HLOD generation/deletion time has been x10 after last update (literally takes hours to do now)

Please select what you are reporting on:

Unreal Editor for Fortnite

What Type of Bug are you experiencing?

UI/Tools

Summary

After recent updates, it takes waaaay longer to generate or delete HLODs. We ve changed nothing in the map. Previously it was 20 mins to generate, now on 20 mins its only 4%
Please address this, we cant spend a day just making HLODs
BezH4FnHUR

Steps to Reproduce

Load a large island with both current build of UEFN and an older one
Build HLOD on both
Compare times

Expected Result

HLODs to take around 20 mins to build/delete

Observed Result

HLODs take 10 times longer to generate

Platform(s)

pc

Your projects are huge, on my little ones, I’ve had validation issues with the HLODs I just totally delete the HLOD layer and make a new one now whenever I fail to upload.
the Delete HLODs from the build menu doesn’t seem to properly work. It’s like the HLOD layer holds old junk info and references that it just doesn’t delete & I wonder how you cope with this on your large projects ?

Well, I think even though it says build failed, it does succeed and I ve noticed project size goes down. I also made a new HLOD layer as well, which does help lowering the overall amount, even without tweaking its settings (they are not exposed anyway).

1 Like

We’ll get someone to take a look.

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hi @Wertandrew ,
In the past UE5 was using Simplygon to build.
Maybe the new 31.00 went back to any early version

Hierarchical Level-Of-Detail | Simplygon 10.3.500.0

IIrc there was a patch note in the latest update that mentioned something about HLODs not loaded into the server or something, I can’t find it now but I read it when the new UEFN patch released. There was also two different things in the build of HLODs:
-Validation fix up tool did something in the HLOD generated meshes when it run
-Some HLODs were locked by another team account accidentally, and URC had some of them locked after they completed building.

hi @Wertandrew ,

Patch note possibly 31.00 Fortnite Ecosystem Updates and Release Notes | Unreal Editor for Fortnite Documentation | Epic Developer Community (epicgames.com)

Modeling

New:

  • LODManager Tool only modifies the target static mesh during acceptance on tool shutdown.

Looking at the UE 5.5 source code
The comment found BaseEngine.ini but this is very different from UEFN version

;HLOD actors now store their source actors using FWorldPartitionRuntimeCellObjectMapping rather than a custom FHLODSubActor class

We UE 5.5 source Developers don’t have access to the Fortnite Validation source code so we cannot see the Verification code to incorporate these changes .
This is a substantial change in use

Yes, thats the one (second one you posted, from BaseEngine)! Not sure how it affects it, but seems related given its the only HLOD edit of the patch notes

Hi @Wertandrew !

Epic dev here. Not sure what could be the issue here. We ran once into a shader compilation issue that caused a regression like this, but since then I haven’t had report of widespread increase in build time. Can you share more details regarding your map setup ? Maybe share a log file too ?
There are specific logs created for the HLOD build, you can usually find them under
C:\Users<user>\AppData\Local\UnrealEditorFortnite\Saved\Logs\WorldPartition\WorldPartitionHLODsBuilder-XXXXXXXXXXXX.log

This will be very valuable in order to understand what’s going on.
Thanks!

Sure thing, here you go I zipped them all together:
WorldPartition.rar (3.1 MB)

Ok so from your logs, this looks like a source control issue.
It seems your connection to the source control is either very slow or is somehow timing out. For example, I’m seeing a ton of 7-8 sec delay like this:

[2024.08.27-22.01.20:696][804]LogWorldPartitionRuntimeSpatialHashHLOD: Display: [6 / 1126] Processing cell Daark_Region_MainGrid_L0_X-8_Y-5...
[2024.08.27-22.01.20:719][804]LogSavePackage: Moving output files for package: /Mercenaries/__ExternalActors__/Daark_Region/5/8U/3IXEV08O6WSG28CZR3QG6Y
[2024.08.27-22.01.20:719][804]LogSavePackage: Moving 'C:/Users/Guest2/AppData/Local/UnrealEditorFortnite/Saved/3IXEV08O6WSG28CZR3QG6YAC1D067A443F5C1C685030B903BEA600.tmp' to 'C:/Users/Guest2/Documents/Fortnite Projects/Mercenaries/Plugins/Mercenaries/Content/__ExternalActors__/Daark_Region/5/8U/3IXEV08O6WSG28CZR3QG6Y.uasset'
[2024.08.27-22.01.28:434][804]LogCommandletPackageHelper: Error: File C:/Users/Guest2/Documents/Fortnite Projects/Mercenaries/Plugins/Mercenaries/Content/__ExternalActors__/Daark_Region/5/8U/3IXEV08O6WSG28CZR3QG6Y.uasset already checked out by TeamAlliance, will not add
[2024.08.27-22.01.28:434][804]LogWorldPartitionBuilderSourceControlHelper: Error: Error adding package /Mercenaries/__ExternalActors__/Daark_Region/5/8U/3IXEV08O6WSG28CZR3QG6Y to revision control.

Can you try again with your source control disabled ?

1 Like

I will next time I generate, good to know. That may confirm my theory that if you have locked HLOD chunks from edits from another user and run it, it may cause this. Hopefully its a specific case. Good find, thanks