A "Toon Shader" (also known as Cel-shading) flattens lighting into distinct bands of color rather than smooth gradients. Think of Xiaolin Showdown , The Legend of Zelda: Breath of the Wild , or Guilty Gear . In MMD, toon shaders transform blocky 3D models into living, breathing 2D illusion paintings.

Advanced shaders like PAToon or Ray-MMD allow for sharp shadow boundaries, which are essential for a clean anime look.