Unexpected unwrapping behavior during UV mapping

I’ve got a simple model consisting of two hex tiles that are stuck together on one of their edge faces (bottom panel, “actual_UV_mapping.jpg”). It’s a single object, it just happens to be a two-hex sized object. I’d now like to do a UV mapping to wrap an image/texture around the tile. I was hoping for a mapping as in the attached the “hoped-for_UV_mapping” jpg.

So, I drew seams around the edges, asked for unwrapping by seams, and I get a UV mapping that is very unintuitive (top panel, “actual_UV_mapping.jpg”). Faces that are adjacent on the original model are not adjacent on the UV map, while some faces that are unconnected on the original model are adjacent in the UV map. Now, I think I could rearrange the polys on the UV map to reorganize them in a more intuitive way, so that it fits what I had originally hoped for. However, that seems like a lot of effort.

Would anyone care to comment on this? Does the unwrapping process generally retain adjacency relationships (excepting seams of course). Could this have to do with the way I created the object? I designed a single hex tile, then extruded a new one, snapped it to the original, and deleted duplicate vertices. Is there perhaps some sort of connectivity that was disordered during this process?

Any help would be greatly appreciated. (blender model file also attached, FYI)


hex_double_blank.blend (416 KB)

You had a face inside the mesh which needs to be removed to give the unwrap you want.
See the attached blend file


hex_double_blank.blend (123 KB)

Easy solution! Thanks much,