Introducing the SimCity 4 Multiplayer Project

[kegsmr 144]

Hello Simtropolis community!

I'd like to share with you something I've been working on the past few months.

As many of you may remember, back in 2018, SimCity 4 got its first real multiplayer mod, in the form of Poppy Multiplayer Regions by @jmak. Many of you may also know that the mod is now deprecated as the main servers have long been shutdown. If you're anything like me and enjoy multiplayer SimCity 4, you might be wondering these past years whether there will ever be a real successor to PMR. That successor is finally here.

These past months I've been working to revive multiplayer SimCity 4, in a project I'm now calling the SimCity 4 Multiplayer Project (SC4MP). This project takes many cues from PMR, while introducing many enhancements. Namely, the barrier of entry to joining and hosting servers has been drastically lowered. Anyone can join a server, without even registering an account, and anyone can host a server, so long as they know how to port forward and bypass firewalls (standard for almost all multiplayer game hosting). 

The code is all open source and on GitHub. And you can download the latest release of the client and/or server and start playing multiplayer SimCity 4 today. I also plan to put a more complete version on STEX in the coming months. There are still a few features planned and certainly some bugs that still need to be resolved.

For now, I would like to list off some of the features of SC4MP that make it the most complete SimCity 4 multiplayer mod to date:

• "Sandboxed" launch directory: like PMR, the SC4MP launcher loads a server's plugins and regions to a special directory specifically for SC4MP, meaning playing on multiplayer will in no way interfere with your singleplayer plugins and regions.
• Claims system: SC4MP uses the same claims system as PMR, with the added feature now that servers can set a "claim duration," after which the claim on the city will expire and other players will be able to claim the abandoned city and continue where the previous player left off. This allows for dynamic region gameplay even late into the lifecycle of a region.
• Godmode filter: by default, servers disallow saving until a player has established a city. This means the cities that appear in the region view are the cities that have already been claimed. Every tile that appears unoccupied in the region view is actually unoccupied.
• Multiple regions per server: servers can host multiple regions at once. Players can switch between them without restarting their game.
• Easy regions refreshing: refreshing regions in SC4MP requires zero interaction with the launcher. Simply load the region titled "Refresh..." and the launcher will do the rest of the work for you. The launcher is able to recognize when you switch into the refresh region by monitoring and parsing the "SimCity 4.cfg" file.
• Support for any region configuration: the SC4MP server is built to interpret save pushes from any region configuration. It does so using a dual-filter system. The first filter eliminates all tiles that do not border all the other tiles. The second compares checksums of the datetime subfiles of the incoming saves and compares them to the ones stored on the server. The second filter only accepts saves in which the in-game time has advanced. This however comes with the caveat that sometimes you are required to unpause your game to save.
• Custom plugins: the SC4MP Launcher allows local plugins to be loaded in alongside server plugins without any modification to your singleplayer plugins directory. Simply specify your singleplayer plugins directory in the launcher settings and your plugins will be loaded in the next time you join a server, so long as that server allows custom plugins.
• Cache: the SC4MP Launcher keeps a rolling cache of files downloaded from servers, sorted by checksum. This allows for fast loading times on servers which you have previously joined. The size of the cache is configurable to save disk space.
• Easy savegame retrieval in the event of server outages: the savegames from the last failed save push are automatically copied into the "downloads" subdirectory of the regions directory when connecting to a server for easy importing in-game.
• Recurring server backups: the SC4MP Server comes with a recurring backup system built-in. The backup system comes with a configurable backup interval and is designed to save space as much as possible.
• Server browser: the server browser allows players to view the list of active servers and connect to them seamlessly. Servers can be sorted by their ping, download size, claimed area and more.

Here are the downloads on GitHub:

• client: https://github.com/kegsmr/sc4mp-client/releases
• server: https://github.com/kegsmr/sc4mp-server/releases

The official server is at:

• host: servers.sc4mp.org
• port: 7240

Stay tuned for more updates. And check out the website: 

• https://www.sc4mp.org/

[kSlank 153]

Thank you!

[nos.17 5,264]

Hi just had a chance to look at this - super impressive!

On 7/15/2023 at 12:53 AM, kegsmr said:

Custom plugins: the SC4MP Launcher allows local plugins to be loaded in alongside server plugins without any modification to your singleplayer plugins directory. Simply specify your singleplayer plugins directory in the launcher settings and your plugins will be loaded in the next time you join a server, so long as that server allows custom plug

This is super cool. I remember years ago (far before PMR) I was a part of some multiplayer coop that worked through syncing plugins and regions through Dropbox (may have been this?). Anyways the big drawback was there could only be a single set of plugins everyone had to use, and there was quite a process to get something new added that everyone had to approve of. Having your own plugins would be very nice. Looking forward to trying it out soon.

[AsimPika3172 1,156]

Nice!

[Flann 1,709]

Really cool, thank you for making this.  I am looking forward to trying it out.

[QuantumChicken 89]

I am running SC4 Deluxe off of Windows 98Se(WIndows 11 is just like Vista compatibility and stability wise). Is it possible to still connect to my dedicated server through that dinosaur of an OS?

[kegsmr 144]

14 hours ago, KillrChicken said:

I am running SC4 Deluxe off of Windows 98Se(WIndows 11 is just like Vista compatibility and stability wise). Is it possible to still connect to my dedicated server through that dinosaur of an OS?

I wish. Unfortunately the compatibility is dependent on the python version, and the version the launcher uses is 3.8.10. This version is compatible with Windows 7 and up.

 

It would be possible (but very tedious), to rewrite the launcher on an older version of python, or to a different language entirely. I'm going to be writing API docs soon, so if someone realllly wants to do that, they can.

[Azeda 14]

How much space does this require on the harddrive..?

[Propfam 2,310]

49 minutes ago, Azeda said:

How much space does this require on the harddrive..?

Very small, under 10MB

[dipsas 14]

I don't even know where to begin. This mod has breathed new life in the game for me. I am addicted to it. If you would like to connect a city and play, my discord is Greasi.

[Homgr 5]

Nice project but, need a auth system for token errors, computer changing.

[ellis896 20]

Hi. Tried to give it a go but this stops me to go forward.

 

 

[kegsmr 144]

On 2/1/2024 at 2:02 PM, ellis896 said:

Hi. Tried to give it a go but this stops me to go forward.

 

 

Hi, I would try downloading the zip file instead and installing manually if the installer isn't working.

[ellis896 20]

On 09/01/2024 at 7:32 PM, kegsmr said:

Hi, I would try downloading the zip file instead and installing manually if the installer isn't working.

Hi, thank you for reaching back. I have tried that too. At some point I could see the servers and when tried to connect no worlds would appear and nothing would happen.

I have deleted everything and started from the beginning and then the above were shown. I may give it another go at some point. Would be nice for a multiplayer game.

[kegsmr 144]

On 11/1/2024 at 3:14 PM, ellis896 said:

Hi, thank you for reaching back. I have tried that too. At some point I could see the servers and when tried to connect no worlds would appear and nothing would happen.

I have deleted everything and started from the beginning and then the above were shown. I may give it another go at some point. Would be nice for a multiplayer game.

Hi, sorry for the delayed response. If you'd like, you can join the discord server and we can get to the bottom of this. Use the #help channel.

[EffTheGrid 3,728]

Hey, exciting stuff! I downloaded the launcher and tried to join the server, and got error 740.

What causes this? Seems like the game won't start from the launcher---SC4 is not running in task manager after the region downloads.

I'm playing the GOG version, and after the launcher prompted, me I selected the correct load destination.

What else can I do to get up and running?

Thanks

[kegsmr 144]

10 minutes ago, EffTheGrid said:

Hey, exciting stuff! I downloaded the launcher and tried to join the server, and got error 740.

What causes this? Seems like the game won't start from the launcher---SC4 is not running in task manager after the region downloads.

I'm playing the GOG version, and after the launcher prompted, me I selected the correct load destination.

What else can I do to get up and running?

Thanks

Hello, have you tried running the launcher as administrator? I've never encountered this issue myself, but I know some other people have had similar problems, and running the launcher as administrator solved them.

[EffTheGrid 3,728]

34 minutes ago, kegsmr said:

Hello, have you tried running the launcher as administrator? I've never encountered this issue myself, but I know some other people have had similar problems, and running the launcher as administrator solved them.

Thanks so much that worked!

Welcome to Corner Harbor

I am so excited!

[EffTheGrid 3,728]

Just a follow up question, and forgive me if I've missed it. Is there a place to journal cities within these multiplayer regions? It would be nice to have a dedicated WIP/showcase area on the site so we can show off our work. I'm excited to be up and running!

Corner Harbor is booming!

Who are my neighbors over in Antokia and South Haven?

I'd love to work together to plan some regional connections, if you'd like.

 

[kegsmr 144]

6 hours ago, EffTheGrid said:

Just a follow up question, and forgive me if I've missed it. Is there a place to journal cities within these multiplayer regions? It would be nice to have a dedicated WIP/showcase area on the site so we can show off our work. I'm excited to be up and running!

Corner Harbor is booming!

Who are my neighbors over in Antokia and South Haven?

I'd love to work together to plan some regional connections, if you'd like.

 

I'm a big fan of your road design. We do have a channel on the Discord server for showcasing cities. But on ST, I wonder if I could create a City Journal that other people can contribute to. If not, I could make a separate showcase thread. 

You can also ask on the discord server who your neighbors are, and you can coordinate neighbor deals with them. Come to think of it, I should also add a way of messaging other cities through the launcher. That will come in a future version.

Glad you're enjoying the mod so far.

[kegsmr 144]

Also, if any STEX admins are lurking this thread and are interested in possibly integrating the multiplayer mod into the website somehow, I did create a web API that provides you the server list in JSON format: http://api.sc4mp.org/servers

I used this to add a live server list to the SC4MP website: http://www.sc4mp.org/

(The stats for official #2 is wrong. I need to fix some bugs in the stat calculation)

You can find all the JavaScript necessary to read the data in the website's source code.

[ellis896 20]

On 15/01/2024 at 1:14 AM, kegsmr said:

Hi, sorry for the delayed response. If you'd like, you can join the discord server and we can get to the bottom of this. Use the #help channel.

I have re-downloaded the files and something is happening by the looks of it.

If it fails again I will join to find the solution.

[EffTheGrid 3,728]

3 hours ago, kegsmr said:

Glad you're enjoying the mod so far.

Enjoying myself is an understatement. This is a very fun new way to play! And I love the way I can launch multiplayer mods separate form my regular plugins.

Also very easy to use. Within 10 minutes I was up and running.

3 hours ago, kegsmr said:

If not, I could make a separate showcase thread. 

I'd personally love that. I think it will generate a lot of buzz for what we are doing. Plus the cities look really cool and deserve a spot to hang on the wall. Discord is cool and useful but it would be better imo to have it right here as well, separate from the support thread.

Thank you for all the work you put into this. I think it will become really popular! l could see this mod going "viral" in the community because of how cool and interesting (and very easy to use) this is.

You've successfully done what SC2013 tried and failed to do with online multiplayer, as well as revolutionized the way people can share their plugins folders. Battles we've been on the losing end of for years!

This also provides the opportunity for creators to host entire showcase regions. Imagine uploading your entire legacy region with plugins as a viewable, interactive city journal. 

You've created a whole new game! Sincere thanks for the doors you've opened. <3

[kegsmr 144]

2 hours ago, EffTheGrid said:

Enjoying myself is an understatement. This is a very fun new way to play! And I love the way I can launch multiplayer mods separate form my regular plugins.

Also very easy to use. Within 10 minutes I was up and running.

I'd personally love that. I think it will generate a lot of buzz for what we are doing. Plus the cities look really cool and deserve a spot to hang on the wall. Discord is cool and useful but it would be better imo to have it right here as well, separate from the support thread.

Thank you for all the work you put into this. I think it will become really popular! l could see this mod going "viral" in the community because of how cool and interesting (and very easy to use) this is.

You've successfully done what SC2013 tried and failed to do with online multiplayer, as well as revolutionized the way people can share their plugins folders. Battles we've been on the losing end of for years!

This also provides the opportunity for creators to host entire showcase regions. Imagine uploading your entire legacy region with plugins as a viewable, interactive city journal. 

You've created a whole new game! Sincere thanks for the doors you've opened. <3

Thank you!! Here's the forum thread:

 

[EffTheGrid 3,728]

Hey, I think my plugins are not loading properly. How do I make sure I have NAM in the megaregion?

[kegsmr 144]

1 hour ago, EffTheGrid said:

Hey, I think my plugins are not loading properly. How do I make sure I have NAM in the megaregion?

The megaregion doesn't come with the NAM, but you should be able to load in your singleplayer plugins folder in the launcher settings under "General".

[kegsmr 144]

The latest version of the launcher is out now, featuring automatic updates, a game overlay, and estimated loading times, among some bug fixes.

You can get it on STEX here: 

 

 

[CorinaMarie 29,899]

On 1/17/2024 at 1:19 PM, kegsmr said:

Also, if any STEX admins are lurking this thread and are interested in possibly integrating the multiplayer mod into the website somehow, I did create a web API that provides you the server list in JSON format: http://api.sc4mp.org/servers

I've been away for a couple of years and am just now catching up with posts and projects I've missed.

What would be the advantage of integrating with the ST server? (As compared to how it all seems to be working fine as you have it.)

[kegsmr 144]

59 minutes ago, CorinaMarie said:

I've been away for a couple of years and am just now catching up with posts and projects I've missed.

What would be the advantage of integrating with the ST server? (As compared to how it all seems to be working fine as you have it.)

Oh the API is just a way to display the server list on a website. It's how I display the server list on https://www.sc4mp.org/.

If anyone is interested in displaying it on another website, maybe even ST or SC4E, you can parse the JSON at https://api.sc4mp.org/servers in JavaScript and display it on a webpage. The API pretty buggy and unreliable right now but I'm working on improving it.

Also planning on making a custom URL scheme, probably `sc4mp://<host>:<port>` that will be associated with the launcher when you install it, so you can have join buttons on a website which open up the launcher and connect to a given server (same way Roblox works if you've ever played it).