> The hand-drawn images are usually faithful representations of the world, but only in a qualitative sense, since it is difficult for humans to draw multiple perspectives of an object or scene 3D consistently. Nevertheless, people can easily perceive 3D scenes from inconsistent inputs!
It is difficult for human artists to maintain perfect geometrical consistency. But that is NOT why 2D animation of 3D scenes is geometrically inconsistent! The reason is that artists stylize 3D scenes to emphasize things for specific artistic reasons. This is especially true for something surreal like SpongeBob. But even King of the Hill has stylized "living room perspectives," "kitchen perspectives," etc. The artists are trying to make things look good, not realistic. And they aren't trying to make humans reconstruct a perfect 3D image - they are trying to evoke our 3D imaginations. It's a very different thing.
Pixar and other high-quality 3D animation studios intentionally distort the real geometry of their scenes for cinematic effect: a small child viewed from an adult's perspective might be rendered with a freakishly long neck and stubby little torso, because the animators are intentionally exaggerating visual foreshortening to emphasize the emotional effect of a wee little child. A realistic perspective would be simply boring. These techniques are all over the place in Pixar movies - it's why their films look so good compared to cheaper studios, who really are just moving a virtual camera around a Euclidean 3D space.
I don't want to comment on the technical details. But it really seems like the authors missed the artistic mark.