Surface lightmaps can be attached to them, though you probably need to toggle some settings about two sided in both material and component lightmass settings
THANK YOU!!!
It is implemented but only for non Substrate materials: Epic's GPUlightmass - #357 by YujiangW
I haven’t tested it for Substrate so idk if the automatic Substrate material converter can make it work
1 Like
Experimental: Graphical Installer 5.7.4 2026.05.10
https://downloads.luoshuangfw.io/gpulm-releases/GPULM-5.7.4-2026.05.10.exe
Back to release list
Now you can install GPULM with this installer. It backups engine files so they can be restored during uninstall:
This isn’t just a QoL change; in the future I will start to modify engine runtime files, and I expect many of them will have only very small difference in binary. Packing all the changed files in a 7z archive will be infeasible because of size. This installer uses HDiffPatch to patch the engine.
The installer won’t try to restore files if it finds the files don’t match the version it has patched.
1 Like
any info on the next updates?
also wanted to ask, should i credit you in the reveal announcement of a project i’ve been involved in?
any info on the next updates?
I will focus primarily on VLM.
also wanted to ask, should i credit you in the reveal announcement of a project i’ve been involved in?
I’d appreciate that.
2 Likes
also, its a long stretch but since you’ll start to edit engine files, it would be EXTREMELY helpful if we could get some sort of “Do NOT Render with VLMs” checkbox on actors
we’ve been really struggling with lightbleeding into large actors like moving trains
i think at some point, i tried a horrible fix by rendering the train interior as unlit and then baking the lighting in blender and using the lightmaps in the shader
Did you try to force the train to use surface lightmaps?
yeah, but nothing changed on our end after trying that
Here, force surface makes the cube retain its lightmap. if you move the cube directly in the editor its lightmap will be invalidated though. this is driven by a sequence
2 Likes
but this now gives us light bleeding from the lightmap
or do you mean i should put the train actor into a pitch black area and then teleport it to the needed area at runtime?
yeah you do need to sacrifice something
1 Like
at the very least, if that means it’ll be pitch black interior wise i can handle that, since my goal is to have no light bleeding at all and then light up the interior with movable light actors
Hello, I wonder how to install GPULM for U.E. 5.7.4. Does anybody have a guide of what to do? I overwrote the folder but still didn’t get it. What to do next?
First use the verify option in the launcher to restore your engine files, then try to use the graphical installer: Epic's GPUlightmass - #922 by yujiang.wang
1 Like
I’m really new to it. I wish to know exactly what to do step by step. I think it would be helpful if there were some instruction on how to install it properly.
I don’t really understand how it works. By default I have CPU light baking; after overwriting folders using the new .exe installer, it’s still baking with the CPU.
(I turn off Lumen, I turn on Allow Static Lighting, I turn off Global Illumination Method to None, and I set Reflection Method to None.) I set lighting quality to production level, and it’s still baking using the CPU.
CPU: AMD Ryzen 7 9800X3D 8-Core Processor
GPU: NVIDIA GeForce RTX 5070 Ti.
The patch is a fix to the official GPU Lightmass. What you need is GPU Lightmass Global Illumination in Unreal Engine | Unreal Engine 5.7 Documentation | Epic Developer Community . There are a few UI and functionality changes.
1 Like
Thank you sir!