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by gwillz 897 days ago
I remember learning A* at uni while at the same time experiencing it's quirks on our shared minecraft server.

The server was really chugging and so I ran a trace on it. I found the zombies were stuck in a loop trying to find their way into a village that we had completely secured with a large fence. Being a naive implementation (at the time) it meant they never gave up.

I recall there being a bug report with a good amount of detail about how they were going about fixing it.
2 comments
Sharlin 896 days ago
A similar long-time bug in Dwarf Fortress: if you have a door or hatch marked as impassable by animals, but a stray tame critter (usually a cat) wants to get through, it will never give up trying to find a path to the other side. This can have a very noticeable effect on your fps, especially if there are several animals all trying to get past the impassable portal.

(Of course, one could argue that it's incredibly realistic behavior for a cat to very insistently demand to get past a closed door. It would be even more realistic if, once the door is finally opened, the cat would immediately change its mind and lose all interest in getting through!)

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justinl33 897 days ago
Been looking around for the past 10 minutes trying to find information on the mob-following implementation in Minecraft - can't find a thing. I assume it's just vanilla A* with some parameters?
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gwillz 896 days ago
Found it!

https://bugs.mojang.com/browse/MC-17630?focusedCommentId=925...

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justinl33 896 days ago
> Since working the (apparently A) pathfinding algorithm...*

Beautiful.

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