<s>
In	O
computer	O
graphics	O
,	O
a	O
texture	B-General_Concept
mapping	I-General_Concept
unit	I-General_Concept
(	O
TMU	O
)	O
is	O
a	O
component	O
in	O
modern	O
graphics	B-Architecture
processing	I-Architecture
units	I-Architecture
(	O
GPUs	B-Architecture
)	O
.	O
</s>
<s>
They	O
are	O
able	O
to	O
rotate	O
,	O
resize	B-Algorithm
,	O
and	O
distort	B-Algorithm
a	O
bitmap	O
image	O
to	O
be	O
placed	O
onto	O
an	O
arbitrary	O
plane	O
of	O
a	O
given	O
3D	O
model	O
as	O
a	O
texture	O
,	O
in	O
a	O
process	O
called	O
texture	O
mapping	O
.	O
</s>
<s>
In	O
modern	O
graphics	B-Device
cards	I-Device
it	O
is	O
implemented	O
as	O
a	O
discrete	O
stage	O
in	O
a	O
graphics	B-General_Concept
pipeline	I-General_Concept
,	O
whereas	O
when	O
first	O
introduced	O
it	O
was	O
implemented	O
as	O
a	O
separate	O
processor	O
,	O
e.g.	O
</s>
<s>
as	O
seen	O
on	O
the	O
Voodoo2	O
graphics	B-Device
card	I-Device
.	O
</s>
<s>
In	O
2013	O
,	O
TMUs	O
are	O
part	O
of	O
the	O
shader	O
pipeline	O
and	O
decoupled	O
from	O
the	O
Render	B-General_Concept
Output	I-General_Concept
Pipelines	I-General_Concept
(	O
ROPs	O
)	O
.	O
</s>
<s>
For	O
example	O
,	O
in	O
AMD	O
's	O
Cypress	O
GPU	B-Architecture
,	O
each	O
shader	O
pipeline	O
(	O
of	O
which	O
there	O
are	O
20	O
)	O
has	O
four	O
TMUs	O
,	O
giving	O
the	O
GPU	B-Architecture
80	O
TMUs	O
.	O
</s>
<s>
3D	O
scenes	O
are	O
generally	O
composed	O
of	O
two	O
things	O
:	O
3D	B-Algorithm
geometry	I-Algorithm
,	O
and	O
the	O
textures	O
that	O
cover	O
that	O
geometry	O
.	O
</s>
<s>
Texture	O
units	O
in	O
a	O
video	B-Device
card	I-Device
take	O
a	O
texture	O
and	O
'	O
map	O
 '	O
it	O
to	O
a	O
piece	O
of	O
geometry	O
.	O
</s>
<s>
Textures	O
can	O
be	O
an	O
actual	O
image	O
,	O
a	O
lightmap	B-Data_Structure
,	O
or	O
even	O
normal	O
maps	O
for	O
advanced	O
surface	O
lighting	O
effects	O
.	O
</s>
<s>
To	O
render	O
a	O
3D	O
scene	O
,	O
textures	O
are	O
mapped	O
over	O
the	O
top	O
of	O
polygon	B-Algorithm
meshes	I-Algorithm
.	O
</s>
<s>
This	O
is	O
called	O
texture	O
mapping	O
and	O
is	O
accomplished	O
by	O
texture	B-General_Concept
mapping	I-General_Concept
units	I-General_Concept
(	O
TMUs	O
)	O
on	O
the	O
videocard	B-Device
.	O
</s>
<s>
As	O
a	O
result	O
,	O
the	O
X1600	O
XT	O
achieves	O
lower	O
performance	O
when	O
compared	O
to	O
other	O
GPUs	B-Architecture
of	O
the	O
same	O
era	O
and	O
class	O
(	O
such	O
as	O
nVidia	O
's	O
7600GT	O
)	O
.	O
</s>
<s>
The	O
number	O
of	O
texture	O
units	O
in	O
a	O
graphics	B-Architecture
processor	I-Architecture
is	O
used	O
when	O
comparing	O
two	O
different	O
cards	O
for	O
texturing	O
performance	O
.	O
</s>
<s>
In	O
modern	O
GPUs	B-Architecture
TMUs	O
contain	O
Texture	O
Address	O
Units(TA )	O
and	O
Texture	O
Filtering	O
Units(TF )	O
.	O
</s>
<s>
A	O
pipeline	O
is	O
the	O
graphics	B-Device
card	I-Device
's	O
architecture	O
,	O
which	O
provides	O
a	O
generally	O
accurate	O
idea	O
of	O
the	O
computing	O
power	O
of	O
a	O
graphics	B-Architecture
processor	I-Architecture
.	O
</s>
<s>
There	O
are	O
different	O
pipelines	O
within	O
a	O
graphics	B-Architecture
processor	I-Architecture
as	O
there	O
are	O
separate	O
functions	O
being	O
performed	O
at	O
any	O
given	O
time	O
.	O
</s>
<s>
The	O
R300	O
GPU	B-Architecture
used	O
in	O
the	O
Radeon	O
9700	O
had	O
four	O
global	O
vertex	O
shaders	O
,	O
but	O
split	O
the	O
rest	O
of	O
the	O
rendering	B-General_Concept
pipeline	I-General_Concept
in	O
half	O
(	O
it	O
was	O
,	O
so	O
to	O
speak	O
,	O
dual	O
core	O
)	O
each	O
half	O
,	O
called	O
a	O
quad	O
,	O
had	O
four	O
pixel	O
shaders	O
,	O
four	O
TMUs	O
and	O
four	O
ROPs	O
.	O
</s>
<s>
The	O
Render	B-General_Concept
Output	I-General_Concept
Pipeline	I-General_Concept
is	O
an	O
inherited	O
term	O
,	O
and	O
more	O
often	O
referred	O
to	O
as	O
the	O
render	B-General_Concept
output	I-General_Concept
unit	I-General_Concept
.	O
</s>
<s>
All	O
data	O
rendered	O
has	O
to	O
travel	O
through	O
the	O
ROP	O
in	O
order	O
to	O
be	O
written	O
to	O
the	O
framebuffer	B-Algorithm
,	O
from	O
there	O
it	O
can	O
be	O
transmitted	O
to	O
the	O
display	O
.	O
</s>
<s>
Therefore	O
,	O
the	O
ROP	O
is	O
where	O
the	O
GPU	B-Architecture
's	O
output	O
is	O
assembled	O
into	O
a	O
bitmapped	O
image	O
ready	O
for	O
display	O
.	O
</s>
<s>
In	O
GPGPU	B-Architecture
,	O
texture	O
maps	O
in	O
1	O
,	O
2	O
,	O
or	O
3	O
dimensions	O
may	O
be	O
used	O
to	O
store	O
arbitrary	O
data	O
.	O
</s>
<s>
By	O
providing	O
interpolation	B-Algorithm
,	O
the	O
texture	B-General_Concept
mapping	I-General_Concept
unit	I-General_Concept
provides	O
a	O
convenient	O
means	O
of	O
approximating	O
arbitrary	O
functions	O
with	O
data	O
tables	O
.	O
</s>
