I’d suggest downloading 4.11 and putting in portals before messing with the .ini settings.
The new version (4.11) is too good to pass up! Now it’s easier, faster and more efficient.
I did download it, but something happened to my scene. I recreated my project in 4.11 and it just didn’t work. After calculating Lightmass everything was looking wrong - I don’t know yet why, I must have forgot about something, or settings are different from 4.10 and I need to adjust/change something to get correct result.
for now, further tests with 4.10:
Light Quality: Medium
Static Lighting Level Scale: 0.2
Num Indirect Lighting Bounces: 20
Indirect Lighting Quality: 10
Indirect Lighting Smoothness: 1.0
BaseLightmass.ini
NumHemisphereSamples = 256
Texture size for walls and floors: 512
Rendering Time: 2.5h
And now question, how to get rid of this artifact? It happens on most points where walls connect with ceilings. It is adjusting the texture size?
And by the way, how to get better AA quality from Highres Screenshot? A screengrab from viewport looks like that (nevermind DOF):
It usually happens this to me when I use a low lightmap dimension, the only fix I found is to increase it.
For the screenshot I heard that it’s a known bug, the AA doesn’t work with the screenshot tool.
I think it’s more because temporal AA is a AA method that takes a couple frames to ‘‘respond’’. Look around in your scene and stop, you’ll see it when the temporal AA kicks in! Apparently that doesn’t work very well with a screenshot because it takes only a single frame!
But hopefully that’s just a bug and it will get fixed!
You can always export 2-4 times higher resolution and downsize it in Photoshop. It helps to get rid of most jagged edges.
Yea, unfortunately I’m having problems with lighting in complexes scenes on 4.11
The portals are great, but the overall indirect lighting from skylight it’s too dark in some corners and the shadows aren’t so sharpen anymore. Also the artificial lights produces more light/shadows leaks than 4.10, even with a high indirect photons.
I have to make more tests or wait for the final release, because I couldn’t achieve a perfect result from my old scenes 
I’ve never used software filled with so many bugs and malfunctions in all my life…
Try making a AA Pc game with Unity; you’ll love it.
If you think lightmass is buggy, I’m sure you’ll love Enlighten in Unity 5.
I actually think whoever works on the lighting side of things does a pretty good job, I’m just irritated that i made a almost finished level, after opening it in the 4.11 preview 2 it doesn’t want to package the project anymore. The reason why is extremely unclear too.
Well, it is a preview release, they typically have dozens of bugs, I wouldn’t expect a preview build of the engine to work with no flaws.
A preview is usually just adding to an older version, i doubt the packaging project malfunctions will be solved. Time to spend all day tomorrow, re-importing every single .fbx file into a brand new unlit un textures scene because of a stupid error that should have been dealt with long ago…
UE4.11 preview releases are expected to be full of problems and not intended to be used to create important projects. Epic had stated that clearly in the Announcement section. But to be honest, I’m tempting to port all of my projects over to UE4.11 since the lighting build time is so fast 
That explains why I’m here 
I’m not a pro but could this just replace lightmass and speed up our process big time? the thing is Octane is a unbiased pathtracer. That could give much more accurate results than photon mapping. It also runs on gpu! (GPUS even)
This is a feature from the upcoming Octane Render 3
**
Advanced live texture baking**: A feature that’s most beneficial for use in real-time game engines, OctaneRender 3 supports unbiased GPU texture baking (UV or volumetric) of global illumination, spherical harmonics and 8D light fields in Unreal Engine 4 and Unity plugins.
source : https://home.otoy.com/otoy-unveils-octanerender-3-worlds-best-gpu-renderer/
I have another question about portals. I made a test scene for improving my skills about interior-exterior scenes. I use 's lightmass settings for 4.10 version.
Are portal lights useful for interor/exterior scenes? If i use them how about my exterior quality?
Portals just tell lightmass where to look for extra detail. You would just put them in the windows, just like you would with an interior scene.
Nice scene there , how long to build?
This is the first time i will build with foliage. But without foliage it took nearly 8 hours medium settings and 's lightmass settings. But i have a workstation. It is really full of power
Now it is building lights with medium settings and original baselightmass.ini file (UE 4.10 version). I will share results 1-2 hours later.