This paper explores the fundamental principles of traditional 2D hand-drawn animation and their application to 3D computer animation. It begins by discussing the evolution of these principles, which were developed at the Walt Disney Studio in the late 1920s and 1930s. Key principles such as squash and stretch, timing, anticipation, staging, follow-through, overlapping action, straight-ahead action, pose-to-pose action, slow in and out, arcs, exaggeration, and secondary action are detailed and explained in the context of both 2D and 3D animation. The paper emphasizes the importance of understanding these principles for producing high-quality computer animations, as they are essential for creating convincing and engaging animations. The author also discusses the application of these principles in specific examples, such as the character Luxo Jr. from the film "Luxo Jr." and the character Andre from "The Adventures of Andre and Wally B." The paper concludes by highlighting the role of personality in character animation, which is the intelligent application of all the discussed principles.This paper explores the fundamental principles of traditional 2D hand-drawn animation and their application to 3D computer animation. It begins by discussing the evolution of these principles, which were developed at the Walt Disney Studio in the late 1920s and 1930s. Key principles such as squash and stretch, timing, anticipation, staging, follow-through, overlapping action, straight-ahead action, pose-to-pose action, slow in and out, arcs, exaggeration, and secondary action are detailed and explained in the context of both 2D and 3D animation. The paper emphasizes the importance of understanding these principles for producing high-quality computer animations, as they are essential for creating convincing and engaging animations. The author also discusses the application of these principles in specific examples, such as the character Luxo Jr. from the film "Luxo Jr." and the character Andre from "The Adventures of Andre and Wally B." The paper concludes by highlighting the role of personality in character animation, which is the intelligent application of all the discussed principles.