Building lightmaps causes .umap to save

When I Build the lightmaps, even when simply building it from the editor Build- > Build Lighting Only, UE4 wants to save the corresponding .umap files, which in turn will require a checkout in P4, causing other people in the team to checkin each time we need to build our maps.

The corresponding _BuiltData.uasset file is also produced, so why the need to modify and change the .umap file too. By the way, if I ignore saving .umap, but keep _BuildData.uasset around, I still see the typical red screen message LIGHTING NEEDS TO BE REBUILT.

I think this is not acceptable and I am sure we don’t have the right settings somewhere, or we are doing something wrong. Can anyone please suggest a solution or workaround for this.


You could revert the files after building, if you’re just building for preview.
If you’re building for production then you do need to check out and commit, and everyone else wlil have to revert theirs and pull yours.
Sub-levels help a bit with this – you should really only have to commit the master map/level when you really need to commit global changes.
Also, a server that builds the production lighting on a schedule (or on certain commits) and commits it, so everyone else can pull it, can help.

Alrght, thank you, at least I know there is no settings, it is the way it is.