Character+Dimension

A 3-D, or round character, seems realistic to the reader. A 3-D character has both good and bad qualities. A 2-D character, or flat character, seems more like a cartoon character and is there to support or show off some quality of the 3-D character. In the book you are reading which character(s) is 3-D and which are 2-D? How do you know? Please give examples from the text to support your answer.