Luoshuang's GPULightmass

[Norman3D]

I am not sure if GPU Lightmass using multiple GPU [2 x 980 TI ] on same workstation. I am using swarm agent to distribute anothe workstation which has GTX 1070. Looks like each single card works perfect expect one of the 980 TI. Can someone explain if GPU Lighmass supports multiple graphic cards on the same machine? Thank You!!

It does not support multi gpu as far as I know. I think the GPU activity in the task manager does not represent very well what GPU is being used. Use a program like afterburner to monitor the temperature. That's a dead giveaway of what GPU is being used by Lightmass. You'll notice that it's only one that is being used.

[thundermax1979]

Hi Luosuang this will work in rtx graphics card?

[Caroo]

@thundermax1979 so far it does not work with RTX card. It always crashes.

[Morningcoffee007]

Note that GPULightmass is still my spare time project. At Epic we're working on DXR/realtime raytracing.

Luoshuang,

If you don't mind me asking, what can we expect to achieve with DXR/ realtime raytracing in UE4 for archviz in particular?

Will we be able to say go from mid day to night time in real time without blueprints? Will we still need reflection captures?

Seeing that you're working on this and you probably know so much more. Probably some things you can't really share with us but I'd like to know what improvements we can expect.

From the demos I've seen I understand it is still a hybrid so the only benefit we'll get is adjusting things while they bake, correct? And only shadows and reflections, right?

I heard some people say this is coming with 4.22 that but I'm not so sure, could you tell us anything about that?

Thanks in advance.


Regards,

Alex.

[ZacD]

Luoshuang,

If you don't mind me asking, what can we expect to achieve with DXR/ realtime raytracing in UE4 for archviz in particular?

Will we be able to say go from mid day to night time in real time without blueprints? Will we still need reflection captures?

Seeing that you're working on this and you probably know so much more. Probably some things you can't really share with us but I'd like to know what improvements we can expect.

From the demos I've seen I understand it is still a hybrid so the only benefit we'll get is adjusting things while they bake, correct? And only shadows and reflections, right?

I heard some people say this is coming with 4.22 that but I'm not so sure, could you tell us anything about that?

Thanks in advance.


Regards,

Alex.

Epic has said there will be DXR in UE4 starting in 4.22 by the end of the year. It's been posted in the forums by staff, and I believe mentioned in the blogs

So far Epic has shown ray tracing for AO, reflections, and shadows. So don't expect light bouncing anytime soon. The Star Wars demo used baked lighting for example.

I think we've stated you'll see some GitHub commits in 2018 and the release of some DXR support in 4.22. I also thought we mentioned GPU support for next version of Lightmass.

[The_Distiller]

The "Speed of light" demo they showed at SIGGRAPH this year had 1 bounce diffuse GI, which is planned to be part of the DXR implementation.

[SenChi]

Does it support a RectLights ?

[thebarz]

Hi,

You can just use the binary distribution. Assuming you're not modifying UnrealLightmass, then the only thing you need to add is to modify Engine\Source\Editor\UnrealEd\Private\Lightmass\Lightmass.cpp to include the dependencies required by GPULightmass, build, then copy the files inside the zip except UE4Editor-UnrealEd.dll and the installation is finished:

search for

const TCHAR* RequiredDependencyPaths64[]

add

TEXT("../Win64/GPULightmassKernel.dll")

to the end of the list (don't forget the comma after tbbmalloc.dll!)

search for

const TCHAR* OptionalDependencyPaths64[]

add

TEXT("../DotNET/ProgressReporter.exe")

Hi, since Regular Lightmass is not working on Linux for me to bake the Lightmaps, I was wondering if I can use your addition. I only see dlls and exe. I believe is not ready for Linux.

[ManyG]

Hi guys,

I use Unified Settings and I can't figure out why the result of lighting is different that from 4.20.2 "standard" lightmass.

With the Unified settings, the lighting is too bright like you can see on the picture. Then I tried severals rendering by tweaking "fireflyclampingthreshold", the valor is around : 0,5 & 0,8.

I would like to obtain the same result that from picure one (old lightmass)

All the lights are from emissive material.

Need help please

[Muchasty]

Old Lightmass based on CPU is not so accurate as GPU version made by Luo.
GPU version gives much better results. For example if you have two walls side-by-side ( or one wall made from two different meshes ) then with CPU bake you could have two different shading (first can be brighter that the second )! With GPU Lightmass everything is coherent.

But still GPU LM gives some white splotches caused probably by bounced rays. (see attachment).


And shadows can give some strange patterns on surface.



Maybe it is when some parts of the surface that gives a bounce are more reflective that others and somehow diffuse is not nicely dispersed on the surface that takes the bounce - I do not know how to say - I am not pro with that matter.

Even that GPU is faster and better - more accurate at lightpropagation than old CPU version.

[ManyG]

Sorry for my bad explanations. My first picture is from GPU Lightmass 4.20.2 and the second picture done with GPU Lightmass Unified.

Today I switched to GPU Lighmass (Not Unified) and the lighting is really nice. Dont know how to work with Unified release, uninstalled it.

[Muchasty]

Have worked with both. Results have pretty the same. US is better cuz there is active function of emissive static surfaces.
In normal version of GPU this option does not work. Maybe this is a "problem" with your scene light that with GPU US your meshes that has active emission gives real light to the scene. In normal version of GPU they are always PASSIVE no matter if u have enable function for emissive mesh.

[ManyG]

Honestly, the lighting I got with normal version is really pleasant, clear better than with US. All the level is done with emissive material, love the soft done with it.

[Sam Joel S]

Will we get for 4.20.3 ???

[GrayAxen]

Will we get for 4.20.3 ???

The current version works just fine for 4.20.3.