<s>
Distributed	B-Algorithm
ray	I-Algorithm
tracing	I-Algorithm
,	O
also	O
called	O
distribution	B-Algorithm
ray	I-Algorithm
tracing	I-Algorithm
and	O
stochastic	B-Algorithm
ray	I-Algorithm
tracing	I-Algorithm
,	O
is	O
a	O
refinement	O
of	O
ray	B-Algorithm
tracing	I-Algorithm
that	O
allows	O
for	O
the	O
rendering	O
of	O
"	O
soft	O
"	O
phenomena	O
.	O
</s>
<s>
Conventional	O
ray	B-Algorithm
tracing	I-Algorithm
uses	O
single	O
rays	O
to	O
sample	B-Algorithm
many	O
different	O
domains	O
.	O
</s>
<s>
For	O
example	O
,	O
when	O
the	O
color	O
of	O
an	O
object	O
is	O
calculated	O
,	O
ray	B-Algorithm
tracing	I-Algorithm
might	O
send	O
a	O
single	O
ray	O
to	O
each	O
light	O
source	O
in	O
the	O
scene	O
.	O
</s>
<s>
Conventional	O
ray	B-Algorithm
tracing	I-Algorithm
also	O
typically	O
spawns	O
one	O
reflection	O
ray	O
and	O
one	O
transmission	O
ray	O
per	O
intersection	O
.	O
</s>
<s>
Distributed	B-Algorithm
ray	I-Algorithm
tracing	I-Algorithm
removes	O
these	O
restrictions	O
by	O
averaging	O
multiple	O
rays	O
distributed	O
over	O
an	O
interval	O
.	O
</s>
<s>
Adding	O
"	O
soft	O
"	O
phenomena	O
to	O
ray-traced	O
images	O
in	O
this	O
way	O
can	O
improve	O
realism	O
immensely	O
,	O
since	O
the	O
sharp	O
phenomena	O
rendered	O
by	O
conventional	O
ray	B-Algorithm
tracing	I-Algorithm
are	O
almost	O
never	O
seen	O
in	O
reality	O
.	O
</s>
<s>
Distributing	O
rays	O
in	O
the	O
spectrum	O
allows	O
for	O
the	O
rendering	O
of	O
dispersion	O
effects	O
,	O
such	O
as	O
rainbows	B-General_Concept
and	O
prisms	O
.	O
</s>
<s>
Conventional	O
ray	B-Algorithm
tracing	I-Algorithm
estimates	O
these	O
integrals	O
by	O
sampling	O
the	O
value	O
of	O
the	O
integrand	O
at	O
a	O
single	O
point	O
in	O
the	O
domain	O
,	O
which	O
is	O
a	O
very	O
bad	O
approximation	O
,	O
except	O
for	O
narrow	O
domains	O
.	O
</s>
<s>
Distributed	B-Algorithm
ray	I-Algorithm
tracing	I-Algorithm
samples	O
the	O
integrand	O
at	O
many	O
randomly	O
chosen	O
points	O
and	O
averages	O
the	O
results	O
to	O
obtain	O
a	O
better	O
approximation	O
.	O
</s>
<s>
It	O
is	O
essentially	O
an	O
application	O
of	O
the	O
Monte	B-Algorithm
Carlo	I-Algorithm
method	I-Algorithm
to	O
3D	O
computer	O
graphics	O
,	O
and	O
for	O
this	O
reason	O
is	O
also	O
called	O
"	O
stochastic	B-Algorithm
ray	I-Algorithm
tracing	I-Algorithm
"	O
.	O
</s>
<s>
Path	B-Algorithm
tracing	I-Algorithm
is	O
a	O
rendering	O
technique	O
that	O
combines	O
all	O
of	O
these	O
integration	O
domains	O
into	O
a	O
single	O
,	O
high-dimensional	O
domain	O
and	O
samples	O
it	O
in	O
a	O
unified	O
way	O
.	O
</s>
<s>
The	O
term	O
distributed	B-Algorithm
ray	I-Algorithm
tracing	I-Algorithm
also	O
refers	O
to	O
the	O
application	O
of	O
distributed	B-Architecture
computing	I-Architecture
techniques	O
to	O
ray	B-Algorithm
tracing	I-Algorithm
.	O
</s>
<s>
Two	O
resolutions	O
to	O
this	O
ambiguity	O
are	O
the	O
term	O
distribution	B-Algorithm
ray	I-Algorithm
tracing	I-Algorithm
for	O
the	O
rendering	O
technique	O
,	O
or	O
the	O
term	O
parallel	O
ray	B-Algorithm
tracing	I-Algorithm
in	O
reference	O
to	O
parallel	B-Operating_System
computing	I-Operating_System
.	O
</s>
