Come across a bit of an oddity that I am unable to account for nor finding any previous examples of anyone having this specific problem elsewhere.
I have started work on a city generation script that uses a 2D array as a grid and places the same prefab floor tile to create the map floor, and initially static batching seemed to be working fine with editor testing reporting 3 draw calls and 3827 batched (using a larger grid to judge higher end load as I work on things).
However when I changed the tile prefab material from the default diffuse to a Diffuse/Bump shader static batching stops working completely even though nothing else has changed.
I have checked to make sure that the tiles aren’t using instances of the material, and have also tried a few other shaders such as bumped/specular, specular and even made a custom bumped shader using Strumpy Shader Editor… but it seems static batching has completely stopped functioning for anything other than the bog standard diffuse material.
Is there something I am missing about static batching that could account for this by chance? Or is it safe to say this is a bug?
Edit: Forgot to mention, I have also created a new scene and tried dropping the prefab into the scene a few times to see if the problem was caused by my script, and the behaviour remains consistent and batching only shows as functioning using simple diffuse.
Unity version - 3.5.0f5 (latest release)
No real time or baked lighting is in place to interfere with the static batching.