Support for multiple, concurrent worlds?

I feel like most of my posts in this subforum are ‘Hey, does x work yet?’, so I apologize!

After reading through some of the UGameEngine tick/processing code today, I noticed comments referencing eventual support for multiple UWorlds. I was firstly wondering if they were meant as concurrent worlds, rather than switching between stored/saved ones, and whether this feature has seen any progress lately, or if any additional information is available.


When you use the single process multiplayer play in editor feature you are running multiple concurrent worlds, one for each instance of the game. While we’ve done a lot of work to make that work there are still aspects that don’t quite work as well as we might want so it is an ongoing process of identifying solutions for the problematic points (for example currently using seamless travel with multiplayer play in editor causes a crash and any solution to the underlying cause is going to be complicated).

Hey, Marc. Is there some intended use case for multiple UWorlds outside of PIE functionality? E.g. a server processing multiple worlds each built out using world composition (‘large worlds’) that each have players in them.

While that might be an interesting initiative in the future to reduce memory overhead by having multiple server instances running in a single process so as to share loaded assets, there are no current efforts that I’m aware of to make use of the multiple game world support to work out of the box for anything other than Play in Editor.

Thanks, Marc!