Lightmap and mirrored meshes.

Unity Engine
1

Hi,
I would love some help with light mapping.
I have tried baking using the Unity auto lightmapping and it has some artifacts that I didn’t like due to the unwrapping process putting these lines diagonally,

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so I have decided to make my own UV set for the LightMapper which fixed these and gave me clean cuts.
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However for some reason even though my scene is completely symmetrical Unity has problems with it, specifically with my walls.

4457815--409108--upload_2019-4-22_22-49-22.png
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I Know that 2 faces on the same UV coordinates should make problems but given my Symmetry i don’t have a problem with the lights double exposing my walls.
I have tried using only one side of lighting and it gives the exact same result,(floor and ceiling lights up on both sides yet the walls have that switcheroo).
as you can notice there are two light stripes on the left wall that light up fine.

BTW the original half in blender is actually the left one.

How would one fix this? or is this a bug in the progressive lightmapper?
Also Emission materials don’t work for me as well I faked Emission using point lights.

LWRP Unity 2019.1.0f2

Thank you, Yossi Cohen.

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2

Since the mirror mesh is sharing the UV space with the original half, you will obviously run into issues due to UV overlaps. There are couple of ways you can mitigate this issue:

  • Merge the mesh into a single object in Blender, and unwrap it as a single object.

  • Split the mesh into original and mirrored variants, and have unwrap them individually.

3

Is 3-rd option possible, adding secondary UV in 3d modeling software ?