I was writing today and was researching something on radiant AI. Unfortunately there doesn't seem to be anything which explain exactly how it is implemented and what it does. From playing the game I have a very brief idea, but I would like to know why the AI behaves as it does and exactly what the new AI system will involve. Is it broken promises again? Does such thing as AI even exist in games, compared to actual research of Artificial Intelligence which learns and responds according to that learning?

I dont know so I turn to you...

Radiant AI is what makes all the NPCs move around and do stuff in Oblivion. There are schedules on where to go during the day, the need to eat, the behavior if something unexpected happens (like being hit with a weapon or being pickpocketed or whatever) and so on.

The Radiant AI system is working on all NPCs in the game, at all times. Although the NPCs that are far away from the player are given far less CPU cycles to work with than those in the same room.

In Morrowind the AI was pretty much nonexistant. They just stood at the same place 24/7 doing nothing, or attacking you. So the system in Oblivion was a big improvement.

At first they planned to let the Radiant AI system to do much more, like forcing people to go out and hunt for food and have a whole ecosystem going on. Unfortunately, that could easily cause large consequences that eventually made all the town NPCs kill eachother so the whole system had to be cut down to not do anything drastic.

If you really want to see how the Radiant AI system works, I suggest you start the Oblivion CS and fool around with the NPC options in there and see how they behave in the game.

As for Skyrim, I'm not really sure how they intend to improve the Radiant AI over the one in Oblivion and what's gonna be new, but we will probably see a fair share of tweaks.

M'aiq hopes that Skyrim will be bright and radiant, M'aiq does not want Skyrim to be dark; darkness and dragons is not good.

thanks for replying Freddo, most of the info I've found and by playing the game does briefly state what the AI should do. Loading up the set is a good idea, was just messing with a "bloated float" teleport to my world the other day.

I think its still unclear though, it just sounds like standard heuristic algorithms with some glossy marketing name. An improvement but it isn't like an NPC in Oblivion makes a decision based on how the game unfolds rather than, essentially, scripting

Now that's interesting, plus it makes a lot of sense, I've always hated that the AI from the E3 demo never made it to retail, but after reading this it makes a lot of sense.

BY THE NINE M'AIQ SPOKE ABOUT IT!!!!!1111onn

If we're lucky, the Skyrim Radiant AI will be what Oblivion's was supposed to be like.

In Oblivion there was a whole story about what Radiant AI was supposed to be and how they had to tone it down.

It gave a description of drugs users in Oblivion who would eventually run out of money, or ways to essentially
get money for skoma (i believe it was called). they would often kill the drug dealers who were selling it.

i think with enough time Radiant AI if tweaked properly could in fact be a really good system. the idea of
skoma users killing drug dealers to get more drugs is amusing, but than so is also a game that offers
you a job opportunity to sell drugs after the drug dealer dies. something lacking in oblivion. im sure at some
point we will see a bethesda game at this level of entertainment if that arent really huge bible thumpers that is.

the e3 ai demo was scripted far as i can tell from MANY hours with the OB CS working on my personal NPC ai/sched mod. the whole paralyzing the dog, setting it on fire was not a dynamic NPC reaction to an event (dog being noisy) but was a scripted event imho. whole thing might as well have been a cut scene. nothing in the cs says it could be done apart from script/package

This is a geat post. I love when Moderators contribute like this. Very clear and simply explain without being patronising. Thanks!

An NPC has scheduled goals. He has some flexibility in how to achieve a goal. His decision-making process approximates human decision-making processes.

When it is time to eat, an NPC will check if he has food in his inventory. If he does, then he will eat it. If he has no food in his inventory, then he may check his environment to see if there is food he can pick up. If so, and if the food is not owned by someone else, or if his responsibility is low enough that it doesn't matter who owns the food, then he will pick it up and eat it. If he has no food in his inventory, and there is no food to pick up, but he has gold, then he will buy food from someone who sells it. If there is no vendor immediately on hand, the NPC will travel to a vendor, providing that there is a vendor within the allowed roaming distance set in the NPC's Eat package. If there is no food to be had, then the NPC will just go hungry. An NPC with a low-enough responsibility may decide to pickpocket food from another NPC.

The reason it is called Radiant is that it radiates outward to the NPC's environment. An NPC is aware of items and other NPCs around him and he reacts to them. I'm sure that glossy marketing is another reason for its name.

Yes thats is, thats was good feature adding needs thats will motivate NPC to complete schedule with all options thats placed around, I test Radiant AI some times with such tasks, NPC able use lock picks to open locked doors, search and take weapons when need protect them self, search and take potions with restore health properties to cure wounds, I create scripted spell thats force Scamps search for items around collect them and them open inventory for player.
Radian AI is good feature but need some scripting enhance

Like in this mods
Put it in its Place - Enhanced Grabbing
http://www.tesnexus.com/downloads/file.php?id=19847
And most of interesting NPC react on my acts in proper way, http://www.youtube.com/watch?v=xv49LK3lytI but they http://www.youtube.com/watch?v=8oujSeIeqhM, they much http://www.youtube.com/watch?v=h2ZLWLXNUZM they tryhttp://www.youtube.com/watch?v=L8gvcTLqzns and many more features, http://www.youtube.com/watch?v=m0K4xkCRLYI, look at others videos and you will agree with me thats really awesome mod thats enchant Radiant AI with some scripting.

Duke Patricks - Near Miss Magic And Arrows Alert The Target
http://www.tesnexus.com/downloads/file.php?id=16150
Casting spells around NPC and shooting around make AI react on such acts in for of alert, AI is aware about surrounding more

Duke Patricks Fresh Kills Now Alert The NPCs
http://www.tesnexus.com/downloads/file.php?id=18065
NPC react on fresh corpses if found them

Phitts Phighting Phixes
http://www.tesnexus.com/downloads/file.php?id=32651
Expand detection range of AI in combat
Allows more actors to follow the player through a loading door in combat

Reneers Guard Overhaul
http://www.tesnexus.com/downloads/file.php?id=5977
Greatly enhance guards AI and crime system work

Todd shows us in E3 demo thats Radiant AI can be expanded with scripts, why they don't do thats in game?
Some additional scripting will help much to remove flaws of just Radian AI logic, but they don't use it.

That "level of responsibility" is where the system was running into problems with Oblivion. The devs did do some posting about it; one site that had quotes isn't there anymore though. One npc would have a job to do, like sweeping the floor. But they wouldn't have a broom. If they had a low level of responsibility, they killed anpther npc that did have a broom so they could take it to do their job. Of course, murder being a crime, the guards got involved and mayhem ensued. Or npcs in a town had lunch on their "to do" list, with one tavern as the location. Worked fine, until they bought out all the food. When that location ran out of food, everyone in town left to find food, leaving the town deserted. If they pickpocketed another npc for food, again, the guards got involved and the end result wasn't good. Sometimes that still happens; City-Swimmer in Bravil usually doesn't last very long when you start a new game, and if you check the body you find he stole food. Or take a look north, outside of Bruma; you'll usually find two foresters trying to kill each other. One is hunting deer, the other was trying to stop him, and they keep fighting until one or the other is dead. Of course, since they aren't named npcs, they respawn, so it happens again, eventually, when they run into one another.

I hope they've worked out at least some of the issues. It could have been a lot more, but I can see why they really pulled it back; there were enough bugs and glitches that caused problems in the game. If the npcs were breaking the quests because of the AI, it would have been too much to deal with. Oblivion did improve on Morrowind's npcs standing around 24/7, now to see whether Skyrim will improve on Oblivion.

A lot of great info in this thread. I'm starting to have a better understanding of how the AI works in previous Bethesda games.

Have any of you seen this http://www.gametrailers.com/video/exclusive-gameplay-the-witcher/713622?

The AI routines for the NPC villagers depicted in the video look amazing, far beyond the level of what was implemented in Oblivion.

From the interviews and information we've seen so far, do you think the AI for townspeople NPCs in Skyrim will be similar to this? Different in some way?

Oh..my...god

That would be the most hilariously epic thing to watch.The novelty of watching towns in chaos would not ware off for a long time.Imagine dropping weapons all around town before the fighting started.

I've also found that within Oblivion, if you cast a frenzy spell on one NPCs, when he attacks another NPC who is not affected by the spell, the non-affected NPC gets angry and continues fighting even after the frenzy spell wears off. This can become complicated further when there is a crowd.

I think the AI in Oblivion failed because they gave the NPC all these needs but there was hardly any means (legal ones anyways) to fill those needs. I think we may see AI cranked back up now that NPCs have a fully fleshed out system of creating anything they may desire.

Even the first Witcher game had more "activity animations" than Oblivion. Even Gothic from 2001 do. But the amount of "activity animations" doesn't really have much to do with the AI, they just do whatever the game designer designed them to do. It's not like a fisherman decides to become a blacksmith or anything. I'm quite fond of these animations, though. They do make the game feel so much more alive

In the very first very first preview of Skyrim by GI, "activity animations" were mentioned but very briefly.

Not sure what else they can do than woodcutting, but there are more activities for the player to do besides woodcutting, like farming, mining, cooking, mixing potions and so on, and I would guess that the NPCs can do those too.

Those mods posted are incredible work, in essence it's like everything is there for an AI with more depth but it's latent (due to reasons explained above). It would be cool if the NPC reacts accordingly (perhaps he just takes the books) everytime the belligerent destroyer-of-literature comes in. I think it could have been worked so that not every NPC is a complete psychopath, in the case of a missing implement for them to function.

I also enjoyed the Witcher video but somehow remain skeptical due to how they present it, like it is something novel. So much info seems odd, like over-promoting. The dialogues between actors does seem cool though.

And all this time i thought radiant AI meant the NPC's would be glow..........

Basically all they did was make more elaborate "stand here for X hours" animations.

Very interesting.

So if I understand correctly, the NPC pathing and activity schedules where they go to different locations and perform activities based on the time of day is not really an AI function, which has more to do with combat decisions?

Nah, I guess I phrased that wrong, it's still AI, sort of.

It's the AI and pathfinding that takes the blacksmith to his work and go home and so on. But if one compare the blacksmith from The Witcher 2 who goes to work and play the same animation for a long period of time vs the Oblivion blacksmith that just go to work and stand there for a long period of time, the difference between the two isn't really that big as far as their AI is concerned. It's just the animation that do them apart, not the their schedules or anything that require them to make any choices or reactions.

Things like what path they should walk to get to their destination, if they are hungry where should they get food, if the player draws his sword how will they react (attacking, fleeing, begging for mercy or whatever), if a dead body is on the ground how will they react to that (try to find the nearest guard or just run away?) or if they hear a strange noise how will they react to that?

I think everyone covered exactly what Radiant A.I. is well enough.

I just hope that there is a better infrastructure for the rules in which NPCs interact with each other. Having social areas generally descend into chaos is the reason most of it was pulled from Oblivion. I hope they improve two main areas for the A.I.: NPCs willingness to stay alive and the number of NPCs in the game.

If random characters have a much higher emphasis on life then they should probably end up in a chaos spiral less often. However, if someone does end up dying, running away, etc. then there needs to be a large NPC population or rapid replacement feature that brings in new NPCs when they are needed.