Swarm documentation: recommended setup for swarm coordinator will only build lights on local machine

The “Setting up Swarm Coordinator” says that I am supposed to copy only two files, SwarmCoordinator.exe and **SwarmCoordinatorInterface.dll **to a new folder.
If I do that only the local machine will work on lightbuilding no matter the setup.

Copying the whole directory, or simply running the exe from the default directory solves this issue.

https://docs.unrealengine.com/en-us/Engine/Rendering/LightingAndShadows/Lightmass/Unreal-Swarm-Overview

Did you make sure that your Agents were pointing to the directory that you made? If so, and you’re still having problems, go ahead and break it again and post the Coordinator and Agent exe configs so that we can take a look.

“Agents were pointing to the directory” - do you mean the CacheFolder?

Other than that I did not realize that I have to setup the agents to point to any other directory.

Yep, though we’re not sure where the instructions might have been unclear without seeing your Coordinator and Agent exe configs when everything broke.

I invested a bit more time with trial and error to get the exact issue, sorry that I did not do that before I reported it.

Here is what I learnt: **SwarmCommonUtils.dll **is also needed in the same directory where **SwarmCoordinator.exe **is.

The documentation says:

  • Now, move (or copy) the following files from the [UE4ROOT]\Engine\Binaries\DotNET folder into the newly created directory: SwarmCoordinator.exe and SwarmCoordinatorInterface.dll.

So this file is not included in the description. If it is missing the coordinator still runs and sees the agents from other machines, but it will never assign them tasks.
I tried like 3 times with/without that dll in the same directory, without any other changes and it confirmed my theory.
Also as long as the **SwarmCoordinator.exe **is running I can’t remove **SwarmCommonUtils.dll **because windows says it is used.

Thanks for digging into this - we confirmed your report and updated our instructions in the Swarm documentation. Many thanks for the feedback!