<s>
Indigo	B-Application
Renderer	I-Application
is	O
3D	O
rendering	O
software	O
that	O
uses	O
unbiased	O
rendering	O
technologies	O
to	O
create	O
photo-realistic	O
images	O
.	O
</s>
<s>
It	O
uses	O
methods	O
such	O
as	O
Metropolis	B-Algorithm
light	I-Algorithm
transport	I-Algorithm
(	O
MLT	O
)	O
,	O
spectral	O
light	O
calculus	O
,	O
and	O
virtual	O
camera	O
model	O
.	O
</s>
<s>
Scene	O
data	O
is	O
stored	O
in	O
XML	B-Protocol
or	O
IGS	O
format	O
.	O
</s>
<s>
It	O
features	O
Monte-Carlo	B-Algorithm
path	B-Algorithm
tracing	I-Algorithm
,	O
bidirectional	B-Algorithm
path	I-Algorithm
tracing	I-Algorithm
and	O
MLT	O
on	O
top	O
of	O
bidirectional	B-Algorithm
path	I-Algorithm
tracing	I-Algorithm
,	O
distributed	O
render	O
capabilities	O
,	O
and	O
progressive	O
rendering	O
(	O
image	O
gradually	O
becomes	O
less	O
noisy	O
as	O
rendering	O
progresses	O
)	O
.	O
</s>
<s>
It	O
also	O
supports	O
subsurface	B-Algorithm
scattering	I-Algorithm
and	O
has	O
its	O
own	O
image	O
format	O
(	O
.igi	O
)	O
.	O
</s>
<s>
The	O
Indigo	B-Application
3	O
series	O
introduced	O
features	O
such	O
as	O
real-time	O
editing	O
capabilities	O
,	O
while	O
version	O
4	O
of	O
the	O
software	O
adds	O
pure	O
GPU	B-Architecture
rendering	O
through	O
a	O
vendor	O
neutral	O
OpenCL	B-Application
path	B-Algorithm
tracing	I-Algorithm
engine	O
.	O
</s>
