Abstract: Character animation is one of the main research topics of computer graphics and virtual reality, and it plays an important role in many applications of digital entertainment, 3D game, manufacturing. Recently, along with the development of 3D animation game and special effects production in film making, physics-based character animation has attracted wide spread attention, and has been one of the hottest topics in the field of computer graphics for many years. As the growth of the requirement for physical reality, many new methods have emerged, which greatly enhance the animation and improve the performance. The most key issue is locomotion controller, which aims to calculate the joint torques to drive character move on. This paper focuses on character animation techniques. Firstly, the researches on character animation based on physical simulation are reviewed. According to the calculation methods of joint torques, these techniques are classified into 7 categories: spacetime constraint, constrained dynamics optimization control, low-dimensional planning, finite-state controller, data-driven technique, dynamic selection of motion examples, integration with statistics model. Their principles and characteristics are detailed, and recent works are highlighted. Secondly, with analyzing the related literatures, the advantages and disadvantages of the existing simulation methods are summarized. Finally, we point out various open research areas and possible future directions.

Key words: character animation, physical simulation, motion synthesis, virtual reality, motion control