[REL] Shoot at periscope

[Rongel]

Originally Posted by Husksubsky

Now I tested with your test mission and it seem to work as purpoused. I put value to -15 again (GetContactDepth() >= -13) Felt weird that they could spot me with peri barly touching surface like they did when I put it to -17.
But what do they see actually? just periscope, or do they spot me like if I was surfaced when above this value? Can I cruise around at 15.5 meters and all is safe since I m to deep for shooting and too shallow for depthcharge? Anyways its a big step in the right directon thx

Thanks for the good report! Glad that you got it working!

your picture say GetContactDepth() >= -13 and you describe GetContactDepth() >= -15..just a little adjust for liking?

Exactly. It's a small mistake, I've been testing what is the best depth value, right now using 15 meters.

SO now Im curious what this value does: ContactPresenceIs(PRESENCE_SENSORS, 15)

This is how I think it goes: If a enemy ship has located you with sensors (it can be any sensor: visual, hydro, sonar, radar) it can open fire if the other condition (GetContactDepth() >= -13) is true also. So it doesn't even need to see you, if dd's sensors show that you are nearby in periscope depth, it will try to shoot you down. There is also a script called ContactPresenceIs(PRESENCE_LOOKOUT, 0) which makes the ships attack you only when the see you visually, but I thought the current is more interesting and challenging. Not 100 % sure which is more historically accurate.

What makes things complicated is that the escorts react always in a different way. Some tests go just beutifully, like you would except, but sometimes escorts do something stupid, like shoot at themselves. Can't figure out why the escorts sometimes continue attacking you even if the script conditions are false. I guess they just want to sink you that badly!

Can I cruise around at 15.5 meters and all is safe since I m to deep for shooting and too shallow for depthcharge?

I think IRAI makes the escorts depthcharge you even if in periscope depth. I'm pretty sure I have witnessed this in my tests.

By the way, I did a long campaign play yesterday with this and had fun with Norwegian destroyer that I mistakenly thought as a neutral unit. I just cruised in periscope depth but then cannon shells started to hit the water breaking the radio and radar. I dove immediately and it stopped the shooting and started to drop depthcharges. It was like an angry bee!

[Vanilla]

Great mod, Rongel!

As of the realism of firing at a submerged submarine, to my knowledge most of the secondary naval guns had special anti-submarine shells, AFAIK they were diving shells - special shells with blunt nose so you shot it into the water and it did not bounce of the water but dived and continued for some distance submerged hopefuly meeting the submarine. Moreover you read in reports of real ASW actions that planes often strafed the spot where the submarine had submerged with their guns, I recon that it is modelled in the AI logic by developers, that is why, I recon, the ships continue to shoot at the last known spot for some time with your mod as well since they use plane's script, I recon that is realistic as well - why would a ship not want to shell the last known spot knowing that the sub is relatively slow to escape? Imagining myself as a DD captain I think I would still fire guns at last know spot for a couple of minutes even if I did not see the periscope any longer and even if I did not have ASW shells, at least there is some hope that a shell would strike something fragile or the sub would be damaged by the HE-shell explosion, even if the shells did not strike they at least would force the sub to be frightened and stay submerged so negating a possibility for the sub to attack me or the convoy - you see enemy, you shoot. The only unrealistic thing I see is the fact that they continue for far too long when you submerge while it should be no more than a minute or two in reality.

If only we could get of the friendly-fire issue... but it is not this mod's issue since if planes do not check for friendly-fire condition they can strafe a friendly DD on a DC run. That means that it is a stock AI error.

[Husksubsky]

Good points Vanilla.
Thx for answer Rongel, I will keep testing but it s hard to keep track of whats happening sometimes.

I m still curious wether that getcontactdepth means your just as visible to the game as if you were surfaced when above 15 m. doesn t look that way since they stop shooting with peri down but anyways I WANT them to shoot if they spot me but I DONT want them to spot me like if I m surfaced when I sneak silent under the surface .

[TheDarkWraith]

Originally Posted by Husksubsky

Good points Vanilla.
Thx for answer Rongel, I will keep testing but it s hard to keep track of whats happening sometimes.

I m still curious wether that getcontactdepth means your just as visible to the game as if you were surfaced when above 15 m. doesn t look that way since they stop shooting with peri down but anyways I WANT them to shoot if they spot me but I DONT want them to spot me like if I m surfaced when I sneak silent under the surface .

GetContactDepth only returns the depth of the contact and nothing more.

[Rongel]

Thanks for the info Vanilla!

Glad to hear that they actually fired cannons at submerged subs! Otherwise this would have been somewhat pointless in the first place!

I m still curious wether that getcontactdepth means your just as visible to the game as if you were surfaced when above 15 m. doesn t look that way since they stop shooting with peri down but anyways I WANT them to shoot if they spot me but I DONT want them to spot me like if I m surfaced when I sneak silent under the surface .

GetContactDepth only returns the depth of the contact and nothing more.

Yep, it doesn't mean that they can automaticly spot you if you are above 15 meters. If they have spotted you with sensors and you are above 15 meters, only then they can fire at you. So you can still sneak silently in periscope depth and they won't spot you.

Been messing with the scripts like crazy (yes, I'm a bit obsessed by this...) but no significant progress. However, I noticed one thing! When you are in periscope depth, and the periscope is up, and they have spotted you and started firing, do not lower the scope, but just dive to safety. Now when you pass the 15 meter line, enemies will see it and know that you are too deep to attack with cannons. This way even DD's will instantly stop firing you.

I'll try to explain it with example... If you just lower the scope when you are attacked with cannons in periscope depth, escorts lose your contact and continue firing the area several minutes. They think that you still might be there even if you are 100 meters below. But if you dive with periscope up (with -15 depth value it has to be all way up) they see you as you pass the magical line and understand to stop. Ofcourse this is not a perfect way either, you are basically helping the escorts by telling them your depth!

So close....

[pedrobas]

[Husksubsky]

I m a bit obsessed too. Thx a lot TDW for clearing that out. (Not that you didn t know Rongel) Finally even I understand how this works a bit more...I think..
I really hated this issue with SH4 and was sad to see it still existed in SH5. They still cant hurt you much at 15 + so I miss those guns Vanilla talked about. Ive heard that depthcharges usully had a preset at 30 60 or 90 meters can that be true? anyways they should have guns to take you out with at shallow depth. Or run fast over you so they would be at somewhat safe distance when the depthcharges explode..(if they could explode above 30 m)anyways I cant think that a sub in reallife would survive long in PD with destroyers present.were supposed to dive away arent we?

Before I play more with the numbers. out of what you say I conclude that
ContactPresenceIs(PRESENCE_SENSORS, 15) . tells the guns to fire if GetContactDepth tells you are above 15.

I stick to visual spot for now.
If they spot my scope when I m at 16 they won t open fire. why not put them both to 17? I can t think of any downsides to it except they started to fire at me even before my scope was above the surface in your testmod.
That means I was spotted but can not tell now wich sensor did it. When I scout I try to keep my scope just above the surface and for short periods. I m still a bit scared that these are the things we mess with to some degree. that it s not how high your scope actually is but how deep you are with scope fully raised. Or have the sensors their own scripts and these shipweapons scripts that you change only come in use if you ALREADY have been spotted.

Sorry for all these qustions but I m very curios

[Vanilla]

Originally Posted by Husksubsky

...
Ive heard that depthcharges usully had a preset at 30 60 or 90 meters can that be true? anyways they should have guns to take you out with at shallow depth. Or run fast over you so they would be at somewhat safe distance when the depthcharges explode..(if they could explode above 30 m)anyways I cant think that a sub in reallife would survive long in PD with destroyers present.were supposed to dive away arent we?
...

Even with a DC set at 30m it can still heavily damage the sub, at shallow depths the explosion expands much further, since the pressure is way lower then down below, and I have read somewhere that the most deadly explosions were the ones just below the sub, don't exactly remember why, though.
There is a nice example of a PD sinking with DCs here: http://www.uboatarchive.net/U-432INT.htm see chapter IV there, note that the sub was at 20m and DCs were set at 34m. So you are absolutely right to say that staying at PD while detected is suicidal. I think a destroyer would use everything available: guns, ramming, DCs, hedgehog and what not (throwing Bertrand overboard? Hygiene tanks flushing?) seeing a sub at shallow depth and with up-scope. Very deadly for the sub unless it timely manages to escape to depth.

[Rongel]

Originally Posted by Husksubsky

Before I play more with the numbers. out of what you say I conclude that
ContactPresenceIs(PRESENCE_SENSORS, 15) . tells the guns to fire if GetContactDepth tells you are above 15.

The "15" in ContactPresenceIs(PRESENCE_SENSORS, 15) is just a default value to make the condition true (it's defined in the ship.aix file). You could probably use "1" as well.

Good way to test the ships behaviour is to have the map contacts on and have the visual sensor data activated in nav map settings. That way you can see if you are in enemy's visual area, passive sonar area, or active sonar area (pinging).

In my tests I have noticed that you won't get any damage from cannons if you are deeper than 20 meters or so. It's a issue with the cannon shell damage and would need modding in that area. Also when you are underwater you rarely get any actual hull damage from guns (and DC's). The water is lowering the damage radically (too much in my opinion!).

So even if get the ships to fire at you when you are 30 meters below for example, the shells couldn't damage you.

But I would be happy if the enemies would fire you when you are in periscope depth and acted logically enough. I have witnessed too many times situations where I'm circling in the middle of the unescorted convoy and have periscope up, and even the armed merchants just zigzag slowly around me, sailors pointing at my direction but too lazy to open fire. Right now it's already working with the merchants, they will shoot you and force you down.

[Husksubsky]

thx for the link Vanilla.
Hygiene tanks flushing lool
Thx for additional info ROngel
I will do as you say in my tests. weird I didn t think about that. Still I think..why not put getcontactdepth to -20? any reason to have them stop firing?

[Rongel]

Originally Posted by Husksubsky

thx for the link Vanilla.
Hygiene tanks flushing lool
Thx for additional info ROngel
I will do as you say in my tests. weird I didn t think about that. Still I think..why not put getcontactdepth to -20? any reason to have them stop firing?

The only reason I want the destroyers stop firing is that they continue it sometimes too long and can hit own ships while doing so. Sometimes they stop at 2 minutes, sometimes longer. And if they detect that you are too deep, they also stop. But you can put the value to -20 also. The only reason I was using -13 was that this way they can sometimes see you diving deeper and will cease firing.

Moreover you read in reports of real ASW actions that planes often strafed the spot where the submarine had submerged with their guns, I recon that it is modelled in the AI logic by developers, that is why, I recon, the ships continue to shoot at the last known spot for some time with your mod as well since they use plane's script

This is true, but I'm starting to wonder why the merchants stop firing when they can't see you, but the warships continue? They are using the same "Plane:FireCannons" command...

[TheDarkWraith]

Originally Posted by Rongel

This is true, but I'm starting to wonder why the merchants stop firing when they can't see you, but the warships continue? They are using the same "Plane:FireCannons" command...

Technically you're breaking the AI routines. The Plane: in front is meant for only plane AI, not for anything else (ships, subs, etc.). Why it works is because there are bugs in the AI routines (in the exe). It shouldn't work. That's the whole reason the ships have their own Ship: identifiers.

[Rongel]

Originally Posted by TheDarkWraith

Technically you're breaking the AI routines. The Plane: in front is meant for only plane AI, not for anything else (ships, subs, etc.). Why it works is because there are bugs in the AI routines (in the exe). It shouldn't work. That's the whole reason the ships have their own Ship: identifiers.

Yep, I know it's not the most sophisticated work-around, but as it doesn't seem to cause any crashes I can live with it . It would be great to have a exe-fix to correct the cannon behaviour properly (like with the hydrophone station) but I haven't got the skills for it. Maybe someday you can look into this when you have the GR2 exporter/importer ready?

It's a serious bug and makes the game too easy in some situations, almost like having some cheat activated.

[pedrobas]

Originally Posted by Rongel

Yep, I know it's not the most sophisticated work-around, but as it doesn't seem to cause any crashes I can live with it . It would be great to have a exe-fix to correct the cannon behaviour properly (like with the hydrophone station) but I haven't got the skills for it. Maybe someday you can look into this when you have the GR2 exporter/importer ready?

It's a serious bug and makes the game too easy in some situations, almost like having some cheat activated.

I agree with this.

[Husksubsky]

To cruise around in PD with the game in this state is cheating. I never do.I dive. If it s drowning or surface I try my best with deckgun and even if overpowered I can t survive long (since my sub is allready a wreck).
still undetected in dec 1939