Hello,
I have a question about lightmass volumes.
I am doing a world with World Composition. For the moment, I am doing the lightning of my third city.
In the two others, I added Lightmass volume arround the houses with interior only.
The light build was fast and it was ok. The light was good (I am using UltraDynamic sky) even if sometimes I had too much shadow on a face of my houses that becomes really dark. But it wasn’t a big deal, I added a street light near that and all was ok (annoying but ok).
In my third city, that is bigger that the two others, I have again issue with dark houses face (For example at 10 AM, one of the face is well illuminated and the other really dark). It happens especially in little street (alleys) where I have not much light. So, again, I found the solution by adding street light (static, a lot of street light). But it is complicated… I need really a lot and it is exausting and even if the light of the alleys at the end is not bad, but have a street light each meter is not beautiful…
So, I saw on the internet that the lightmass importance could help in the indirect lightning. I added importance volume in my city to cover each streets and each houses that have interior. Then, I build the light (it takes a lot of time… Really much more than before…). And at the end, I can’t really see a big difference…
Should I leave then ? Or delete them and do the same as the other cities (keep only for house with interior) ?
By the way, if somebody have an idea for the dark shadows…
- sky light intensity doesn’t help
- shadow amount help a bit but it is not enough
- distance field is enable
Thank you for your time and help ! 
PS : I am using 4.26
All the best