Uncanny Valley

3D animated films do absorb a sense of realism into their aesthetics but keep that cartoon like appearance to suit the child audience. The animated film 'Polar Express' took this further and made realistic 3D models for their animation, using motion capture and modeling the characters close to their actors. The film itself held a good narrative but personally I don't find the realistic approach to the models that aesthetically pleasing; I prefer the cartoon inspired 3D animations, much like Megamind and The Lorax. The amount of realism added to the models gives a lifeless expression to their faces, the eyes seem void of any emotion compared to other popular 3D animations. 

"There is a theory to explain people’s strange dislike of artificial characters which look too real, called the ‘Uncanny Valley’. Basically the idea is that when a doll, or a CGI character, looks too much like a human, viewers notice small differences which distinguish it from a genuine living thing, become disgusted by its artificiality" - vividscribe.com

The Uncanny Valley hypothesis is used to describe the viewers distaste in 3D animation or robotics when they look too realistic, it causes some viewers a sudden reaction of disgust. However there is no extensive research on this to prove whether there is a solid basis for this to be recognized.
The Uncanny Valley hypothesis does explain why this perception of thought towards 3D animation is depicted; a sense of identity towards the characters are lost through how the audience see through the artificial quality of the animation, purely for the amount of realism the animation has taken. I believe that the motion capture of the movements do give characteristics and a sense of personality to the characters animations however the expression, the eyes of the models stop us from connecting with the character. 

Polar Express