Lightmap problem


Any ideas why do I have this strange shading on my walls?
These are basically two boxes snapped together in max.



Instead of using a block to make the wall section you need to have the walls come together at the corner.


Using simple planes instead of blocks can be a solution?

For the most part–if you have sunlight outside then it helps to have an outside surface to block the sun, and you also need to make sure that a surface is made from only one mesh, so something like a section of wall needs to be one continuous mesh.