Baked GI issues when using tangent space low poly models

Unity Engine
1

Hello, everyone! This is the first time I’m trying to use fully baked global illumination in my game and I’m disappointed. I’m using low poly meshes with normals baked from high poly. My models look perfect when global illumination is off or Realtime GI is on. But Baked GI is another story. There are some screenshots where you can see the problems with objects’ shading.

[Album] Unity Baked GI issue
[Album] Unity Baked GI issue

  • My low poly models are using smooth shading and exported from Blender with “Tangent Space” checked.

  • All models were unwrapped for lightmapping (i.e. have second UV map).

  • Normal maps were baked from high poly models in Substance Painter.

  • All models look perfect in Substance Painter and Unity with Realtime and Realtime GI lighting modes.

  • There are no problems with models that use flat shading.

I have spent some time playing with my models and Enlighten settings without success. I’ve tried Progressive Lightmapper too with no luck. So I’d really appreciate any help with this issue.

2

Hi @Twainxxi

This sounds like an issue that we need to investigate. I’m pretty sure you enabled it but just asking to verify: you have directional mode enabled, right? In Non-directional mode, it is not expected to work but directional lightmaps store the information for the direction of light and average of light color (we have a small comparison of non-directional and directional modes here). If you author the normals of your geometry and play with your normal map, you should be able to get closer results. But technically, it is not expected that baked lightmaps match with realtime solution. In realtime GI, it still works because direct lighting is not precomputed and works in realtime.

Can you perhaps provide a small reproducible project through bug report so we can check it on our end? You can share the bug ID here or send it to me via DM.

Thanks