Epic's GPUlightmass

ive done all the c++ training… just too much ■■■■… i’d rather just stick to cpu lightmass if i had to do programming ever again. lol.

do lightmass portals work with gpu lightmass? Or are they just ignored?

How will these changes affect the use of the path tracing mode as an offline renderer? It will support more of Unreal’s shaders/features to be more 1:1 with the original realtime scene?
Or will this affect mainly how things are being calculated for raytracing/lightmass baking/lumen etc?

Looking forward to see what’s coming! :slight_smile:

Is anyone experiencing crashes with GPU Lightmass in 4.26 release? I’m getting crashes at the de-noising stage about 2 out of 3 times I bake, and UE4 just closes without any error messages. If I turn off de-noising it stops crashing.

I have the same question about portals, also what about Lightmass Importance Volume?

i need help …
oh my god … after long build with gpulightmass with raytrace i try to pakaging android … and the error was
UATHelper: Packaging (Android (ASTC)): LogInit: Display: LogOutputDevice: Error: Ensure condition failed: TextureData.Layers.Num() == 1 [File:D:/Build/++UE4/Sync/Engine/Source/Runtime/Engine/Private/TextureDerivedDataTask.cpp] [Line: 262]
UATHelper: Packaging (Android (ASTC)): LogInit: Display: LogOutputDevice: Error: Texture VirtualTexture0_1 has 1 layers bu VirtualTexturing is not enabled, only layer0 will be availiable
UATHelper: Packaging (Android (ASTC)): LogInit: Display: LogOutputDevice: Error: Stack:

6gb Vram is enought the new GPU Lightmas ?

I found the problem in the log. I’m not sure if it’s my own memory limitation (I have 16GB RAM) or a memory management bug in UE4:


[2020.12.07-17.02.44:107][966]LogMemory: Warning: Freeing 33554432 bytes from backup pool to handle out of memory.
[2020.12.07-17.02.44:118][966]LogMemory: Warning: MemoryStats:
AvailablePhysical 572383232
AvailableVirtual 69783552
UsedPhysical 11002134528
PeakUsedPhysical 12108525568
UsedVirtual 38617370624
PeakUsedVirtual 38695047168
[2020.12.07-17.02.44:118][966]Allocator Stats for TBB: (not implemented)
[2020.12.07-17.02.44:121][966]LogOutputDevice: Warning:

Script Stack (0 frames):

[2020.12.07-17.02.44:123][966]LogWindows: Windows GetLastError: The operation completed successfully. (0)
[2020.12.07-17.02.47:431][966]LogWindows: Warning: SymLoadModuleExW. Error: 8
...
[2020.12.07-17.02.47:435][966]LogWindows: Error: === Critical error: ===
[2020.12.07-17.02.47:435][966]LogWindows: Error:
[2020.12.07-17.02.47:435][966]LogWindows: Error: Fatal error: [File:D:/Build/++UE4/Sync/Engine/Source/Runtime/Core/Private/GenericPlatform/GenericPlatformMemory.cpp] [Line: 197]
[2020.12.07-17.02.47:435][966]LogWindows: Error: Ran out of memory allocating 74520768 bytes with alignment 0
[2020.12.07-17.02.47:435][966]LogWindows: Error:
[2020.12.07-17.02.47:435][966]LogWindows: Error:
[2020.12.07-17.02.47:435][966]LogWindows: Error: [Callstack] 0x00007ffd11e23e49 KERNELBASE.dll!UnknownFunction ]
[2020.12.07-17.02.47:435][966]LogWindows: Error: [Callstack] 0x00007ffc9e5dc386 UE4Editor-Core.dll!UnknownFunction ]
[2020.12.07-17.02.47:435][966]LogWindows: Error: [Callstack] 0x00007ffc9e5dfae8 UE4Editor-Core.dll!UnknownFunction ]
[2020.12.07-17.02.47:435][966]LogWindows: Error: [Callstack] 0x00007ffc9e2edd5d UE4Editor-Core.dll!UnknownFunction ]
[2020.12.07-17.02.47:435][966]LogWindows: Error: [Callstack] 0x00007ffc9e0f0c8a UE4Editor-Core.dll!UnknownFunction ]
[2020.12.07-17.02.47:435][966]LogWindows: Error: [Callstack] 0x00007ffc9e193a56 UE4Editor-Core.dll!UnknownFunction ]
[2020.12.07-17.02.47:435][966]LogWindows: Error: [Callstack] 0x00007ffc9e193b93 UE4Editor-Core.dll!UnknownFunction ]
[2020.12.07-17.02.47:435][966]LogWindows: Error: [Callstack] 0x00007ffc88c74c38 UE4Editor-GPULightmass.dll!UnknownFunction ]
[2020.12.07-17.02.47:435][966]LogWindows: Error: [Callstack] 0x00007ffc88c1c33a UE4Editor-GPULightmass.dll!UnknownFunction ]
[2020.12.07-17.02.47:435][966]LogWindows: Error: [Callstack] 0x00007ffc88c0530c UE4Editor-GPULightmass.dll!UnknownFunction ]
[2020.12.07-17.02.47:435][966]LogWindows: Error: [Callstack] 0x00007ffc88c0f505 UE4Editor-GPULightmass.dll!UnknownFunction ]
[2020.12.07-17.02.47:435][966]LogWindows: Error: [Callstack] 0x00007ffc88c22a2d UE4Editor-GPULightmass.dll!UnknownFunction ]
[2020.12.07-17.02.47:435][966]LogWindows: Error: [Callstack] 0x00007ff6c43a9b6a UE4Editor.exe!UnknownFunction ]
[2020.12.07-17.02.47:435][966]LogWindows: Error: [Callstack] 0x00007ff6c43c113c UE4Editor.exe!UnknownFunction ]
[2020.12.07-17.02.47:435][966]LogWindows: Error: [Callstack] 0x00007ff6c43c121a UE4Editor.exe!UnknownFunction ]
[2020.12.07-17.02.47:435][966]LogWindows: Error: [Callstack] 0x00007ff6c43d527d UE4Editor.exe!UnknownFunction ]
[2020.12.07-17.02.47:435][966]LogWindows: Error: [Callstack] 0x00007ff6c43d7faa UE4Editor.exe!__scrt_common_main_seh() [d:\agent\_work\5\s\src\vctools\crt\vcstartup\src\startup\exe_common.inl:288]
[2020.12.07-17.02.47:435][966]LogWindows: Error: [Callstack] 0x00007ffd13927034 KERNEL32.DLL!UnknownFunction ]
[2020.12.07-17.02.47:435][966]LogWindows: Error: [Callstack] 0x00007ffd1455cec1 ntdll.dll!UnknownFunction ]
[2020.12.07-17.02.47:435][966]LogWindows: Error:
[2020.12.07-17.02.47:463][966]LogExit: Executing StaticShutdownAfterError
[2020.12.07-17.02.47:964][966]LogWindows: FPlatformMisc::RequestExit(1)
[2020.12.07-17.02.47:964][966]LogCore: Engine exit requested (reason: Win RequestExit)
[2020.12.07-17.02.47:972][966]Log file closed, 12/07/20 12:02:47

Try it and see? I can tell you it works fine with 8.

Has anyone figured out good settings for GPU Lightmass to bake: A. Good lighting (and fast) and B. Amazing lighting

With GI and all the available/supported bells and whistles.

A) Default settings, enable IC + FBRG
B) Turn off the denoiser, use IC + FBRG and push your GI samples to 8k, IC quality to 8k, trial samples to 2-4k

Thanks. Wasn’t there some issue with FBRG that created splotched lighting ?

In areas with very low indirect light you will get noise when not using FBRG, when using FBRG the result will be much smoother, but you may get blocky artifacts in those areas. You could turn it off and use the denoiser, but I wouldn’t recommend this unless you’re also turning lightmap compression off (probably a bad idea unless it’s an archviz scene) as the denoiser + lightmap compression produces patches of color banding.

Basically you have to choose between noise or blocky artifacts, in some scenes one might be better than the other. Turn FBRG on/off accordingly.

i will buy new rtx card 2060 i can’t try ! your work any big scene maybe vram usage share to me ?

Fairly sure GPU memory doesn’t matter as it is using virtual textures for lightmaps, I may be wrong. I don’t have a scene I would consider “large” to test. My test scene is 92 objects with an average lightmap resolution of 512~ and GPU memory is basically permanently pegged at 50% in fast mode.

As a brief test I copy pasted the scene 4x (368 static meshes with ~512px average LM resolution) and it is still stuck at 50% GPU memory usage.

Unrelated to that, I really wouldn’t suggest buying a graphics card until the 30 series are widely available, and just getting one of those instead. Just my opinion.

virtual texture but old gpu lightmass is 4gb vram is not enough for my home project:https://youtube.com/watch?v=gdp5fwozuYMand room by room old gpu lightmass en all together is cpu lightmass max lightmap is 512 i guess.
i try 5 box 4096 lightmap and virtual texture or virtual lightmaps cant work old gpu lightmass and out of memory error. Please you try it for me

and maybe your level is bottleneck. maybe push the vram %50 but is bottleneck and slow

Seems you’re right. Was able to get 9 cubes with 4k lightmap resolution, but at 10 it crashes, which seems in line with your experience.

so ? 4k its can’t work ?

Not if you have 10 of them on an 8gb card I guess.

what is 10 ? is it tiles ?
maybe change the tile size and tile border size ?