Killer Kangaroos

[Tony Bowden]

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.

-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 232 bytes
Desc: not available
Url : http://mail.pm.org/archives/belfast-pm/attachments/20010623/2d4a8ea5/attachment.bin