Issues with Shadows on Objects consisting of tiled meshes.

I'm in the process of making a modular level that shares all textures on a single texture sheet. Naturally, this workflow calls for walls, etc to be made by snapping flat planes together with seamless textures.

The issue I'm having is that when other objects are placed in front of a tiled wall, weird lighting errors occur. Here are some pictures to better clarify.

Object Far Away



Object Near



Object Really Close



As you can see, certain mesh patches are being totally darkened based on the proximity of other objects. I have no clue whats going on here.

My objects are set to static
Scale Factor - 1
Mesh Compression - off
Optimize Mesh - On
Generate Lightmap Uvs - On

Any Help?

 

How are the LM UVs set up? Did you do them yourself or through the import options? Whats the scale of the LM on those objects? Clicking on the "Shaded" dropdown in the Scene view allows you to see the Checkered pattern of the Lightmap resolution when clicking on "Baked" on the bottom of that dropdown.