<s>
id	B-Operating_System
Tech	I-Operating_System
6	I-Operating_System
is	O
a	O
multiplatform	O
game	O
engine	O
developed	O
by	O
id	O
Software	O
.	O
</s>
<s>
It	O
is	O
the	O
successor	O
to	O
id	B-Application
Tech	I-Application
5	I-Application
and	O
was	O
first	O
used	O
to	O
create	O
the	O
2016	O
video	O
game	O
Doom	B-Application
.	O
</s>
<s>
The	O
PC	O
version	O
of	O
the	O
engine	O
is	O
based	O
on	O
Vulkan	B-Application
API	I-Application
and	O
OpenGL	B-Application
API	O
.	O
</s>
<s>
John	O
Carmack	O
started	O
talking	O
about	O
his	O
vision	O
regarding	O
the	O
engine	O
that	O
would	O
succeed	O
id	B-Application
Tech	I-Application
5	I-Application
years	O
before	O
the	O
latter	O
debuted	O
in	O
Rage	B-Application
,	O
but	O
following	O
his	O
departure	O
from	O
id	O
Software	O
in	O
2014	O
,	O
Tiago	O
Sousa	O
was	O
hired	O
to	O
replace	O
him	O
as	O
the	O
lead	O
renderer	O
programmer	O
at	O
the	O
company	O
.	O
</s>
<s>
In	O
2008	O
and	O
while	O
id	B-Application
Tech	I-Application
5	I-Application
had	O
yet	O
to	O
be	O
fully	O
formed	O
,	O
John	O
Carmack	O
said	O
the	O
next	O
engine	O
by	O
id	O
Software	O
would	O
be	O
looking	O
towards	O
a	O
direction	O
where	O
ray	B-Algorithm
tracing	I-Algorithm
and	O
classic	O
raster	B-Algorithm
graphics	I-Algorithm
would	O
be	O
mixed	O
.	O
</s>
<s>
The	O
engine	O
would	O
work	O
by	O
raycasting	O
the	O
geometry	O
represented	O
by	O
voxels	B-Algorithm
(	O
instead	O
of	O
triangles	O
)	O
stored	O
in	O
an	O
octree	B-Data_Structure
.	O
</s>
<s>
The	O
goal	O
of	O
the	O
engine	O
would	O
be	O
to	O
virtualize	O
geometry	O
the	O
same	O
way	O
that	O
id	B-Application
Tech	I-Application
5	I-Application
virtualized	O
textures	O
.	O
</s>
<s>
However	O
,	O
he	O
also	O
explained	O
during	O
QuakeCon	O
08	O
,	O
that	O
the	O
hardware	O
that	O
would	O
be	O
capable	O
of	O
id	B-Operating_System
Tech	I-Operating_System
6	I-Operating_System
did	O
not	O
yet	O
exist	O
at	O
the	O
time	O
.	O
</s>
<s>
In	O
July	O
2011	O
,	O
Carmack	O
explained	O
that	O
id	O
Software	O
was	O
beginning	O
research	O
for	O
the	O
development	O
of	O
id	B-Operating_System
Tech	I-Operating_System
6	I-Operating_System
.	O
</s>
<s>
An	O
early	O
version	O
of	O
the	O
fourth	O
main	O
Doom	B-Application
game	O
was	O
being	O
built	O
on	O
id	B-Application
Tech	I-Application
5	I-Application
but	O
id	O
Software	O
restarted	O
development	O
in	O
late	O
2011	O
to	O
early	O
2012	O
,	O
after	O
Bethesda	O
expressed	O
concerns	O
about	O
its	O
creative	O
and	O
technological	O
direction	O
.	O
</s>
<s>
When	O
development	O
was	O
restarted	O
it	O
was	O
decided	O
to	O
begin	O
with	O
the	O
id	O
Tech	O
5-based	O
Rage	B-Application
codebase	O
but	O
take	O
"	O
big	O
leaps	O
back	O
in	O
certain	O
areas	O
of	O
tech	O
"	O
and	O
"[merge]	O
Doom	B-Application
features	O
to	O
Rage	B-Application
"	O
.	O
</s>
<s>
Doom	B-Application
was	O
first	O
shown	O
to	O
the	O
public	O
during	O
QuakeCon	O
2014	O
,	O
where	O
it	O
was	O
confirmed	O
it	O
was	O
running	O
on	O
an	O
early	O
version	O
of	O
id	B-Operating_System
Tech	I-Operating_System
6	I-Operating_System
.	O
</s>
<s>
The	O
developers	O
 '	O
goals	O
when	O
creating	O
the	O
engine	O
were	O
described	O
as	O
being	O
able	O
to	O
drive	O
good	O
looking	O
games	O
running	O
at	O
1080p	O
on	O
60	O
fps	O
but	O
also	O
reintroduce	O
real-time	O
dynamic	O
lighting	O
which	O
was	O
largely	O
removed	O
from	O
id	B-Application
Tech	I-Application
5	I-Application
.	O
</s>
<s>
A	O
technical	O
analysis	O
of	O
Doom	B-Application
found	O
that	O
the	O
engine	O
supports	O
motion	O
blur	O
,	O
bokeh	O
depth	O
of	O
field	O
,	O
HDR	O
bloom	O
,	O
shadow	O
mapping	O
,	O
lightmaps	O
,	O
irradiance	O
volumes	O
,	O
image-based	B-Algorithm
lighting	I-Algorithm
,	O
FXAA	B-Algorithm
,	O
volumetric	O
lighting/smoke	O
,	O
destructible	O
environments	O
,	O
Water	O
Physics	O
,	O
Skin	O
sub-surface	O
scattering	O
,	O
SMAA	B-Algorithm
and	O
TSSAA	B-Algorithm
anti-aliasing	O
,	O
directional	O
occlusion	O
,	O
screen	O
space	O
reflections	O
,	O
normal	B-Application
maps	I-Application
,	O
GPU	O
accelerated	O
particles	O
which	O
are	O
correctly	O
lit	O
and	O
shadowed	O
,	O
triple	O
buffer	O
v-sync	O
which	O
acts	O
like	O
fast	O
sync	O
,	O
unified	O
volumetric	O
fog	O
(	O
every	O
light	O
,	O
shadow	O
,	O
indirect	O
lighting	O
affects	O
it	O
,	O
including	O
water	O
caustics	O
/	O
underwater	O
light	O
scattering	O
)	O
,	O
tessellated	O
water	O
surface	O
(	O
on	O
the	O
fly	O
without	O
GPU	O
tessellation	B-Algorithm
.	O
</s>
<s>
On	O
July	O
11	O
,	O
2016	O
,	O
id	O
Software	O
released	O
an	O
update	O
for	O
the	O
game	O
that	O
added	O
support	O
for	O
Vulkan	B-Application
.	O
</s>
<s>
Following	O
Carmack	O
's	O
departure	O
from	O
id	O
Software	O
,	O
Tiago	O
Sousa	O
,	O
who	O
had	O
worked	O
as	O
the	O
lead	O
R&D	O
graphics	O
engineer	O
of	O
several	O
versions	O
of	O
the	O
CryEngine	B-Application
at	O
Crytek	O
,	O
was	O
hired	O
to	O
lead	O
development	O
of	O
the	O
rendering	O
.	O
</s>
<s>
Bethesda	O
's	O
Pete	O
Hines	O
has	O
commented	O
that	O
while	O
id	B-Operating_System
Tech	I-Operating_System
6	I-Operating_System
reuses	O
code	O
written	O
by	O
Carmack	O
,	O
most	O
of	O
the	O
decisions	O
made	O
about	O
the	O
engine	O
's	O
direction	O
were	O
taken	O
after	O
he	O
left	O
.	O
</s>
