To render the ink lines along the object edges as seen from the camera, use a spotlight that is aligned colinear with the camera. The camera and spotlight should be aimed at the same point and angle. If you need to move the camera for animation, it may be useful to place the camera and spotlight in a folder, then move the folder to keep the camera and spotlight synchronized. The the lion rendering used the default values for shader parameters, except for threshold . Larger values of threshold tend to thicken the edge lines and bring out more detail.
Shadows can have a significant effect on objects using the toon shader.
The lion rendering was done with shadows turned off. Other methods are available for cartoon-style images.