Okay, my final goal is shell shading.
BI can use the shadow border as a masking factor and can directly specify the color of both sides.
Cycles’ Toon shader does not look like that.
Guilty Gear Xrd, who is rated the ultimate NPR art style in the current production interview, shows that they uses a separate map to compensate for the color of dark areas for more beauty.
BI, on the other hand, is very intuitive because it does not need a map.
Normal Editing is now possible in Blender due to ‘User Normal Translator’ or ‘Blend4Web’.
In addition, the intuitive coloring of BI and the fast pace of OpenGL rendering make it a great combination for creating NPR-style footage.
When BI disappeared due to EEVEE, I hope EEVEE or Cycles will do the same, but it seems difficult at this time.
tell me your opinions please.