Resolved Normal Map Inverts During Object Rotation

I'm trying to make a very simple Toon Shader with normal maps, starting from the Unlit Graph, and I've worked out transforming my normals to world space and then taking the dot product of them with an arbitrary light direction vector, but for some reason the resulting light information seems to be getting reversed when the object is rotated.

I don't know if I'm even doing the nodes right because I can't find any examples of custom unlit shaders that use normal maps.





You can see how the lighting seems to rotate twice as far as the cube actually does.

 

I'm using Unity 2019.2.0f1, and Lightweight RP version 6.9.1. I updated LWRP to try and fix it as well, thinking that might have been the problem, but I got the same results before and after the update.


Perhaps this information could be of use. I've noticed an inconsistency. When I rotate the cube through the Z axis, the side that was previously facing up has now had it's normals inverted.


But if I rotate it through the X axis, the side that was previously facing up began with upside down normals and retains those upside down normals.

 

Ok I guess I actually answered my own question. The problem wasn't with my nodes or my versions, it was the normal map itself. The rotational inconsistency finally made the connection in my head, and it turns out that my Green channel is inverted. Multiplying it by -1 seems to fix all the issues.

Thanks for the reply anyway.

 

For future reference, your normal maps were exported with -Y format, or "Direct3D style". Unity uses +Y, or "OpenGL style" normal maps. Basically Direct3D tangent space normal maps look like they're being lit "from below" and OpenGL tangent space normal maps look like they're being lit "from above".