A split save file is a map which is divided up into different segments.
Each segment can be edited & saved individually, without affecting the other parts of the save file.

Split save files can then be merged & combined together, taking all the sub-segments and turning them back into one single map.

This has a few main uses:

• Dividing up large maps for editing - If you are working on a big map and want to focus on editing smaller areas, you can split up the save file. You can then load only one smaller part of the map without needing to load the entire thing. E.g. if you have a city in your map that you want to detail, you could split the city into its own sub-segment, then edit just the city, and re-combine the save once you're done. This saves on long loading times for large maps.
  
  
• Collaborating with other people - If you split a map into segments, you could then share out the save file to other people, who can then edit one segment each. Each person can save their changes individually, then when you want to re-combine the map you can grab the individual saves back from everyone who made changes. Since people are only editing one segment each, their changes wont overlap and you can combine them all!
  
  
• Improve performance on low-end PC's for large maps - If your PC struggles to run larger maps, you can use this system to create segments of your map one-by-one, and then only combine them at the end. This means you can create a map much larger than what your PC can handle without needing to have the whole save file loaded in one go.

In this example, I'll show step-by-step how to take a pre-existing save file and split it into multiple different segments.

Say you have a map like the Santa Fe, and you want to split it into its two skyboxes (the desert and the canyon areas). You can use the split save file system to do this.
Once you have split the map into two segments, you can edit each one individually without affecting the other.

Firstly, load the Santa Fe map and save a local copy.
You can load it from the "pause menu -> official maps -> main maps" menu:



Save a local copy using the menu "pause menu -> new save -> save":



Now that you have a local copy of the map saved, go to the "pause menu -> Manage saves" menu.
You can now open the "Advanced save options" menu:



From here you can view all of the "segments" of the save file.
Since this is a regular non-split file, it will only show "Combined" and "Base".

The "Combined" option will load all of the segments together in a temporary save file. There will be more info about this later in the guide.

The "Base" option refers to every part of the map which is not included in a seperate segment. Since this map has no segments, the "Base" save file contains the entire map.

To create a new segment, click on "add new" and call it "canyons":



The next step is to define what this new split save file contains.
Our goal is to divide the canyon side of the map (and its skybox) into it's own split file, so start by clicking on the "Add bounds box" option and covering the whole canyon area:







All the props inside these "bounds boxes" will be selected. Make sure to cover the whole area you want to include in the new split save file.

Next up, there are a couple of other things we want to enable.
Firstly, tick the "Include QuickTerrain" option:



Enabling this option means that the terrain 3D model will be included in both the "Base" and split save file, which will make editing things much easier. When the split segments are re-combined again later it will automatically just keep one copy of the terrain.

Secondly, we want to include the entire "Canyon" skybox.
Select it in the "Skybox regions full" list (it will be on the second page):



Enabling this will mean that the whole canyon skybox will be included in this split file, regardless of whether it fits into the bounds that we added to the map.

This option is very useful when you have multiple skyboxes that overlap each other, you can include the props in a skybox even if they overlap other parts of the map!

Next, simply click the "save segment and reload map" button.



This will create a new save file for just the parts of the map you have chosen. Afterwards, it will load the "Base" segment of the map, which now no longer contains the segment you've removed:



As you can see, all of the selected props around the canyon area are removed, but the rest of the map remains. This is the "Base" segment of the map now.

Now that you've made a new split segment, you can load it and have a look.
Go to the "Pause menu -> Manage saves" menu, and you will see that your save file now shows up as a "Split save file". Click on "Load" and choose the new segment you've made from the list:





When you load this segment you should see just the canyon area, with the rest of the map missing:



Excellent! You've now split the save file into two parts.
You'll also see that the whole canyon skybox has been included if you go into miniature mode:





When you have this split save segment loaded you are free to make edits and new additions and save them. Saving will only overrite this segment! The rest of the save file (the base segment) will not be affected.

For example, place some new props down and then save (pause menu -> QuickSave):





These changes are now saved in the canyon split save.

You can low load the combined map again to merge the "Base" and "canyon" segments.
To do this, click "load" on the save file again, but choose the "load combined map" option:



This will load all segments together, and you will see your new changes mixed with the rest of the map:





When you have a combined save file loaded it behaves a bit differently to a normal save file.
It only exists temporarily. You can load a combined save file to view how all the changes you've made to the individual segments look together.

If you want to save the combined map you have two options, you can make a new save file with a different name (making a copy of the map) E.g. "Santa Fe merged", you can do this from the "Pause menu -> Save game":



Making a new save file like this will not override the old split file, it is a new copy with a new name and save file.

If you want to combine the save file and override the original, you can do this in the "pause menu -> manage saves -> advanced save options -> combine and merge save file":



This will completely remove the split segments, and you will not be able to reverse this step.
It is recommended that you only do this option if you have no intentions of editing the map in segments, and only want to add final touches that requite the full map to be loaded in one go.

At all times it is highly recommended to make manual copies of your save files before doing things like splitting and merging save files!

The other main use for save file splitting is to enable a group of multiple people to work on a map together without overriding each other's changes.

You can split a map into multiple segments, then have each person only edit one segment each.
When they have made changes to their own segment, you can grab the save file back from them and update the original copy. This section of the guide will explain how to do this!

Firstly, let's start with an example of a bare-bones map with just some framework.
Block-out the rough shape of your map, along with any major track connections. You'll want to make sure that any track that crosses between different segments of the map is in place before you split the map up!



Create a new save file for this map:



Our first goal is to split this map into a few different segments, these will be:
- Forest
- Yard
- Mountains



As described in the previous section, to create a split save file firstly go to the "pause menu -> manage saves -> advanced save options -> create split save file" menu.

From here you can add a new segment. Call this one "forest".
Place the bounds boxes around the green forest area, and then click "save segment and reload map" button.



The map will reload and you should see the forest area removed (it has been added to its own separate save file).



Next up we can make the rest of the segments, like the "yard" and the "mountain" areas:



Once you have made all these segments, they will appear in the popup load list when trying to load the save file.
For example, if you wanted to edit the "yard" segment, you can click on "pause menu -> manage saves -> load -> yard":



It should look something like this:
(just the yard area on its own)




To collaborate on this newly split map, you will need to access the save files directly.
You can easily open the save file folder from the "pause menu -> manage saves -> open save folder" button:



This will open the save's folder, which should contain a few different save files for each segment:



To share this with someone else, copy the whole folder for the save file.
In this example, it is called "collab map"
Copy this folder, and send it to your fiend. They need to then add it to their own "saves" folder:
Depending on where you have Steam installed, your save folder should be somewhere like:

C:\Program Files (x86)\Steam\steamapps\common\Rolling Line\Saves



Your friend can now load this map on their own PC.

Lets say for example that they want to extend the yard, without editing rest of the map.
Firstly, they should load the "yard" segment of the save file:





They can add new props, track, etc and then save their changes:





Since they are editing just one segment, only that single save file will be modified.
In this case, it was the "Yard" segment.

Open the save folder again, and find the "Save_yard.txt" file:



Send this newer copy of the file to the original map owner.
They can then replace the older copy with the newer copy to include your new changes!

You can continue this process as much as you want, with different people each editing their own segment of the file and sending their updated save files back to the original owner.

Make sure to only replace the save file of the segment that was edited! Don't override them all!
E.g. if someone has worked on the "forest" segment, they should only send you the "save_forest.txt" file, and if they worked on the yard, they should send you the "save_yard.txt" file.

For another example, lets say that someone else wants to add some scenery to the "forest" segment.
Just like before, send them a copy of the whole save's folder (including all the segments) so that they can edit the map themselves.

They should then load the "forest" segment, and start making their changes and save them:





They can then also open their own save file folder and send you the "save_forest.txt" file:



Now with both of the newest copies of those files, your own version of the map should include all of the other people's changes:



Once you have all the up-to-date files, you can load the combined map yourself and see the new changes!





And that's all there is to it!
Simply keep an up-to-date copy of the individual save segments that each person is working on. When the whole map is complete, you can combine the save file again and upload it to the Steam Workshop.

For those interested, here is how the split save system works under-the-hood.

Basically all the game needs to recognize a save file as a "split save file" is whether there are multiple save.txt files in the save's folder, and it uses the name suffix on each file to name each segment.

E.g. if a save folder contains:

- save.txt
- save_kaikoura.txt
- save_picton.txt
- save_ward.txt
- thumbnail.png

The game will automatically treat this as a split save file with the segments:

- base
- kaikoura
- picton
- ward

In-game you can load each of these segments individually, or combined. No extra steps necessary!
Note: All save files must contain a default "save.txt" with no suffix in the filename. This file will be treated as the "base" segment of the split file.

These save files don't even need to be from the same map, you can throw any files you want in there. This can be used to combine two entirely different save files together if you want.

E.g. if you wanted to add two whole maps together into the same save file, you could do this:

- save.txt (copied from one save file)
- save_paste.txt (renamed copy of the "save.txt" file from another save)

You can then load this combined in-game to merge the two files.
Note: If both maps have their own unique QuickTerrain model, then only one QuickTerrain will be used in the merged file.