The Future of SC4 Modding: The Matter of Digital vs. Disc, and Windows vs. macOS in the DLL Era

[Tarkus 6,934]

There are currently several different versions of SimCity 4 Deluxe out in the wild, including the various digital editions (i.e., GOG, Steam, and the now-patched EA App version), the original disc version, and the Steam and App Store versions of Aspyr’s macOS port of the game.

As one may have noticed while scrolling the STEX in the past three months, a once uncommon, “Holy Grail” type of mod has begun to appear with some frequency: DLL mods.  DLL mods are capable of modifying aspects of the game that have been previously off-limits to SC4 modders over the past 20 years.  The two best-known DLL mods prior to this point are, of course, the SC4 Extra Cheats DLL, a file Buggi was authorized to release from the original developers at Maxis, and simmaster07’s revolutionary SC4Fix, which fixed two of the most notorious bugs with the game in a modded environment: the Puzzle Piece vs. Transit-Enabled Lot CTD, and the Prop Pox.

Thanks to the efforts of those continuing simmaster07’s line of work, namely Null 45 and memo, these sorts of revolutions are about to become more commonplace, bringing with them everything from improved game stability on modern systems, to long-requested new features and quality-of-life (QoL) improvements.  Null 45 has already released over a dozen DLL mods on the STEX since November, one of the most recent of which allows more Building Styles.  While I can’t reveal too much at this point in time, I will note that DLL files will become important components of major SC4 mods in the very near future.  Suffice to say, we’re entering a very exciting time in the SC4 modding community.

There is, however, one caveat with this development: these new DLL mods will only work with Version 1.1.641 digital editions of the game on the Windows platform, while the older Windows disc versions and the Aspyr macOS port (in all its guises) will not be supported.

To those users who are running those versions, this almost certainly comes as a grave disappointment.  There are, however, technical reasons that pose essentially insurmountable barriers toward bringing this new and exciting DLL-based functionality to those versions of the game, and effectively render them "legacy versions" of SC4:

 

• Back in December 2017, simmaster07 had produced a mod known as SC4MacInjector, which provided a means for DLL-based mods to be converted into .so files and run in the macOS port via injection.  Unfortunately, the changes that Apple made in macOS Catalina (10.15) effectively broke SC4MacInjector permanently, forcing simmaster07 to discontinue it in June 2020.  With Apple moving to discontinue x86 architecture support in the near future, SC4MacInjector’s days were likely numbered either way.
• With regards to the Windows disc-based versions of SC4, Microsoft’s removal of the secdrv.sys driver from Windows 10 effectively broke the SafeDisc copy protection system that EA used, thereby preventing the disc version from running (at least without complicated or legally questionable workarounds).  The fact that the disc versions’ hardcoded aspects are also differently-structured (and encrypted) complicates the prospects of providing support for it to the point of practical impossibility.

For those of you running the Aspyr macOS port, unfortunately, Apple’s constant drastic changes to macOS and their entire hardware architecture have taken that version of the game out of the running.  The only option to play on Mac with these new developments is some form of dual-booting and/or WINE with a digital copy of the Windows version of the game (which can readily be made to run on Linux).  If you happen to be playing on the Steam version, you have access to the Windows version at no additional cost, since SC4 is a SteamPlay title.  Unfortunately, with the App Store version, there is no such crossplay option available, and one will have to purchase a new copy.

In order for these developments to work directly with the Mac version, Aspyr would need to patch the game, preferably allow direct reading of .so files (the Mac equivalent of DLL files) without code injection or running afoul of Apple's "Hardened Runtime" feature.  Given that Aspyr, while updating their port to deal with Apple's myriad drastic mandatory architecture changes over the years, has refrained from even issuing an equivalent of the 20-year-old 1.1.638/EP1 patch for the Mac port, or the almost-as-old 1.1.640/BAT nightlighting patch--the odds are even longer that they would do this.

For those on the disc on Windows, acquiring a legal Version 1.1.641 digital copy is the only way to get this functionality.  Redeeming your CD Key with EA (via the EA App--EA Help can assist with this if one encounters difficulties) is one way to get one without having to buy the game again.  The other option is to wait for the GOG edition to go on sale (typical sale price is US$4.99)--since GOG's digital edition is DRM-free, it’ll be more “yours” than the disc version ever could be, as evidenced by the disc’s old DRM/copy protection scheme thwarting its use on newer versions of Windows.  (And acquiring some sort of pirated/"cracked" version is, of course, a violation of ST Guidelines, Section 5(a).)

Again, in short:

Version 1.1.641 Windows Digital Copies - Supported

Version 1.1.640 and earlier Windows Disc Copies - Not Supported (but CD Key may be redeemable for free Version 1.1.641 digital copy with EA)

macOS Port on Steam - Not Supported (but SteamPlay offers free Windows Version 1.1.641 digital copy with Steam for dual-boot/WINE use)

macOS Port on App Store - Not Supported (no option for compatible free replacement, purchase new copy)

All Other Versions - Not Supported (no option for compatible free replacement, purchase new copy)

Pirated/"Cracked" Copies - Not Supported, and in violation of ST Guidelines, Section 5(a).

-Tarkus

[Wiimeiser 452]

1 hour ago, Tarkus said:

The fact that the disc versions’ hardcoded aspects are also differently-structured (and encrypted) complicates the prospects of providing support for it to the point of practical impossibility.

Why does this differ between the versions? Is it akin to the crack protection from Spyro 3 where the checksum of the file matters a whole lot and they can be part of the data being checksummed? Or a CASC like Starcraft II, where one file affects all the other files? Or don't we know?

[rsc204 21,869]

Long and short DLLs work by injecting code, but this must be in sync with the code you are referencing to alter things.

The older versions essentially have encryption that makes this hugely more difficult but would also requiring different coding if we can get past this.

So instead of developing for multiple versions of SC4, all focus is being put on the digital versions because that’s what most folks will be using in 2024. It just doesn’t make sense to devote a lot of time and energy supporting a small % of users running older Windows versions and disc versions of the game.

[nathan67003 5]

So exactly what stops me from using simmaster07's injector if I'm still running 10.14?

[Null 45 3,140]

26 minutes ago, nathan67003 said:

So exactly what stops me from using simmaster07's injector if I'm still running 10.14?

The fact that none of the current DLLs have been compiled for for MacOS 10.14, and that the DLLs which patch the game's code in-memory to alter its behavior would not work on the Mac or Windows disk versions of the game due to those memory patches being specific to the version 1.1.641 Windows Digital Copies. Those DLL mods include things like the Allow More Building Styles plugin.

[jdenm8 362]

34 minutes ago, Wiimeiser said:

Why does this differ between the versions?

The patches work by altering the game code in-memory. The 1.1.640 EXE (which was the only other version remotely considered for support, though only very recently) not only puts the code in different places, but is encrypted. The Encryption makes it significantly harder to find the needed addresses since the EXE can't be reverse engineered. You can't patch the code in memory if you don't know where it is in memory.

I would have stressed the Encryption much more strongly than the DRM. SafeDiscShim was released at the beginning of the month, which solves the issues with SafeDisc without the legal complications or messing with driver signing. I've confirmed that the SafeDisc DRM in 1.1.640 passes validation under Windows 10 with SafeDiscShim installed. My copy immediately crashes afterwards, but that can be pinned on a dirty installation from 2012 (which hasn't been touched since 2013) that needs to be re-done.

[Girafarig 1,440]

Aspyr has been a real sore spot for us Mac players since… well, probably the very start? I should be grateful that they even patched SC4 to work on Apple Silicon (though just barely), but the matter of fact is that they're not a very good company to deal with.

EDIT since some people are confused: I've used Macs all my life. Many Mac ports (I'd say, at least for a period of time, this meant "any game not made by Blizzard") were not handled by the developer or the publisher, but by Aspyr, who were founded specifically to cater to that market segment. I have played a lot of Aspyr-ported games, especially during my teenage years, but Aspyr ports are… not good, to be honest. We all know (I think) that SC4 was unplayable for SEVERAL years, and that's just to name one. The transition from PowerPC to Intel chips was both a blessing and a curse, in that Universal Binary ports were really bad, but it allowed Aspyr to cut a lot of corners by essentially porting games as fancy WINE containers, which of course worked great(ish) until Apple switched back to Apple Silicon.

SimCity 4 got ported again (though I'd argue version 1.2.2 is still a bad port), but many other games weren't so lucky. You want to play Modern Warfare 2? Tough luck and thanks for the 20 bucks.

But hey, they have Civilization 5, so that's something, huh?

  Edited February 15, 2024 by Girafarig  
A bit of history on Aspyr

[Membrillo 56]

17 hours ago, Tarkus said:

DLL files will become important components of major SC4 mods in the very near future.

40 seconds? But I want it now!

Homer Simpson.

[nathan67003 5]

21 hours ago, Null 45 said:

The fact that none of the current DLLs have been compiled for for MacOS 10.14, and that the DLLs which patch the game's code in-memory to alter its behavior would not work on the Mac or Windows disk versions of the game due to those memory patches being specific to the version 1.1.641 Windows Digital Copies. Those DLL mods include things like the Allow More Building Styles plugin.

I'd commented on the DLL injector's page and simmaster07 said the following:

This would still work on Mojave, it's just that (1) no version of macOS supporting Apple Silicon also supports code injection, and (2) 10.14's been unsupported for a few years now and I wouldn't endorse anyone downgrading their OS to use this mod.

So apparently it does still work but only in the very specific case of someone using Steam's macOS version on 10.14; not sure how this meshes with the Windows versioning, however...I'd assume the v11revA update under Maxis Files on the STEX updates to .640? No idea.

[rsc204 21,869]

23 hours ago, nathan67003 said:

So apparently it does still work but only in the very specific case of someone using Steam's macOS version on 10.14; not sure how this meshes with the Windows versioning, however...I'd assume the v11revA update under Maxis Files on the STEX updates to .640? No idea.

So your first problem is you must have the out of date Mac Version of SimCity 4 (the 32-Bit version). If you can stop Steam automatically updating it, which I doubt. Your second problem is that 10.4 is not long for the chop in terms of Steam support, then you simply won’t be able to use Steam or SC4 anymore.

In fact to my knowledge you need the AppStore version, since you can refuse to update it. But you need to still have the old version, there is no way for new purchasers to have access to it.

The Mac version of SC4 isn’t even equivalent to 1.638 or the EP1 patch and no patches exist for it either. So even assuming the first issues didn’t apply, there is still a version mismatch preventing the current batch of .DLLs working with that version. Once more it would require decoding the memory addresses specifically for the unpatched version.

When all is said and done, such a small number of people fit into this category that it doesn’t make sense to cater for them.

Let me bottom line this, because I know it will come up again and again. If you can’t run the digital 1.641 version, you won’t get any additional DLL based mods. That’s been decided and there are very good reasons for it. It’s a case of do we support the majority (90%+) of users to bring previously thought impossible mods to the game. Even if this means leaving those with other versions behind. Or do we do nothing with the newfound discoveries because not everyone can use them. 

[masochist 111]

3 hours ago, rsc204 said:

Let me bottom line this, because I know it will come up again and again. If you can’t run the digital 1.641 version, you won’t get any additional DLL based mods. That’s been decided and there are very good reasons for it. It’s a case of do we support the majority (90%+) of users to bring previously though impossible mods to the game. Even if this means leaving those with other versions behind. Or do we do nothing with the newfound discoveries because not everyone can use them. 

This is definitely the right call. Not only is it impractical to try and cater to a tiny population of people who fit into these categories, but it's also unsafe for those who still have an OS old enough to run the old version of the game. Minimum versioning is vital to software services; you have to have a cutoff line because at some point the simple process of developing tools like the Injector becomes a much bigger hassle than its worth.

I don't blame Aspyr for this, either. It was a miracle they took on the task of porting SC4 to begin with, but it's a legacy game without support from anyone. I feel they could have done more to for the port when it was released, but I also think we would have ended up in this spot when all was said and done anyways.

Anyways, I finally bit the bullet and caught both SC4 and SC3KU on sale on GOG. All the mods, .exe commands, and saves work as intended once you move them over to the correct folder, so I don't think it's too big an ask to upgrade to that version to get the latest, greatest, and safest version of the game.

 

...also hello.

[Kurzov22 18]

I had the idea of creating these little icons one could place on a download or whatnot to indicate this kind of "weird version difference stuff", but I guess that won't be needed anymore.

It is now my understanding that all "official" ("official" meaning around here, that is) support going forward is solely for 1.1.641 (digital) for Windows only? Will [name your favorite large SC4 'super-project' e.g. NAM, CAM, etc] also follow this line of thinking?

[Ulisse Wolf 4,477]

29 minutes ago, Mayor-Kurzov said:

It is now my understanding that all "official" ("official" meaning around here, that is) support going forward is solely for 1.1.641 (digital) for Windows only? Will [name your favorite large SC4 'super-project' e.g. NAM, CAM, etc] also follow this line of thinking?

Yes.

Already CAM 2.5 would have imposed these limitations. 

[Tarkus 6,934]

19 hours ago, masochist said:

...also hello.

Great to see you around!

17 hours ago, Mayor-Kurzov said:

It is now my understanding that all "official" ("official" meaning around here, that is) support going forward is solely for 1.1.641 (digital) for Windows only? Will [name your favorite large SC4 'super-project' e.g. NAM, CAM, etc] also follow this line of thinking?

The one absolute given in the equation is that any DLL-based features are strictly the province of the Windows digital version, Version 1.1.641.  Is Version 1.1.641 going to become required to use some of these "super-projects" in any form?  As far as getting official technical support, I'd generally say yes.  1.1.641 is going to be our design and testing specification going forward, and there should generally be a way to switch over to that version at no cost, and worst case scenario (particularly App Store users), minimal cost.

Does that mean that a disc or macOS user is going to be locked out of using a mod (or a new version of one) entirely, even on an "as-is"/unsupported basis?  Are they still going to be able to use parts of it?  It depends on how heavily reliant the mod is on DLL files, and what kinds of non-DLL-based functionality is part of it.  If it's an existing mod (i.e., the NAM) that has entered a "DLL Era", generally, barring any truly drastic changes, things that worked before should still work, and anything new that is added that isn't DLL-reliant should also work, to at least some degree.

I would, however emphasize those terms, "as-is" and "unsupported".  If one runs into issues with the mod while running something other than Version 1.1.641 of the game, it will be up to that user to solve those issues on their own, and not the mod developers' responsibility to provide support.

-Tarkus

[Wiimeiser 452]

I'm curious... Would diagonal streets, RHW tunnels and disabled autoconnect, adjacent bridges, and NC streets and OWR now be possible? Or would they require more than just a dll?

[Ulisse Wolf 4,477]

18 minutes ago, Wiimeiser said:

I'm curious... Would diagonal streets, RHW tunnels and disabled autoconnect, adjacent bridges, and NC streets and OWR now be possible? Or would they require more than just a dll?

TOP SECRET

[Null 45 3,140]

18 minutes ago, Wiimeiser said:

I'm curious... Would diagonal streets, RHW tunnels and disabled autoconnect, adjacent bridges, and NC streets and OWR now be possible? Or would they require more than just a dll?

It would depend on how the game's restrictions that prevent those features are implemented.

[TheMurderousCricket 5,153]

On 14.02.2024 at 1:30 PM, Tarkus said:

one of the most recent of which allows more Building Styles

I have one particular question about this bit.

Does it mean that we actually have new iLive value(s) that stand for, I don't know, Asian, Scandinavian etc?

If I understand this right, this truly is a breakthrough... I can have better variety of buildings just by ticking building styles in-game, rather than try to create building families...

[Tarkus 6,934]

13 minutes ago, TheMurderousCricket said:

I have one particular question about this bit.

Does it mean that we actually have new iLive value(s) that stand for, I don't know, Asian, Scandinavian etc?

If I understand this right, this truly is a breakthrough... I can have better variety of buildings just by ticking building styles in-game, rather than try to create building families...

There's still a lot of discussions about the logistics of it, and particularly on things like ID values and standardization, but it is very much something that exists now, thanks to Null 45's DLL modding work.  It can be downloaded off the STEX here, and the thread for it is here.

-Tarkus

[asasnat 222]

15 hours ago, Wiimeiser said:

I'm curious... Would diagonal streets, RHW tunnels and disabled autoconnect, adjacent bridges, and NC streets and OWR now be possible? Or would they require more than just a dll?

NAM DLL (

 ) accomplishes diag streets and disabled autoconnect, as well as street tunnels. I don't see why it wouldn't be possible to make RHW tunnels as well. No comment on adjacent bridges or NC streets/OWR.

[TheMurderousCricket 5,153]

1 hour ago, Tarkus said:

There's still a lot of discussions about the logistics of it, and particularly on things like ID values and standardization, but it is very much something that exists now, thanks to Null 45's DLL modding work.

Combined with Cori's tutorial on adding new building styles this can be a very fun tool to use. I even had some success with tweaking and resizing UI fields in the building style selection box. However, I lack the knowledge to add an actual checkbox to this menu item that would correspond to a new style. Well... my first try ever editing UI.

[Shadow Assassin 336]

On 2/16/2024 at 7:46 AM, Mayor-Kurzov said:

It is now my understanding that all "official" ("official" meaning around here, that is) support going forward is solely for 1.1.641 (digital) for Windows only? Will [name your favorite large SC4 'super-project' e.g. NAM, CAM, etc] also follow this line of thinking?

 

On 2/17/2024 at 3:35 AM, Tarkus said:

The one absolute given in the equation is that any DLL-based features are strictly the province of the Windows digital version, Version 1.1.641.  Is Version 1.1.641 going to become required to use some of these "super-projects" in any form?  As far as getting official technical support, I'd generally say yes.  1.1.641 is going to be our design and testing specification going forward, and there should generally be a way to switch over to that version at no cost, and worst case scenario (particularly App Store users), minimal cost.

Just to clarify regarding @Tarkus's post - this was actually a very difficult decision to make, but considering our resources are incredibly limited (it's a 21 year old game, after all!) We have to choose our battles to fight.

Note that you'll also be able to use the Windows version in WINE, so Linux users also don't miss out. In addition, this could also be another option for people on Mac (especially as Asahi Linux gains traction - to my knowledge, it's getting support for x86 applications very soon)..

TL:DR; if you want the full feature set these DLL mods offer, in general you will need to use the 1.1.641 version of SC4.

[Jackspital 391]

This is such a momentous moment for the community. Whole DLL files have been around for a while, the recent breakthroughs will change the game completely in the future. It's astounding to me that after 20 years we're still cracking the game's code. It's a shame that physical copies may become redundant due to these DLL mods, however, the amount of new life injected into the game will help more people continue to play into the future.

I'm not sure what the conversation is these days on an open source SC4? I know that TTD was reverse engineered for modern systems etc. Could these new DLL mods mean we might be on the verge of another conversation about open source? 

[Girafarig 1,440]

10 hours ago, Shadow Assassin said:

Note that you'll also be able to use the Windows version in WINE, so Linux users also don't miss out. In addition, this could also be another option for people on Mac (especially as Asahi Linux gains traction - to my knowledge, it's getting support for x86 applications very soon)..

It seems like a bit much to ask Apple Silicon Mac users to download and use a whole OS (in addition to WINE, mind you) just to run a single game. We just lost the ability to install Windows on the new chips, I very much doubt that installing Linux is going to be very easy (especially for a beginner, non-tech-savvy user).

Now, there used to be WINE for Mac, which I used extensively but barely works at all on Apple Silicon. The paid version, Crossover, which is essentially someone crafting you a custom wrapper to run a videogame, does list SC4 on its compatibility database. But it's a pretty terrible "Installs, Will Not Run" two-star rating, so it's gonna be a while before that idea, which I find more feasible, gets off the ground.

Also, mind you, Crossover is still setting you back US$64, which doesn't sound like a lot but it's three times the cost of the actual game. And all this for something that it's not even guaranteed to flawlessly run SC4 plus however many DLLs we end up getting (WINE is kind of fiddly when it comes to DLLs and the like). 

I think this is the death knell for SimCity 4 on the Mac. Which, I guess, I'm not complaining –I got a lot of fun out of 20 bucks spent 10 years ago– but it's still sad.

[rsc204 21,869]

As one of the few who’s played SC4 on both Mac and Windows, the death of SC4 on Mac this isn’t. Because the game is terrible on a Mac the moment you want to start using mods, just awful. Now I’m not talking about simply installing the NAM here either, rather trying to play a fully modded game. So many hoops to jump through and I’m anything but a novice user. Given all the other issues the Mac version has, it’s been dead to me since I bought it.

Two options will remain for those who can’t/won’t run Windows. Either SC4 on Mac is played vanilla without mods, many folks enjoy the game without mods and they still will. Or, Mac users will have to live with the limitations on future addons. Although anything that works now will continue to do so into the future. So you’ll miss out on those new things needing DLL mods. That probably doesn’t mean no new NAM or features full stop, just those specific ones that require DLLs. Even in a scenario where one day the full NAM stopped supporting Macs entirely, you could still stick with the last legacy version that did. In this case and on an unsupported basis, I think the team would OK keeping a legacy NAM version available for that purpose.

[rsc204 21,869]

I used to run SC4 on a 2009 MacMini running WinXP on Bootcamp. OK a problem today, because of XP RAM limitations prevent using the 4GB patch/full RHW controller. But a similar setup using a cheap old Mini that supports Win7 64-Bit or newer would be simpler than f*ing around with Linux and cheap. Only problem is driver support for Intel integrated GPUs, which could be tricky considering that’s all most Mac mini’s have for a long time. The point is, if modded SC4 and all the latest features are really important to you, you’ll find a way to run Windows. And even if that means a special machine, there are cheap solutions there. Sure 100 $/£/€ is a lot in the context of the game’s price. But it’s nothing to play a game, folks spend stupid money on PC rigs to play a particular game all the time.

[Girafarig 1,440]

1 hour ago, rsc204 said:

Sure 100 $/£/€ is a lot in the context of the game’s price. But it’s nothing to play a game, folks spend stupid money on PC rigs to play a particular game all the time.

£100 is a month's salary here. Well, if you make minimum wage, that is.

And I don't think using mods on a Mac is a particularly terrible experience. Sure, EXE files are a pain and locating the Plugins folder is an adventure, but once you have located it, drag and drop will take you all the way to… well, to when you need to use JDatPacker. But it takes a long while to get there, and in the meantime, you have enough time to learn about those things.

The game's halfway there. Which is why it's sad that Aspyr won't do anything but the bare minimum so people won't ask for refunds. Alas, that's their business model and we can't do much about it, now can we?

[simmaster07 1,221]

7 hours ago, Jackspital said:

I'm not sure what the conversation is these days on an open source SC4? I know that TTD was reverse engineered for modern systems etc. Could these new DLL mods mean we might be on the verge of another conversation about open source? 

There's interest in it and some efforts have popped up occasionally, but there hasn't been a coordinated push for it, and the work that has been done is coming from a lot of different angles:

• @Null 45 has been contributing back to the gzcom-dll project and writing their own DLLs, which work from the "top down," modifying game memory and inspecting SC4's interfaces to make changes to the game logic.
• I, personally, have mostly pivoted to "bottom up" work by reverse engineering the game engine and framework components (Scion) before getting at the SC4 bits built on top of that. (And I don't exactly have the free time I did in college, so the time commitment's been pretty shaky for years now.)
• Others still have been taking a complete clean room approach (OpenSC4) and rewriting as much as they can in game engines like Godot.
• I've also gotten emails from maintainers on "Open Sims 2"-like projects -- even though it's a different game, SC4 and TS2 share a lot of internals, so there's mutual interest in whatever's happening between the two.

There's still a lot of quality-of-life changes that can be made without making a whole OpenSC4 project, so it's probably not something worth prioritizing right now. But having an active DLL modding scene helps with building up the kind of knowledge and expertise that can push a project like that forward, and I predict it'll gain more traction when other avenues for improving the game are exhausted. It's also a project that would require a lot of manpower, since SimCity 4 is a bigger game with a more complicated engine than projects like TTD and RCT2.

There would also have to be ground rules established on what a project like that should look like. For example, even if no assets like DAT files are distributed, it might not be okay to create a straight-up EXE replacement, since that could be used to circumvent copy protection, which is what got projects like Bnetd in trouble. It would also be a bad idea to try porting the game to mobile, as FreeSO tried with The Sims Online before getting a cease-and-desist. FreeSO's port would've competed with The Sims Mobile; doing that for SC4 would compete with SimCity BuildIt. EA backed off of FreeSO when that port was cancelled.

[Ulisse Wolf 4,477]

1 hour ago, simmaster07 said:

There's still a lot of quality-of-life changes that can be made without making a whole OpenSC4 project, so it's probably not something worth prioritizing right now. But having an active DLL modding scene helps with building up the kind of knowledge and expertise that can push a project like that forward, and I predict it'll gain more traction when other avenues for improving the game are exhausted. It's also a project that would require a lot of manpower, since SimCity 4 is a bigger game with a more complicated engine than projects like TTD and RCT2.

I agree that realizing now an OpenSC4 is unnecessary also because there is a lack of coordination and personnel to deal with such a project. Also only with the development of the DLL Mod are they allowing us to study how the game is structured and discovering new things that was impossible before. But still it remains an obstacle as there is a lack of tools that allow more people to investigate in the game code.

Also it must be said that currently the best approach for SC4 is a hybrid type approach where changes are made by modifying the game memory and in critical components such as the pathfinder (The traffic simulator is pathfinder dependent) have to be rewritten from scratch allowing better modifications. In addition, the only coordination center for mod DLL development is SC4Evermore's discord server although mod DLL development also depends on the feedback people provide

 

[Ulisse Wolf 4,477]

By the way, the DLL Mod statement ended up on PC Gammer

https://www.pcgamer.com/SimCity-4-modders-are-cracking-its-deepest-recesses-in-ever-greater-numbers-enabling-extensive-new-changes/