The Swarm Agent

The process of building lightmaps is an automated one, which means there is no specific length of time that it will take. Based on your map or game and its complexity, building lightmaps could take too much time and performance from the machine.

But Unreal Engine is full of supporting tools that are built in such a way as to serve you by saving time and delivering the best content. There is a small C# tool that is connected to the Unreal editor, which plays the role of manager to handle the communications between the lightmass and the editor. That manager is called Swarm Agent.

Swarm Agent is autofired in order to perform its job and stay minimized (this means that you don't have to manually run it from somewhere); it was written to know the time that it has to start and finish its job and then shut down:

For more information about Swarm Agent, you can check the Unreal Engine 3 UDN documentation site, http://udn.epicgames.com/Three/Swarm.html, as Swarm was not well covered within...