Hello,
I am trying to build lighting with only certain levels visible. However, the lighting build always gets stuck if I don’t have my level “CBD_Bedroom” visible (see screenshot). Provided this level is visible, lighting builds fine.
http://puu.sh/nAznv/1937f8110e.png
The percentage it gets stuck at varies depending on how many levels I have visible. I tested by deleting assets from a level one by one to see if lighting would build, and with every asset I deleted the build got stuck sooner than the last time (e.g. get’s stuck at 93% with 10 assets, and 90% with 9 assets).
Not sure what’s going on here, thanks in advance!
Hi Sarah,
It’s hard to say without more information what may exactly be happening. It’s also been a couple of weeks since you posted so you may have already solved your own issue, but for the sake of reference and troubleshooting for future projects here is some things that could help you narrow down what is going on. 
If this level, or any other level is specifically causing the build to get stuck try opening Swarm Agent (task tray in Windows with a yellow/black S icon).
Once this is opened, you can navigate to the Settings tab and change the Verbosity to Super Verbose (Especially helpful if you need to post this on AnswerHub since it’ll have all the information needed typically, where the default may not). Then in the Log tab, copy this to a text file for upload, or look through the log for any standout issues that may be marked. Ignore the Coordinator warning. That’s not relevant since most people are not using Swarm Coordinator for build farms.
A lot of times if you’re under the impression that Swarm Agent has gotten stuck, when you open it you should see some activity in the Log or even just the Status tab. Sometimes it can take a while to process some assets depending on a number of variables, like lightmap resolutions, vertex count, lighting build quality, etc.
If you manage to get a build with all levels visible, in the Editor you can go to WIndow > Statistics > then when the window comes up, you can change the option to “Lighting Build Info” to see specifically what was taking the longest to build for each asset that is visible when lighting was built. This can help give a good idea of why the build may appear to hang sometimes, especially if you see a particular mesh was taking longer. This could be because it has a higher lightmap resolutions, higher vertex count, and so on.
I hope this helps.
Tim
Hi Tim!
I haven’t yet solved this so thank you for the reply! I tried building a level which got stuck at 96%. My issue is unless a certain level is visible (CBD_Bedroom) lighting won’t build. As long as CBD_Bedroom is visible, I can build any level.
Here’s what I got from the Swarm Agent:link text
I tried to build my level “CBD_Friends” on it’s own when I got this result.
I looked into the Lighting Build info and didn’t see anything unusual. The levels all build together, but won’t build separately with the exception of CBD_Bedroom.
Looking at the log, it looks like it’s not finished yet, but still processing. Have you tried waiting longer periods of time than ~6.5 minutes to see if it completes?
Can you make visible the CBD_Bedroom level visible and build lighting, then paste that log here as well once it completes.
Can you also list here the numbers of actors you have in that one level that is hidden along with what types of actors they are like, Lights, Static Meshes, BPs, etc?
Also, It’s not the usual workflow to build lighting separately for these types of levels where you need to hide and build lighting. There could potentially be things that break doing that. If you detail the context for doing this or what your ultimate goal to achieve is maybe I know a workaround or some suggestions to help you get the look and feel you’re after.
I’ve waited about 15 minutes in the past. I will let it run for longer and see if any progress is made.
Here’s the log when I baked the light with all levels visible: link text
I’m not sure which level you’re referring to for me to list assets from. Do you mean the level I need to have visible to be able to build lighting?
You play through the same area continuously, and as you progress new rooms appear. The issue was each room is on a different level that gets loaded so I didn’t want the lighting info baked earlier before it appears. We’ve changed the locations of the rooms now to get around this, but I’d still like to know why I can’t seem to bake lighting on separate levels.
EDIT: I just waited 40 minutes for the build and it remained stuck on 93%.
One additional thing to try as a test if you have access to it would be to make a copy of your project and open it with 4.11 Preview 7. There have been some lightmass improvements to increase light build speed that could help as well. If you don’t have it downloaded or have no plans currently, that’s OK too, just a thought.
I’m not sure which level you’re
referring to for me to list assets
from. Do you mean the level I need to
have visible to be able to build
lighting?
The level that is hidden that is causing the issue. I’d be curious if it’s not many assets, if you move them to a new level that is always visible or has worked previously, and then build lighting with the level that causes the issue hidden with nothing in it works. If so, there is probably an asset in that bunch that is causing the issue, which has been an issue for some in the past. I’ve not had that ever happen personally, so I’m really just putting some troubleshooting elimination ideas out there to see if it can be narrowed down. It can be tedious I know.
You’re working a workflow that’s not that typical, so narrowing down where some issues may be can be harder for specifics. Typically in a situation like this all the levels would be baked at once, regardless of when they show. Since the levels can be streamed in with Streaming Level Volumes or Loaded within Blueprints via a trigger box it shouldn’t really matter if they are all baked together. The only time I see people really trying to avoid baking everything together is for very specific lighting circumstances when they want to do what Lighting Channels in UE4 could do.
If I make a new level with nothing on it, or one light and one mesh, that new level still doesn’t build on its own, so I don’t think it’s the hidden levels. But thanks for the help.
I’m not sure how to bake lighting with all levels visible without the shadows being visible when the levels aren’t loaded?