5. Custom normals

Change only the shading, keep the shape.

Custom normal amount t Bumpiness Light direction (left/right) Light height Toon shading Toon threshold Show vertex normals

Triangles: · Drag the view to turn it.

The normals of a smooth sphere (pointing out from the center) are blended into a bumpy sphere. t = 0 is the computed normals, t = 1 is the sphere's normals.
As t rises, the toon shadow takes the shape of a sphere's shadow. But the outline stays bumpy: only the shading changes.
At t = 1, some places no longer match the shape. How much to blend is decided by eye.