the update to 4.21 is live in my GitHub fork’s master branch 
Thanks, , already working with it.
This is so amazing! I was seeing this effect in Yakuza Kiwami 2 and wondering if how I can reproduce it with Unreal. Great work!!!
(Btw, probably you know, the github page of the pull reques says there are conflicts)
nice to see someone else trying it
yeah I’m aware the pull request says there are conflicts. it will probably get worse over time due to the upcoming rendering changes but I’ll wait until 4.22 is out to take care of them
Actually, I have I question. I don’t completely understand how it works. In my video, why is it completely dark inside the reflection capture? Shouldn’t it be “reflecting” some sky from the open side?
if I remember correctly to achieve what you want, you need to tweak the sky distance so it gets included in captures. I can’t remember if the option is in the skylight or in the reflection captures themselves
Nevermind, it works. It’s just very dark, you have to wait for eye adaptation. I did some more testing and you have both reflection and diffuse inside the enclosed area. I’ve put a big white wall in front of the entrance and a metllic shpere inside, and it seems to work.
Some screenshots. IBL UE4 - Album on Imgur
Changing the brightness of the capture makes it brighter inside.
Also, it’s funny but the sphere makes 3 shadows. I don’t even understand where they come from.
So, basically, with IBL each reflection capture becomes a local skylight?
I mean, as I understand it, without IBL, if you have a skylight, a reflection capture and some objects, then outside the capture reflections and diffuse come from the skylight, and inside the capture reflections come from the capture but diffuse still from the sky.
And with IBL, when inside the capture volume both reflections and diffuse are from the capture, so the skylight is completely overridden.
Right?
I doubt the 3 shadows are IBL-related, as the IBL would never produce such a sharp result
I suspect they come from DFAO. perhaps your walls are upscaled meshes or some other thing that DFAO doesn’t like
Shadows are definitely from DFAO, and they are 3 even with ibl disabled. Walls are not upscalled, so it should be some other dfao artifact.
So, with ibl reflection captures completely override the skylight effect, right?
with IBL, reflection captures override the skylight as much as you set the contribution value to. the default value is 1.0 which is why the skylight is completely not present for you
So the reflection capture becomes like a local skylight. You can have multiple “skylights” per level. Pretty cool!
I don’t know if the skylight influences more things than the reflections and the diffuse, so maybe there is still something else coming from the global skylight even with IBL.
Btw, what the “IBL” means?
no, a skylight only influences reflections and diffuse lighting (and controls DFAO parameters). reflections were already “overridden” in local areas by reflection captures, and my IBL system just fills in the gap so it also can occur for diffuse lighting.
btw IBL means Image-Based Lighting
Any news about implementing this feature directly in Vanilla Unreal?
It seems so amazing 
no news sadly, the pull request is just ignored.
atm there are code conflicts but I’m waiting for the final-4.22 to release to re-integrate it into 4.22
This is a really awesome work, but at the moment we are very busy with 4.22 and GDC madness. We will look into it after it calms down a bit, and evaluate if it should become an official feature.
I had some free time and did some more testing of IBL. First screenshot is lightmass, for reference (that’s what I would like to see with dynamic light lol). Second is movable sun/sky,dfao, IBL disabled. Third is with IBL enabled. I had to put sun indirect to 6.
I like ibl (screenshot 3) much more than the screenshot 2. But still, I couldn’t have any influence from the skylight (from the right). I tried to put skylight indirect to some big number but it does nothing. Is there a possibility to have skylight influence in ibl too?
nice to see some work with this!
you can get some skylight back by reducing the probe’s local IBL contribution. this is exactly how I achieve the gif of the lifted roof in the first page of this thread. this would of course reduce the light ‘cast’ by the probe but you can still ramp the probe’s brightness to compensate for that.
if you only have one probe in your room it would make the entire room get some skylight though. from what I can see it seems you have 2 box probes for this room. so if you want the middle part of the room to not get any skylight you’d probably need to have 3 box probes in the room and make the middle one have full contribution while those next to windows have less contribution so some skylight leaks in.
I don’t know how good it would look though. semi-translucent windows seems like a very hard challenge for transferring light in any sort of dynamic light system 
btw I already made a 4.21 IBL branch in my fork which uses the latest 4.21 release.
I will shortly start implementing this into an updated master branch to go along with 4.22
Thank you, I will try this next. Actually I only have 1 box reflection capture aligned with the room. Concerning translucent doors, I also tried without them on the right, but the skylight is still not taken into account. Is there a technical reason why it’s not captured?
I used 4.21 branch I think, the one I downloaded in January. But I will try with 4.22 when it’s out.
Thank you.
the skylight is probably not captured simply because it is not visible through the windows. I don’t know for sure since I don’t know the exact setup you have. are your paper windows solid but with emissive (you fake the light) ? are they translucent (with very high opacity) and there’s actual light coming through them?
The paper is translucent and stationary. But you right, the problem was that. Somehow the sun light is captured but the skylight is not. I removed the doors on the right, rebuilt the captures and then placed them back, and it looks better already I also lowered the reflection capture contribution a little so there is some blue reflections back. Any ideas if I can improve it more? Capturing with doors in place will be optimal. Maybe I can hide them from reflection capture somehow ?