Luoshuang's GPULightmass

Ohh thanks a lot for the heads up, man! Really hoping his legacy will be continued!

I am using the GPU baking function quite often. Due to the change to an Nvidia RTX GPU I have a bunch of questions. I would be very gratefull, if someone can comment or answer them:

  • Will there be a GPU baking version for 4.23 ? I use 4.23 (preview) now, because twosided foliage will be rendered with shadows and ao now in raytracing mode.
  • Does raytracing GI for example “revolution” the way of baking lightmaps? I have not really a clue, but it seems it could speed up this process somehow a lot.
  • When will be the GPU baking officially implemented in the UE4 engine?

thanx a lot and greetings,

p.s. the post above mine explains almost everything i asked. Reading makes smarter i guess. ;-(

Hi everyone,

After working on 3D visualisations for a while I have recently worked on an Unrel VR project and I feel quite amazed about the results.

I was not able to use the GPULightmass yet as my graphic card was not in the list.

As I want to buy a new computer to improve my workflow it would be great if anyone can give any info about those graphic cards that are in the list for using the GPULightmass.

Many thanks in advance.


try to make it work, run it with the script, replace files and it does not work, keep calculating by CPU my current version is 4.22.3

After I use GPU render, it’s fast but I get these light spot at my wall. Could you help me to fix this?

Here is the screenshot

go back few posts earlier:

increasing TDR delay to 300 solved out of memory issue.
PC Specs:
32 GB DDR4
Zotac GTX 1050 ti

Hy everyone !

I want to show you my latest work with GPU Lightmasss.

The rendering takes 3h on 1080.

I hope you like it

Apologies, but can someone clue me into where I can learn more about this official GPU Lightmass development?

good job. i heard Luoshuang is hired by epic. so GPULightMass will improve greatly in future. fingers cross :slight_smile:

It won’t be getting improved as he’s no longer working on GPU lightmass. Read the thread.

He is however working on improving current lightmass and working on a future version. GPULightmass however is open source and nothing to do with him anymore.

I used the 4.21 version of this and had a bat file to change quality config. the version of 4.22 I downloaded doesn’t have anything like this nor an uninstaller. Help please :_D

Has anyone been able to figure out problems like this where it seems like indirect lighting just doesn’t work? Using 4.22.3 and running into this problem with no bounce-lighting on ceilings, on a purely indoor scene with just point and spot lights.

Yeah it’s bugged in 4.22.3, see Issue with Parameter Texture Object node in 4.22 - Unreal Engine Forums
It seems fixed in the current 4.23 beta build (preview 3)

Oh god…you’re right, I just tested it. Thanks for the link, I would never have figured that out on my own.

How did such a massively game-breaking bug not get fixed after three updates…or even get released in the first place…I hope I can cherry-pick that fix commit into 4.22.3 because it’s not feasible to upgrade at this point.

I’m in the same situation…I don’t really know how to backport the fix to 4.22.3…so I’m waiting for Epic to wake up (I don’t want to use a beta build for my current professional project)

About gpulightmass: anybody knows how to use it in 4.23 preview?

Are you using Rect lights?

Fix is in 4.23, it’s an issue with the material compiler. You’re going probably to backport the fix to 4.22.3, it’s what we did. If you’re not a programmer, you should probably move to 4.23. I’ll be very surprised if Epic find time to fix this in 4.22.3 (even if it’s basically a copy/past, it’s taking no more than 10min), generally they’re moving forward and ask to people to update. It shouldn’t be dangerous for your project since the big jump was 4.22 rendering wise.

I was, but I switched them out for spot lights to see if they were bugged with GPULM.

I used git cherry-pick to merge the commit into my 4.22.3 build and it seems to work. It looked like it was still broken at first, but it seemed to fix itself after I made some meaningless changes to my material instances and re-saved them. Maybe the material data is cached somewhere and not updated unless it’s modified.

AFAIK rect lights do not support more than one bounce of GI calculation with GPULightmass so I would recommend not using them.