<s>
In	O
3D	O
computer	O
graphics	O
,	O
a	O
lathed	O
object	O
is	O
a	O
3D	O
model	O
whose	O
vertex	O
geometry	O
is	O
produced	O
by	O
rotating	O
the	O
points	O
of	O
a	O
spline	B-Algorithm
or	O
other	O
point	O
set	O
around	O
a	O
fixed	O
axis	O
.	O
</s>
<s>
The	O
reason	O
the	O
lathe	B-Algorithm
has	O
this	O
name	O
is	O
because	O
it	O
creates	O
symmetrical	O
objects	O
around	O
a	O
rotational	O
axis	O
,	O
just	O
like	O
a	O
real	O
lathe	B-Algorithm
would	O
.	O
</s>
<s>
Lathes	B-Algorithm
are	O
very	O
similar	O
to	O
surfaces	O
of	O
revolution	O
.	O
</s>
<s>
However	O
,	O
lathes	B-Algorithm
are	O
constructed	O
by	O
rotating	O
a	O
curve	O
defined	O
by	O
a	O
set	O
of	O
points	O
instead	O
of	O
a	O
function	O
.	O
</s>
<s>
Note	O
that	O
this	O
means	O
that	O
lathes	B-Algorithm
can	O
be	O
constructed	O
by	O
rotating	O
closed	O
curves	O
or	O
curves	O
that	O
double	O
back	O
on	O
themselves	O
(	O
such	O
as	O
the	O
aforementioned	O
torus	O
)	O
,	O
whereas	O
a	O
surface	O
of	O
revolution	O
could	O
not	O
because	O
such	O
curves	O
cannot	O
be	O
described	O
by	O
functions	O
.	O
</s>
