Why might I be getting flat shaded poly's here? My model is smooth shaded (no hard edges, etc). There's not image texture on the Normal node which is usually where I see this problem come up; the image texture is not set to 'non-color' or 'linear'. Any ideas?
It's going to be difficult to diagnose from here.
In this screenshot we're looking at the result of this node:
but there's a lot of Normal vector data being passed around all over the place.
There are a few posts on this site detailing how to mix Normal Maps, and by my estimation you are running into one or more of the problems discussed there.
You say you aren't using an Image Texture so I assume you're generating everything procedurally with Blender's built in nodes. What I would do is work with the black and white data and pass it along the node tree until the very end right before the Principled BSDF and put the Normal Map node there.
My supposition is that Normal Map data is currently being added using Vector Math -> Add and this magnifies the blue channel such that it can't properly interpolate down to a value that makes sense anymore... Idk if that makes sense.
