AI Stuck on walls & stuck when storming

[Byg]

I wasn't sure where to post this as it is a question posed to all players of all mods. Is there anyone out there at all that is using or has a solution to the age old problem of ai units quite often getting stuck when storming castles etc. Maybe it's the mods I'm using and some of you don't get this problem. I'd like to know please.

[Swagger]

well.. the list of the mods you're playing would be helpful


are you using any AI mod? (like XBAI, Lusted's..etc?)

[Taiji]

The 'quite often' bit is definately sorted with mine, reduced down to somewhere like 'not very often at all really' or even 'hardly ever'.

DLV 6.2 has it.

But if you are using 250 man units you should expect it to happen every now and then - though they can climb the ladder they can't all fit and it causes problems.

It certainly helps to increase the throughput for ladders, towers and stairways. Of course it means they can rapidly get into trouble but it also means they are more likely to escape it. This is probably the single most important factor I've noticed.

Plus I think some stalls are caused by orders that fire as the unit is half on a wall and half off. When the order is repeated they resume movement.

Sometimes the order is to form up inside the gate and that order completing may take a while for the units to get into position. If one or 2 units get stalled on the order then the formation never gets completed and the army will not move until provoked. So reducing the <percentage-formed> for the reform can help.

[Byg]

It seems like you said, Taiji, in your last paragraph. Is your battle ai freely available or DLV only? If not then does anyone else have a battle ai which addresses this issue?

I'm using SS with xai, but it has happened for years even back when I used to play an old DLV and other mods I think.
In SS, before xai I used germanicus and before that I used Lusted's. All caused the ai to get stuck quite often. I have been using large rather than huge unit size to see if it helps, but appears to make no difference.

In one example battle (that was the last straw) the ai had ram,ladder and tower and mangonels.
It used up its mangonels quite uselessly on the walls then a ladder came forth, got on the wall, exited the wall on the inside, advanced a bit then formed up and waited. At that point everything outside was stuck too.

I've just now been playing about with the files, using different combinations for the same battle. That way I know what works and what was at fault. My solution (as far as the test battle was concerned) was to remove modded battle ai files altogether and revert back to vanilla. The ai was then able to scale the walls, enter, then open and use the gates to let the rest of the army in and then all attack the town centre, etc. Once the ladder was up other methods, like the siege tower and ram were abandoned, but that's fine as they were able to use the gate. At least they didn't get stuck.

Now the problem is that I'll be stuck with vanilla ai in outdoor battles, though all the above mentioned battle ai are superior in that scenario.

[Taiji]

Are you using RRRC? If so I will try tailor it for that mod where necessary and upload it here for you.

[Byg]

Are you using RRRC? If so I will try tailor it for that mod where necessary and upload it here for you.

Yes, the RRRC compilation mod here
Thanks a lot, that would be amazing if it solves this issue, as for me this is one of the last areas of annoyance I have been unable to address in my otherwise fantastic campaign!

[Taiji]

Try this Attachment 56553, it should be OK.

I haven't looked much at XBAI recently so I'm not sure how this will compare with that AI. For example skirmish distances are different in SS and if you're using XBAI's instead SS's there's not much point me copying in SS's.

If you have probs with skirmish related stuff (or anything else) let me know

edit: some problem with first upload... 1 sec

edit: OK done. Added an order repeat in the attack settlement section... I wonder if it will make everything mess up ... testing as soon as I've had something to eat...

[Byg]

Try this Attachment 56553, it should be OK.

I haven't looked much at XBAI recently so I'm not sure how this will compare with that AI. For example skirmish distances are different in SS and if you're using XBAI's instead SS's there's not much point me copying in SS's.

If you have probs with skirmish related stuff (or anything else) let me know

edit: some problem with first upload... 1 sec

edit: OK done. Added an order repeat in the attack settlement section... I wonder if it will make everything mess up ... testing as soon as I've had something to eat...

That was quick!. Thanks, I'll try them now in the same battle as above. I don't know about the skirmish thing. As your files replace the XAI files I'll be using RRRC skirmish distances wont I?

Anyway it says this on the RRRC instruction page:
If you want to use another BattleAI, make sure that you have the following text at the top of the data/battle_config.xml file:

<config>
<!-- global combat balancing factors -->
<combat-balancing>
<missile-target-accuracy>
<infantry>1.0</infantry>
<cavalry>1.5</cavalry>
<elephants>0.75</elephants>
</missile-target-accuracy>

<melee-hit-rate>2.00</melee-hit-rate>
</combat-balancing>

Also I recommend you don't use another descr_formations_ai file as it may cause a crash due to the new 'Skirmisher' class.

[Taiji]

Well... how to say this and not sound critical?....

Skirmish distances being correct relies on testing. If my distances have not been tested with SS then I cannot assume they are correct.

Also the bottom point about the skirmish class, it doesn't matter. The skirmisher class is not new it's just mostly unused in mods and not at all in vanilla, it is a hard-coded class though. Formations have at least 1 block with 'unit_type any' so the skirmishers will not be excluded. Either way, my formations stuff is designed with skirmishers as they are used in DLV in mind. So if SS differs in it's use of them then my formations might be sticking them in the wrong place.

Please let me know what happens with your test... I still haven't eaten and I'm half expecting the whole siege assault stuff to die a horrible death as a result of my last minute tinkering. When BAI s up it just resorts to hardcoded parameters within the engine(my discovery afaik), it even ignores the vanilla files.

edit:

I just tested and was dissappointed... I'll remove my tinkering and test again.

edit:

Maybe better but again dissappointing, I suspect there is something wrong with the pathfinding in relation to this settlement. With both tests I've had some idiot cav runing around in circles!!!... I'll try to find some new pathfinding stuff and test again... please let me know how it is going for you

edit:

I think I worked out the problem, I was making things pretty hard for the AI by leaving a small unit in the top of the gate and rest of my army in the square. I get the impression that the Artificial Idiocy was trying to use a cav unit to get the unit above the gate... With both tests it was single cav units that were stuck by my inaccessible unit. Just as I was about to try new pathfinding I decided to see what would happen if I attacked the cav with the unit they couldn't get to. As expected they resumed normal function and began attacking properly. While all this was going on the rest of the AI army seemed OK.

[Byg]

Right, just finished the same test battle as before, but using your battle ai.

A good start. Instead of waiting for the mangonels to fire off all their useless ammo the whole army moved forward together.
However, once in range the magonels proceeded to fire, catching a few of their own troops. That's not important to this test though.

Meanwhile the troops holding the ladder reach the wall. At this point the rest of the army stops and pulls back.
Once the first unit is inside he hares off on his own chasing down my general unit who was my only unit by the gate (just there to keep the towers firing). All the rest of my army is in the centre.

This lone ai unit chases my general to the centre and fights everyone else until he routs (actually he just routed, but didn't run. I guess he was stuck)EDIT come to think of it as another unit had taken down the ladder he had no way out so probably froze for that reason.
Back at the gates two other units had first moved up to the wall. One grabbed the ladder and the rest of the army froze.

So in conclusion, vanilla ai was the only one where a unit had the sense to open the gate for the rest of the army rather than running off on his own and was the only ai that did not get stuck.

Obviously I'm only testing sieging ai here and so can't be fair to your ai in other battle types.

So what do you make of it? Something important from vanilla missing in others or something in others messing up?

[Taiji]

Well lets take a look at vanilla:

Spoiler Alert, click show to read: 

<attack-settlement>
<detachment>
<engine-collection>
<!-- when stealing an engine, prioritise being out of combat over distance -->
<prioritise-out-of-combat>1</prioritise-out-of-combat>
</engine-collection>
<commit>
<!-- commit sufficient forces to outnumber the enemy by this ratio -->
<strength-ratio>1.6</strength-ratio>
</commit>
<perimeter-attack>
<termination-criteria>
<enemy-in-perimeter>0.25</enemy-in-perimeter>
</termination-criteria>
</perimeter-attack>
<max-plaza-assault-groups>5</max-plaza-assault-groups>
<units-per-plaza-assault-group>4</units-per-plaza-assault-group>
<artillery-times>
<!-- successful assaults performed for at least 1 minute -->
<minimum>1.0</minimum>

<!-- don't prolong the bombardment longer than 6 minutes if we have no targets left -->
<maximum>6.0</maximum>

<!-- stall test is a moving average that checks if any artillery is active (moving/firing/reloading) each tick -->
<stall-test>
<!-- minimum number of ticks to collect before detecting a stall -->
<minimum-samples>900</minimum-samples>

<!-- track at most this number of samples -->
<maximum-samples>1200</maximum-samples>

<!-- if the artillery has be inactive for at least 75% of its time -->
<limit>0.5</limit>
</stall-test>
</artillery-times>
</detachment>
<tactics>
<assault-gate>
<inside-position-dist>25</inside-position-dist>
<formation>ai_settlement_assault_gate</formation>
</assault-gate>
<reform>
<offset>30</offset>
<formation>ai_settlement_attack_reform</formation>
<percentage-formed>10</percentage-formed>
<advance-timer>1.0</advance-timer>
<siege-equipment-advance-timer>6.0</siege-equipment-advance-timer>
</reform>
<capture-plaza>
<reform-dist>120</reform-dist>
</capture-plaza>
</tactics>
</attack-settlement>

and now mine:

Spoiler Alert, click show to read: 

<attack-settlement>
<detachment>
<!-- interval to repeat the order at (in 1/10ths of a second) -->
<order-repeat-rate>200</order-repeat-rate>
<engine-collection>
<!-- when stealing an engine, prioritise being out of combat over distance -->
<prioritise-out-of-combat>1</prioritise-out-of-combat>
</engine-collection>
<commit>
<!-- commit sufficient forces to outnumber the enemy by this ratio -->
<strength-ratio>0.9</strength-ratio>
</commit>
<perimeter-attack>
<termination-criteria>
<enemy-in-perimeter>0.1</enemy-in-perimeter>
</termination-criteria>
</perimeter-attack>
<max-plaza-assault-groups>4</max-plaza-assault-groups>
<units-per-plaza-assault-group>5</units-per-plaza-assault-group>
<artillery-times>
<!-- successful assaults performed for at least 1 minute -->
<minimum>1.0</minimum>
<!-- don't prolong the bombardment longer than 6 minutes if we have no targets left -->
<maximum>1.0</maximum>
<!-- stall test is a moving average that checks if any artillery is active (moving/firing/reloading) each tick -->
<stall-test>
<!-- minimum number of ticks to collect before detecting a stall -->
<minimum-samples>200</minimum-samples>
<!-- track at most this number of samples -->
<maximum-samples>340</maximum-samples>
<!-- if the artillery has be inactive for at least 75% of its time -->
<limit>0.5</limit>
</stall-test>
</artillery-times>
</detachment>
<tactics>
<!-- interval to repeat the order at (in 1/10ths of a second) -->
<order-repeat-rate>200</order-repeat-rate>
<assault-gate>
<inside-position-dist>50</inside-position-dist>
<formation>ai_settlement_assault_gate</formation>
</assault-gate>
<reform>
<offset>30</offset>
<formation>ai_settlement_attack_reform</formation>
<percentage-formed>10</percentage-formed>
<advance-timer>0.5</advance-timer>
<siege-equipment-advance-timer>2.0</siege-equipment-advance-timer>
</reform>
<capture-plaza>
<reform-dist>170</reform-dist>
</capture-plaza>
</tactics>
</attack-settlement>

At first glance those 2 in red stand out as likely to affect the gate taking. I'd try the vanilla values there.

BTW I can't really work out what is happening in your screen shot.... the ladders are down but the unit is inside??? A second AI unit took down the ladder??? what the hell is going on there! ...like what is that siege tower doing back there? ... That's funny, I'm seeing a ton of stuff in that screenshot that I've honestly never seen. Maybe some XBAI pathfinding stuff... really not sure.

Also don't worry about making negative criticisms, I want to hear them

And half the time with BAI it's a case of choosing one stupid behaviour over another... so yes, ultimately it's pretty stupid

Back to the issue, once it had captured the gate with vanilla, did it then attack or sit there?

edit:

Noticed that the lines in green on mine definately do not work, that was the tinkering I refered to earlier. Where they are they cause no problems but they have no effect. Put into a place where they have an effect they cause problems... I tried sticking it in </capture-plaza> and boom! They froze after taking the gate... or so it seemed. Either way, if it was working I would hear the units shouting 'yes sir' every 20s or so and I'm not hearing that.

edit:

Just had an instance of the AI assigning a unit to a wall it couldn't fit on and that unit froze. Otherwise it's all going fine...

It occurs to me that you could try PMing Germanicu5, I don't know if you've tried his AI but if it has the same issue he might be interested in having your save (since he writes BAI for SS).

[xeryx]

The issue with units getting stuck, has a few underlying issues. In a nutshell, here they are.

1) orders of units (in essence timing) not getting completed.
2) Path finding, from walls to the streets and around obstacles.
3) The number of troops allowed to pass through the portals or siege equipment.
4) The path finding file itself.

All of these issues have to be addressed, or worked around in an BAI and the path finding file.

So why do units get stuck? They get stuck for couple of reasons; Orders not getting reissued to them, until they complete the task. And because path finding is poor with vanilla files (path finding and map structures).

The first and foremost thing to mess around with is the ladders and siege section in the BAI.
WARNING, these numbers are a double edged sword, if you open up too many troops to get in, then the AI will "flood" and overwhelm defenses quickly. Path finding from the wall to the ground often is terrible at best. But is is also terrible going through gates. Test it by clicking on a unit on a wall, in the first tier of a castle and then click behind a castle gate in the second tier, it will not accept it as a valid path. or go from the ground up to a wall in the second tier, it will also not count it as a valid path. only when the unit gets into the second tier after the gate can you give them orders to get on the walls. In all honesty I doubt anything was really updated in path finding from RTW to MTW2, as I don't think they accounted for a second and third tier of walls.

While still on path finding, the actual construction of a castle or town structures is problematic as well. There are many errors in the structures that hinder smooth path finding, like little props added to buildings. Many of the street tiles also have poorly defined borders. I also believe the portals for the walls have issues. This is unfixable.
as new "props" would need to be made, and that code is locked.

So when a unit tries to flee a wall, because it has sustained damage, if the unit cannot get through the portal fast enough the unit "forgets" its order and stays there. This is also true for fleeing units, sometimes they forget their orders. There are ways to adjust these.

Of course don't forget, many "stuck" units, have lost soldiers, that prevent the unit from moving until that soldier gets back to the unit, again this is due to path finding. I have made advances in the path finding file, but unfortunately..the community is disinterested in the work, and also the increase in processor power, which makes it less viable on lower end systems.

I'm glad the "white rabbit" did not use med2's path finding, to get where he was going!

[Hanny]

I wasn't sure where to post this as it is a question posed to all players of all mods. Is there anyone out there at all that is using or has a solution to the age old problem of ai units quite often getting stuck when storming castles etc. Maybe it's the mods I'm using and some of you don't get this problem. I'd like to know please.

I went i different route.

First i increased the siege equipment avaialble via traits and ancilrays, roughly doubled the amount, (typicaly a 2-4 rams/2 towers 2 ladders attack from first turn.) Second i made the attack and defense of rams lower, so that the gate breach occurs ( first ram wont do it most of the time as its just under 50% of a chance to breach a rienfouced gate) after the tower and laddr assualts have been enacted. Third i changed the AI formations for siege so that they are in 3 waves, with a large distance between them, so they come forward seperatly in waves rather than a bunch. Fouirthly and something im still working on, is to script ladders for any siege in progress world wide so the atacker has more ladders.

[Taiji]

Xeryx, good points. I learnt the point about ladder throughtput, etc. largely from looking at your work.

I just tried your 3.4 pathfinding files with my siege issue and it didn't help, I suspect the issue may not be pathfinding related afterall. However I noticed that pathfinding for my own troops seemed improved, which is very nice indeed.

So I'm wondering if you can explain the process of making these new pathfinding files... specifically how do I make a new .db ??? This baffles me.

Hanny, I think you're best off raising gate and wall hitpoints. It will make defending slightly easier for you and much easier for the AI. Especially if you choose not to place a large proportion of the AI defenders on the wall. More gate and wall hitpoints gives the defenders more time to respond to breach threats.

I've been using the trait trick for a while now and with good results, recommended

The last point you make about scripting extra ladders, can you show us the script? This is very interesting

Byg, another consideration is reducing the chances of over manning the walls by reducing the initial wall defenders and setting an optimum defender to attacker (or vice versa) ratio of less than 1. So you only let the AI send one unit onto a wall at a time.

Ultimately players have to behave themselves. If they have a 30 man unit and place it on a tiny section of wall when the AI has units that cannot fit on that section of wall then they deserve to get a freeze. Either we use unit sizes that are compatible with the small wall sections or we have to adjust our play, this is the bottom line.

[Byg]

A lot of interesting things there from everyone.

Bear in mind that the ai was freezing in my test battle when noone was on the walls.
]
I tried pathfinding files both in and out from mods, but only when the battle ai files were left as vanilla did the freeze not occur.

[Taiji]

..the battle ai files..

Which files, just the 2 I uploaded? Not formations?

If yes to both then it would be nice to know if the cause is both files combined or just one, and then which one.

Then if you're willing you can go through replacing sections of the new AI with sections from vanilla until you find the offending section. Then stick the previously replaced sections back in and test.

You could almost half the AI with vanilla, then quarter it, etc. it might not take many tests to find the problem or it's rough proximity.

[Byg]

Which files, just the 2 I uploaded? Not formations?

If yes to both then it would be nice to know if the cause is both files combined or just one, and then which one.

Then if you're willing you can go through replacing sections of the new AI with sections from vanilla until you find the offending section. Then stick the previously replaced sections back in and test.

You could almost half the AI with vanilla, then quarter it, etc. it might not take many tests to find the problem or it's rough proximity.

Yes, just the 2 battle config type files.

In other battles they would also freeze on walls or half off, but they seem to consistently be doing that thing where you can hear them reissuing an order every few seconds whilst stuck.

[Hanny]

Hanny, I think you're best off raising gate and wall hitpoints. It will make defending slightly easier for you and much easier for the AI. Especially if you choose not to place a large proportion of the AI defenders on the wall. More gate and wall hitpoints gives the defenders more time to respond to breach threats.

I've been using the trait trick for a while now and with good results, recommended

The last point you make about scripting extra ladders, can you show us the script? This is very interesting

.

Well thats the reverese of what i did but the end result is the same, unless you take into acount siege weapons attcks on citys, so i think increasing gate and wall hits points is making more work in the long run that reducing the rams attack and hit points to a level of a quarter or so.

Extra ladders can easily be forced on the AI by bincreaing all ancilrys and traits refernces to siege equipment, i went witha min of 65 asa refernce to a max of 13o in any single trait anc, but made them more common, so charcters turn up with plenty of siege points to buy stuff with. Getting them to buy a good mix i could not not find how to modify. so a script like a garrison script which checks all settlements for siege and places/spawns ladders/towers if they exist is easy enough to do, but 2 twoers seems the most the AI will use ina an assault at ant time in any event.

[Taiji]

Well thats the reverese of what i did but the end result is the same, unless you take into acount siege weapons attcks on citys, so i think increasing gate and wall hits points is making more work in the long run that reducing the rams attack and hit points to a level of a quarter or so.

That's the point really. With vanilla values (and every mod I've tried) the AI does not get enough time to respond to wall and gate breaches. So I can either decrease the damage of the rams and engines or the hitpoints of walls and gates, walls and gates seemed simpler.

Extra ladders can easily be forced on the AI by bincreaing all ancilrys and traits refernces to siege equipment, i went witha min of 65 asa refernce to a max of 13o in any single trait anc, but made them more common, so charcters turn up with plenty of siege points to buy stuff with. Getting them to buy a good mix i could not not find how to modify. so a script like a garrison script which checks all settlements for siege and places/spawns ladders/towers if they exist is easy enough to do, but 2 twoers seems the most the AI will use ina an assault at ant time in any event.

I think the AI will buy ram then ladder then tower, and repeat. This is probably why we only see 2 towers unless we're defending huge walls, when the enemy besieges us for 1 turn.

Personally I added SiegeEngineering to a trait that only AI generals will receive, to avoid giving the player any advantage.

[Hanny]

I think the AI will buy ram then ladder then tower, and repeat. This is probably why we only see 2 towers unless we're defending huge walls, when the enemy besieges us for 1 turn.

.

Not sure about that, i can get the AI to buy 4 rams 2 ladders 2 towers easy enough, and use one ram at a time, and use both, 2 of each, ladders and towers at the same time.