Factorio Forums

I am experiecing an issue similar to the one reported in this pending bug report:

[0.18.12] Enemies pathfinding cannot navigate to the base
Post by Barbossahector » Fri Mar 13, 2020 6:58 am
viewtopic.php?f=29&t=82269

That post noted that the issue is also similar to this report:

[0.17.79] Weird Behavior with Biter Pathfinding or something similar.
Post by GregoriusT » Thu Jan 23, 2020 10:51 pm
viewtopic.php?f=7&t=80392

The biter behavior I see is similar to these reports, which seems to be what is expected if they can't find a path to the turret. I'm not sure if my circumstances are exactly the same, however, so I'm posting a new bug. Feel free to file this as a duplicate if appropriate. I am on the latest version 0.18.22 with all default starting options and no mods.

In my case, after placing an artillery outpost that shells spawners, the biters just gather in larger and larger clumps instead of travelling toward the artillery turret and attacking. Eventually they disperse into a nearby group of spawners if all of their home spawners are destroyed. This started after around 200 hours of gameplay. I believe that the behavior started abruptly in between saving the game one night (2020-05-06 23:28 CDT) and loading the game and continuing the next evening. When I load that save now, I see one swarm already in motion that attacks the artillery turret outpost (just a couple of seconds after loading), but then no subsequent shells fired after loading the save provoke attacks. This might have coincided with an update that was applied before I resumed playing the next day, but I'm not positive of the timing. The new behavior continued for several hours of gameplay with multiple artillery turrets and multiple groups of spawners before I noticed it a few days later and went back to investigate.

Log file is attached. Save file can be downloaded from Dropbox: https://www.dropbox.com/s/ao12okbnwh3qp ... 0.zip?dl=0

Please let me know if I can provide any additional information that would be helpful.

The artillery outpost active when the save file is loaded is in the upper far left corner of the map:
Instead of attacking, the bugs gather in large clumps:

MINOR CORRECTION: After carefully watching the first several minutes after loading this save file. I discovered that while most groups of biters behave as I described, a few groups do break away and show the normal behavior attacking the artillery turret outpost.

For the first couple of minutes, all the biters to the northwest of the outpost just swarm around in larger and larger groups. Around the 2 min 45 sec mark, one normal sized group finally breaks off and begins an attack run on the outpost. The remainder swarm around for a few more minutes, and around the 4 min 30 sec mark, they start to merge upward into the nearby enemy spawners. During this timeframe a few more normal groups attack the outpost from the northeast.

Even with some small percentage attacking the output, the net effect is still that instead of completely clearing the area for expansion, the artillery turrets leave a large number of antagonized biters wandering around aimlessly (or adopting a new base that is out of range) and driving UPS down significantly.

I missed this other bug report from a few days ago when I was searching earlier. Pretty sure mine is a duplicate of this one:

[0.18.22] Launched artillery at bugs which couldn't path, game slowed down significantly
Post by AngledLuffa » Sat May 02, 2020 12:02 pm
viewtopic.php?f=7&t=84530

Yea, if there is way too many bugs, they just need to wait for the pathfinder.