Toon shading (also known as cel shading) is a non-photorealistic rendering technique used in MikuMikuDance (MMD) to give 3D models the appearance of 2D, hand-drawn anime or comic book art

To fix this, we use external (like the Dx9Shader addon or Raycast) to load custom .fx files that perform real dynamic cel shading.

If your model has jagged shadows, you might need to adjust the mesh normals to force the toon shader to recognize which direction a face is pointing.

Open a 256x256 pixel canvas in Photoshop/MediBang.

MMD's original renderer uses (grayscale .bmp or .png images) assigned per material. These textures act as a 1D ramp lookup table. The engine computes the dot product between the vertex normal and light direction, then indexes into the Toon texture horizontally.