Weird issues with Lightmaps

I am getting same issues in 4.21.2 and 4.22p6.

Here is pre-baked look and lightmap UV of the model (I also had different UV layout and still had the same artifacts):

And here is after baking lighting using stock Lightmass (non-GPU; note that the same model on the left has no artifacts):

Has anyone had same kind of issues? Why is this happening? How do I fix it ?

Thanks beforehand

Your Lightmap is literally ■■■■.

You would need a Resolution > 2048 to have proper lighting
You waste alot of space

Are you mirroring(scaling the model negative) or something?
That is one of a terrible lightmap unwrap btw.

If you say so… Has anyone ever taught you that when people ask for help you either help them or not say anything useless ?!

This is a test case (with a way less seams), to make sure there is nothing weird going on with standard lightmap UV layout.

Nope, I simply copied (Ctrl C) model and rotated it.

I know, right (re: my reply to the previous smartass poster) :rolleyes:

There’s a lot of little issues that might be contributing. The obvious things like make sure you are using a lightmass importance volume, baking on production. What does the model look like? Are there open edges? Posting the OBJ file might help with trouble shooting as well. Probably should post a Lighting Only view as well, textures can mask the issues.

That is horrible advise. Waste of memory and time to use resolutions like that on assets that don’t need it.

Yep, I got the volume.

Nope, baking on Medium. I noticed that these artifacts don’t go away between Preview and High settings. Therefore I assume Production will end up the same.

Model looks just like on screenshots - a corner pillar. No open edges. Unfortunately I can’t post OBJ since it’s from one of the Marketplace packs.

Lighting Only view looks the same (also all models have solid color textures).

One thing I noticed is that those dark faces are comprised of 2 co-planar adjacent triangles aligned in vertical plane. I don’t if if that’s a contributing factor or not (really shouldn’t be).

After messing with vertices and edges on those problematic areas the issue is gone (for now). It shouldn’t really be an issue (I don’t recall having these problems with GPULightmass).

I believe the GPULightmass handles geometry and vertex normals differently. That’s why it doesn’t have the same issues with modular flat pieces not matching up in lighting.