ALiVE.OS · ALiVE 3 Development
Persistent Craters
Shells, rockets and bombs leave craters that stay, and the big ones dig into the ground.
New · ALiVE 3
ALiVE 3 is in active development. This briefing describes work in progress, and the behaviour it covers is subject to change as testing continues. Check the changelog at the foot of the page for what has moved recently.
On this page
Overview
What Persistent Craters does
Persistent Craters is a single Eden module that makes explosions leave their mark. Mortar rounds and rockets leave a scorched crater mark on the ground. Artillery shells, from 155 mm up, and bombs also lower the ground under the blast into a bowl you can take cover in. Every player sees the same craters, including players who join later, and the craters are kept over a save. Place one anywhere; it syncs to nothing.
Craters come only from rounds that really go off in the world, fired by players, AI near players, the server or a headless client. Fights between virtual (unspawned) profiles have no rounds, so they leave no craters. The module keeps places that matter clear: nothing on roads, runways, buildings, FOBs or the AI Commander's military objectives, and only a mark, never a dug crater, in towns, civilian objectives, beside a road or near a building. Once the cap is reached the oldest crater fills back in, and the ground goes back to exactly its old height.
How it works
What gets saved, and when
ALiVE writes a campaign to disk when an admin uses Server Save and Exit, and every few minutes when Autosave is set. Player state can also be written on a timer of its own.
- Set upPlace ALiVE Data and leave Database Source on Local. Cloud is the old War Room service, which is offline, so with Cloud nothing is saved. Set Persistent to Yes on each module whose state you want kept: ALiVE Virtual AI System, Military AI Commander, Military Air Component Commander, Military Logistics, Military Close Quarters Battle, Military IED Threat (Persist IEDs) and Player Command/Control (C2ISTAR) (Persistent Tasks). All of them start at No. Player FOBs is the exception: its Persistent starts at Yes, and without ALiVE Data it saves to the server's profile instead. Persistent Craters works the same way: its Keep craters over a save starts at Yes. For players, place ALiVE Player Options and set Save to Database to Yes. Persist By there picks who the save follows: Player (the default) or Slot.
- Where it goesInto the Arma 3 profile of the machine running the mission: the dedicated server, the host, or your own PC in singleplayer. Each save is named after the mission and the map, so a copy on another map starts a campaign of its own.
- While you playEach player's kit, health, position and score are copied into the server's memory every 5 minutes and when they leave. With Save to Database on and ALiVE Data on Local, Auto Save Interval also writes players to disk. With Autosave set on ALiVE Data, the whole campaign is written as well, every 5, 10, 15, 30 or 60 minutes, the same as Server Save and Exit writes it, and the mission carries on. It needs Database Source on Local.
- SavingAn admin, or a player whose Steam UID is in Save Server Allowlist on ALiVE Data, picks SERVER SAVE AND EXIT (Admin Only) in the Esc menu, or ALiVE SAVE (Single Player) in singleplayer. Everyone else is saved and sent out first, then the save is written and the mission ends.
- What it writesPlayers (with the AI they recruited, which can still be dismissed after a load), the virtual forces, the commanders (with their minefields and high value target), IEDs, CQB and Military Logistics where Persistent is on; the air commander's aircraft and the tasks players made in C2ISTAR, which only load back where Persistent is on; moved objects, and vehicles bought at a Recruitment point where Player Logistics is placed, which keep their buyer and can still be dismissed; markers and reports; roadblocks and outposts; and the date with Save Mission Time on.
- Anything else saves nothingA mission that ends on a trigger, a win or a loss, or a server that's shut down, writes nothing more than the last save. Player Exit only updates that one player in the server's memory.
- Next startEach module with Persistent on loads its own save. The virtual forces come from the save instead of the placement modules, so placement modules you've added or changed since don't add any troops until you start a fresh save. Players get their saved state once the server has finished loading, matched by Steam ID by default. With Persist By set to Slot, the state belongs to the unit's Eden variable name instead, so whoever takes that slot gets its kit, position, vehicle and health; name, face, rank and scores stay out of it. A slot with no variable name falls back to the player's ID. Saved markers and reports show for every player once their side is known.
- Starting overAs admin, open the ALiVE menu and go to Module Settings, then Persistent Data. Clear Current Mission's Data removes this mission's save on this map, and Wipe ALL ALiVE Data removes every mission's.
Worth knowing. Plan every restart around SERVER SAVE AND EXIT: a restart without it loses everything since the last save, apart from what Autosave or Auto Save Interval wrote. Map markers, SPOTREP, SITREP and PATROLREP reports and objects moved with player logistics are saved without anything to switch on, and so are roadblocks and outposts unless Save Roadblocks/Outposts is off. Autosave is off by default; with it on, a crash only loses what changed since the last autosave. Player FOBs keeps its own saves: every Save Interval (60 seconds by default) once something has changed, and straight away when a FOB is deployed or taken. Persistent Craters saves every Save interval (120 seconds by default) once a crater has changed, and with the autosave and SERVER SAVE AND EXIT.
Capabilities
What it handles
The blast decides what it leaves
Mortars and rockets leave a crater mark. Artillery digs a crater, and bombs dig a bigger one, half as deep again. A bigger hit on an old crater digs it deeper, never shallower. Bullets, smoke and flares never leave anything.
Roads, bases and buildings stay usable
No crater on a road, runway, taxiway or building, within 8 m of a building, inside a FOB or in an AI Commander's military objective. Towns, civilian objectives, ground beside a road or near a building, across a trench or near sea level get a mark only.
Multiplayer and late joiners
Hits from players, the server and headless clients all count. Each crater is dug once on the server and shows for every player, including those who join after it was made.
Kept over a save
Craters are saved through ALiVE Data when the mission has it, otherwise in the server's profile, on the save interval, with the autosave and with SERVER SAVE AND EXIT. Nothing is saved until the old craters are back in, so a slow start can't wipe them.
A barrage can't flood the server
One player's machine can send at most 30 hits in ten seconds, and the server digs at most 8 a second; the rest wait their turn. The cap (150 by default) keeps the number of craters down, filling in the oldest first.
How to use it
Getting started
- Place the moduleDrop one Persistent Craters module anywhere on the map. It syncs to nothing, and only the first one placed is used.
- Pick what countsSmallest hit that leaves a crater is Mortars and rockets and up by default. Pick Grenade launchers and up for more marks, or Artillery and bombs only for fewer.
- Decide on diggingDig the ground is on by default, with Crater depth (metres) at 0.6. Turn it off for marks only, with no change to the ground.
- Keep them over a saveKeep craters over a save is on by default. Add ALiVE Data to the mission to save through it; without it the server's profile is used.
Settings
Every setting, and what it does
These settings decide which hits leave a crater, how deep the big ones dig, how many are kept and whether they're saved.
Quick setups
Marks only, no change to the ground
- Dig the ground: No
Every hit that counts leaves a crater mark, and the terrain is left alone.
A battlefield that shows every grenade
- Smallest hit that leaves a crater: Grenade launchers and up
Grenade launcher rounds leave a mark too. Raise Most craters kept so they don't fill in too soon.
Craters for one mission only
- Keep craters over a save: No
Craters still stay for the session, but a loaded game starts without them.
General
6 settings
Choices: No / Yes
Writes what happens to each hit to the server's RPT, including why a hit left no crater or a mark only, and marks every crater on the map.
Choices: Grenade launchers and up / Mortars and rockets and up / Artillery and bombs only
The smallest blast that leaves anything. Bullets, smoke and flares never do.
AffectsOnly artillery and bombs dig the ground, whatever this says; smaller hits leave a mark.
When there are more than this, the oldest fill back in and the ground returns to its old height. 1 to 2000.
Choices: Yes / No
Artillery and bombs lower the ground under the blast. No leaves a crater mark only, for every hit.
How deep artillery digs. Bombs dig half as much again. 0.2 to 1.2.
AffectsShows only with Dig the ground on.
No digging this close to a building, a crater mark only. Within 8 metres there's no crater at all. 8 to 200.
Persistence
2 settings
Choices: Yes / No
Saves the craters with the mission and puts them back on load. Uses ALiVE Data when the mission has it, otherwise the server's profile.
Saved this often when something changed. The autosave and SERVER SAVE AND EXIT always save. 10 to 3600.
AffectsShows only with Keep craters over a save on.
Recent work
What's changed lately
- New modulePersistent Craters is new: shells, rockets and bombs leave craters that stay, and artillery and bombs dig the ground. Find it with the other ALiVE modules in Eden.
Status
Where it stands
Marks and dug craters
Mortars and rockets leave a mark, artillery and bombs dig the ground, and a filled crater puts the ground back to exactly its old height. Tested on a dedicated server with a player and a headless client.
Saving
Craters come back the same after a restart, through ALiVE Data or the server's profile.
No craters from virtual fights
Fights between virtual (unspawned) profiles fire no real rounds, so they leave no craters. Only rounds that go off in the world make one.
Testing
How you can help
Place one Persistent Craters module anywhere (it syncs to nothing) and set Debug to Yes, which marks every crater on the map and writes each hit to the RPT. Fire mortars or rockets at open ground for marks, then call in artillery or drop a bomb for a dug crater. Try a road, a town, a FOB and an AI Commander's military objective to see them kept clear or given a mark only. Lower Most craters kept to a handful to watch the oldest fill back in. With Keep craters over a save on, save, restart and load: the craters should come back where they were. RPT lines start with ALiVE Persistent Craters.
Spotted a problem? Please report it on the ALiVE issue tracker on GitHub, with the map, rough location and what the units were doing so it can be reproduced.
Changelog
Updates to this page
- 2026-11-02An admin's Clear current mission's data (and Wipe ALL) now removes the saved craters too; before, they came back on the next load.
- 2026-11-02New module, Persistent Craters: shells, rockets and bombs leave craters that stay, and artillery and bombs dig the ground. Roads, runways, buildings, FOBs and military objectives are kept clear, and craters are kept over a save.