For large worlds, I would avoid using lightmaps, at the very least you will end up with a large amount of hard drive space taken up by them and a huge game install.
If you can wait to test out upcoming 4.8 it has some dynamic GI updates and might suit your purpose better. The Kite demo will also be made available which is a large outdoor world example.
Not to bump an old dead thread, but I have had this issue still on multiple jobs, shots, and experiences now. Has there been any solution to large scene lighting especially for real-time or not real-time global illumination? I see Epic throwing a lot of time and resources in Raytracing which is the new next big thing, however this will not work well for scenes with a lot of foliage and will definitely not work for VR. Not every game is a corridor shooter. I know Epic uses distance fields and dynamic lights in Fortnite, which works great for them. This is a special case because assets have to be built and chunked specifically for that technique in mind, which in many ways too granular for a VR game. There were solutions in the past like landscape based height field GI which would be perfect for my situation or Light Propagation Volumes both of which seems like they are no longer in development. Are there any solutions on the horizon for this scenario? I feel like anyone doing a game or a shot that requires a large landscape and view are just our of luck at the moment.
Currently I am trying to light an large outdoor scene for a VR project. I feel like I am out of luck as I cannot relay on dynamic lights as they are too expensive and the scene is too large for Lightmass to handle as it crashes. This is even with world composition and proper object culling set up.
Yeah, I ran into this problem as well. Was trying to bake a massive outdoor scene, but swarm couldn’t handle it. Crashed too many times to count and was forced to move to a level streaming model. Would be super useful to have a solution for this issue.
The real answer is “get a better swarm” unfortunately.
for any high quality production this usually isn’t an issue, they do have 10+ high end computers on hand to add into the swarm.
for the indy dev this can be problematic, if not impossible.
For 4km map bakes I been using 2 i7s with 1080s overnight. Probably doesn’t take all night either I just put it off until then so as not to end up watching paint dry…
There just isn’t a good solution for dynamic GI, especially large environments, in general for games.
Most large, open world games don’t even use fully dynamic GI and instead use some sort of simplified color(not taking into account nearby light bounces) or precompute spherical harmonics. UE4 supports SHs in the form of Volumetric Lightmaps, but they’re coupled with static lighting so you’re still forced to have decent lightmap resolutions for every mesh and pay for the static lighting overhead in nearly every material.
LPVs, while not directly supported by Epic, are still functional if you want GI from the directional light only. There’s also screen-space GI, which suffers from the usual screen-space issues, but works really well otherwise. DFGI is deprecated and removed iirc from a recent commit on dev-rendering.
I agree with Wozner, using dynamic lighting (movable) would be a much faster and easier way for large open worlds. There are a lot of tricks you can do with movable lighting to make it cheap and still look good, such as putting shadows on high and and increasing cascades to 5 or higher, also using distance field shadows. What I typically do is make dynamic shadows cutoff close (5000) and then let the cheap distance field shadows cover the rest.
Yes this a great solution for anything but VR, at the most we can get on maybe 2 Dynamic lights. I guess we can look into maybe trying to make things cheaper with light channels.
as this thread has been revived, i’m gonna put my grain of salt. What is best a build farm, or a multi cores beast (32, 64 cores…)
I’m using Sun &Sky with world comp, and I get these weird , circular (I think ,kinda hard to tell) shadows that move with my character, but not in all areas of map oddly…what is causing, how to fix ? 
Thx
came across that interesting article. according to the author pre-built lightning is not recommended for very large worlds. according to him the only way to go for that kind of project is dynamic lightning. He even explains the procedure. It sounds logical to me. as when your world has thousands of assets you need to store all this somewhere. and if you succeed the miracle to build it. then you may give an indigestible meal to the client. dynamic is dynamic, but you can tweak it. and it’s streamed so if it’s there it’s there, but when the chunk is unloaded, it’s unloaded. i’m new to Unreal, so i may say silly things, but this is how i see the thing
Was that for me or OP , etal,anyway great article, feel better about dynamic lighting being cautious, but I still have those dain circular shadows followig character, ruining realism
MAYBE 4.25 will fix, I’ll let thread know, but its still an issue at least herein 4.24.