How to use the NormalFromFunction material node?

How can I use the NormalFromFunction node in the material editor? The description and the input pins don’t offer any explanation on how to use the function. Let’s say I want to generate a normal map from the SphereGradient-2D function, how would I go about that? I’m assuming plugging the output of the SphereGradient-2D into all three Function(UV) inputs, but I tried several different functions and values for the other inputs and I only get a uniform, deep blue output.

The documentation is also missing any mention of this function. (Procedurals | Unreal Engine Documentation)

Any suggestions?

There is a brief explanation about NormalFromFunction material function in this post.

Thanks you very much. Offsetting the function by “Heightmap UV Offset” in x and y direction for the Function(UV2) and Function(UV3) inputs seems to produce acceptable results.