Luoshuang's GPULightmass

The_Distiller · October 20, 2018, 2:18pm

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.

https://cdn.80.lv/80.lv/uploads/2018/10/IMG_2961.jpg

SenChi · October 21, 2018, 9:58pm

Does it support a RectLights ?

anonymous_user_f00a60b0 · October 26, 2018, 2:31am

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 · October 26, 2018, 6:33pm

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 · October 27, 2018, 1:41pm

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 · October 27, 2018, 10:32pm

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 · October 27, 2018, 10:45pm

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 · October 29, 2018, 11:07am

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.

ig_ToxXxic · October 29, 2018, 3:34pm

Will we get for 4.20.3 ???

GrayAxen · October 29, 2018, 3:37pm

The current version works just fine for 4.20.3.

Morningcoffee007 · October 29, 2018, 4:14pm

Better ask for 4.21 we’ll need that one quite soon!

anonymous_user_cc004a28 · October 29, 2018, 4:57pm

Would this work for 4.20.3 (installed with Epic Games Launcher, non-source build)?

GrayAxen · October 30, 2018, 12:27pm

2 posts up.
It works just fine for 4.20.3

Nocturness · October 30, 2018, 12:44pm

thx Loushuang. using unified settings(128/32) and seems not issue with emissive materials.

Ixiguis · October 31, 2018, 1:54am

I’m getting a crash when GPU Lightmass is about to start. Any ideas?

System is Windows 7 64 bit, GTX 1070, latest NVidia drivers (CUDA 10.0.132), and I did set the TdrDelay (and restarted the computer). UE4.20.3. Already cleared Lightmass cache. Started the editor in Admin mode.



[2018.10.31-01.24.08:784][702]=== Lightmass crashed: ===Unhandled Exception: EXCEPTION_ACCESS_VIOLATION reading address 0xe78f0000
Unhandled Exception: EXCEPTION_ACCESS_VIOLATION reading address 0xe78f0000

0x000007fea24dadb0 nvcuda.dll!UnknownFunction ]
0x000007fea24daf8b nvcuda.dll!UnknownFunction ]
0x000007fea25c449f nvcuda.dll!UnknownFunction ]
0x000007fea26bc6b8 nvcuda.dll!UnknownFunction ]
0x000007fea25c4e6c nvcuda.dll!UnknownFunction ]
0x000007fea249d6c4 nvcuda.dll!UnknownFunction ]
0x000007fea24a22e6 nvcuda.dll!UnknownFunction ]
0x000007fea249ab1a nvcuda.dll!UnknownFunction ]
0x000007fea2624172 nvcuda.dll!UnknownFunction ]
0x000007fea469dbd5 GPULightmassKernel.dll!UnknownFunction ]
0x000007fea469f093 GPULightmassKernel.dll!UnknownFunction ]
0x000007fea469db6a GPULightmassKernel.dll!UnknownFunction ]
0x000007fea4693c5c GPULightmassKernel.dll!UnknownFunction ]
0x000007fea4693cd9 GPULightmassKernel.dll!UnknownFunction ]
0x000007fea4692882 GPULightmassKernel.dll!UnknownFunction ]
0x000007fea46aabff GPULightmassKernel.dll!UnknownFunction ]
0x000000013f5ff6bb UnrealLightmass.exe!UnknownFunction ]
0x000000013f5b6bf9 UnrealLightmass.exe!UnknownFunction ]
0x000000013f57e141 UnrealLightmass.exe!UnknownFunction ]
0x000000013f52e45c UnrealLightmass.exe!UnknownFunction ]
0x000000013f551632 UnrealLightmass.exe!UnknownFunction ]
0x000000013f572dd7 UnrealLightmass.exe!UnknownFunction ]
0x000000013f60a0e8 UnrealLightmass.exe!UnknownFunction ]
0x00000000778059cd kernel32.dll!UnknownFunction ]
0x000000007796383d ntdll.dll!UnknownFunction ]

[2018.10.31-01.24.08:784][702]*** CRITICAL ERROR! Machine: USER-PC
[2018.10.31-01.24.08:784][702]*** CRITICAL ERROR! Logfile: UnrealLight_USER-PC_D71F88A0417396A03C9153AF8320F57D.log
[2018.10.31-01.24.08:784][702]*** CRITICAL ERROR! Crash report: 
[2018.10.31-01.24.08:788][702]LightingResults: Error: <None> === Lightmass crashed: ===Unhandled Exception: EXCEPTION_ACCESS_VIOLATION reading address 0xe78f0000
Unhandled Exception: EXCEPTION_ACCESS_VIOLATION reading address 0xe78f0000

0x000007fea24dadb0 nvcuda.dll!UnknownFunction ]
0x000007fea24daf8b nvcuda.dll!UnknownFunction ]
0x000007fea25c449f nvcuda.dll!UnknownFunction ]
0x000007fea26bc6b8 nvcuda.dll!UnknownFunction ]
0x000007fea25c4e6c nvcuda.dll!UnknownFunction ]
0x000007fea249d6c4 nvcuda.dll!UnknownFunction ]
0x000007fea24a22e6 nvcuda.dll!UnknownFunction ]
0x000007fea249ab1a nvcuda.dll!UnknownFunction ]
0x000007fea2624172 nvcuda.dll!UnknownFunction ]
0x000007fea469dbd5 GPULightmassKernel.dll!UnknownFunction ]
0x000007fea469f093 GPULightmassKernel.dll!UnknownFunction ]
0x000007fea469db6a GPULightmassKernel.dll!UnknownFunction ]
0x000007fea4693c5c GPULightmassKernel.dll!UnknownFunction ]
0x000007fea4693cd9 GPULightmassKernel.dll!UnknownFunction ]
0x000007fea4692882 GPULightmassKernel.dll!UnknownFunction ]
0x000007fea46aabff GPULightmassKernel.dll!UnknownFunction ]
0x000000013f5ff6bb UnrealLightmass.exe!UnknownFunction ]
0x000000013f5b6bf9 UnrealLightmass.exe!UnknownFunction ]
0x000000013f57e141 UnrealLightmass.exe!UnknownFunction ]
0x000000013f52e45c UnrealLightmass.exe!UnknownFunction ]
0x000000013f551632 UnrealLightmass.exe!UnknownFunction ]
0x000000013f572dd7 UnrealLightmass.exe!UnknownFunction ]
0x000000013f60a0e8 UnrealLightmass.exe!UnknownFunction ]
0x00000000778059cd kernel32.dll!UnknownFunction ]
0x000000007796383d ntdll.dll!UnknownFunction ]

Ixiguis · October 31, 2018, 8:01pm

Nevermind, turns out the map was corrupted somehow (even though it opens in UEd). I solved it by recreating the map (easy, since almost everything was in streaming levels).

Morningcoffee007 · November 1, 2018, 9:33am

Thanks for pointing that out might come in handy some day!

Cheers.

Luoshuang · November 5, 2018, 4:23pm

marcClintDion:

I didn’t read the whole thread so please forgive me if I say something that goes against your stated intentions.

If your goal is simply to get UE4 up-to-date with a GPU scene baker then have you considered going with a CUDA/OpenCL based renderer that’s already feature complete and also free and open source.
Blender Cycles originally offered a choice between CPU and CUDA rendering for many years and then some engineers from AMD did a partial rebuild that allowed it to work with OpenCL as well.

It can take advantage of multiple GPU’s and recently gained the ability to split the rendering load between the GPU and CPU for scenes that require extraordinarily large amounts of RAM.

So far as I understand it, integrating Cycles into UE4 would be mostly just a matter of building the interface between UE4 and the Cycles stand-alone application. Once that’s completed, users would simply have to download the Cycles engine and drop it into the appropriate folder.

The official Cycles development team could always use help to improve the engine if that’s what you like doing, no pressure

Here are some link to show what people have done with Cycles and the last link has some information on how to get started with the Cycles stand-alone application.

https://www.cycles-renderer.org/

https://www.blenderguru.com/articles…tworks-of-2017

https://wiki.blender.org/wiki/Source…les/Standalone

Quick question: how is its speed compared to GPULightmass?
An example is Unity’s recent GPU Lightmapper - while also being GPU-based, it is much slower than GPULightmass
EDIT: Unity’s videos about their GPU Lightmapper make people hyped, but from my point of view they show a lot of heavy textured scenes and the scene is generally dark which makes it easy to hide GI quality problems. I tested both the Unity’s official one and Arthur “Mr. F” Rakhteenko’s Bakery- which is a third-party GPU Lightmapper for Unity - in the SunTemple scene, and Bakery performs much better. Also I had a nice talk with Arthur and I’ve decided to integrate Arthur’s ideas about lightmap-space sampling to eliminate lightmap space artifacts.

Bulut_1 · November 5, 2018, 10:52pm

Thanks mate, I managed to finish a VR project with your gpulightmass and my clients loved it! Here is a sneak peak. Look at the shadows!! this is amazing and very fast

Lhorkan · November 6, 2018, 10:39am

What’s the latest on RTX support? Anyone got it working, or does it still crash?