W_SuperNormal v2.1

With W_SuperNormal, there are two ways to select the surface angle:

1) P_Matte has been the inspiration for this tool to do with normals what it does with position data, and as such there is the colorpick method like P_Matte:

I like to look at the alpha output, hold ctrl+alt and glide over the surfaces to find the right angle. This is all you need a lot of the times, but when the geo has too little or too much detail it can be difficult to get the angle you want, so you can also manually offset the rotations.

2) Horizontal and Vertical Rotations:

If you have used similar tools for normals, this is my one answer why you should also try mine. Instead of separate XYZ rotations, it uses a horizontal/vertical model where the vertical axis is always parallel to your chosen plane. It is possible to reach any angle with rotations around two axes(with 90-degree rotation in Y, rotated X axis will be the same as the original Z). With the horizontal/vertical method you only need to remember which way is up in your scene and the rotations happen in a predictable manner. With XYZ rotations, unless you have an extraordinary level of spatial awareness and can keep track of rotated local axes, it becomes very hard to predict which way the sliders will rotate. Here's another gif with more complex geo just because it is so fun and satisfying to play:

Here is the entire interface:

One tip when you colorpick a new plane, reset the manual rotations for best result. When you do manual rotations you do not have to reset the plane because the rotations start from the plane you picked. For 'Mask by Alpha' and 'Unpremult' options the input must have a proper alpha channel.

On a final note, this version was completed on Nuke 10.5, but I don't see why it wouldn't work on earlier versions, as the first version existed since 2016 and there is nothing fancy inside.

*The 3D models used for demonstration were modelled by me.