We encountered an issue with the lighting channels.
We use multiple lighting channels for lighting the interior of a moving vehicle and for the exterior environment. The environment use fully baked lighting, and the moving vehicle has some movable point lights attached to it which light the interior but should not affect the exterior (and vice vers).
Lighting channels is obviously a solution for this, and it works as well, but there is one mesh in the vehicle, that has some errors in the shading, when we set its lighting channel to 1. When we set it back to 0, the error goes away. But we would need to somehow get channel 1 working correctly, so we can have consistent errorless lighting in the vehicle interior. So our question is, where is this error coming from, and how to fix it.
Some quick notes:
- it has two materials
- one of the materials uses UV channel 1 for the normalmap
- when we apply a material which does not have the said normalmap, the issue is not present
- other meshes with the same material do show up the error
- other meshes of similar kind, with exact same technique produced do not produce the issue
- the normalmap is baked from a highpoly