dzo_mapstream

A DayZ server mod that puts big Editor-made maps (bases, events, bunkers, shooting ranges, ...) into your server without the usual lag and network load.

Workshop page: https://steamcommunity.com/sharedfiles/filedetails/?id=3812840035

You build a map with the DayZ Editor, save it as a .dze file and drop the file into a folder on your server. The mod does the rest.

Supported DayZ version: 1.30 (tested on the 1.30 stable server, build 25963285).

What it does (and what "networked" means)

Normally the server keeps track of every object in the world and sends it to every player. That is called a networked object. It is needed for anything players interact with: a door has to be open or closed for everybody at the same time. But it is expensive. A map with thousands of decorative objects (fences, crates, walls, ...) can slow the server down and make players join slowly.

This mod does it differently for most objects:

• The server sends the map to each player once, as a small block of plain data. The player's game saves it, so the next visit needs no download.
• Every player's game, and the server, then create these objects locally. Nobody has to keep them in sync, because they never change. Zombies and AI treat them as normal, solid objects.
• Objects that must work for everybody (doors, ladders, levers, wells, ...) stay networked: the server creates them the normal way. The mod decides which ones with a list of rules (see Networked rules); the defaults already cover the usual cases.
• Everything else becomes networked only near a player who can use it: the DayZ client cannot climb or vault onto objects that exist only locally, because the server must agree on which object the player is standing on. So the server swaps the local objects around a player (150 m on foot by default) for real networked copies, and swaps them back once nobody is near. A player in an aircraft or a fast car, or sprinting, gets nothing swapped, so fast movers cost the server almost nothing. See Climbing and proximity networking.
• Objects that you deleted in the Editor (to clear space on the map) are hidden in the game, too.

Installation

1. Get the mod and its requirement from the Steam Workshop and put them into your server directory:

   • this mod: https://steamcommunity.com/sharedfiles/filedetails/?id=3812840035
   • Dabs Framework (required): https://steamcommunity.com/sharedfiles/filedetails/?id=2545327648

   Your hosting provider may have a mod manager that does this for you.

2. Start the server with both mods in the -mod= parameter, for example:

   -mod=@DabsFramework;@dzo_mapstream -profiles=profiles
   

   Use the names of the mod folders you have, and keep Dabs Framework first. Use -mod=, not -servermod=: players need the mod too, and the launcher then downloads it for them automatically. They do not have to do anything.

3. -profiles=<folder> is required. Everything the mod stores on the server lives in that folder.

4. If your server checks signatures (verifySignatures), copy the .bikey files from the keys folders of both mods into the keys folder of your server.

5. Start the server once. It creates the folders and the settings file described below.

6. Copy your .dze files into <profiles>/dzo/mapstream/DZE/ and restart the server.

Whenever the mod is updated on the Workshop, update the server's copy too, otherwise players cannot load the maps.

Where to find things

All paths are inside the folder you gave with -profiles=:

dzo/mapstream/
  config.json     the settings (created on the first start)
  DZE/            put your .dze map files here

• Every *.dze file in DZE/ is loaded, in alphabetical order. You do not have to list the files anywhere. To remove a map, remove its file (or disable it, see below) and restart.
• Changes to config.json or to the files in DZE/ need a server restart.
• Players do not need to configure anything. Their game keeps a cache in its own profile folder (dzo/mapstream/cache/); deleting it makes the next join download everything again. The file is encrypted with a key the server sends, so a copy of it is useless without joining the server.

Checking that it works

Look at the newest script_*.log in your profiles folder and search for [dzo-mapstream]. You should see one line per map file, for example:

[dzo-mapstream] harbor_market.dze: 12 networked, 230 local, 0 invalid, 0 editor-only, 0 duplicates, ...
[dzo-mapstream] 1253 objects (164 networked, 1089 local) in 23 batches, digest ...
[dzo-mapstream] ready: digest ...

A batch is a group of nearby objects. Players load a batch when they come close to it (see viewDistance below), so the map appears around them as they walk or fly.

If something goes wrong, the log says why (lines with WARNING or ERROR).

config.json

The server writes a working default file on the first start. A settings file that has an error is not touched and no maps are loaded; the error is in the log. A complete example:

{
    "maps": [
        { "file": "harbor_market.dze", "networked": ["*Container*", "!Land_Container_1Bo"] },
        { "file": "bunker_entrance.dze", "disabled": true }
    ],
    "networked": ["@doors", "@ladders", "@actions", "@fixedItems", "Land_Underground_Panel*", "*WaterSpring*", "*Switch*", "*Stair*"],
    "viewDistance": 0,
    "proxyDistance": 0,
    "batchSize": 0,
    "disableCache": false,
    "cacheKey": "",
    "debugLog": false,
    "configVersion": 1
}

A value of 0 (or a missing line) means "use the default".

Setting	Meaning	Default
networked	The rules that decide which objects are networked (see below).	the list above
maps	Optional. Special settings for single files in DZE/. Files without an entry here are loaded normally.	empty
maps[].file	The file name, without folder.	entry ignored
maps[].disabled	true = do not load this file (without deleting it).	loaded
maps[].networked	More rules only for this file, applied after the global ones.	none
viewDistance	Players see (and download) a batch of objects when they are closer than this many meters. 100 to 20000.	1500
proxyDistance	Networked objects only exist for a player when they are fairly close (about 1000 m). Further away, the player sees a plain copy so the map does not have holes. 100 to 20000.	1000
batchSize	Maximum objects per batch. 50 to 1000.	400
cacheKey	64 hex characters: the key the players' cache files are encrypted with. Empty = a key is generated once and kept in dzo/mapstream/cachekey.bin in the server profile; deleting that file makes every player download everything once.	generated
disableCache	true = players do not keep a copy of the map; they download it on every join.	cache on
networkRadius	Radius in meters around a player on foot in which objects become networked. 5 to 500.	150
vehicleRadius	The same for a slow vehicle. 5 to 500.	40
maxFootSpeed	On foot and faster than this (m/s): no networked objects for that player.	6
maxVehicleSpeed	In a vehicle and faster than this (m/s): none.	8
maxHeight	Higher above the ground than this (m), for example in a helicopter: none.	20
maxNetworked	The most objects networked at one time by proximity networking. 1 to 20000.	6000
proximityExclude	Object types that are never made networked by proximity, for example plants: patterns like in the networked rules, without @.	none
disableProximity	true = proximity networking off: objects stay local, and players cannot climb them.	on
configVersion	Written by the mod. Do not change it.	1
debugLog	true = write extra details to the log (which objects are networked and why, where every batch is).	off

Updates of config.json

config.json has a version. When a mod update needs a newer layout, the server migrates your file on the first start: it copies the old file to config.json.v1.bak (the number is the old version), then writes the new one and logs what changed. Your rules and settings are kept. If the backup cannot be written, the file stays as it is and the server uses the migrated settings until the next start. A file from a newer mod version is used as it is and never changed.

Networked rules

The networked list says which objects are networked; all others are local. Each object type is checked against the list from top to bottom and the last matching rule wins.

Rule	Matches
Land_Lighthouse	exactly this object type
*Stair*	* stands for any characters, ? for exactly one
!pattern	like pattern, but the object becomes local (to switch something off again)
@doors	objects with doors
@ladders	objects with a ladder
@actions	buildings that offer their own actions (wells, levers)
@fixedItems	placed items players cannot pick up (targets, territory flags)
!@doors, ...	the same, but make the objects local

Upper and lower case do not matter. In doubt, keep the defaults. If a door, ladder, lever or well from your map does not work, add a rule that makes that type networked. With debugLog the log lists every networked type and which rule matched it, which tells you what to change.

Climbing and proximity networking

Players can only climb or vault onto an object that exists networked: the DayZ server checks the climb and has to know which object the player grabs, and objects that every game creates locally have no identity it could use. Networking the whole map would bring back the load this mod avoids, so the server networks only what a player can actually use:

• A player on foot who is slower than maxFootSpeed (6 m/s, walking and jogging) gets a zone of networkRadius (150 m). A player in a vehicle slower than maxVehicleSpeed (8 m/s) gets vehicleRadius (40 m). Anybody higher than maxHeight above the ground, dead, or faster gets no zone. A zone opens after the player has stayed in these limits for two seconds.
• Objects inside a zone are replaced by networked copies, nearest first, a few per frame. Players see no change: the game removes its local copy only after the networked one has arrived.
• An object goes back to local when no zone has been near it for 30 seconds (and it is farther than 1.5 times the radius, so nothing flickers at the border).
• The server keeps at most maxNetworked objects networked at once; the nearest ones win.
• Objects the networked rules already make networked (doors, ladders, ...) are not touched.

If the server is busy, make networkRadius smaller or maxNetworked lower, and add object types that nobody climbs (plants, small decoration) to proximityExclude. With debugLog the server logs once a minute how many objects are networked, how many were swapped in the last minute, the time spent, and the object types promoted most often; the last list is what to put into proximityExclude. disableProximity switches all of this off.

The server keeps the object it swaps out for five seconds, so the zombies' path graph (the AI's idea of where walls are) has time to take the new object in.

Server and players must run the same version of the mod (the protocol changed). The first join after an update downloads the maps again, because model objects are now stored at the position the engine puts them, which is where the Editor shows them.

Troubleshooting

• Nothing appears in game. Players only see objects within viewDistance of them. Stand at the place where you built the map. The log lines batch N: ... center <x, y, z> (with debugLog) show where the batches are.
• A map file adds no objects. If the log line for the file counts all objects as editor-only, the file marks them as Editor-only helper objects, which are skipped on purpose. Change that in the Editor and save the file again.
• Players cannot join, "mod not on the server" or a signature error. Check that the mod is in -mod= (not -servermod=), that the server's copy is up to date and that the .bikey files are in the server's keys folder.
• A door or ladder does not work. Make that object type networked (see the rules above).

License

Copyright (c) 2026 Bernd Zeimetz bernd@bzed.de

Licensed under the Bohemia Interactive DayZ Public Licence (DPL): noncommercial, DayZ only, attribution required. See LICENSE (source: https://www.bohemia.net/en/licenses/dayz-public-license-dpl).

Developers: see DEVELOPMENT.md and DESIGN.md.

Disclaimer

This mod is not affiliated or authorized by Bohemia Interactive a.s. Bohemia Interactive, ARMA, DAYZ and all associated logos and designs are trademarks or registered trademarks of Bohemia Interactive a.s.