Why does Build stop at 50% lighting

Pressing the Build button, goes into Building Lighting, and then stops at 50%.
There’s not actually any objects in my level; it only has UMG guis.
I have to cancel it to get back to normal editor.

Using a GTX 980 on Windows with UE 4.9 release.

Build Log:

MapCheck: New page: Map Check
Cmd: MAP REBUILD ALLVISIBLE
LogEditorServer: Rebuildmap Clear paths rebuilt
MapCheck:Warning: Warning WorldSettings_1 Hierarchical LOD System is disabled or no HLOD level settings available, unable to build LOD actors. 
LogStats:          STAT_HLOD_BuildClusters - 23.907 ms
LightingResults: New page: Lighting Build - Sep 6, 2015, 7:09:24 AM
LogStaticLightingSystem:Warning: No importance volume found, so the scene bounding box was used.  You can optimize your scene's quality and lighting build times by adding importance volumes.
LogStaticLightingSystem: Running Lightmass w/ ImmediateImport mode ENABLED
LogStaticLightingSystem: Running Lightmass w/ ImmediateProcess mode ENABLED
LogStaticLightingSystem: Running Lightmass w/ Sorting mode ENABLED
LogStaticLightingSystem: Running Lightmass w/ Mapping paddings ENABLED
LogStaticLightingSystem: Running Lightmass w/ Mapping debug paddings DISABLED
LogEditorBuildUtils: Build time 0:00:04
Job has failed! Job is closed while Tasks are still RUNNING

Adding an importance volume doesn’t change this behavior.
This used to work in 4.8.

Same error here ! I’m using a HD radeon 7800 on windows 7.

For what it’s worth, I’ve backed down to 4.8 for now because this is a blocker.

Hi jwatte,

If you try building a simple scene like the default one (static mesh floor, atmos fog, skysphere, etc) when you create a new level and then add one of the basic cubes or meshes from the Modes panel, does this build?

Any details anyone has to recreate this, possibly link your DxDiags here as well. I’ve not had this issue on any machines I’ve tested on, and using the default scene with a basic mesh or two is a good starting point for testing. This doesn’t include any extra things that may have been created by you and added.

If lighting builds at this point, we can narrow down what other objects or assets could be the root of the problem.

Also, I see " MapCheck:Warning: Warning WorldSettings_1 Hierarchical LOD System is disabled or no HLOD level settings available, unable to build LOD actors." listed. If you’ve got any HLODs used in your scene there is already a bug reported where these will not build static lighting, thus always leaving the ‘Lighting needs to be rebuilt’ warning present. This will not hinder lighting from building though that I’ve seen.

Let me know.

Tim

See update with repro, DxDiag, and movie, here: Building Lighting in 4.9 never completes (repro case/move) - Rendering - Unreal Engine Forums

My previous bug report on this matter was “accepted” so I think a new report that’s actually open would be best.

I have reproduced the problem where building lighting never finishes in 4.9. It seems that this happens for scenes that have no BSP geometry. The default scene, delete the default floor, has this problem. Add a static mesh cube, it still has this problem. Delete the static mesh cube, add a BSP block cube, and it works again.

I have made a 2-minute mp4 video demonstrating this on a fresh 4.9 with a fresh empty project:
(the 5 MB forum attachment limit is exceeded, so get it from here:)

Here is the previous report: https://answers.unrealengine.com/questions/297993/why-does-build-stop-at-50-lighting.html
I’ve also attached my DxDiag.txt file here to this post.
link text


Also, another hint: If I change the size of the BSP cube to 5x5x5 cm, then lighting build never finishes. 200x200x100 works fine. So it’s possible the problem with the static cube is the size of it, not the fact that it’s static.

The reason this matters to me is that I have some levels that have no geometry, just UMG user interfaces. Those never finish building. The work-around is to stick some black BSP geometry somewhere, I guess, but it’d be nice if this just wasn’t a problem!

I was able to reproduce this. Thank you for the details and the video demonstration. Another one of our techs is submitting a ticket for this right now. Once that is entered I will add any additional details needed and post the ticket reference here.

Thanks, jwatte!

Tim

Reported with UE-20872.

This will not make it into 4.9.1 HotFix, but if we do a 4.9.2 HotFix and this has been resolved we’ll definitely make a push to get it in there.

Thank you; I appreciate the update!

I can confirm this happens as well, and also if you check the Swarm Agent after cancelling the build at 50% you’ll notice the Distributed Progress shows 100% and same if you clear the cache in Swarm Agent, if you don’t cancel it sticks to the 50%.

Using the above mentioned steps the build takes forever and doesn’t complete, even with the simplest of settings it sticks to 87.50%.

The problem starts when you create a new blank level and create a UMG widget object only.

The other problem this may cause, since this information isn’t cooked on mobile devices such as Android the level might be stuck in a loaded loop where the Begin Play actually seems to tick, and so the next level using an Open level node or command does not load the level, due to the map not being cooked, the game will only try and load the first level that it see’s and then fall back on that level, which causes the constant reloading.

I put a Print String node in front of the Begin Play event before the widget was created and noticed it kept outputting the Hello message over and over again, when I attempted to add the DoOnce node to do it only one time, it continued doing it over and over, so I knew the level was constantly reloading.

Hopefully, this is fixed soon.

I had this happen in a 4.9 project that REFUSED to package. Might go back to 4.8

The work-around is simple: Plunk a BSP cube into the level anywhere (I put it 100000 units down negative Z)
Annoying, but works.

Works!
Thank you!
Edit: This method only works sometimes… :frowning: