<s>
The	O
Rich	B-Language
Representation	I-Language
Language	I-Language
,	O
often	O
abbreviated	O
as	O
RRL	B-Language
,	O
is	O
a	O
computer	O
animation	O
language	O
specifically	O
designed	O
to	O
facilitate	O
the	O
interaction	O
of	O
two	O
or	O
more	O
animated	O
characters	O
.	O
</s>
<s>
The	O
research	O
effort	O
was	O
funded	O
by	O
the	O
European	O
Commission	O
as	O
part	O
of	O
the	O
NECA	B-General_Concept
Project	I-General_Concept
.	O
</s>
<s>
The	O
NECA	O
(	O
Net	B-General_Concept
Environment	I-General_Concept
for	I-General_Concept
Embodied	I-General_Concept
Emotional	I-General_Concept
Conversational	I-General_Concept
Agents	I-General_Concept
)	O
framework	O
within	O
which	O
RRL	B-Language
was	O
developed	O
was	O
not	O
oriented	O
towards	O
the	O
animation	O
of	O
movies	O
,	O
but	O
the	O
creation	O
of	O
intelligent	O
"	O
virtual	O
characters	O
"	O
that	O
interact	O
within	O
a	O
virtual	B-Application
world	I-Application
and	O
hold	O
conversations	O
with	O
emotional	O
content	O
,	O
coupled	O
with	O
suitable	O
facial	O
expressions	O
.	O
</s>
<s>
RRL	B-Language
was	O
a	O
pioneering	O
research	O
effort	O
which	O
influenced	O
the	O
design	O
of	O
other	O
languages	O
such	O
as	O
the	O
Player	O
Markup	O
Language	O
which	O
extended	O
parts	O
of	O
the	O
design	O
of	O
RRL	B-Language
.	O
</s>
<s>
The	O
language	O
design	O
specifically	O
intended	O
to	O
lessen	O
the	O
training	O
needed	O
for	O
modeling	O
the	O
interaction	O
of	O
multiple	O
characters	O
within	O
a	O
virtual	B-Application
world	I-Application
and	O
to	O
automatically	O
generate	O
much	O
of	O
the	O
facial	O
animation	O
as	O
well	O
as	O
the	O
skeletal	O
animation	O
based	O
on	O
the	O
content	O
of	O
the	O
conversations	O
.	O
</s>
<s>
The	O
application	O
domain	O
for	O
RRL	B-Language
consists	O
of	O
scenes	O
with	O
two	O
or	O
more	O
virtual	O
characters	O
.	O
</s>
<s>
The	O
representation	O
of	O
these	O
scenes	O
requires	O
multiple	O
information	O
types	O
such	O
as	O
body	O
postures	O
,	O
facial	O
expressions	O
,	O
semantic	B-Application
content	I-Application
and	O
meaning	O
of	O
conversations	O
,	O
etc	O
.	O
</s>
<s>
the	O
body	O
posture	O
,	O
the	O
facial	O
expression	O
and	O
the	O
semantic	B-Application
content	I-Application
of	O
the	O
conversation	O
need	O
to	O
coordinate	O
.	O
</s>
<s>
An	O
example	O
is	O
that	O
in	O
an	O
angry	O
conversation	O
,	O
the	O
semantics	B-Application
of	O
the	O
conversation	O
dictate	O
the	O
body	O
posture	O
and	O
facial	O
expressions	O
in	O
a	O
distinct	O
from	O
which	O
is	O
quite	O
different	O
from	O
a	O
joyful	O
conversation	O
.	O
</s>
<s>
The	O
different	O
types	O
of	O
information	O
used	O
in	O
RRL	B-Language
require	O
different	O
forms	O
of	O
expression	O
within	O
the	O
language	O
,	O
e.g.	O
</s>
<s>
A	O
key	O
goal	O
in	O
the	O
design	O
of	O
RRL	B-Language
was	O
the	O
ease	O
of	O
development	O
,	O
to	O
make	O
scenes	O
and	O
interaction	O
construction	O
available	O
to	O
users	O
without	O
advanced	O
knowledge	O
of	O
programming	O
.	O
</s>
<s>
Borrowing	O
theatrical	O
terminology	O
,	O
each	O
interaction	O
session	O
between	O
the	O
synthetic	O
characters	O
in	O
RRL	B-Language
is	O
called	O
a	O
scene	O
.	O
</s>
<s>
RRL	B-Language
uses	O
a	O
discourse	O
representation	O
system	O
based	O
the	O
standard	O
method	O
of	O
referents	O
and	O
conditions	O
.	O
</s>
<s>
RRL	B-Language
supports	O
three	O
separate	O
aspects	O
of	O
emotion	O
management	O
.	O
</s>
<s>
In	O
RRL	B-Language
the	O
term	O
gesture	O
is	O
used	O
in	O
a	O
general	O
sense	O
and	O
applies	O
to	O
facial	O
expressions	O
,	O
body	O
posture	O
and	O
proper	O
gestures	O
.	O
</s>
<s>
Interface	O
to	O
external	O
modules	O
that	O
handle	O
player-specific	O
renderings	O
such	O
as	O
MPEG-4	B-Algorithm
Face	O
Animation	O
Parameters	O
(	O
FAPs	O
)	O
.	O
</s>
