Research On Motion Generating And Controlling Problems Of Computer Animation

With the rapid growth of computer hardware and graphics algorithms,computer animation is penetrating various fields of our life as a creativity work with high technique, high intelligence and high art. Although computer animation is getting mature,its automaticity, verisimilitude and flexibility remain to be improved and bring the higher challenge to researchers. Therefore,computer graphics researches have been focusing on algorithms related to computer animation in recent years.Considering the theory problems and difficulties of the motion generating and controlling in the computer animation, exploit the approach to generate natural motion effectively. Some key technologies, such as keyframe interpolation, motion capture and motion synthesis are deeply studied. Building a series of new approaches and probing into the connection among controllability, complexity and verisimilitude of motion generating and controlling, improve the interactivity and sense of reality in the computer animation.As traditional keyframe interpolation often results in motion that appears jerky, velocity interpolation algorithm is proposed. To represent motion of an object, a parametric curve, 2D implicit curve or 3D implicit curve is used to specify motion path. Given the motion path and speed profile which is adopted to describe the motion timing, different point sequences along the curve are resulted, from which diverse frame sequences may be generated. Given the different motion path and motion speed, velocity interpolation technique allows easy creation of a wide variety of motion sequences that specifically meet the needs of vivid animation and good reusability.Furthermore, velocity interpolation technique can be used in human animation. We firstly discuss the approach to apply parametric curve velocity interpolation algorithm to articulated kinematics. Combined with velocity interpolation algorithm and inverse kinematics, we can derive the relationship of joint angle and speed. This approach can map articulated kinematics relating to speed. Take the case of waling, human motion control approach based on velocity interpolation is proposed. The human ambulant model is constructed, and joint angle and assistant joint angle are introduced to make the process of velocity interpolation more expediently. Given the different skeleton and motion form, velocity interpolation technique still can be applied in human animation flexibly. Motion capture based on single-view video is discussed. The 2D tracking of human joints is achieved through the optical flow tracking method and the 3D reconstruction is processed using the 2D motion information in every frame. For the self-occluding phenomena during the 3D reconstruction, we present a new occlusion-recovering approach with geometry and motion constraints. According to the prior human skeleton model, the accurate result is resumed using the skeleton length and the movement constraints. The proposed approaches provide an easy computation and low cost technique of single-view video motion capture.A novel motion synthesis assorting method is proposed by looking for the characteristics of issues of motion synthesis. The processing of motion synthesis is divided into motion blending and motion connecting. Combined with traditional time warping algorithm and uniform scaling method, the least fame distance based time regulating is proposed to search the best blending path. Interpolation is used to edit motions in motion fusion and motion inlay. At the same time, motion connecting is segmented into motion transition and motion crossing according to the time relationship among the motion sequences. Separately using the most or the least fame distance recomputes the transition or crossing segment, in order to assure the continuous and smooth motions. Finally, analyzing constraints of the synthesis results, the principles of constraints matching are given to inosculate synthesis results to factual motions.The problems of motion animation have been analyzed completely and researched deeply on the aspects of kayframeing, motion capture, motion synthesis and human motion. These solutions and algorithms solve the major problems such as high calculated amount and unverisimilitude in the computer animation. These methods can be a good complement to the current technology and have shown certain theoretical implications on the relevant research in future.