Weird effect on walls

[nimble haven]

hi, do you guys know why this happens? the left side is black

[ripe valley]

what happens if you increase the lightmap quality, did you try clear the light maps and a rebake

[nimble haven]

yes It's my second time rebaking and the lightmap resolution is set to 20 which should be enough no?

but I'll try rebaking with higher resolution

[ripe valley]

are these walls even been baked makre sure to include them in your bake

you cna do that by marking your gameobjects as static

but i guess you know that

[nimble haven]

Oh yeaaa ofc, they’re all static, sorry I didn’t see your answers

[onyx mason]

How did yo make those walls ?
Could it be that the objects have a negative scale ?
Do they have lightmap UVs ?
What does it look like in the lightmap preview ?

You can also refer to this documentation page : https://docs.unity3d.com/6000.3/Documentation/Manual/troubleshooting-lightmapping-artifacts.html

[nimble haven]

I just used probuilder and added textures on them, they haven't got a negative scale and yes they have lightmap uvs

[tall schooner]

Confirm that you've generated lightmap UVs from ProBuilder, as meshes under its control must be modified from the tool itself

[nimble haven]

I’m not sure what you mean but there was a message popping up saying the light maps were incorrect or something like this after I changed the mesh sizes and I just clicked on the fix button and then rebaked, so I don’t think it’s an issue

[tall schooner]

Does that mean you no longer have the issue after rebaking or that you do?

[nimble haven]

I still do

But that means its probably not the probuilder light maps the issue I think

[tall schooner]

It didn't confirm if there actually are valid lightmaps UVs, or if you enabled their generation where it's meant to

[nimble haven]

well the message disappeared after I fixed them so I suppose this is confirming, but what should I do to confirm it and see whether they are valid lightmaps uvs or not?

[tall schooner]

Use the scene view debug modes to check for UV overlap, and check that the lightmap UV generation is enabled in the right place

You only mentioned changing size

So the warning is unlikely to be related

[nimble haven]

sorry, I had a personnal issue which made me unable to answer, thank you so much for helping me, the uvs are indeed incorrect, after restarting and rebaking one more time, I see that there are no lightmaps generated for the walls, but they're static, contribute gl which is weird

[tall schooner]

It's not weird
Contribute GI means the mesh contributes to global illumination during baking
To additionally receive GI to lightmaps, the mesh needs valid UVs for them in its mesh data

[nimble haven]

how to make valid uvs?

should I use an external tool such as blender?

[tall schooner]

If the mesh is handled by ProBuilder, generate them from within ProBuilder
Probably this: https://docs.unity3d.com/Packages/com.unity.probuilder@6.0/manual/Object_LightmapUVs.html
If the mesh exists outside of ProBuilder's control, it uses the lightmap UV generation defined in model import settings
https://docs.unity3d.com/6000.3/Documentation/Manual/FBXImporter-Model.html

[nimble haven]

thank youu so much, so I should just enable the "generate lightmap uvs in model import settings right?

[tall schooner]

...Only if your mesh isn't controlled by ProBuilder as it overrides those settings

[nimble haven]

oh okay, thank you for helping me.

I'll have to rebuild everything😭

[tall schooner]

Why?

[nimble haven]

because it will modify the prefab only right? and the actual prefabs in the scene won't be fixed?

[nimble haven]

isn't there a way to generate the lightmaps without replacing the prefabs?

[tall schooner]

I don't follow
Every mesh, whether in a prefab or not, gets its data from the original mesh asset
Either that's managed by model import settings, or by ProBuilder

[nimble haven]

yeee, sorry I'm kinda lost today, but I just enabled the generate lightmap uvs and it didn't fix anything

[tall schooner]

You can convert a probuilder mesh into a "real" imported model asset managed by import settings
Or an imported model into probuilder's own ephemereal format managed by the tool

Both work for lightmapping, you just need to know which one you're working with

[nimble haven]

actually, the probuilder meshes don't have the issue anymore but the imported meshes are the one problematic

and I don't really wanna convert them to probuilder meshes, that sounds like a lot of work for nothing

[tall schooner]

They are managed by model import settings so no need for that

Double check that you're changing the correct mesh's model import settings, that you apply, and that you rebake
Then verify with UV overlap scene window debug view

[nimble haven]

yes so I just need to enable the "generate lightmap uvs" and apply right? I just did this and it hasn't fixed anything

[tall schooner]

It's possible there's other lightmapping issues besides UVs, but you want to make sure they're correct

[tall schooner]

Not just, you do have to bake again

[nimble haven]

it's indeed the right mesh model and here's the UV overlaps

[nimble haven]

yes I did

[tall schooner]

The translucent walls which appear darker have not been lightmapped, possibly they've not been set to receive GI to lightmaps
You should take a screenshot of the same spot in contributors/receivers debug view
Red means UV overlap, and it can indicate missing lightmap UVs, but overlap can happen for other reasons too
Mainly that the mesh's "minimum lightmap resolution" in lightmap UV generation settings is larger than the resolution you're baking them with

[nimble haven]

ohhh ok , I didn't know this, and yee the minimum lightmap res in the model import settings is larger than the baked resolution, this causes them uvs to overlap and that's why they miss their lightmap uvs?

I just set the min resolution to 20 and also to 20 in the scene baked lighting so that would work but it doesn't help

so the issue isn't this one but the fact they miss lightmap uvs as you said, but I did enable the generate lightmap uvs on the model import settings so I don't understand

oh no my bad, they weren't red lol, sorry I'm really dumb today

so if I refer to what you said, it's because they haven't been lightmapped but how to lightmap them? because I did it as you told me and it doesn't work

[tall schooner]

can you fold out this field from the arrow

And also tick this

The above screenshot seems to indicate that the have not been included in the last bake
Maybe the bake didn't properly start/finish
But seeing the Baked Lightmap field may give some kind of clue

[nimble haven]

where is this if you don't mind? I can't find it lol

[tall schooner]

Scene window in GI contributors/receivers view

[tall schooner]

Since according to GI debug views those walls don't exist, it's hard to draw any kind of conclusion
On top of all that it looks like your lights could be clipping into the walls so can't tell if the lighting that isn't fully bugged out is correct either

At this point I'd go fully emprical and test what truly works and what does not
New scene with one wall, one floor, one default cube and one light

[nimble haven]

ohh okay I'll do this, thanks for helping

[tall schooner]

In a big scene there could be five different light baking problems, each of which obfuscates the others
And there's many steps to follow to do the bake right to begin with

[nimble haven]

well, at first before baking, they weren't bright enough so I thought adding these lights would help and it indeed did even if it's kinda wrong

[nimble haven]

could you tell me them please? I'll make a new scene right away when i'll be back home

[tall schooner]

So a test scene with no unknown or unpredictable variables is your best ally

[tall schooner]

You should always double check from documentation (and tutorials won't hurt either), but off the top of my head

1. Set meshes as contribute GI static, receive GI to lightmaps
2. Enable lightmap UV generation on meshes or otherwise confirm they have valid lightmap UVs
3. Set lights that should be baked to type Baked
4. Enable Baked Global Illumination in Lighting Settings
5. Bake
   Important to note:
6. Not all meshes need lightmapping, small and complex meshes should receive GI from light probes, if they need to contribute to GI at all (Light probes are also very important, but practice lightmapping alone first)
7. Meshes should not have exposed backfaces
8. Lights should not be too close to geometry, and their ranges should be sufficiently high
9. Don't enable Realtime Global Illumination, it's a different lightmapping system with a whole another set of quirks
10. The simpler scenes you practice bakes with, the less time you spend waiting as well as hunting issues arising somewhere from the complexity