At the same time, it all certainly worked. Gollum worked and felt like a real character even though so much of what we saw on his face was created digitally. Andy Serkis’ performance was just as “real” as any other in many ways, and perhaps that’s why it all worked so well. Gollums face was not real but the expressions were based on those that Andy Serkis did, and the same is true for the physical movement of the character. If nothing else, you have to figure the guy needed to practice that walk if only to avoid pulling a muscle on set.