I understand, but it is still a lot more work when it can be solved by just padding the lightmap, I wouldn’t mind manually doing this if I were given access to the lightmap assets. It is a much faster fix than going through every tileable game asset and modifying uvs to make sure they sit on the grid points and then reimporting everything. That would solve the seam issue but in the image I provided, it doesn’t look like seams are the only issue, the whole scene is lit by a directional light and a skylight and if the uvs are set up right for the wall 400x300 mesh this issue should not be occurring. Each mesh looks like it has its own indirect color which appears to be a different problem