Lightmap sampling bug

Unity Engine
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1

Hello,

I created a project based on the HDRP template. I removed the default assets and light probes but keep all the other settings. Then I imported my own meshes which make up a building from some simple meshes (2x2m each) and a ground plane. Then I set each mesh to static (contribute GI and batching static) and activated “Contribute Global Illumination” and triggered lighing generation. The resulting scene displays bright and dark areas which is wrong. Maybe the building consisting of many small meshes (2x2m) is not suitable for light mapping but I don’t see the reason for this output. Looking at the light map itself in the two images below the light map does not reveal this changes of brightness. I tried both the GPU and CPU light mapper but no difference. The images below illustrate the problem. I select a mesh and it can be seen how it coveres the respective portion of the light map.
Thank you for any suggestions !

6597781--750163--upload_2020-12-7_18-24-27.png
6597781--750163--upload_2020-12-7_18-24-27.png1148×677 962 KB

6597781--750169--upload_2020-12-7_18-26-37.png
6597781--750169--upload_2020-12-7_18-26-37.png1145×679 118 KB

6597781--750175--upload_2020-12-7_18-26-52.png
6597781--750175--upload_2020-12-7_18-26-52.png1070×810 30.2 KB

2

Hey! Unfortunately, there’s no easy way to solve this issue. For some pointers on how to mitigate it, please read through my posts in other similar threads:

3

Hi, no it was another problem. My meshes had no UV2 channel and I also have not activated UV2 generation in Unity when having imported the models. Apparently Unity used the first UV channel when processing the lightmap. I would suggest to display a warning in this case.