Out of memory when building HLOD

[liyangyang0901]

All meshes work fine in editor even if all objects are loaded. But crash when building HLOD.
wired Resource Width: 16777216

[2022.11.25-07.14.54:869][ 62]LogMaterial: Display: Missing cached shadermap for FExportMaterialRenderer MI_External_Model_Tile_+000_+002_L22_000211300 in PCD3D_SM6, Default, SM6 (DDC key hash: 2F37E65560A61DCBE7B95637BFC119DC64022DD2), compiling.
[2022.11.25-07.15.16:815][ 62]LogShaderCompilers: Warning: Performance Warning: It took 21.963289 seconds to launch 19 ShaderCompileWorkers
[2022.11.25-07.16.20:121][ 62]LogD3D12RHI: Display: D3D12 CreateCommittedResource failed with params:
        Heap Type: 3
        Heap Flags: 4096
        Resource Dimension: 1
        Resource Width: 16777216
        Resource Height: 1
        Format: 0
        Resource Flags: 0
[2022.11.25-07.16.20:122][ 62]LogD3D12RHI: Error: hr failed
 at D:\build\++UE5\Sync\Engine\Source\Runtime\D3D12RHI\Private\D3D12Resources.cpp:307
 with error E_OUTOFMEMORY

[SupportiveEntity]

Hey there @liyangyang0901! Could it be that your landscape is being checked for HLODs? This has been the case for a couple questions I’ve seen recently:

Packaged game with World Partition level crashes from high memory usage

Hey, thanks for the reply. I think this was fixed by switching the Targeted RHI to DirectX 11. Before doing that, I actually couldn’t even load the level in PIE - Separate Window mode, or the same crash would happen. Edit: After testing more builds this was in fact caused by THE HLODs According to 5.1 docs, landscapes are not supported by HLOD actors. I had run World Partition > Build HLODs without changing anything, so it pulled in the massive landscape. I suppose landscape actors ha…

[liyangyang0901]

@SupportiveEntity Thanks for your reply. In my map, there is only some meshes, no landscape. It always happens when I try again and again. The GPU memory used increases quickly and then the build process crash.
In the log file, I can’t find the reason why. only the screen capture like this

BTW, the engine version is UE5.1.

[SupportiveEntity]

Hrm, try to build an empty map and gauge how low the VRAM usage is, it could be a 5.1 specific issue with the HLOD mapping. I haven’t been able to replicate these spikes on my build.

[liyangyang0901]

I have tested many times. Now, I 'm it’s a bug in UE5.1. What I have done is:

1. place some actors(about 5 thousand) in my scene, these actors seperated into 5 folders. like this:
   
   
   
   Then build HLOD, and the process crashes.
2. exclude actors in the four other folders. Just keep one folder in HLOD, every time it work fine.
   
   
3. Enable HLOD settings of folder 1,2 or folder 1,3 or folder 2,3, works fine. But crashes when enabling 1, 2, 3.
4. Do the same thing in UE5.0.3. HLOD always builds successfully.

[SupportiveEntity]

Absolutely, I can’t seem to reproduce it exactly, but having decent spikes nonetheless. I’ve seen a few issues with HLODs recently because they had some changes and don’t apply to all objects quite yet. However that seems to be bleeding into other aspects. 5k actors isn’t the highest I’ve seen even in previous builds.

I think you’re right, it’d be best to go ahead and report it, and if it’s an inefficiency introduced with 5.1 the team might be able to zero in on it easier.

Report a Bug

[liyangyang0901]

Yeah, For now, My project file is too heavy, I will collect some details to make the issue more clear. I will try to report it.