Game Development Reference
In-Depth Information
FIGURe 3.3
Tower Defense:
Lost Earth HD
Feedback loops Can Stabilize or Destabilize a System
Ecosystems are another classic example of complex systems. Ecosystems seem to be
quite well balanced: The various animal populations within an ecosystem do not
change much over time. What's more, nature seems to include all sorts of mecha-
nisms to maintain this balance. This is best explained by looking at predator and
prey populations. When there are many prey, the predators will find food easily.
This will cause their number to increase. However, as more and more predators sur-
vive, the prey population will decrease. At a certain point, there will be too many
predators, and the situation reverses: Now the predators won't find enough food,
and their population will decrease. Because there are fewer predators, more prey will
survive and produce offspring causing their population to rise again.
This particular balance between predators and prey in an ecosystem is attributed
to what is called a feedback loop . A feedback loop is created when the effects of a
change in one part of the system (such as the number of predators) come back and
affect the same part at a later moment in time. In this case, an increase of the num-
ber of predators will cause a decrease of prey, which in turn will cause a subsequent
decrease of predators. The effects of the changes to the predator population size are
quite literally fed back to the same population size.
 
Search WWH ::




Custom Search