Hello guys,
I have a problem with the Bumbed Specular Legacy Shader. Problem can be observed from following screenshots (top image - with normal map; bottom image - without normal map) and also here with normal map again.
Unity versions I tried are: Unity 5.4.0b13 and Unity 5.4.0b15
This weird “chess board” glitch is visible only in the place where reflection happens and only when I am using my normal map.
Do You have any idea why this happens?
Thanks,
Steven
Looks like a precision problem.
When you are using a bumpmap, some vectors are transformed into tangent space, and that is probably done a little inexactly for the sake of performance.
It looks like Unity is using half3 vectors to represent both viewDir and lightDir through all lighting calculations.
I think maybe using float3 vectors would solve it, but it would take me several hours to rewrite the lighting framework to be higher precision. And the result would be a very ugly shader.
What you might do is add a little noise to the smooth parts of your cubemap to hide the artifacts.
ETC1 texture compression on my normal map was the cause here! Thank You for Your effort anyway 
Entirely my fault in the end.