Levels and maps

Open, create, save and edit maps, including streaming, lighting and navigation builds.

What it’s for

This is the everyday area for opening and editing maps. Ask your assistant to create a new level, open one in the editor, save it, rename or duplicate it, or export and import it as text. It works on the .umap assets your project ships.

It also handles the parts of a map you build rather than place: static lighting and lightmap bakes, navigation mesh builds for AI, and the full Build All. Some of these take a long time, so they run in the background while your assistant waits for them to finish.

It can answer questions about a map without you clicking through the editor: which actors belong to a level, how big the area they cover is, and details such as the package path and actor count. It also manages streaming sublevels, adding and removing them and turning them on or off.

Your assistant can also work on what sits on top of a map: data layers, HLOD, level instances, packed level actors and the level blueprint graph. New maps almost always use World Partition, so the sublevel features matter mostly for lighting scenarios and older projects. See World Partition.

Things you can ask

Create a map, add a light, and save it

You get a new level with a directional light, saved to disk.

You: Make a new map called Arena under /Game/Maps, add a directional light, and save it.

Created /Game/Maps/Arena, added a directional light, and saved the map.

Open a map and measure its size

The level opens in the editor and you get the size of the area its actors cover.

You: Open the test track and tell me how big it is.

TestTrack is open. It spans roughly 160×120×9 m, centered near the origin.

Rebuild navigation after changing geometry

The navigation mesh rebuilds in the background so AI can find paths again.

You: I moved a lot of walls around, rebuild the navmesh so the AI can path again.

Rebuilt the navigation mesh for the current level. The build finished without errors.