I have this problem with Gpu lightmass and I am not sure how to solve it, light is hiden static, everything is boxed except ceiling but behind ceiling there is another double box ceiling so light doesn’t come from the back, I am not sure how to solve this?
ok its lightmap resolution of ceiling, I cant believe its not enough 256. I had to put it to 1024 for this result. Anyway can I make lightmap just for bottom of box all across UV so the rest of box lightmap is outside UV because nobody see it and its not important? That way ceiling will have bigger space across UV space and I could maybe go with 512 of lightmap resolution, its tedious job to do this to all assets, but if you want quality I guess I have to do it? Your thoughts on this ?
ehh. that’s the thing with optimized lightmapping. essentially you gotta build it with planes or externally modelled interior geometry. that’s the only way i know to avoid baking exteriors. there are modelling tools being worked into the engine. maybe check them out and remove any geometry you don’t want to be included in the bake.
3ds max is ok, but you lost time twiching UVs, although I got used to, and UE5 UV tools makes me nervous, I tried once and left it. I can make all custom UVs just need time 
It would be cool to have some kind of automated process like what camera see that polygons stretch in UV space rest remove. Plugin or script I think some expert would make it easily