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HOI4 Dev Diary - Modding and Traits

Hi everyone! Todays dev diary will be a 3 meal course. First we are going to be talking about the new admiral traits in Man the Guns, then we will be showing off some new modding toys, and finally there will be an extra dessert in the form of more modding stuff posted here in the modding forum. Hope it’s to your tastes :)

Admiral Traits
With Man the Guns following Waking the Tiger and focusing on the naval aspects of the game we knew we wanted to give Admirals more progression and traits as well as new skills. Going over all the traits is going to be spoiling a bunch of upcoming stuff as well, so you will need to be patient with the details on some of that ;)

We have expanded the single skill level of Admirals in a similar way to how we did Generals in WTT, so there are now 4 traits to better reflect their skills and personality: Attack, Defense, Manoeuvring and Coordination. Attack and Defense are pretty straight forward. Maneuvering is the more tactical skill that will matter for fleet positioning and movement while Coordination is the more organizational skill and affects missions and other things outside combat more. We’ll be covering these in more detail once we start breaking down fleets, task forces and combat.

Admirals will now get access to more earnable traits as well as personality traits. Some personality traits carry over from Generals, like Career Officer as well as new ones like Battleship Adherent. There are also assignable traits you can unlock and tailor your admirals. Finally there are terrain traits which are earnable and help in different naval terrain (see future diary for details). As admirals level up they gain 3 points across their skills for each level, more likely in their strong points. Every second level they also unlock the slots needed for assigned traits similar to how it works for generals. The assignable traits and admiral screen will be in Man the Guns while the base stuff like personality traits and earnable traits will be in the free patch. So just like with Waking the Tiger’s general traits.
commanders.jpg


Here is the whole trait tree:
traits.jpg


As you can see most traits will have dependencies on having earned traits first.

There are stuff like Ironside if you want to focus on powerful capital ships, Air Controller for carrier abilities as well as things like Blockade Runner, Concealment Expert and Silent Hunter for raiders. There are also paths for improving the use of lighter ships under Flyswatter and Fleet Protector. This matters because light ships are going to get a whole lot more necessary for your fleets and naval operations.


Modding!
Hello everyone! @shultays here. I am a programmer in HoI4 team and I have exciting updates for all our modders and for the players that enjoy their mods! In this dev diary I will introduce a couple new scripting features that will be especially appealing for our modders. It is a bit early for such tech dev diary but we wanted some feedback on those features, and also have enough time to iterate on such feedback.

I will give short descriptions and small examples here, more in-depth stuff can be found in my other post that I made in modding forums.

Arrays

The people with programming experience are already familiar with the concept of arrays. For those who are not, arrays are basically containers of data. In HoI4, they are containers of variables (and things that can be stored as variables, such as states and countries).

Array support is an extension on the existing variable system. You can store arrays anywhere you can store variables (countries, states, unit leaders or globally). You can access individual array elements using existing effects & triggers that changes or compares variables (the syntax for accessing an element is array_name^index) or you can use them in the effects/triggers that accepts variables. And there are many additional effects and triggers to interact with arrays, like effects that can add/remove elements or triggers that can check for every or any elements.

Let's give an example:

Code:
#create an example array with 3 countries, named "array_example"
add_to_array = { array_example = GER }
add_to_array = { array_example = ITA }
add_to_array = { array_example = TUR }

# calculate total pp of these 3 countries
set_temp_variable = { sum_pp = 0 }
for_each_scope_loop = {
    array = array_example
    add_to_temp_variable = { sum_pp = political_power }
}

if = {
    # do they have more than 100 pp?
    limit = { check_variable = { sum_pp > 100 } }
 
    # remove 33 pp
    for_each_scope_loop = {
        array = array_example
 
        add_political_power = -33
    }
 
    #pp spent, now do business
}

Here I assumed Germany, Italy and Turkey made some kind of pact and I want to run an effect if they have more than 100 pp in total. This effects builds an array of 3 countries using add_to_array effect, calculates the sum of their pp by iterating on this array using for_each_scope_loop effect and removes 33pp from each if the sum is > 0 again using for_each_scope_loop.

This is just one example to usage of arrays. There are many more ways to interact with arrays, which can be found in my other post.

In addition to arrays that you can create or change, the game will also support "game variable arrays". Similar to "game variables", in various scopes you will be able to access such constant arrays which are built using in game data. For example accessing "enemies" array in country scope will let you access enemies of a country. If you loop through enemies, you will loop every for every enemy of that country. Current list of game variables and arrays can be found in my other post, please check it if you are interested and feel free to post your suggestions.

Meta-Effects and Meta-Triggers

This is something we borrowed from EU4, but the implementation and the usage is different. Meta-effects and meta-triggers will let modders to use non-dynamic effects/triggers (the ones that do not accept modifiers and can only use static tokens or constant values) as if they were accepting variables. It is hard to explain and so let's give an example! Consider following code

Code:
add_equipment_to_stockpile = {
    type = infantry_equipment_2
    amount = eq_amount
}

In this effect, amount is dynamic and can be set using a variable (here it is being set to eq_amount variable). However this effect does not let scripters to use a variable as equipment type. You can not store infantry_equipment_2 in a variable and use it here.

But with meta-effects anything is possible! Meta-effects will let scripters to use variables & scripted localization within their effect to build effects as if they were texts and run them. Now let's make previous effect accept equipment type and equipment level as variables stored in eq_type and eq_level.

Code:
set_temp_variable = { eq_type = 1 }
set_temp_variable = { eq_amount = 10 }
set_temp_variable = { eq_level = 2 }

meta_effect = {
    text = {
        add_equipment_to_stockpile = {
            type = [EQ_TYPE]_[EQ_LEVEL]
            amount = eq_amount
        }
    }
    EQ_LEVEL = "[?eq_level|.0]"
    EQ_TYPE = "[This.GetEquipmentName]"
}

# scripted localization
defined_text = {
    name = GetEquipmentName
    text = {
        trigger = {
            check_variable = { eq_type = 0 }
        }
        localization_key = "infantry_equipment"
    }
    text = {
        trigger = {
            check_variable = { eq_type = 1 }
        }
        localization_key = "artillery_equipment"
    }
    # give all equipment an index here
}

Here we created a meta_effect that takes two arguments. These arguments will be used replacing the parameters ([EQ_TYPE] and [EQ_LEVEL]) inside the meta effect. EQ_LEVEL will be replaced by [?eq_level|.0] which is the integer value of eq_level (in this case 2.000 becomes 2). EQ_TYPE is a bit more complicated, it is being replaced by a scripted localization. This scripted localization will check eq_type variable and depending on its value it will return the key token for the equipment. If it is 0, it will return infantry_equipment. If two, it will return artillery_equipment.

So the final result is [EQ_TYPE] is being replaced by "artillery_equipment" and [EQ_LEVEL] is being replaced by "2" and in the end our effect will be built as:

Code:
add_equipment_to_stockpile = {
    type = artillery_equipment_2
    amount = eq_amount
}

which will give you 10 artillery_equipment_2! Now you might think that this is extremely convoluted way of giving 10 artillery_equipment_2. But it will be possible to use and replace meta_effects in the scripted_effects or scripted_triggers, so this convoluted parts will be only written once.

Dynamic Modifiers

Currently our modifiers can only contain static values and you can't use variables in them. With dynamic modifiers, it will be possible add such modifiers to country and states. To keep things simple, we limited adding and removing dynamic modifiers only through effects, although some QoL improvements may be added in future.

Their declaration is similar to static modifiers, except that they will accept variables as modifier values.

Code:
dynamic_modifier_example = {
    political_power_factor = pp_factor_variable
}

And after declaring a dynamic modifier like that, you can run following effect to add this modifier to current scope.

Code:
set_variable = { pp_factor_variable = 0.15 }
add_dynamic_modifier = { modifier = dynamic_modifier_example }

This example will add "dynamic_modifier_example" dynamic modifier to the country of the scope. This modifier will give country pp gain factor equal to "pp_factor_variable" stored that in country. In this example we stored, 0.15 so the country will get 15% more pp gain. When you change the value of pp_factor_variable later through another effect, the bonus the country gets will also be updated.

Additionally you can define a scope while adding dynamic modifiers. In that case the modifier will fetch the variables from the scope that you specified. This will also let scripters to add multiple instances of same dynamic modifier that is targeting different countries (or states) so you can use them as if they were relationship modifier.

While adding modifiers, you can specify a duration as well, which makes them automatically removed after certain number of days. And it is possible to define a trigger, which will also remove the modifier when the trigger is false.

It will be possible to give dynamic modifiers icons. In that case they will show up in GUI. For example dynamic modifiers that are added country will show up if they were "national spirits" if an icon is defined.

dynamic mods.png


In this example Turkey has two dynamic modifiers in it. And we defined an icon here so it shows up in national spirits list. Both of these dynamic modifiers are same but one is targeted at Italy and the other one is target at France and value of "Fuel Capacity" is being read from those scopes (and root is Turkey, you can use targeted variables if you want). Also the effect that added those modifiers defined a duration, and these modifiers will be removed in two days because of that.

More Scripted-GUI features

Modders are being extremely creative with this feature and I am delighted to see all those new cool mods that is being developed or in the workshop. Other than fixing some unfortunate bugs and insights in the live version, we are also adding "dynamic lists" support for scripted GUIs.

Dynamic lists will let modders to create their own lists and fill those lists using an array they specify. In an older dev diary, I showed this sneak peek:

output.gif


This one is actually implemented using arrays. Each cell here is dynamically created using an array of 64 elements and value of each element represents the cell state. Each cell element is being built using the scope and the value of the the array element.

Another, more down to earth, example:

output.gif


Bottom list is populated using allies of the country (using “allies” game array in country scope). For Germany, this array has two elements, Italy and Turkey and thus it creates two entries in the bottom list. While building the elements of the bottom list, it changes scope to each entry in the element (if the element is not scopable, there are ways to access the value & index of the element, which are also being shown in the example)

Top list is built using an array that is stored in country scope and initially it is empty. Pressing “Add Item” button at top calls an effect that adds random country to that array, which also updates the list itself.

The medium flags that are being shown as a grid is also another dynamic list. This example is given to show that the lists inside lists also possible.

And that is all from me for now. If you are interested more on those topics, check the in-depth topic on modder's forum and please give feedback.
 
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@podcat

OCD alert: the "Admiral traits" title should be "Admiral Traits"
 
I was totally losing for testing purposes

That is your story, you sticking with that, lol?

But seriously, is there a limit on array size?
 
Will carriers still be able to send out only 200 planes max into any individual naval combat? Or will fuel supplies play a role in that?

edit: this was a little off topic but something I hope the devs expand upon at some point.
 
Your traits are backwards. The latter traits have to be learned as line officers before becoming a flag officers.

Yamamoto commanded from the Yamoto's bridge during Midway. Yamamoto died at the hands of US intelligence. His plane was shot down over New Guinea after the US code breakers determined his flight plans. You cannot expect HOI IV to simulate this kind of assassination. Still, there is risk of losing one's life in service and Admirals are subject to the same fate as seamen caught in mortal situations.

Oooohh... very nice. New information in regards to the navy rework is always great.

I've been wondering though, will there be any way to tell my carrier fighters not to attack ships during naval combat? While probably a really niche feature, I'd rather let my BBs, BCs, and CAs hammer the enemy fleet to bits. There's just something underwhelming about aircraft kills on ships in my opinion.

Go get a World War I simulator. Carriers ruled in WWII and with good reason. Aircraft ranges in the day exceeded 100Km. When I see carriers closing in at 44Km in the current HOI IV, i literally cringe. Carrier planes should have been engaging hours before this hits the screen. I am hoping MtG takes care of this vast short coming.
 
2. Arrays? I remember how afraid I was of those buggers when they were introduced in programming class. What's next, locks and synchronizations? :D
Pointer. They always make my head burn when I try to read code that I cannot debug...
 
Very cool. HoI4 is the new IntelliJ
 
even if there isn't when it comes to performance...

The array limit is never to small nor is it ever too large, it is precisely as big as Johan intends it to be.

- 24 hours later, a hotfix for an out of bounds exception is published.
 
What about : "
Grand admiral (Großadmiral) " like Dönitz

I believe in UK the rank is called Admiral of the fleet.

https://en.wikipedia.org/wiki/Admiral_of_the_fleet

It should be possible to set an Admiral for the high command of the whole Navy, in the wiki above there are the different names. But it should have not only five (usually)Admirals , it should be more.

People like Dönitz really belong in the High Command section of the Country tab, don't they?

I wonder whether it would be better to have Commodore (Kommodore) and Admiral as the two levels of the OOB.
 
Cheers for the DD Podcat and Shultays :D. Will be great to have more depth to our admirals, and great to see a wide range of traits :). As for the modding support, that looks beyond wonderful :cool:. Arrays is particularly awesome in terms of mod data handling, but dynamic modifiers are also all kinds of awesome (I can imagine they're the kind of thing that make re-scripting some of the Soviet national spirits tempting ;)). I think I like dynamic modifiers most because they don't give me a headache thinking about them, but I'm a huge fan of what's possible with arrays (which I have worked with, both for fun and profit, but they still give me headaches :)).

Lots of potential naval pics for this DD - I'm going to go with this one, what traits would one give this character? ;).

Marc_Mitscher_g236831.jpg


On a sort of related note, I've noticed the AI using carrier fighters, CAS, and NAV as if they were normal planes when their respective carrier is sunk. Any chance the AI could be told to auto-disband air wings composed of carrier aircraft that aren't on carriers?

Historically, at least in the RN, when carriers were lost, air wings that survived generally continued operating (although some were wrapped into other air wings). The AI is being historically plausible, more or less, in this regard (some air wings were joined with others, and some were disbanded, but squadrons were often kept as operational units). The IJN may have had a different approach, but they also commonly operated carrier aircraft from land, so it's not crazy for them to be doing this. Drawing a blank on the USN right now, sorry I can only cover (the smallest) two of the big three.

Only thing I'm a little bit dissapointed is that all the modding stuff seems to be for the "top 5% nerd modders". For the me as a weekend modder, it would be helpful to get some simple new modifiers just to create new mission types or new air/land/ sea models and really nation specific tech trees.

Those dynamic modifiers look like things that can be added fairly quickly and simply :).

Green water sounds much better than brown water. Is there any historical reference to a “brown water navy”? (Other than derogatory, lol). Littorals is the only term I’ve heard of over the last few decades, highlighted by the need from the gulf of Sidra clashes.

I've seen the term 'brown water navy' used plenty of times (and not in a derogatory sense, although right now can't think of an example). It may be more historical (I don't read much modern stuff - and the modern term I bump into most tends to be littoral)?

People like Dönitz really belong in the High Command section of the Country tab, don't they?

I wonder whether it would be better to have Commodore (Kommodore) and Admiral as the two levels of the OOB.

If there were two levels, then Admiral and either Vice or Rear-admiral (probably Vice, unless the plan is to add a lot more admirals). Commodores/Kommodores were definitely a thing, but at HoI4's level I'd think the Konteradmiral/Vizeadmiral level would be more appropriate. As ever, though, that's just my 2 cents, and I could well be wrong :).
 
I'm becoming increasingly concerned with the possibility that MTG may simply be giving us additional mechanics added on top of still broken core systems. Are battles still going to be black holes where fleets are trapped for weeks? Can ships still teleport 3 sea regions away simply by assigning the relevant missions? Can we strike enemy air bases with our carriers? Can we sink supply and resource convoys with aircraft, instead of only troop transports? Can we engage in night surface combat? Will attacking airfields actually damage wings based there, or will assigning wings missions still render them immune to destruction on the ground?

I apologize if this post comes across as unappreciative. Fuel, for instance, is a great addition to the game. I am simply concerned that there is no sign yet of overhauling those of HOI4's core mechanics which are totally insufficient to convincingly model WW2 naval warfare.
 
The wait is killing me at least I'll have Dharma in the morning to tide me over.
 
I'm becoming increasingly concerned with the possibility that MTG may simply be giving us additional mechanics added on top of still broken core systems. Are battles still going to be black holes where fleets are trapped for weeks? Can ships still teleport 3 sea regions away simply by assigning the relevant missions? Can we strike enemy air bases with our carriers? Can we sink supply and resource convoys with aircraft, instead of only troop transports? Can we engage in night surface combat? Will attacking airfields actually damage wings based there, or will assigning wings missions still render them immune to destruction on the ground?

I apologize if this post comes across as unappreciative. Fuel, for instance, is a great addition to the game. I am simply concerned that there is no sign yet of overhauling those of HOI4's core mechanics which are totally insufficient to convincingly model WW2 naval warfare.

Calm down lad, there are only a couples of DD released so far, and they haven't mentioned about naval combat, mission and other mechanics yet. Let's see what will happen soon.
 
Inshore fighter? That was the one trait that did catch my attention more closely. River combat perhaps? Would be quite appropriate for the Chinese theatre and for hipothetical South American wars.
DIE WACHT AM RHEIN!

*Drops battleship in river*
 
I've seen the term 'brown water navy' used plenty of times (and not in a derogatory sense, although right now can't think of an example). It may be more historical (I don't read much modern stuff - and the modern term I bump into most tends to be littoral)?
The first time I've seen the terms blue and brown water/navy was the tech tree of Victoria 2.
And I understood in an instance what these terms meant.
Littoral would make sense, too, I guess.
But when I hear green water I think of a lake covered with algae.
But that's just me. If it's the right term, please use it.