Where does UE4 store lightmaps?

I don’t need and access to the file but atleast where to find a baked lightmap in the editor? I’d like to see how is the padding works and overall look etc.

Thank you.

I dont know how you go about viewing them, they are actually embedded in the .umap file. Here is a comment from Noland in a forum post in regards to it, the last sentence is of interest to you:

The World you see in your list above contains Level objects, which in turn contain Actor objects, some of which may be StaticMeshActor or Blueprint instances that in turn contain a StaticMeshComponent. However, none of them will contain UStaticMesh objects since those are assets stored in a .uasset, rather than a .umap (the components may reference an asset, but won’t contain it; the one exception being lightmap textures which are kind of like assets but return false for IsAsset because they are embedded)

They are stored in the map package (umap). You can see them in the content browser if you enable the filter that allows map assets, which is off by default. They are stored in an encoded SH format so they won’t appear as regular rgb textures.

Is there a view to actually view them? I would need to inspect the map to better understand several issues I’m trying to solve

Hi , would not be better to store the lightmaps in a separate file - outside the umap? When the project is source-versioned, you lose a lot of time exchanging out-of-synced lightmaps, that usually are re-built less frequently than editing the map content.

@Kafu ZOMG THIS A THOUSAND TIMES. THIS. We are working on an absolutely massive level right now transferring via P4 and it is killing my mindcells.

We are also running into issues of lighting builds locking out a lot of our devs’ time. We are wondering if there is a way to building lighting to a separate file so that the umaps don’t have to be locked out for other devs during the day. Changes are coming in frequently so we would like to refresh the lighting changes as soon as possible all the time. Our current short term solution will be nightly builds.

Sounds great! Thank you

@DanielKarp

With 4.14 this was added for this exact reason! The light build data now stores in the MapBuildDataRegistry asset. The relevant lighting build info will be stored here. This keeps the umap(s) to be checked out and worked by multiple developers.