Computer animation is the process of generating animated images using computer graphics. Modern computer animation typically uses 3D graphics to create virtual worlds where characters and objects can move and interact in a realistic manner. There are three main types of animation: traditional (hand-drawn), stop motion (manipulating real-world objects), and computer animation. Computer animation encompasses both 2D and 3D techniques and has largely replaced traditional animation due to being faster and less expensive to produce. Pixar and DreamWorks are notable studios that have produced highly successful computer animated feature films.