hi @GrigLog
how properly install on new eversion the is no quality gisamples jsut copy paste doesnt works
Those settings only applies to the old, CUDA based Luoshuang's GPULightmass. For this version, just change settings in the GPU Lightmass UI panel. If you don’t know where to find it, see GPU Lightmass Global Illumination in Unreal Engine | Unreal Engine 5.7 Documentation | Epic Developer Community. Note that this community fork has fixed lots of things compared to the official version, so some limits in the doc no longer apply.
Spline meshes aren’t supported in GPULM yet.
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hi again @yujiang.wang
so just replace engine files and dat’s all no patches or something not needed yes?
i just work with gpulightmas, plugin when i need bake i bake it from gpu lightmass or from build lighting
i know its loot of question but i cant find anyone who can help with this
thaanks aaloot
Before you ask again, just try it your self. It won’t break your computer. If you cannot setup the plugin by yourself you will have even more questions when you start to use it later, and I’m not sure if I’m going to answer them.
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i am tryin very long time myself. install and reinstall and make to many examples for this and it feels nothing worked .and i think this forum is for this situations to help each other that’s i think i can ask u question , thanks anyway u answer ones to me. hope when u will need help u dont get same answer on forum which u gave me now. good luck
Release 5.7.4 2026.03.19
https://downloads.luoshuangfw.io/gpulm-releases/GPULM-5.7.4.7z
Back to release list
VLM quality has been improved by picking cell positions in a more structured way instead of randomly picking points inside the cell (SSAO is disabled for better clarity in the corners):
This should resolve the issue where VLM cells that are very close to walls are very noisy even if a high sample count is used. Though, to avoid light leaks, your walls still need to be at least 2x the cell size thick.
Also, a bug related to backface detection has been fixed.
Update: there was a parameter issue and it has been fixed.
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@yujiang.wang Are there any changes made by Epic or to GPUlm in 5.7.4 that could cause these artefacts? In 5.7.3 they were not there. Nothing changed to the project. Only upgraded to 5.7.4 and the newest gpuLm. Can send you download link for a small debug scene as pm if you like.
Anyone else noticed block-artefacts in their projects?
Sure. Gimme your scene and I’ll take a look
Hi @yujiang.wang! Just yesterday I had the exact same issue as @maxbrown, and I spent the whole day running tests. To figure it out, I tried quite a few things:
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With the Directional Light set to Static, my first step was enabling Two Sided on the glass. This seemed a bit strange to me, but it worked. After that, I changed the material back without any issues. In another scene, that didn’t work out; however, using a simple material with the Blend Mode set to Translucent and a Constant of 0 didn’t require me to enable Two Sided, and then I just swapped the material back.
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With the Directional Light set to Stationary, I was absolutely forced to combine the previous steps and uncheck Distance Field Shadows.
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Another thing I tried was increasing the thickness of the air gaps in the glass, just in case they were too close together, but that didn’t work either. It felt weird because it wasn’t an issue in the previous version, but I wanted to at least try it.
I ran more tests with a few other things, but those were the main steps that actually made a difference.
The glass in your project is already in the fixed state and I need the original one.
Hint: you can use zip project in the file menu to package your project and it will only include the necessary data:
In your .zip file uploaded the DerivedDataCache folder was taking up 15.3GB and it was not useful (would be regenerated on each light build)
Hi again! Here is the updated link with the zip file and the error visible in the viewport
This is weird. I cannot repro the issue. To make sure that there isn’t any stale file, I’ve updated GPULM-5.7.4.7z and you can download & try again.
great. Uploaded a download link to the zipped project. see pm.
I’ve identified the issue and got a fix which should make GPULM work in your scene. GPULM-5.7.4.7z has been updated.
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I tested and it looks good again. Many thanks!
HI, I am currently having two issues in UE 5.6 with baked lighting for a Quest 3 standalone project, and I am trying to figure out whether this is related to the foliage / instance bug you mentioned.
First, Unreal keeps reporting:
Lights with unbuilt interactions: 1
Light: DirectionalLight
Primitives with unbuilt interactions: 1
Primitive: StaticMeshComponent /Game/maps/VR_uni_t_wereld.VR_uni_t_wereld:PersistentLevel.StaticMeshActor_1.StaticMeshComponent0
The problem is that I cannot find this actor anywhere in the World Outliner, so I cannot identify which object is still causing the unbuilt interaction.
Second, one specific tree type turns completely black after baking. What is strange is that I have two different tree types, and only one of them has this problem. If I place the same tree manually in the level as a normal Static Mesh Actor, it bakes correctly. The issue only appears when it is placed as foliage.
Because of that, I am wondering whether this is the same UE 5.6 foliage / instancing bug you mentioned in your post.
I also tried the suggested workaround before baking:
r.RayTracing.InstanceBuffer.RLE 0
but in my case that does not solve the issue.
Does this sound like the known 5.6 bug, or could this be a different problem?
Fixed. needed tot set de lightmap resolution to 6.
Hi. I used the version for UE5.7.4, and it works perfectly without Interactive preview, but activating interactive preview needs to have Virtual Lightmaps activated, and doing that makes all baked maps turn dark when baked, even with CPU Lightmapper…
Hello @yujiang.wang, thank you for developing and uploading the plugin! I’ve copy and replaced the files in the engine folder, hopefully that’s the correct way installing it.
I made a new project with the VR template in UE 5.7.4 with forward shading, I’ve enabled static lighting in project setting, set all meshes into static, applied a simple emissive, default lit material to the mesh, enabled “emissive light source” in the detail panel, but after GPULM bake the emissive mesh is simply not lighting the scene up, please see the images attached, also there is a weird defect on the blue cube where edges are glowing light where they should not be light up.
it’s a bit similar to what @anloarq has experienced with his chair not glowing up but I have checked that my material has been set to default lit.
my spec is AMD Ryzen 7 9800X3D + RTX5090
please find the zipped project files attached:
I’ve tried to debug for two days but can not get the emissive material to light up in GPULM, any help would be greatly appreciated!
Update: “Use Emissive for Static Lighting” under light mass advanced settings needs to be ticked so the object with emissive material can emit light in GPULM