Questions 11-20 are based on the following passage.
The warmongering ores depicted in the Lord of the
SOCIAL SCIENCE: This passage is adapted from the article[br]
"Model Behaviour" by The Economist (©2009 by The Econo-[br]
mist Newspaper Limited).[br]
Rings trilogy are evil, unpleasant creatures that leave
death and destruction in their wake. But if you find
yourself in a burning building a few years from now,
5 they might just save your life. That is because the tech-
nology used to make hordes of these menacing,
computer-generated monsters move convincingly on
screen turns out to be just what is needed to predict
how crowds of humans move around inside buildings.
10 The simulation of the behaviour of crowds of
people and swarms of animals (not just mythological
ones) is being applied to many unusual situations.
When the first film in the Lord of the Rings trilogy
was released in 2001, much was made of its heavy
15 reliance on computer-generated imagery. But what was
perhaps most impressive were the epic battle scenes,
which broke new ground in special effects by showing
huge numbers of characters with an unprecedented
degree of detail and realism. For this the trilogy's direc-
20 tor, Peter Jackson, largely has Stephen Regelous to
thank. Regelous is the founder of Massive Software,
based in Auckland, New Zealand. His firm's software
made it possible to generate as many as half a million
virtual actors in a single shot, each behaving in an inde-
25 pendent and plausible manner
That is because every character was, in effect,
given a brain, says Diane Holland, Massive's chief
executive. Each one was modeled as a software "agent"
with its own desires, needs and goals, and the ability to
30 perceive the environment and respond to the immediate
surroundings in a believable way. Any given orc, for
example, could work out which other fighters on the
battlefield were in its line of sight, and hence whether it
should flee or attack. This produced far more realistic
35 results than orchestrating the motions of the digital
extras in a scripted, choreographed way.
Taking a similar approach is Dr. Demetri
Terzopoulos, a computer scientist at the University of
California in Los Angeles. He is using agents to simu-
40 late the behaviour of commuters passing through Penn-
sylvania Station in New York. His agents have memory,
but they also have a sense of time and the ability to
plan ahead. An agent entering the station will typically
seek out the ticket office, stand in line to buy a ticket,
45 and then perhaps kill some time watching a street per-
former if he has a few minutes before his train arrives,
says Terzopoulos. If he is running late, by contrast, he
may try to push his way to the front of the ticket line
before sprinting for the platform.
50 Terzopoulos's research has shown that agents can
simulate complex behaviours with great realism. Work-
ing with Qinxin Yu, a graduate student, Terzopoulos
has modeled how people behave in public when some-
one collapses. People crowd around to help, and some
55 agents will even remember if they recently saw a police
officer nearby, and run to get help, he says. Such real-
ism is useful in the development of automated closed-
circuit television security systems. Using real cameras
for such research would raise privacy concerns, so he is
60 making agent simulations available instead to
researchers who are training cameras to detect unusual
behaviour. Another intriguing application is to help
archaeologists study ancient ruins. Using a model of the
Great Temple of Petra in Jordan, Terzopoulos has eval-
65 uated how it would have been used by the people who
built it. He has concluded that the temple's capacity had
previously been greatly overestimated.
Agents need not even represent humans. Massive
has been working with BMT Asia Pacific, a marine
70 consultancy, to model the behaviour of the thousands of
ships operating in Hong Kong harbour. This involves
simulating the behaviour of the ships themselves, each
of which may be under the control of several people,
says Richard Colwill of BMT. And rather than assum-
75 ing that everyone will adhere to the maritime traffic
code, which determines who has right of way, it can
incorporate acts of bravado and incompetence. "We get
about 150 collisions. each year in Hong Kong," says
Colwill. His firm plans to use the software to determine
80 which traffic-management strategies will be least dis-
ruptive during the construction of an immersed road
tunnel that will need to be lowered into the harbour.
As agent software becomes better able to capture
complex real-world behaviour, other uses for it are sure
85 to emerge. Indeed, this could soon become a crowded
field