AI reactions and reasonable doubt

[zergrush]

TDM AI is pretty configurable at this point as far as range of sight and hearing goes, but one of the things that I still find lacking is the absence of a reasonable interval between spotting a target in full light and reacting upon it. Even if at lower AI vision difficulty setting, AI will go from "uh, what is this" to drawing its sword without a moment to question itself or to let the player react to the initial warning.

 

An example: I was playing Sotha's The Bakery Job today, and I was standing on top of the canopy outside of building. While I briefly stepped into full light when moving into the corner, the guard walking inside the building, meters a away from the window, immediately took an aggressive stance, only having spotted me for a split second and with a very narrow line of sight. You may find attached some screenshots of the situation below.

 

What struck me at that moment was that despite AI vision difficulty being set at "Forgiving", the lack of any setting for controlling AI reaction time turned that particular moment in an overly punishing situation for the player: in short, losing track of the light gem on a moment of distraction can make the difference between finishing a mission or having to reload.

So I would like to suggest an optional setting to control AI reaction time on spotting. People always have a sense of reasonable doubt when spotting objects at a distance, even if in full light. They will generally question what they saw first, then investigate, and then become aggressive. For TDM this would mean players would be allowed to make some mistakes and even take some risks without having to plot a quick escape. Hardcore stealth runners wouldn't lose either, since moments of reasonable doubt would also add to stealth score. All in all this would reduce the amount of times less experienced players have to load the game, and for hardcore ones, the setting could be turned off any time.

Edited March 25, 2019 by zergrush

[zergrush]

Another example, this one from Tears of St. Lucia, Expert mode, played with "Forgiving" AI vision difficulty. Staring down from this position at the street tunnel in the cityscape, this guard will go from spotting you to chasing you in about 3/4 of a second (I timed it with a chronometer). Hardly any time to react, and even if already moving out of the way you are still spotted! I find this case to be particularly punishing, since the distance from the guard does not even allow you to hear him make a warning sound.

Edited March 25, 2019 by zergrush

[New Horizon]

Hmmm. That sounds odd because I remember a couple of years ago that the AI were given reaction times that increased based on distance from the player. I can't remember exactly how it worked, but it might have been something like the further away you were, the impact of a bright lightgem would be decreased over distance. Sounds like that is broken.

[zergrush]

I've produced a save game for the bakery job showcasing this issue.

 

The guard will be walking through the door downstairs this time, and he will immediately draw his sword as soon as he comes within line of sight of the player.

 

https://www.mediafire.com/file/0s7c7yr36m8vl50/bakery.zip/file

Edited March 25, 2019 by zergrush

[Springheel]

Hmmm. That sounds odd because I remember a couple of years ago that the AI were given reaction times that increased based on distance from the player. I can't remember exactly how it worked, but it might have been something like the further away you were, the impact of a bright lightgem would be decreased over distance. Sounds like that is broken.

 

Yes, I was pretty sure something like this had already been implemented.

[zergrush]

Well then something is definitely not working fine then. I'm running 2.07 hotfix on GNU/Linux using default difficulty settings ("Forgiving" for AI Vision and "Challenging" for AI hearing). Reaction time from AI is still too fast, as you should be able to see on the save game I uploaded. Whether this is a bug or not, I think making reaction time an adjustable difficulty setting would be a good idea.

 

Shall I file a bug report though?

[OrbWeaver]

Whether this is a bug or not, I think making reaction time an adjustable difficulty setting would be a good idea.

 

I disagree. Adding individual options for every little piece of AI behaviour is poor game design, and an abdication of responsibility from the designers. It clutters the UI, and potentially confuses players, who now have to understand not only what each option does, but the many more ways in which each option interacts with each other option (a quantity which increases exponentially as more options are added).

 

Having a couple of overall difficulty sliders is fine, and these can in turn influence various other aspects of AI behaviour based on the setting (for example, AI reaction time could be influenced by the Visual difficulty slider, since they are reacting to what they see). But adding an entire control just for reaction time is far too much detail, in my opinion.

[zergrush]

 

I disagree. Adding individual options for every little piece of AI behaviour is poor game design, and an abdication of responsibility from the designers. It clutters the UI, and potentially confuses players, who now have to understand not only what each option does, but the many more ways in which each option interacts with each other option (a quantity which increases exponentially as more options are added).

 

Having a couple of overall difficulty sliders is fine, and these can in turn influence various other aspects of AI behaviour based on the setting (for example, AI reaction time could be influenced by the Visual difficulty slider, since they are reacting to what they see). But adding an entire control just for reaction time is far too much detail, in my opinion.

 

That's fair enough and it seems like a simpler way of doing things. But how to solve the current AI overreaction issue then?

Edited March 25, 2019 by zergrush

[OrbWeaver]

That's fair enough and it seems like a simpler way of doing things. But how to solve the current AI overreaction issue then?

 

Based on the comments from New Horizon and Springheel, it does sound like you have encountered a bug that will need to be fixed (or at least investigated to determine if there is a mismatch between expected behaviour and what is actually happening).

[Guest]

I think this has a lot to do with TDM stock lights which are rather on the right end of intensity scale. I experimented with custom models, shaders, and lighting, using values more similar to what Thief: Deadly Shadows used. I noticed that using lights with lower intensity (like 96, 128, 160) made the guards react in more smooth manner, which seems more fair gameplay-wise.

[nbohr1more]

Are you using capped or uncapped FPS?

[New Horizon]

 

That's fair enough and it seems like a simpler way of doing things. But how to solve the current AI overreaction issue then?

 

Well the issue will have to be investigated in order to find out if something has become broken...because reaction time was definitely worked on. I remember testing it myself.

[zergrush]

Are you using capped or uncapped FPS?

 

Capped

[zergrush]

 

Well the issue will have to be investigated in order to find out if something has become broken...because reaction time was definitely worked on. I remember testing it myself.

 

Would it be possible to move this thread to the bug tech support session then? Will I also need to file a bug on the tracker as well?

 

*EDIT*

 

Filed a bug report. Also replicated the issue again in Cleaning up the Neighborhood, by some1stoleit. Please find the save game in the link below.

 

https://wetransfer.com/downloads/33bec10066e14e6f228a7d41b3f17a2f20190325222824/4fad18

Edited March 25, 2019 by zergrush

[grayman]

This is the first report of an issue in this area since I fixed it all 6.5 years ago. Since it's been that stable, no changes have been made.

 

So if there's a problem now it was introduced by the math/lightgem/lighting/whatever changes made in 2.07. (my guess)

 

It'll be a few weeks before I can look at this problem.

[zergrush]

That's ok, but would it be possible for someone to have a look at the savegames to confirm the issue is there? Otherwise I can slso try to record a video of it.

[zergrush]

Created two videos showcasing the problem:

 

https://youtu.be/hdbvKxbNFhk

 

https://youtu.be/t1iHjblJLSc

[Springheel]

Based on the video, I'm not sure anything is broken.

 

The AI in both cases don't go directly to full alert when they spot you. There is a second or two grace period where you can see them ramping up, particularly the guard that's further away.

[grayman]

I should point out that the sword is drawn when the guard enters alert level 4. At that point, he hasnt yet decided that youre an enemy. Its enough, though, to draw him to you, and when he gets close enough, he makes up his mind and goes to alert level 5 (combat).

 

I can imagine that even at the nearly blind setting, you being in full light will get his attention. It just takes a bit longer to arrive at level 5, but in full light, the difference between good eyesight and bad eyesight might just be a fraction of a second.

 

Which is all speculation, of course, without any measurements to back it up. In time.

[Guest]

It seems like a normal AI reaction to me as well. Also, before you go changing anything in the engine, please remember to check things by moving from single case to global scope (particular map level to the engine level), otherwise we'll end up with another situation like before, where changing global settings for one aspect or person would break up the whole game for everybody else.

[chakkman]

I also think it looks quite alright in the video.

 

Even though i also frequently curse about the difficulty of TDM (which IMO is rather mission related though).

[Guest]

Mappers should experiment more with light intensity settings. Stock TDM lights are awfully bright, and AI reacts a bit slower when they're a bit more dim. No need to change anything in engine, at least from what I saw.

[zergrush]

Well, if it's not a bug it's still mighty unforgiving especially given the distances and the fact the game difficulty is set to forgiving. A less than 1 sec reaction time is not what I would consider fair in any case, hence why I initially suggested this grace period should be controllable and customizable by the player in the options menu, if anything to compensate for the difficulty of some missions. As it stands now It is neither realistic or enjoyable, just plain frustrating.

[Guest]

[grayman]

Perhaps, this being a stealth game, the solution is not to stay in full light for more than a split second.