Krug
Newshound
The CNN article echoes my feelings when I saw the trailer.
Not live action, and not totally computer-generated animation either, "Polar Express" uses motion- -- or performance- -- capture technology. This process allows a filmmaker to use actual human beings acting out their roles on an empty soundstage, and then merges them into a three-dimensional computer-generated world.
Without getting mired down in technological gobbledygook, this complicated system involves the performers dressing in skintight bodysuits with hundreds of infrared sensors covering the suits and their faces. These sensors then relay the smallest nuance of movement back to a computer, where it's all translated into human motion -- and emotion. (The same process was used for Andy Serkis' portrayal of Gollum in "The Lord of the Rings.")
The results are breathtakingly realistic except for two vital facial areas: the inside of the mouth and the eyes, where the sensors cannot be placed. Therefore, these areas have to be computer generated. It just doesn't work, and this fact is called into sharp relief since the faces of the actors are so incredibly expressive.
To quote an old cliche, the eyes are the windows to the soul -- so these characters look soul dead. When the characters are experiencing extreme emotions, such as fear or surprise, the animation seems to work. But when the characters are still -- and processing information from each other -- they look lifeless.
To put it another way, you can knock, but nobody's home.
The mouth action is also less than overwhelming, since the characters' tongues look like slabs of meat when they speak their lines.