LightMaps Edges appear Wrong, and uvs distort in hard edges

[Fere201]

Hi there. I’m having some problems with the lightmaps on my scene, probably because the way i export the fbx from blender?

My current “worklow” is:

1. Making the scene in blender
2. Making 2 uvs maps (one for bridge textures and one for correct uvs)
3. exporting the fbx
4. importing into lvl in ue5
5. adjusting the correct uv coordinates and checking lightmap density

The thing is i get some weird density display errors and some distortion on some edges of the mesh.

Starting with the lightmaps:

Lightmap edges look highlighted with a strange density, but when selected they appear “correctly”. This happens with most of my meshes so i suppose it has something to do with my fbx export settings:

The other thing is that some meshes have distortion in their edges, even when they have their respective uv coordinates assigned and look good in blender.

Thanks in advance for any help and sorry for my bad english!

[ClockworkOcean]

You might find you only need to get the UVs right in Blender, the engine can make pretty good lightmaps from that.

If you want to know if the UVs are good once the model is imported, just drop the world grid material on it ( not the demo level world aligned one ).

Are you specifically using static lighting? I’m just checking, because a lot of people miss the fact that with Lumen you don’t need to build light.

[Fere201]

Hi, the edges appear like that even when i use the uv coordinates that ue creates when importing.
Yes i am using static lighting (disabled lumen in project settings etc)

[ClockworkOcean]

Can you show the corner with the default material?

[Fere201]

[ClockworkOcean]

Yup, so it’s a UV problem

And I don’t think there is a way to map UVs around a beveled corner.

Well, you can do, maybe 3 faces fine, but you going to have some ugly lines somewhere…

[Fere201]

Hi, i understand that the material error is an uv problem, the thing is that in blender it looks correctly without distortion and in ue5 it doesn’t.

Any idea about the lightmap edges?
(thanks for the quick responses )

[ClockworkOcean]

I’m not sure here. One I fix UVs in Blender, then they import ok to UE.

Can you show the uv map of this wall in Blender?

Once you sort the UV, the lightmap will fall in line.

[IslandPlaya]

Try checking Use High Precision UV (or something) in the material/import options.
This used to fix some similar artifacts for me in UE4.
Good luck.

[Fere201]

The texel density is 20.48 px/cm in a 2048 texture (to use later with bridge)

[Fere201]

Tried to, didn’t work, ty

[ClockworkOcean]

It’s hard to see, not the view I’m used to. Looks ok on the face of it.

If you want, you can upload an FBX here. Or PM me, and I’ll take a look ( would be a bit later though… )