@Makigirl - I have to say that I always use 2 sided material. 
Out of memory. But my scene is very little only one room and couple stufs. gtx 650 ti 1gb. fx 6300 maybe more good than 650 ti
Didnt have an internship at Epic already? Thats when he built the multibounce skylight if I remember correctly^^
Hi ,
Thank you so much for sharing this with us.
Just ran a few tests and it works great.
I have never been happier with the GI quality in unreal !!!
And the speed… ■■■■ its fast
Someone at Epic get off their butt and get this in the engine ASAP
Honestly…I think Epic is working on a realtime raytraced viewport for lightmaps…like Unitys progressive lightmapper and I think what is sharing atm is just a first step in that direction. If you wanna bake lightmaps on the fly in the viewport you FIRST have to write a GPU solver anyways and then build upon that. So yeah…I think Epic actually has that in the pipeline already 
Also…lets not forget that they showed exactly that at GDC in cooperation with nVidia
PS: what I am trying to say is it will end up in the engine eventually^^
@Muchasty I had the same leaks in the corners with the gpu lightmass in a test scene where the inner planes of walls were detached as planes and was a 2 sided material assigned to them!
Hi,
I just opened my scene and when I wanted to rebuild the lighting this error popped up…what am I doing wrong? It was working before 
Makigirl How to produce such clear shadows? I can not make them look like this …
Well you don’t really have much control but lightmap resolution with gpu lightmass… + post process…
Just as Geza Kadas, GPU Lightmass started crashing for me today. Haven’t done anything special that I know and I have done several light bakes today without a problem, and now my light bake was just interrupted by this nice little message:
If I click OK, I get the option to abort (which aborts the bake), retry (which immediately crashes) or Ignore, which just goes back to getting the launch failure, and around and around 
Except for this strangeness, I’m quite impressed with what you’ve achieved; I’ve rebaked several old projects, and it is 5-10x faster AND gives higher quality than I’ve had before =D
EDIT: Apparently there is something in one of my levels that causes the crash, cause when I tried baking ligt in other levels in the same project, there was no problem, Didn’t even restart my computer or UE. There was really nothing special at all in the scene as far as I can see, just a few meshes, a few lights, a skylight and a postprocess volume, more or less. Any idea what could have caused the problem?
That’s an Unreal bug unfortunately. Open Swarm, and clean the cache. That should fix it.
Hard to tell. The best way to do it would be just try until it breaks lol.
Try further increasing TDR to something like 300.
It looks like you’re using SourceLength which is not supported by GPULightmass currently and the lights will emit less energy in total; the ‘rotated lights’ is a UE4.19 bug.
Thank you, will try it later today !
It’s too fast :o 
THanks so much :o
I7-7700 vs GTX 1080ti
Thanks **duke22 ** clearring the swarm cache done the trick !!!
- thanks for explanation. In free time I will try to fix this scene and re-render the light maps.Then I will show the results.
**BTW: THANK YOU VERY, VERY MUCH for you effort in developing the rendering part of UE4 ! **
— Maybe you should think about some PATREON. I think that many of us could support you with few of bucks monthly. Just a FB UE4 - group has over 10k members ! $1 from only 1k of members could give you some nice financial support for more coffee and/or beer at work — Look at the campaign of the HDRIHAVEN.com —
I also ran into the same issue with the swarm cache causing the lighting to fail to build but once it did, it did in a fraction of the time and I really like the results. Awesome plugin. Thanks
+1 for PATREON, this effort deserves financial support!
After some changes ( material One-Sided, replaced point light lines by spots ) Image look better, but still have some “sparks” mostly visible on the ceiling ( but is everywhere - mostly on walls )