I have a question because I'm deeply ignorant about NPC AI and the way that different mods change it, and I note that people here have a good notion of what they are talking about.
My main question goes around mods like Immersive Citizens that claim to change the NPCs AI. How they do that? how can they be sure that's not going to mess other mods?
Ok I'll try and explain. All NPC's have something called an "AI package" that basically defines their default behaviours. Every regular NPC has a usually collection of packages that tell to perform routines at certain times of day. For example sleep 12-8, sit and eat meal 8-9, go outside and work the forge, 5-6pm head indoors and eat meal, before heading to bed at night. This gives them the illusion of being "alive". All regular NPC's have a set of default packages added directly to the NPC.
There are things that can override default behaviour one is being in a combat situation, thats handled by the game engine mostly, the other is quests. Quests can have their own AI packages and they always override default packages. Thats so NPC's can leave their regular routines and head off on a quest, follow the player, etc. Immersve Citizens uses this approach to add an overlay of new behaviours as its considered bad practise to directly modify default AI packages. How can it be sure it won't mess with other mods? It can't, it can only attempt to limit the problem.
For example, Immersive Citizens seems to do the same that "Guard dialogue overhaul" and "Run for your lives", yet the mod author states that they are not incompatible. On the contrary, the interiors and city modification mods seem to be the incompatible ones. How's that possible? Is a problem of Navmeshes? Does that means that mods that alter NPC behavior become redundant or they keep being useful despite being overwritten by other behavior mods?
I'm from a social science background, so I don't understand several concepts about this.
Actually it doesn't, GDO modifies guard dialogue it doesn't modify their AI packages. So anything that modifies their AI ought to be compatible. The problems with IC come not from its packages per se but rather the fact that it adds objects to cities i.e. Brenuin now has a bed and a shelter where he sleeps etc (there are also other things like invisible markers added that will be overwritten by city mods but I won't go into that). Partly its navmeshes too, yes as IC includes though too. Basically any two (or more) mods that attempt to remodel cities will probably conflict and with IC and since its not obvious what it modifies its harder to explain why its a problem.
Does that mean other mods that alter behaviour become redundant? Not really, unless they cover exactly the same NPC's and the same areas. Bethesda set it up that AI behaviour modifications can co-exist comfortably with each other, anything that directly modifies that same worldspaces not so much.
Now theres one other thing to understand about quests, they have priorities. An AI package on a high priority quest will always override packages on a lower priority quest. Thats how Run For Your Lives works it''ll override IC's packages in addition to an npc's default packages. When the threat is over the quest stops its packages cease to run and the NPC's will default to their lower priority packages and return to what they were doing before.
Not exactly "incorporated". In the IC page, it is said that the author utilizes another method by basically rewriting all the NPC AI packages individually (or that's what I understood), that why NPC added by mods (Interesting NPCs, new lands, etc.) use vanilla behaviors... Or at least I think that should be how they work, but I'm not 100% entirely sure.
IC doesn't "know" about custom npc's so it can't give them new behaviours by default, however it does attempt to dynamically attach some packages to unknown npc's if it finds them.
Edited by soupdragon1234, 04 June 2018 - 11:22 AM.