Computer animation is the process of generating animated images using computer graphics by exploiting the persistence of vision to make a series of images appear animated. Three films from different eras are analyzed: the 1980 Star Wars had unrealistic rocket and planet shapes formed from basic geometric objects with little detail or characters; the 2007 Power Puff Girls Movie had more sliding scene transitions and better character design than earlier works; the 2010 Shrek Forever After featured much higher quality 3D characters and presentation that was more realistic and had more humor through the new technology.