Rectangular static lighting glitches

Forgot to attach the screenshots.

I have exactly the same problem. The level I have this on is totally stylized, the materials are just plain textures, not tweaks whatsoever. It also has trees. Lighting is stationary ( directional and skylight ).

Would be interested to hear any answers on this…

I’m wondering if it’s something to do with the tree leaves?..

Hello.
I’m trying to make a nice forest level, but getting weird issues:

  1. Rectangular light/dark areas on the landscape. Small rectangles, large sections etc.
  2. Some trees’trunks get black.
  3. Rarely small rainbow areas appear on the ground or objects, disappear when I hit “play”

The lighting settings are standard. I’ve tried to replace the trees by the completely different ones - still the same issue.
I’ve tried many things:

  1. Rebuilding many times in a row gives the same result, rectangles on the same place.
  2. Moving trees changes the rectangles.
  3. Replacing the landscape material by a simplest color-only one changes nothing.

Tried different settings for lightmap scale etc - nothing makes much difference. I’m running out of ideas. What can be wrong?

UPD: looks like it happens when a lot of complex meshes (trees) are pretty close to each other. I’ve tried 4 different tree types from different packs. Also I can reproduce it on two different computers.

Excuse me highjacking your question, but maybe we can find a pattern here.

Another thing I notice, maybe you could check, is that it’s only happening up one ‘end’ of the map.

My sun is just off midday and throwing shadows slightly to the south ( let’s say ), then the problem is up the south end of the map.

It’s happening around the entire map unfortunately. Mostly where multiple trees are located close to each other.

Hmmm, it is something to do with shadows from the canopy I’m sure, but no idea what.

So, new project. Made a landscape a put a few trees on it, boom:

I discovered that the squares get smaller when you increase the land lightmap res, not really a suprise.

Interesting with land wire mesh on and detail lighting:

You can see the edges of the squares line up with the landscape wire mesh.

Not affected by mesh distance fields.

Different tree did work for me. Not the tree I want, but…

After a lot more fiddling about I’d lay my money on it being the model of tree.

I know you tried other trees. Did you try trees from a different maker / pack / source?

I’m starting to think it’s some kind of light leak caused by the way the upper foliage is constructed.

I’ve tried different packs indeed, made by different authors. Will try to get a minimal reproducible set with just one tree type.