EN_Devkit
The Liberation Devkit mission.sqm contains all needed markers etc. to create a new Liberation map. In this article I'll explain what each marker does and what you need to do with them. If you've never ported a map before, I'd highly recommend taking a look at one of the dev-made Liberation missions in the editor to see what a finished map port should look like.
To start you should just open the devkit in the editor. Mark everything and copy it. Then you open the map you want to finish for Liberation and paste it in there, then you just have to adjust the things which are descibed below.
Spawn grasscutters for the basic mission functionalities.
Spawnpoint for players if they spawn at the startbase (on the Freedom for example). Also the camera target for the first flyby of the intro cinematic.
Spawnpoint for the Huron transport helicopter.
Spawnpoint for the first FOB container at the start of the campaign.
Spawnpoints for the starting Little Birds. You can copy paste this one after you placed it to create multiple spawnpoints. So if you want to provide 3 Little Birds at the start you place three of them via copy/paste. Just ensure, that they're then named littlebird_0, littlebird_1 and littlebird_2 (which will happen automaticly if you copy/paste the 0 one)
Used similarly to the littlebird_0 spawnpoint, but for the boats at start. You don't have to place them if you don't want any boats at your starting area.
Mod specific things
This building has the variable declaration for the medical facility attribute in its init line. Place that building at the starting point to provide ACE players a place where they can heal their friends (if they play with the provided userconfig from our community). You can also use a medic tent or similar which may fit better in your setting. Then you have to copy the code from the init to the new building.
Basic map markers
Place this marker at your starting base for the players.
This marker should be placed near the huronspawn. It will adjust automaticly at mission start, but placing it directly near the spawn will avoid a weird "jumping marker" at mission start.
Invisible and very important markers
At this invisible marker the "preview objects" will spawn during building etc. So you should place it somewhere where players wouldn't see it and on a nearly flat ground. Mostly it's placed near the spawn area (group 6) just outside the trigger zones at a suitable position.
The spawn point for the enemy air vehicles which may come as reinforcements, etc. You should (via copy/paste) place about 8 - 10 of them on the map. Common places are at the edges of the map and about 2 - 3 on each side. You should keep a "safety distance" in the area of the startbase of about 3 - 4km. Just have a look at the finished map to get an idea maybe.
These markers can be the most "annoying" ones to place. With these markers you set positions where secondary missions, battlegroups, reinforcements and also "preplaced start FOBs" will be placed. So you will have to place around 100 - 150 of them mostly all across the map. Keep in mind when placing them, that they should be on flat terrain with about 50x50m size as there will be also spawn the enemy FOB templates for FOB hunting. It should be best to have a look at finished maps to get a feeling where and how many you should place around your map.
Sector map markers which can be copied once and than pasted on the suitable positions.
With these markers you define where the Radio Towers will spawn. At each marker position there will spawn a Radio Tower inGame, so no need to have a look for towers on the map. I've provided also a area marker in the devkit which shows the range of the radio towers for showing enemy map markers and also provide reinforcement capabilities to sectors within the Radio Tower range. Personally I place the "range help markers" around the map, so they cover all terrain and the ranges of the towers will overlap sometimes. Also keeping some capitals in a overlapping area of 2 - 3 towers, so that players can't cut the capital sector from any reinforcements by only taking one tower. After I've placed the "help markers" I copy the tower marker to the clipboard, delete a help marker and set via paste a tower marker directly on the center of the deleted help marker. You don't need to rename the marker, this will happen automaticly to mission start. So all Radio Towers should have the marker text Radio Tower.
Markers for the military bases which also lock certain vehicles. Place them on military camps which are preplaced on the map first. You should have at least 20 military sectors on the map to have enough for the locked vehicles. If there aren't enough military sites on the map you could place some basic custom structures via the editor and place the military marker there. These markers have to be named after placing individually.
You define the position of "capture" sectors, commonly named "Cities/Villages" with these markers. Most maps typically have enough cities/towns already named on the map, so just place these markers in the center of these towns. You should have at least 30 capture markers scattered around your map.
Placed on "industrial" areas on the map. They will provide sectors with all production capabilities, so you should have at least 20 of them on the map. These sectors shouldn't be too clustered together, otherwise they make too easy of a target. You should have at least 400m distance between factory markers to avoid issues with factory storages.
These are the main objectives for a Liberation campaign. The players have to liberate each capital sector to win the campaign. So you should have about 6-8 capital sectors on the map. If not already too crowded, these are best placed on the largest cities on a map. To keep the game interesting the capitals should be spread out across the map, even if it means making a larger city be a simple capture town and a smaller town be a capital. You don't want players winning the game by only taking a small portion of the map.
The respawn area or "debug zone"
All objects here should always be moved by selecting all of them first. Just to be sure that all linkings will stay and the units are still in the triggers. You can change the playable units, but I would highly recommend to just change the unit type on the unit directly instead of delete the old one and place a new one, so you can be sure you don't break anything. Basically changing the unittype from vanilla to a rhs classname for example is pointless. The players will choose their loadouts from the arsenal, no matter what they're wearing at the start. Only if you change to OPFOR it would be senseful, sure. But you could change some of the units from normal riflemans to medic or engineer class for example, if you like. All "spawn units", triggers, modules, etc. should be placed (like the ghost_spot) at an mostly flat area and where nothing other could influence the spawning etc. So best a lonely island somewhere far away of the main island or on the edge of the map.
After finishing the creation of the mission.sqm you're nearly done. Next you have to copy all files from the missionframework folder inside the folder where your mission.sqm is located. Then use a program like PBO Manager or PBO View to compress the folder to a pbo. That one into the mpmissions folder of your ArmA 3 client or server and you're good to go.
Have Fun and feel free to ask for further help in our Liberation Discord.