Luoshuang’s GPULightmass Unreal Engine 5.4.3 and 5.4.4 patch

Development Rendering
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Hello @Jimbohalo10

First of all I would like to thank you immensely for your dedication in keeping this “renderer” alive, because no other realistic rendering method (CPU Lightmass, Epic GPU Lightmass, Lumen, Ray Tracing and, in many cases, Path Tracing) can provide such realistic results for us, the Archviz community, and for the classic @Luoshuang GPU Lightmass, especially when it comes to real-time interactions. In addition to the quality achieved, LGPU Lightmass offers very fast rendering and, best of all, without the need for Ray Tracing! Many people still use modest video cards and still manage to do an excellent job.

What you do is of great importance to us, thank you very much!

I always come here to the forum to follow and download the latest version. As you mentioned, I noticed that version 5.5 will be “skipped” as it happened in 5.2, but that didn’t worry me when you said that the update work would be resumed in 5.6. I’m still anxiously awaiting the engine update!

I know that many people are getting used to using Lumen/Nanite, but in my case, as well as many 3D artists who value maximum quality and performance, nothing, so far, replaces the Luoshuang GPU Lightmass from 2018. Even Epic’s official GPU has many defects in addition to requiring RTX to work. Here in Brazil, most people do not have video cards with Raytracing.

After @pax_invictus, your updates have been essential for the development of our work. I would like to know if you will continue updating LGPU Lightmass… that you skip version 5.5 and resume with 5.6… and if that’s the case, I can even pay you for the updates of this work, but I ask that you consider my appeal, as it is very important that this code remains active in our community.

Sorry for any spelling mistakes, as I am writing the text in Portuguese and I ask Google Translate to translate it before posting it here.

Best regards,

Ana Rita

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hi @AnaRitaMoreira @Miguel1900 , and all

Don’t expect a working version until the 5.6.1 production binary is released.

Trying to get a working early version is why 5.5 failed

This has resulted in making a new GitHub forked repository called UnrealEngine25

If you have the ability to see these being part of the Epic Developers group you will see GitHub announce

Luoshuangs-LGPU-5.6-2025 had recent pushes 52 seconds ago

This is the announcement that the new LGPU 5.6 has been started.
If you have authorized access to Epic Source use the link.
jimshalo10/UnrealEngine25: 10th May 2025 Version 5.6 only due to a corrupted repository source for LGPU 5.1 to 5.5 got deleted
If you get error 404 you don’t have authorized access to the source

The starting point is the same as the newly released 5.6 Preview Binary now on Epic Launcher
Here is my additional LGPU 5.6 readme notes

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Luoshuangs-GPULightmass-5.6-preview Started 10th May 2025,

based on past work, possibly 6 months of work over 246 patches required, the 5.6 production binary has not been released

and spending the most time on UEFN 5.6 Fortnite island support

About This branch of Unreal Engine 5.6 preview with Luoshuangs GPULightmass

New LEGAL Requirement for 5.4 onward
UE 5.4 introduced a new EULA that will govern this and subsequent releases. Depending on the work you create with Unreal Engine, you might be subject to new or different fees. Please review the EULA here and make sure you understand how these changes apply to you. By downloading or using the UE 5.4 or later, or by otherwise indicating your acceptance of the EULA, you are agreeing to be bound by its terms. If you do not or cannot agree to the terms of the EULA, please do not download or use Unreal Engine 5.4 or later. This include the branch has updated to 5.6 Preview

Please follow the 5.2 documentation on how to set up GPULightmass, even though this describes CPU Lightmass. see https://docs.unrealengine.com/5.2/en-US/gpu-lightmass-global-illumination-in-unreal-engine

You must follow and make the settings work if you intend to use the Nvidia RTX 4000 series for Substrate, previously known as Strada.

The minimum of al least Nvidia RTX4000 drivers versions R525 U3 (528.02) are required

There is NO BINARY because it’s NOT an Epic official version. Users who are Market Creators have asked to go to 5.4 for performance reasons on Nvidia GTX VRAM being better

This version is all the patches and files to build “Luoshuangs GPULightmass”. LGPU Lightmass patches from the commit GPULightmass5-0-0-cherry-pick repository and others have been added

Use of this repository is without warranty and no responsibility for the use and any subsequent problems are accepted This is for research, development, and training quality, not professional quality.

This version will require at least 170GB of Solid State Drive(SSD) NVRAM to build this.

This version has been patched to remove the 48 Gigabytes of debug PDB file not needed for LGPU Lightmass speeding up build times

The SSD takes about 3 hours to build in on a hobby PC. On a hard drive, this may not complete at least 27 hours

Download Visual Studio 2022 Community, if you have not got this size (31GB configured on SSD)

This UE 5.4 version has support for Visual Studio 2022 17.7 Preview 1 onwards Visual Studio 2019 is no longer supported.

Downloading Visual Studio 2022 Community - Visual Studio (microsoft.com)

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That means development is underway. Don’t expect a working version until the 5.6.1 production binary. Trying to get a working early version is why 5.5 failed.

This is just to say the source code GitHub Repository UnrealEngine-5 for past versions got corrupted and was deleted by GitHub. Working only on any past versions is impossible.

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I hope to see GPULL in 5.6, one day!