Epic's GPUlightmass

[kurylo3d]

You can't have distributed lighting build with GPUs afaik (or maybe you can, but it's not trivial task perhaps).

I was "just an artist" too. Had to learn some things to get ahead instead of waiting for Epic to provide what I needed in the launcher build

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.

[UElaci]

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

[SirKlu]

Coming in the following releases, but may take a little bit longer than expected. Like, we have fixed a bunch of path tracer correctness issues in UE5.0

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!

[virtualHC]

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.

[virtualHC]

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

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

[ASMS2015]

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:/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:

[enoes]

6gb Vram is enought the new GPU Lightmas ?

[virtualHC]

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 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

[Arkiras]

6gb Vram is enought the new GPU Lightmas ?

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

[motorsep]

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.

[Arkiras]

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

[motorsep]

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 ?

[Arkiras]

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.

[enoes]

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

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

[Arkiras]

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.