<s>
Volumetric	B-General_Concept
lighting	I-General_Concept
,	O
also	O
known	O
as	O
"	O
God	O
rays	O
"	O
,	O
is	O
a	O
technique	O
used	O
in	O
3D	O
computer	O
graphics	O
to	O
add	O
lighting	O
effects	O
to	O
a	O
rendered	O
scene	O
.	O
</s>
<s>
Examples	O
of	O
volumetric	B-General_Concept
lighting	I-General_Concept
are	O
seeing	O
sunbeams	O
shining	O
through	O
a	O
window	O
and	O
seeing	O
sunbeams	O
radiating	O
when	O
the	O
Sun	O
is	O
below	O
the	O
horizon	O
,	O
also	O
known	O
as	O
crepuscular	O
rays	O
.	O
</s>
<s>
In	O
volumetric	B-General_Concept
lighting	I-General_Concept
,	O
the	O
light	O
cone	O
emitted	O
by	O
a	O
light	O
source	O
is	O
modeled	O
as	O
a	O
transparent	O
object	O
and	O
considered	O
as	O
a	O
container	O
of	O
a	O
"	O
volume	O
"	O
.	O
</s>
<s>
Volumetric	B-General_Concept
lighting	I-General_Concept
requires	O
two	O
components	O
:	O
a	O
light	O
space	O
shadow	O
map	O
,	O
and	O
a	O
depth	O
buffer	O
.	O
</s>
<s>
One	O
way	O
to	O
optimize	O
volumetric	B-General_Concept
lighting	I-General_Concept
effects	O
is	O
to	O
render	O
the	O
lighting	O
volume	O
at	O
a	O
much	O
coarser	O
resolution	O
than	O
that	O
which	O
the	O
graphics	O
context	O
is	O
using	O
.	O
</s>
<s>
Another	O
technique	O
can	O
also	O
be	O
used	O
to	O
provide	O
usually	O
satisfying	O
,	O
if	O
inaccurate	O
volumetric	B-General_Concept
lighting	I-General_Concept
effects	O
.	O
</s>
