I'm currently experimenting with NPR shading in the style of Guilty Gear Xrd and I have a model I'm trying to adjust the vertex normals on to achieve a good cel-shaded lighting effect, but most software I have has very limited normal editing tools - i.e. 3DS Max's Edit Normals modifier is very basic.
What I'd prefer is some way to essentially use a brush to comb the normals a certain way if possible, but if not I would accept another method other than adjusting every single vertex by hand.
Replies
http://wiki.polycount.com/wiki/VertexNormal#Editing_Normals_in_3ds_Max
Would you consider using a normal map to do the job? A normal map gives you control of the normals, at a per-pixel level. If you want the most control, you could try painting the flow into an object-space map.
http://wiki.polycount.com/wiki/Flow_map