In the context of a multiplayer persistent world with an authoritative server, I need that multiple level are loaded in the same time at any time.
Essentially, one main map and multiple little levels ( cave, dungeons, …).
What is the best tool available in unreal engine 5.6 to do it?
Can I do it with one of the level using world partition?
Hello there @Kanthuns!
From what I could gather around the community, the best approach for this setup would indeed be a main map with multiple sub-levels. Using WP + Level instances, you can create the main, persistent map, and interconnect caves and dungenons as instances. From those, you can set the ones you always need available as “Always Loaded”. UE has a lot of documentation on the matter, please give it a look:
Why? Aren’t the needs still local to each player?
The server shouldn’t be “loading” so to speak? I mean the whole thing should always be up in ram for a server to manage what happens.
Personally I wouldn’t even disable AIs by proximity (but, sure, you have to because it kills the server to calculate that much).
Explain a bit more of what your setup and needs are like 
Hi @brs-sebascova ,
Thanks for the reply, I already check the official doc and unnofficial one aswell. From my understanding of level instance, its only a bunch of actor we can conveniently load/unload and duplicate.
With this tool I dont know how I can make a specific level aside the world partition map.
I take an exemple, the player take a magic portal and is teleported in a magic plane. In this magic plane, lets say a fire plane, I would like to setup different sky than the one on world partition, one very red . I would like that the main map directional light doesnt affect my fire plane because I want something different in a fire plane. Same things in a cave or in a dungeon, I want to setup the atmosphere without being affected by some existing general actor present in the main map.
@MostHost_LA rightfully mention the multiplayer aspect. From my understanding, level instances are replicated. It means we cant use them to remodel the view client side becasue any level instance which is loaded/unloaded on the server will be loaded/unloaded on all the clients as well.
If I take the example of the fire plane again, if I unload all my actors from the main level and load all my actors to build the fireplane by using level instances. Even the player that havent teleport to the fire plane will see the world change.
So the need is simple, I want the player on the main map still able to play on the main map and if a player take a portal to somewhere. I want this player to be teleported in that place while others players are unnaffected.
On top of that, I need the place the player is teleported to to not be affected by the main maps envrionment actors ( sky atmosphere, sky light , directionnal lights) to make it easily special.