Is there any way to make it work on AMD cards?
I’m having the same problem as someone else
I’m having the same problem, around 5% GPU usage with 4.24.1. Worked well before. Any fix for this?
Just a recent experiment. I have compiled UE4.24 from original 4.24 source (with all last fixes)
I’ve replaced file provided here, the binaries ones and GPU lightmass is working well
The only things is that the gpulightmass windows doesn’t appears when building lights but it’s not a problem for me, you can follow the swarm agent and the GPU (cuda) usage in taskmanager.
Thanks to all for your hard work to provide this GPU lightmass
@Metathesus , trouble is I don’t have ‘cuda’ anywhere, not even under ’ 3D’, anyone know why ? I have latest nvidia and I don’t recall seeing anywhere I needed to download cuda sdk as I have no intention to DEV with it,or Do I need to to have CUDA show up ? If so, I guess that would explain my lowly 5% max usage of GPU , maybe.
Seeing a lot of people talk about editing this setting in the lightmass.ini file to remove firelfies in my scene, but i can’t find it anywhere. Can anyone point me in the right direction?
FireflyClampingThreshold=10.0 ----> FireflyClampingThreshold=1.0
I used this that Pax Invictus made. Readme on how to install is in there.
It specifies the value at which to disregard rays. Having it set to 10 will mean any values above 10 units in brightness will be clamped down. It helps with the occasional times you get stray rays causing extremely bright points of light where they shouldn’t, though this rarely occurs. You should rarely be set this low. If you’re using physically correct lighting values (up to 100k lux) the clamping threshold should be set somewhere above that: “FireflyClampingThreshold=200000”
Great thanks,
Where abouts do i find the value to change it, i can’t find it in the editor, nor can i see it in the normal baselightmass.ini file
Thanks for the response, thats actually useful to know.
I only ask as i’m trying to solve this. I literally only have a skylight in the scene, intensity set to 1 but i’m getting terrible results even on production settings
Yup I know where its at, but unlike what your pic shows none of my ‘graphs’, show Cuda at all.
I just happened to bake scene with CPU Lightmass and then GPU Lightmass (same project, very simple, testing stock 4.24.1 vs Oculus 4.24.1 with has GPU Lightmass). I noticed that CPU Lightmass takes environment color from World Settings for Skylight when no cubemap is specified (and if skysphere is missing). GPU Lightmass ignores it completely (so my indirect lighting is pitch black).
I never noticed that before because I always had skysphere. Is it a bug or an unsupported feature in GPU Lightmass ?
EDIT: After chatting with the Man himself, it sounds like it’s unsupported 
Has anyone figured out a workaround for GPU Lightmass crapping all over LODed static meshes ?
Apparently LODs are also not supported and if there is no workaround, it was nice knowing you folks, but I would have to go back to CPU Lightmass 
As mentioned before, is there any way to use this command on macOS or Linux?
I tried “UnrealLightmass” command in ProjectFolder\Engine\Binaries\Linux instead of UE4Editor-Cmd.exe on Ubuntu 18.04 LTS, but got error below again and again…
Failed to open scene channel with GUID {00000123}:{00004567}:{000089ab}:{0000cdef}
LogInit: Error: Timed out waiting for the recipient (TimeWaitingSec = *****)
Hey guys its just a dumb question, but i read a lot of pages in this thread and still couldnt figure out, how i can setup the GPU Lighmass properly. Can you give me a litttle help?. Do i have to build the Engine from source and then switch out the selectet Engine Binary files?
Look back one page to the posts by Bdcoll, Theirs a link to download the GPU Lightmass in a format that just needs extracting to the right folder, and the folder location is all in the Readme in that link. No need to rebuild from source etc. just extract that to the right place
Sorry my bad, i had to wait for the Swarm Agent to push the data to the GPU Lightmass. It worked
Skylight casts very scattered light and it looks like you’ve got a low ray count, you need to edit your BaseLightmass.ini.
Medium quality is I believe:
DevOptions.GPULightmass]
NumPrimaryGISamples=32
NumSecondaryGISamples=16
Extreme (I wouldn’t go any higher than this) is:
DevOptions.GPULightmass]
NumPrimaryGISamples=256
NumSecondaryGISamples=64
The lightmass configuration script makes it very quick and easy to change this.
Ah thats great thanks for this. I’ll have to look into using the script as i dont see a GPULightmass option in my BaseLightnmass, despite having it installed -_-
Edit: Actually i lie, its tucked away down at the bottom of everything, and Ctrl+F was failing to find it for some reason
