Any clues what I'm doing wrong with lightmap here?

Hi!

64 and 128 resolution lightmaps for such a huge and complex mesh won’t be enough!
You should have a higher (1024?) one and your shadows will be more accurate!
…you can also break up your mesh into modular pieces and set lower lightmaps per piece!

Hi,

I’ve been stuck here for very long and can’t focus where the problem is, some help plz ^^´.

This is what lightmap does, each arc has 2 Uv channels, one for texture the other for the lightmap. In this specific screen i set the top arcs line with unreal generated lightmap uvs,and the bottom arcs line with my generated secondary uvs, that seem to be correct; but the result is the same(that sounds preaty weird dont do?), those weird artifacts with only one directional light.

Top Arc config

Bottom Arc config

Thanks for your time.

Oh, i also looked at some other posts & tutorials, but couldn’t fin the source of this error, they mention 2 good tutorials in case somebody else find them useful.

https://www.youtube.com/watch?v=gMXye-JhCyQ

ouch, sorry to say increasing quality to 1024 & 2048 didnt work, the same artifacts on the same spots, I’ll try splitting the mesh, maybe that works, thanks anyway for the quick response.

Subdividing the mesh reduced the artifacts, there are still some, but this could become aceptable now as this will be far environment.
Anyway, could be a better aproximation for the environments?, cant believe they fight with this troubles when they only want a background that doest consume too much resources.

Hey there.
If the whole circle or arcs is a single mesh then I think the problem is your Lightmap resolution being too low for it at 128px.
It will be best if you take a more modular approach by importing just a single arc element to then instance around a circle within the editor. In this case you could probably get away fine with a 128 (or less) lightmap per object rather than a 2K+ one for the single object.

Not sure I follow you but instancing modular meshes can consume far less resources than a huge hero mesh like this one. While fixing your lightmap issues at the same time.

Either way, glad you got it working! Cheers