<s>
OpenFlight	B-Application
(	O
or	O
.flt	B-Application
)	O
is	O
a	O
3d	O
geometry	O
model	O
file	O
format	O
originally	O
developed	O
by	O
Software	O
Systems	O
Inc	O
.	O
for	O
its	O
MultiGen	O
real-time	O
3d	O
modeling	O
package	O
in	O
1988	O
.	O
</s>
<s>
Originally	O
called	O
Flight	O
,	O
the	O
format	O
was	O
designed	O
as	O
a	O
nonproprietary	O
3d	O
model	O
format	O
for	O
use	O
by	O
real-time	O
3d	O
visual	B-General_Concept
simulation	I-General_Concept
image	O
generators	O
.	O
</s>
<s>
The	O
format	O
was	O
later	O
renamed	O
to	O
OpenFlight	B-Application
to	O
denote	O
its	O
nonproprietary	O
image	O
generation	O
(	O
IG	O
)	O
usage	O
.	O
</s>
<s>
The	O
MultiGen	O
modeling	O
package	O
(	O
known	O
now	O
as	O
Creator	O
)	O
and	O
the	O
OpenFlight	B-Application
format	O
were	O
rapidly	O
adopted	O
by	O
the	O
early	O
commercial	O
flight	B-Application
simulation	I-Application
industry	O
in	O
the	O
later	O
1980s	O
and	O
early	O
1990s	O
.	O
</s>
<s>
The	O
early	O
advantage	O
OpenFlight	B-Application
held	O
over	O
many	O
3d	O
geometry	O
model	O
file	O
formats	O
(	O
.obj	B-Application
,	O
.dxf	O
,	O
.3ds	O
)	O
was	O
its	O
specific	O
real-time	O
3d	O
graphics	O
industry	O
design	O
.	O
</s>
<s>
This	O
means	O
that	O
the	O
format	O
is	O
polygon	O
based	O
(	O
rather	O
than	O
NURB	B-Algorithm
surfaces	O
)	O
,	O
and	O
provides	O
a	O
real-time	O
tree	O
structure	O
essential	O
for	O
real-time	O
IG	O
systems	O
.	O
</s>
<s>
Most	O
early	O
graphics	O
file	O
formats	O
,	O
such	O
as	O
Wavefront	B-Application
Technologies	I-Application
,	O
or	O
Alias	O
Systems	O
Corporation	O
,	O
tried	O
to	O
focus	O
more	O
on	O
visual	O
aesthetics	O
for	O
non-real-time	O
based	O
rendering	O
graphics	O
packages	O
.	O
</s>
<s>
The	O
OpenFlight	B-Application
file	O
format	O
is	O
still	O
widely	O
used	O
today	O
in	O
the	O
high	O
end	O
real-time	O
visual	B-General_Concept
simulation	I-General_Concept
industry	O
as	O
the	O
standard	O
interchange	O
format	O
between	O
different	O
IG	O
systems	O
,	O
and	O
is	O
currently	O
administrated	O
by	O
Presagis	O
.	O
</s>
<s>
OpenFlight	B-Application
models	O
can	O
have	O
several	O
associated	O
files	O
in	O
different	O
formats	O
,	O
that	O
define	O
elements	O
such	O
as	O
material	O
characteristics	O
or	O
shaders	O
.	O
</s>
<s>
There	O
are	O
several	O
modeling	O
tools	O
currently	O
on	O
the	O
market	O
that	O
both	O
read	O
and	O
write	O
the	O
OpenFlight	B-Application
file	O
format	O
.	O
</s>
<s>
Because	O
the	O
OpenFlight	B-Application
file	O
format	O
allows	O
for	O
vendor	O
specific	O
data	O
field	O
additions	O
,	O
some	O
modeling	O
and	O
simulation	O
tools	O
might	O
not	O
fully	O
support	O
vendor	O
specific	O
additions	O
to	O
the	O
file	O
format	O
.	O
</s>
