The reuse of some object-oriented code has caused tactical headaches for
Australia's armed forces. As virtual reality simulators assume larger
roles in helicopter combat training, programmers have gone to great
lengths to increase the realism of their scenarios, including detailed
landscapes and, in the case of the Northern Territory's Operation Phoenix,
herds of kangaroos (since disturbed animals might well give away a
helicopter's position).
The head of the Defence Science & Technology Organisation's Land
Operations/Simulation division reportedly instructed developers to model
the local marsupials' movements and reactions to helicopters. Being
efficient programmers, they just re-appropriated some code originally used
to model infantry detachment reactions under the same stimuli, changed the
mapped icon from a soldier to a kangaroo, and increased the figures' speed
of movement. Eager to demonstrate their flying skills for some visiting
American pilots, the hotshot Aussies "buzzed" the virtual kangaroos in low
flight during a simulation. The kangaroos scattered, as predicted, and the
visiting Americans nodded appreciatively... then did a double-take as the
kangaroos reappeared from behind a hill and launched a barrage of Stinger
missiles at the hapless helicopter. (Apparently the programmers had
forgotten to remove that part of the infantry coding.)
The lesson? Objects are defined with certain attributes, and any new
object defined in terms of an old one inherits all the attributes. The
embarrassed programmers had learned to be careful when reusing
object-oriented code, and the Yanks left with a newfound respect for
Australian wildlife. Simulator supervisors report that pilots from that
point onward have strictly avoided kangaroos, just as they were meant to.
From June 15, 1999 Defence Science and Technology Organisation Lecture
Series, Melbourne, Australia, and staff reports.
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