I have read MANY tutorials and threads on lightmap UVs, but it seems I am still missing something here. I made a very simple tile to try some lightmap UV unwrapping. Even though I though I followed all the "rules", I still got a little bleed on a couple of edges. (the offending edges are not the ones on the edge of the UV)…
Thanks for the suggestions. I did figure out a better way to pack it, which was to make the sides of the tile longer and stack them up on Y. This solved the issue, but I am still trying to understand the original cause. I used the grid in blender, which was divided in 32 to line things up and scale nicely, but still had…