Mobile Bumped Diffuse - weird dark surfaces and not enough bump?

I’m trying to create a simple block, with the outer edges extruded, from a normal map… On mobile, when I switch from mobile diffuse to mobile bumped diffuse, the results are not as expected…

  1. Depth from normal map does not seem to appear…
  2. Lighting becomes really weird… Not sure why some sides have the white-part of the normal map turn dark?

See below for two screenshots of the cube in the same state with different shaders.

A) Mobile Diffuse

B) Mobile Bumped Diffuse



I had a similar problem. Using the mobile bumped diffuse shader the material appeared dark with little or no bump mapping effect, and when run on Android the object was completely black.

Eventually found that the problem was due to the model itself, it was set to import tangents but the tangents were either missing or bad (not sure which, the asset came from the unity store). We changed the model import setting to calculate tangents and that fixed brightness, the bump map became visible, and the android render was fixed.