Fake directional light effect?

I’ve found this tutorial while looking for ways of creating an effect I want to implement in my game, but the problem is while rotating meshes and characters the lighting rotates with them, since it’s not world aligned. I’m not good enough in materials so I don’t know how to do that. I really will appreciate if someone will help me with it.

Are your setup exactly the same as described in tutorial?

Usually, when you take normals, transform them from tanget to world and make DotProduct with some vector, it must be in world coordinates.