Luoshuang's GPULightmass

GPULightmasKernel.dll <---- Looks like a misspelling in your Lightmass.ccp. GPULightMasSKernel.dll - Missing one S.

I have been getting a strange bug where certain faces usually facing in one direction in both positive and negative render completely back. all of a sudden it started happening on meshes I haven’t touched or changed anything on. I have tried what seems like everything, I have re uv’d, changed lightmap res, and countless other things. in one section i have had luck with just simply exporting and re importing while changing nothing and it has fixed the issue. In other areas that fix dosent seem to work. Ill post some images in lit, unlit, and lighitng only.
Its the horizontal beam above the ceiling.

Thanks in advanced,

Well, you’ll need to know how to compile the engine from source if you are using this version to install. Have you built the engine successfully from Source code using Visual Studio 2017? Make sure when you’re building, you follow instructions on what to edit along with SceneExport.h here: Luoshuang's GPULightmass - Unreal Engine Forums

I’d advise using the Binary version instead of Source. Are you modifying the engine source code? It’s usually not necessary unless you’re doing a lot of engine code edits. I presume you’re not since you said you’re not a game programmer. Stick with Binary and use Situx’s script.

2080TI it work smooth in 4.22

Still having this error, here are some more images. i tried migrating the level to a fresh project and it fixed some but introduced others. I also tried using cpu lightmass and im getting similar unpredictable errors.
I am at a loss, I dont understand why all of a sudden these meshes started acting like this and I just cant figure out a fix or why its happening.

Is there a way to use more than 1 local gpu? Can I run an example using four gtx1070 at the same time?

Multiple GPU on one machine is not supported. You can setup four different machines and use Swarm. That works.

You can use lower spec power computers and pop the 1070s in there.

[quote=“dustintinkler, post:1051, topic:109474”]

Still having this error, here are some more images. i tried migrating the level to a fresh project and it fixed some but introduced others. I also tried using cpu lightmass and im getting similar unpredictable errors.
I am at a loss, I dont understand why all of a sudden these meshes started acting like this and I just cant figure out a fix or why its happening.

I recommend you reimport the mesh and see if it fixes it. Depending on which UE4 (4.20 I think) version, there is a nasty bug where you have a import the new mesh with a different name or delete the old Uasset together before it refreshes correctly.

There are other oddities with static mesh imports sometimes…

are you using double face materials? this causes problems.

Hi Everyone,

my first comment here, just love this GPU lightmass project.

I’m busy with my first project and I’m very impressed with quality. I am however now starting to get this error on lightmass calculation below, can anyone please help me decode what the problem is?

The failure happens just before the GPU lightmass calcs start, so before the progress bar pops up. CPU, RAM and GPU memory seems fine (I have two GPUs, 1070ti on two monitors and 1080ti for rendering) and I have cleared the cache

Much appreciated.

<None> === Lightmass crashed: ===
Assertion failed: (Index >= 0) & (Index < ArrayNum) [File:c:\ue4-gpulightmassintegration\engine\source\runtime\core\public\Containers/Array.h] [Line: 611]
Array index out of bounds: 9745770 from an array of size 9745770

0x00007ffc09918e6c KERNELBASE.dll!UnknownFunction ]
0x00007ffb31aded47 UnrealLightmass-Core.dll!UnknownFunction ]
0x00007ffb31ae16d7 UnrealLightmass-Core.dll!UnknownFunction ]
0x00007ffb3197234a UnrealLightmass-Core.dll!UnknownFunction ]
0x00007ffb318fd699 UnrealLightmass-Core.dll!UnknownFunction ]
0x00007ffb318fdde9 UnrealLightmass-Core.dll!UnknownFunction ]
0x00007ff76b026528 UnrealLightmass.exe!UnknownFunction ]
0x00007ff76afa8b70 UnrealLightmass.exe!UnknownFunction ]
0x00007ff76afa905a UnrealLightmass.exe!UnknownFunction ]
0x00007ff76afa905a UnrealLightmass.exe!UnknownFunction ]
0x00007ff76af6b39b UnrealLightmass.exe!UnknownFunction ]
0x00007ff76af9374a UnrealLightmass.exe!UnknownFunction ]
0x00007ff76afb6dd9 UnrealLightmass.exe!UnknownFunction ]
0x00007ff76af6bb64 UnrealLightmass.exe!UnknownFunction ]
0x00007ff76af8f36d UnrealLightmass.exe!UnknownFunction ]
0x00007ff76afae4da UnrealLightmass.exe!UnknownFunction ]
0x00007ff76b021bb8 UnrealLightmass.exe!UnknownFunction ]
0x00007ffc0a1313d2 KERNEL32.DLL!UnknownFunction ]
0x00007ffc0c6454f4 ntdll.dll!UnknownFunction ]

I should start by saying a big thank you to @Luoshuang for the amazing work on this project. I’m using a 2080ti and it reduces my build times to about a fifth of that on CPU, I couldn’t believe it first time.

However, my main stumbling block is that I’m using a single skylight as the only pre-rendered light source in my game. This light is set to Stationary which meant, when I was using CPU-lightmass, this light’s intensity could be reduced over time via a blueprint and its baked lightmaps in the world would be reduced along with it. This was how my day/night cycle was working (there was only ever one general lighting condition during the day).

However, with GPU Lightmass, this light (I’m assuming) gets converted to a static light (as stated in the description) and so the lightmaps stay at a fixed intensity, even when the light is turned down via blueprint. In other words the whole map looks illuminated at night (even when all lights are off).

I know, for now, this is a hard limit of the GPU Lightmass method but is there any news on current / future development to remedy this?

I would be eternally grateful for a solution to this problem. Thanks!

Why the SWARM does not work anymore?
I have connection. All hosts are seeing each other and the Coordinator.
But the task is not distributed to the networked hosts even if AvoidLocalExecution is TRUE ( then the main host still baking the Lightmaps even if it should not ).

Anybody knows what’s happen ?

Fixed: ESET Firewall Problem. SWARM works.

I use GPU calculations to light scenarios levels.
I have found a problem when calculating.
lets say “night” level after successful build lightmap calculation, other level “day” got mostly lights and some objects already calculated turn back to “need to be rebuild”.
I migrated main level and his light scenarios to clean project, did try clean new light levels and problem persist.
I don’t have any new idea how to solve it, can it be that it is a bug?
I would appreciate a lot your help. I’m stack with my project.

Hi guys,

i just wanted to share some GPULightmass shots!
It took 50 minutes with 12 x RTX 2080ti in our ARCWARE Studio.
Sorry for the Compression quality of the images, it was impossible to upload Quality Shots due to 550kb upload limit.

i use multiple light scenarios with GPU lightmass and it has no issies renedering them. PM me, I’ll try to help you, but i don’t think this is related to GPU.

Looks gorgeous! But 12 GPUs? I thought it was only able to use 1 GPU at a time…?

I suppose they are using 12 separate PC’s with one card each

Anybody? Nobody?

Seems to me I had similar problems when started using GPU.
For memory problem I increased swapfile

no that’s not it, but thanks for replying!

Does anybody know where the memory limits lie with this solution? I use a GPU offline renderer so I know that this scene fits on a 1080ti.

However currently if I add one more asset to this scene, it crashes on lightmass generation as above. Works perfectly this far.

I monitor GPU load, RAM usage as well as page file size etc but it still crashes if I load any further geometry into this scene.

What is the memory bottle neck with this GPU Lightmass?

EDIT: the below image is a raw and unfinished UE4 render of the scene as it is at the time of crash. Not too much there however I haven’t done any mesh optimization yet.