Abnormal is a Blender add-on to enhance the usability of the vertex normal editing for game models and NPR artworks. This add-on is funded by the BNPR community with the BEER development fund.
Vertex normal editing is used to fix shading problem on lower geometry mesh objects and used to decouple silhouette of a mesh from its shading. As a result, shading will look more under control and more natural.