Asymptote’s Zombie Infection Simulator — Version 2.0

NOTE: I submitted the model to the NetLogo website, and it can now be found in applet form (and downloaded) here.

After discovering that my previous Zombie Infection Simulator post had gotten a mention on SquidTalk, and found that they were expecting a release in a few weeks, I thought I ought to try not to disappoint them. However, my previous simulator was, to put it nicely, rather rough around the edges, so I spent a lazy afternoon re-writing it. Without all the extra garbage cluttering up the code, it ran a little faster, and exhibited some new behaviors I hadn’t seen before. I also built in a simulator mode that includes the walls seen in the original version of the simulator, although that mode is somewhat broken.

Flocks of humans form as they did in the previous version. Nothing new, really.

The infection has started. I don’t know if it’s visible or not, but the zombies are displaying a great deal more organization, thanks to a greatly improved directional targeting method. Thank goodness for towardsxy.

The infection is spreading rapidly, and, as seen in the previous version, social order is beginning to degenerate. I know it’s not exactly obvious in this still picture, but note the dense little group of humans just above the large group in the center, to the upper left of the cluster of zombies. This group actually broke away in a coordinated fashion when some of its members panicked and fled. I’d expect to see runaway parties like this in a real zombie infection.

Social order begins to falter. Human flocks are beginning to be broken up by panic, and there aren’t enough fighters to rally them.

The little simulated society begins to break down. A few groups are still together, but they’re beginning to collapse as the onslaught continues. The zombies are much more organized in Version 2.0, which actually puts them at a great advantage over the humans. Not only do they form flocks, but they are much more effective hunters, so they tend to infiltrate human groups and pick them off and infect them before panic can disperse them.

As I said in the introductory paragraph, I added a secondary mode to the simulator complete with walls. Since there is still a bug in my simulator, and all the flocks tend to become oriented towards the South, the flocks tend to get “stuck” to the Southern walls of the buildings, where they become immobile. Also, panic is able to spread through the walls. So, I guess I’ll leave fixing these bugs for Version 3.0.

AZIS 2.0 (sounds like the name of a guided missile or something, doesn’t it?) can be found in applet form at here.