@Jimbohalo10
Can you make build for 5.1.1 ?
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Luoshang GPU Lightmass 5.1.0 works with 5.1.1. But it will crash when you try open any material.
I fix it by Verify my engine. Now I can open my material again.
When I replace the Luoshang 5.1.0 again, it crashed again when I try to open material. I return it to original, now I can open again.
It’s reproducible. In short, if you want to modify your material, replace with UE original lightmass, when you want to bake with luoshang, you can use 5.1.0 version it works.
Any workarounds?
*Btw I tried downgrading my nvidia driver to 522.25, but it still crash opening material.
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Can you make build for 5.1.1 ?
I have updated the original post to 5.1.1 as well
’s GPULightmass - Development / Rendering - Epic Developer Community Forums (unrealengine.com)
Remember this is all experimental and not for production.
Also see the update needed for your Nvidia drivers
Epic’s GPUlightmass - Development / Rendering - Epic Developer Community Forums (unrealengine.com)
IMPORTANT
When using the GPUlightmass 5.1 code with 5.1.1 BINARY
the follwing needs to be added at the bottom of
C:\Program Files\Epic Games\UE_5.1\Engine\Config
BaseLightmass.ini
Using Notepad
[DevOptions.GPULightmass]
NumPrimaryGISamples=32
NumSecondaryGISamples=16
FireflyClampingThreshold=1000.0
If you dont do this 5.1.1 will crash possibly with an obscure error
Fatal error: A required key was missing from BaseLightmass.ini. This can happen if BaseLightmass.ini is overwritten with an old version.
GConfig->GetInt(TEXT("DevOptions.GPULightmass"), TEXT("NumPrimaryGISamples"), Scene.GPULightmassSettings.NumPrimaryGISamples, GLightmassIni) failed
at C:\Engine\Source\Editor\UnrealEd\Private\Lightmass\Lightmass.cpp:2481
I have problem when using the 5.1 GPU code on 5.1.1 BINARY as well. I CANNOT make this addition to the original 5.1 code file, because I dont own/support the code
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@Jimbohalo10
The community would be very grateful if you could help us with the new version of the plugin. Many newcomers have encountered a problem with GPU Lightmass 5.1 running on UE 5.1.1
2 Likes
The Man wasn’t @ ?
Hi! Have gradient lines artifacts on plane surfaces when baking. Baking settings NumPrimaryGISamples=256
NumSecondaryGISamples=128
What the reason?
compress lightmass uncheck?
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maybe u’ll have to increase the lightmaps resolution for these surfaces and don’t skip the advice to uncheck the compress light maps option
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anyway we can only hope’n’wait , Nikita)))
Solved! Thank you!!!
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Did you managed to find a solution to this bug?
I’m having the same issue here. I can only work with materials using the default lightmass otherwise the crash is inevitable.
I’m dealing with this issue this way for some days… But now even after reinstall the gpu lightmass after dealing with materials. I have a crash saying something about an error on Arrays.h
This crash persists even after I do a clean and validate in swarm agent.
Edit: Somehow this crash was solved, idk why nor how… But now, indirect light isn’t calculated by the gpu lightmass… only direct light. 
No, I’ll just wait for the 5.1.1 update
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Hi @Nick_Tarasov @MikeArtist and others,
I have found time to update the repository from 5.03 to 5.1.1. I have updated the README to reflect this.
I have updated the original post to 5.1.1 as well
's GPULightmass - Development / Rendering - Epic Developer Community Forums (unrealengine.com)
The new updated README is at
GPULightmass-patch-511/README.MD at GPULightmass-patch-511 · jimshalo10/GPULightmass-patch-511 (github.com)
There is a preview working version for 5.3 Preview, which requires building with VS 2022 described in
UE5.3 Preview GPULightmass description linked to (ue5-main)
4 Likes
Update 21st February 2023
The 5.1.1 version is updated Read the README at
I have updated the original post to 5.1.1 as well
’s GPULightmass - Development / Rendering - Epic Developer Community Forums (unrealengine.com)
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Maybe someone could make this GPULightmass 5.1.1 to download please?
A lot of people will be very very gretful ))
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I swear that I tried to compile it myself… But my lack of knowledge in coding / compiling stuff didn’t help at all 
I’m also will be very greatful for someone to make the binaries available for download.
2 Likes
@ Hi Dear Can You Please make Loushang GPU Lightmass for UE 5.1.1 and the Installation of it same as old way. Thank you.
2 Likes
Hi @GiovanniLuccaArt @Olegsbr @3darchstuffs.com @ and everyone using 5.1.1 BINARY
IMPORTANT Answer to using GPU 5.1.0 code for 5.1.1 BINARY
When using the GPUlightmass 5.1.0 code with 5.1.1 BINARY
the following needs to be added at the bottom of
C:\Program Files\Epic Games\UE_5.1\Engine\Config
BaseLightmass.ini
Using Notepad add to the bottom using copy and paste
[DevOptions.GPULightmass]
NumPrimaryGISamples=32
NumSecondaryGISamples=16
FireflyClampingThreshold=1000.0
If you dont do this 5.1.1 will crash possibly with an obscure error
Fatal error: A required key was missing from BaseLightmass.ini. This can happen if BaseLightmass.ini is overwritten with an old version.
GConfig->GetInt(TEXT("DevOptions.GPULightmass"), TEXT("NumPrimaryGISamples"), Scene.GPULightmassSettings.NumPrimaryGISamples, GLightmassIni) failed
at C:\Engine\Source\Editor\UnrealEd\Private\Lightmass\Lightmass.cpp:2481
I had problem when using the 5.1.0 GPU code on 5.1.1 UE BINARY as well
I have put the updated version for 5.1.1 of BaseLightmass.ini in the repository
For BINARY 5.1.1 support see my post
About The GPULightmass-patch-5.1.1 for Unreal Engine 5 Binary
Thanks to @ for making the original 5.1.0 code
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This lines are already there in Binary of UE 5.1.0. So what to do in this case.
I dont use 5.1.0 BINARY as it wont work but just upgraded to 5.1.1 via Epic Games launcher which needs the patch to BaseLightmass.ini as its removed during upgrade from 5.1.0 to 5.1.1
1 Like