This one seems really weird to me. Drove up to a military outpost (one of the big 3x3 overmap tile ones, surrounded by minefields), killed the NPC bandits at the gates, got out of my vehicle and headed inwards and found it started lagging pretty badly. Was hearing lots of sounds from below, so assumed this was just a natural consequence of the lower z-levels being insanely full of mobs doing things, but it turned out that wasn’t the issue at all.
It quickly turned out that the lag only happened on ground-level and outdoors at this location. As soon as you go into one of the corridors, performance returns basically to normal, although still a little slow, and much worse if you’re near a window or door to outside. As soon as you go underground or onto the roof, the lag disappears completely.
Then after I’d cleared out most of the zombies downstairs, I came back up to bring my loot back to my car, and the lag just became absolutely insane. Literally took me about five minutes of real time to cross the little courtyard. Ended up using the debug menu to teleport me across instead. No lag at all while the debug menu was open, if that’s significant.
Was still getting a little lag at the end of the bridge outside the outpost, and inside my truck, but nothing compared to what it was on the bridge or in the courtyard.
Any ideas wtf that was about? Seems really odd to me, given how literally nothing was happening there and the lag actually got worse after killing all the mobs…