We will now change the cel shading look by changing parameters of the material instances.
Cel shading is an artistic process rather than physical process and the parameters assigned much affect the overall look of the character.
We will demonstrate the features of our customizable cel shading material with the face material instance of the scene we setup before.
We close up the face and open a MI_figure_girl_face_cel material instance.
We start from changing the specular highlight intensity.
Currently, the skin highlight is too strong and we will change the intensity of the highlight. To do so, we go to the specular parameter group and change the specular intensity from 4.0 to 1.0.
We now want to make highlight smaller. To do so, we change the specular cut location from 0.995 to 0.999, which means we only captures pixels having 0.999 highlight intensity as cel highlight, while ignoring highlights below 0.999.
Although cel shading usually uses hard highlights, we will make the highlight smoother here to make the skin looks softer. To do so, we will change the specular cut smoothness from 0.0 to 0.05.
Now we will move to the diffuse parameter section. We first change the cel boundary which decides the bright and dark cel regions. To make the face has less dark cel regions. we will change the Diffuse Cut Location from 0.7 to 0.5. Here the 0.5 means only the back face pixels seen from the light direction becomes dark. Now the face skin becomes almost flat only the small regions around nose has shades.
The Diffuse Cut smoothness changes the smoothness of the cel boundary, The following images show the images having different smoothness
 |
 |
 |
 |
|---|---|---|---|
| 0 | 0.05 | 0.1 | 0.4 |
We will remain the smoothness 0.0 here.
Now we change the brightness of bright and dark cels.
We change the brightness of the bright cel from 1.0 to 1.5.
We also change the brightness of dark cel from 0.4 to 0.25.
We now try to change the skin color. We change the Diffuse Tint color from (1,1,1) to (1,0.848, 0.889).
We will now move to the rim light group. We will first exaggerate the rim light by changing the intensity from 1.0 to 10.0.
Then we change the rim light hardness from 8.0 to 4.0, which makes the rim light softer and broader.
Then we change the rim light color from (1,1,1) to (1,0.374, 0.101).
