Research And Implementation Of Physical-based Motion Style Using Spacetime Constraints

Physical-based character animation is known for its realistic characteristic, and has been an activity topic these years. Notwithstanding, this method has been weaken for it fails to create the realistic motion especially in the circumstance that the constraints are weak or the energy is low. The proposition of motion style is utilized to work out this problem. This problem is solved by defining the parameters of the style using the physical parts on the model. The animation sequences are generated by resolving the parameters of the style.The basic part of the physical-based character animation is modeling. The question of using what kind of model to describe the character is the key part of this domain. The research in the biological anatomy domain has facilitated the correctness in modeling the human body. A double spring structure is used to analogy the muscles and tendon joint stick structure because it better fits the empirical data in the medical experiment. The formula is set up upon this model and the motion is calculated using the least energy consumption principle.How to apply the style into the physical-based model is another problem for its abstract nature. The style parameters are defined with those of in the model. The constraints formula and goal formula are set up using spacetime constraint method, from which the initial values of these parameters are gotten. Then the Lagrange method helps to work out the motion sequences.Meanwhile, a new velocity spline is adopted to interpolate the position of the animation sequences to conquer the drawback that the conventional spline fails to support the physical-based method.The experiment result demonstrates that our method is useful in producing the realistic character animation.