Bug Lightmap artefacts on small gaps

Some time ago, i had to bake a lightmap for a scene in my project, it went pretty smoothly and all, but now I had to add more assets to the scene, consequently, having to bake another LightMap, but as soon as I baked the new lightmap, I started to notice some "Extreme light dense" on the gaps of the floor.

This is the previous lightmap, no errors at all.



And this is the new light map generated.
Here we can view some lighter spots that are inside the gaps of the floor. (those gaps are 3D modelled with the floor itself).

 

This is the previous lightmap (the one that works)




This is the new lightmap (the one that doesn't)

 

I noticed that when i place the new lightmap to a edition tool, such as gimp, the parts that have the artefacts was transparent.

 

Both Texel Validity and UV Overlap in either, before and after the issue are getting me the same results.

 

Try disabling stich seams, this might bring other issues, but you can check to see if it's the cause of your current issue.
For me unity's stich seams caused light leaking for some meshes, but disabling it creates other issues.

 

Unfortunately changing the scale on lightmap didn't had any changes.

 

Thanks for this, it wasn't perfect as you said, but removed the big light focus, I will use this as an alternative solution for now, and try to study more to improve the scene.