O
control	O
.	O
</s>
<s>
Between	O
2002	O
and	O
2005	O
,	O
five	O
TrackIR	B-Operating_System
camera	O
models	O
were	O
released	O
,	O
bringing	O
improvements	O
such	O
as	O
doubled	O
frame	O
rate	O
and	O
increased	O
resolution	O
,	O
leading	O
to	O
more	O
responsive	O
and	O
accurate	O
tracking	O
.	O
</s>
<s>
The	O
proprietary	O
TrackIR	B-Operating_System
interface	O
has	O
become	O
commonplace	O
for	O
view	O
control	O
in	O
PC	O
games	O
and	O
simulations	O
and	O
is	O
only	O
intended	O
for	O
use	O
with	O
TrackIR	B-Operating_System
products	O
.	O
</s>
<s>
As	O
more	O
developers	O
and	O
games	O
added	O
support	O
for	O
TrackIR	B-Operating_System
,	O
developers	O
were	O
successful	O
in	O
reverse	O
engineering	O
the	O
proprietary	O
interface	O
allowing	O
non-TrackIR	O
devices	O
to	O
be	O
used	O
for	O
view	O
control	O
,	O
including	O
generic	O
webcams	O
.	O
</s>
<s>
However	O
,	O
due	O
to	O
the	O
fact	O
that	O
older	O
TrackIR-1	O
and	O
TrackIR-2	O
products	O
use	O
software	O
drivers	O
which	O
are	O
no	O
longer	O
maintained	O
,	O
they	O
are	O
also	O
incompatible	O
with	O
titles	O
using	O
the	O
newer	O
interface	O
.	O
</s>
<s>
Some	O
reviewers	O
found	O
the	O
TrackIR	B-Operating_System
4	O
Pro	O
with	O
TrackClip	O
Pro	O
bundle	O
to	O
be	O
expensive	O
at	O
the	O
$200	O
–	O
$220	O
price	O
,	O
while	O
still	O
considering	O
it	O
a	O
worthwhile	O
purchase	O
for	O
serious	O
simulation	O
users	O
.	O
</s>
<s>
Additionally	O
,	O
one	O
review	O
noted	O
that	O
the	O
TrackIR	B-Operating_System
4	O
Pro	O
runs	O
at	O
a	O
temperature	O
which	O
they	O
consider	O
higher	O
than	O
normal	O
when	O
it	O
is	O
actively	O
tracking	O
.	O
</s>
