Enemy pathing behavior through hidden areas

[Robb]

Not sure if this is a bug or working as intended

My base is in mountainous valley with only one opening to the north. All sides are at least 25-30 tiles thick. When a raid happened I expected them to attack from the north, but they ran straight to one of the sides. After mining 2 tiles they opened up a huge hidden area which was then only another 2 tiles of mining to enter my base.

Should enemies know about where every hidden area is? Have had them do it a few times. If it was only one tile thick I could see potential hidden areas (and could understand raids noticing too) but this time there was nothing to indicate there was one at that spot.

If working as intended, then it's just something I will have to plan for. But it just seems that my pawns should have a much more intimate knowledge of surrounding area than the raiders do.

[giannikampa]

Happened to me as well, can't belive it is working as designed because why and how could they know how is the area they are visiting? did they already explored all the world? or did they scanned all the mountains?
I can imagine even some performance increase if the pathing had to process a smaller (just the visible) region

[OFWG]

I've seen this but it always seemed like just a coincidence to me. The sappers seem to come straight for your base (the center of it? IDK) and mine through anything in the way.

[freemapa]

Seems like you could just set the travel speed over hidden tiles to be the same as the time it would take to mine the tile. Then the pathing algoirthm would treat them exactly the same. The AI may stumble on them accidentally, but would not "know" about them.

[Dashthechinchilla]

This is probably related to the known issues in A17 like creatures in ancient dangers becoming aggressive.

[Yoshida Keiji]

While hidden areas aren't "visible" to the player, the sounds hints us when our view is centered over such areas. Like a fire burning inside, although once I open them, nothing is on fire. Some kind of wind current maybe?

[TheMeInTeam]

I've seen this but it always seemed like just a coincidence to me. The sappers seem to come straight for your base (the center of it? IDK) and mine through anything in the way.

Walls have some cost for sappers when compared to nothing, it's just so tiny that they don't usually redirect them.

In Bjorn's video he did say that at some amount > 20 thick walls (I forget exact number) sappers did go around.  That's completely impractical to build as a defense against them, but it would explain the situation described in OP.

[Wanderer_joins]

If working as intended, then it's just something I will have to plan for. But it just seems that my pawns should have a much more intimate knowledge of surrounding area than the raiders do.

Sappers see the map without fog. So yes, if there are two tiles of rock and a large cavity they'll go for it even if all you can see is a huge mountain.

[Yoshida Keiji]

I had Sappers open an Ancient Structure and die by the mechanoid guards, but they took my chance to recruit the spacers in crypto sleep.

[ColonistGirl]

I had Sappers open an Ancient Structure and die by the mechanoid guards, but they took my chance to recruit the spacers in crypto sleep.

I had something similar happen to me the other night, but not as enjoyable.

My new colony fended off an early raid (distress call so we saved the person), and the raiders started to retreat. However, one of them decided that his path of retreat needed to be directly through a mountainside, so he started digging. And he popped open the ancient danger, which spawned the hives and bugs. Greaaaat. Since the colonists were all injured from the raid, they couldn't run out and deal with it immediately.

Finaly healed up the next day, and ... raid. A normal one this time, not a distress call raid. Damn it. So they barely fended that raid off, the main gunner having been knocked down and really badly hurt in the fight. So she had to heal up for another day. Cue hives spawning additional hives.

I tried a bunch of ploys to deal with them, but the bugs were just too numerous and the colonists were too few, and not enough firepower. So I had to give up and reload. Boo.

[Vlad0mi3r]

I believe pathing is a major update for A18. I really do hope it is because its the one thing that is almost stopping me from playing (Almost I am a bit of a junkie for RimWorld).

I had a game with a lone psychopath just wanted to chill out with one maybe two pawns and feed people to my huskies. Anyway had a beautiful box canyon, natural defences basically a kill box made of mountains. Getting things set up and then the sappers rock up and start digging into some random bit of mountain and hay presto two blocks worth of digging and they are at my new back door.

The other pathing issues are fires and doors. I lost two trained animals and almost one colonist due to pathing around fire. Fire spreads but paths are not recalculated at all so you end up with a path that goes straight through the hottest path if you have a decent travel time. Colonists love doors as well if there is one door or two doors they can go through to get somewhere the open and shut them as much as they can. Now I have a one door per room policy.

[SpaceDorf]

My base is in mountainous valley with only one opening to the north. All sides are at least 25-30 tiles thick. When a raid happened I expected them to attack from the north, but they ran straight to one of the sides. After mining 2 tiles they opened up a huge hidden area which was then only another 2 tiles of mining to enter my base.

In one game that happened to me as well. First I thought really guys ?
Digging through half the map of mountain ?

But then they discovered this huge valley to farm in, right next to my base
Which gave me the opportunity to open an exit where it suited me best and
ambush the suckers.

Good times.