<s>
Nvidia	O
OptiX	B-Algorithm
(	O
OptiX	B-Algorithm
Application	O
Acceleration	O
Engine	O
)	O
is	O
a	O
ray	B-Algorithm
tracing	I-Algorithm
API	B-General_Concept
that	O
was	O
first	O
developed	O
around	O
2009	O
.	O
</s>
<s>
The	O
computations	O
are	O
offloaded	O
to	O
the	O
GPUs	B-Architecture
through	O
either	O
the	O
low-level	O
or	O
the	O
high-level	O
API	B-General_Concept
introduced	O
with	O
CUDA	B-Architecture
.	O
</s>
<s>
CUDA	B-Architecture
is	O
only	O
available	O
for	O
Nvidia	O
's	O
graphics	O
products	O
.	O
</s>
<s>
Nvidia	O
OptiX	B-Algorithm
is	O
part	O
of	O
Nvidia	B-Application
GameWorks	I-Application
.	O
</s>
<s>
OptiX	B-Algorithm
is	O
a	O
high-level	O
,	O
or	O
"	O
to-the-algorithm	O
"	O
API	B-General_Concept
,	O
meaning	O
that	O
it	O
is	O
designed	O
to	O
encapsulate	O
the	O
entire	O
algorithm	O
of	O
which	O
ray	B-Algorithm
tracing	I-Algorithm
is	O
a	O
part	O
,	O
not	O
just	O
the	O
ray	B-Algorithm
tracing	I-Algorithm
itself	O
.	O
</s>
<s>
This	O
is	O
meant	O
to	O
allow	O
the	O
OptiX	B-Algorithm
engine	O
to	O
execute	O
the	O
larger	O
algorithm	O
with	O
great	O
flexibility	O
without	O
application-side	O
changes	O
.	O
</s>
<s>
Commonly	O
,	O
video	O
games	O
use	O
rasterization	O
rather	O
than	O
ray	B-Algorithm
tracing	I-Algorithm
for	O
their	O
rendering	O
.	O
</s>
<s>
According	O
to	O
Nvidia	O
,	O
OptiX	B-Algorithm
is	O
designed	O
to	O
be	O
flexible	O
enough	O
for	O
"	O
procedural	O
definitions	O
and	O
hybrid	O
rendering	O
approaches.	O
"	O
</s>
<s>
Aside	O
from	O
computer	O
graphics	O
rendering	O
,	O
OptiX	B-Algorithm
also	O
helps	O
in	O
optical	O
&	O
acoustical	O
design	O
,	O
radiation	O
and	O
electromagnetic	O
research	O
,	O
artificial	B-Application
intelligence	I-Application
queries	O
and	O
collision	O
analysis	O
.	O
</s>
<s>
OptiX	B-Algorithm
works	O
by	O
using	O
user-supplied	O
instructions	O
(	O
in	O
the	O
form	O
of	O
CUDA	B-Architecture
kernels	O
)	O
regarding	O
what	O
a	O
ray	O
should	O
do	O
in	O
particular	O
circumstances	O
to	O
simulate	O
a	O
complete	O
tracing	O
process	O
.	O
</s>
<s>
A	O
light	O
ray	O
(	O
or	O
perhaps	O
another	O
kind	O
of	O
ray	O
)	O
might	O
have	O
a	O
different	O
behavior	O
when	O
hitting	O
a	O
particular	O
surface	O
rather	O
than	O
another	O
one	O
,	O
OptiX	B-Algorithm
allows	O
to	O
customize	O
these	O
hit	O
conditions	O
with	O
user-provided	O
programs	O
.	O
</s>
<s>
These	O
programs	O
are	O
written	O
in	O
CUDA	B-Architecture
C	B-Language
or	O
directly	O
in	O
PTX	O
code	O
and	O
are	O
linked	O
together	O
when	O
used	O
by	O
the	O
OptiX	B-Algorithm
engine	O
.	O
</s>
<s>
In	O
order	O
to	O
use	O
OptiX	B-Algorithm
a	O
CUDA-capable	O
GPU	B-Architecture
must	O
be	O
available	O
on	O
the	O
system	O
and	O
the	O
CUDA	B-Architecture
toolkit	O
must	O
be	O
installed	O
.	O
</s>
<s>
Using	O
the	O
OptiX	B-Algorithm
engine	O
in	O
a	O
ray	B-Algorithm
tracing	I-Algorithm
application	O
usually	O
involves	O
the	O
following	O
steps	O
:	O
</s>
<s>
rays	O
can	O
be	O
shot	O
in	O
parallel	O
,	O
in	O
a	O
perspective	B-Architecture
fashion	O
or	O
like	O
a	O
gradient	O
field	O
)	O
,	O
ray	O
missing	O
(	O
when	O
a	O
ray	O
does	O
n't	O
intersect	O
any	O
object	O
)	O
,	O
an	O
optional	O
exception	O
program	O
(	O
when	O
the	O
ray	O
cannot	O
be	O
shot	O
for	O
some	O
reason	O
)	O
,	O
a	O
bounding	B-Algorithm
box	I-Algorithm
program	O
(	O
the	O
program	O
that	O
provides	O
a	O
bounding	B-Algorithm
box	I-Algorithm
intersection	O
test	O
for	O
a	O
given	O
object	O
)	O
and	O
an	O
intersection	O
program	O
.	O
</s>
<s>
Define	O
buffers	B-General_Concept
,	O
variables	O
that	O
might	O
be	O
used	O
inside	O
the	O
supplied	O
programs	O
.	O
</s>
<s>
Buffers	B-General_Concept
are	O
memory	O
areas	O
that	O
allow	O
host	O
code	O
(	O
i.e.	O
</s>
<s>
normal	O
CPU	B-Device
code	O
)	O
to	O
communicate	O
with	O
device	O
code	O
(	O
i.e.	O
</s>
<s>
the	O
code	O
that	O
gets	O
executed	O
on	O
the	O
GPU	B-Architecture
)	O
and	O
vice	O
versa	O
.	O
</s>
<s>
Variables	O
are	O
OptiX	B-Algorithm
's	O
internal	O
way	O
of	O
communicating	O
and	O
using	O
buffers	B-General_Concept
to	O
transfer	O
data	O
back	O
and	O
forth	O
.	O
</s>
<s>
In	O
order	O
to	O
render	O
a	O
complex	O
scene	O
or	O
trace	O
different	O
paths	O
for	O
any	O
ray	O
OptiX	B-Algorithm
takes	O
advantage	O
of	O
GPGPU	B-Architecture
computing	O
by	O
exploiting	O
NVIDIA	B-Architecture
CUDA	I-Architecture
platform	I-Architecture
.	O
</s>
<s>
Since	O
the	O
process	O
of	O
shooting	O
rays	O
and	O
setting	O
their	O
behavior	O
is	O
highly	O
customizable	O
,	O
OptiX	B-Algorithm
may	O
be	O
used	O
in	O
a	O
variety	O
of	O
other	O
applications	O
aside	O
from	O
ray	B-Algorithm
tracing	I-Algorithm
.	O
</s>
<s>
Starting	O
from	O
OptiX	B-Algorithm
3.5.0	O
a	O
second	O
library	O
called	O
OptiX	B-Algorithm
Prime	O
was	O
added	O
to	O
the	O
bundle	O
which	O
aims	O
to	O
provide	O
a	O
fast	O
low-level	O
API	B-General_Concept
for	O
ray	B-Algorithm
tracing	I-Algorithm
-	O
building	O
the	O
acceleration	B-Data_Structure
structure	I-Data_Structure
,	O
traversing	O
the	O
acceleration	B-Data_Structure
structure	I-Data_Structure
,	O
and	O
ray-triangle	B-Algorithm
intersection	I-Algorithm
.	O
</s>
<s>
Prime	O
also	O
features	O
a	O
CPU	B-Device
fallback	O
when	O
no	O
compatible	O
GPU	B-Architecture
is	O
found	O
on	O
the	O
system	O
.	O
</s>
<s>
Unlike	O
OptiX	B-Algorithm
,	O
Prime	O
is	O
not	O
a	O
programmable	O
API	B-General_Concept
,	O
so	O
lacks	O
support	O
for	O
custom	O
,	O
non-triangle	O
primitives	O
and	O
shading	O
.	O
</s>
<s>
Being	O
non-programmable	O
,	O
OptiX	B-Algorithm
Prime	O
does	O
not	O
encapsulate	O
the	O
entire	O
algorithm	O
of	O
which	O
ray	B-Algorithm
tracing	I-Algorithm
is	O
a	O
part	O
.	O
</s>
<s>
Thus	O
,	O
Prime	O
cannot	O
recompile	O
the	O
algorithm	O
for	O
new	O
GPUs	B-Architecture
,	O
refactor	O
the	O
computation	O
for	O
performance	O
,	O
or	O
use	O
a	O
network	O
appliance	O
like	O
the	O
Quadro	O
VCA	O
,	O
etc	O
.	O
</s>
<s>
At	O
SIGGRAPH	O
2011	O
Adobe	O
showcased	O
OptiX	B-Algorithm
in	O
a	O
technology	O
demo	O
of	O
GPU	B-Architecture
ray	B-Algorithm
tracing	I-Algorithm
for	O
motion	O
graphics	O
.	O
</s>
<s>
At	O
SIGGRAPH	O
2013	O
OptiX	B-Algorithm
was	O
featured	O
in	O
Pixar	O
's	O
realtime	O
,	O
GPU-based	O
lighting	O
preview	O
tool	O
.	O
</s>
<s>
OptiX	B-Algorithm
has	O
been	O
integrated	O
into	O
the	O
GameWorks	B-Application
developers	O
library	O
along	O
with	O
PhysX	B-Operating_System
and	O
other	O
CUDA	B-Architecture
powered	O
graphics	O
engines	O
and	O
frameworks	O
.	O
</s>
