<s>
A	O
visual	B-Algorithm
hull	I-Algorithm
is	O
a	O
geometric	O
entity	O
created	O
by	O
shape-from-silhouette	O
3D	B-Algorithm
reconstruction	I-Algorithm
technique	O
introduced	O
by	O
A	O
.	O
Laurentini	O
.	O
</s>
<s>
The	O
intersection	O
of	O
the	O
two	O
cones	O
is	O
called	O
a	O
visual	B-Algorithm
hull	I-Algorithm
,	O
which	O
is	O
a	O
bounding	O
geometry	O
of	O
the	O
actual	O
3D	O
object	O
(	O
see	O
the	O
bottom	O
right	O
thumbnail	O
)	O
.	O
</s>
