They are so vital to creating exactly what we want in our art. It is often overlooked as something technological and not artistic, but It is still important though. If you are unable to present you charachter or scene in an interesting way then it makes your model look flat and boring. Materials sell you on an object and as the article states, it was very important that they got the them right. So they should not be overlooked as the technical side of CGI but as an important step in the creation process. sssss
They talk alot about theyer motion capture they used foir this movie, and that is becasue they made serious inovations to the process. ILM says in this article that they took their indoor soundstage and turned it into a motion capture studio aswell. This allowed the actors to give their vocal performance while doing the action that would be translated to the onscreen character. This advancement gave the characters more belivable performances.