Efficient animation techniques balancing both user control and physical realism

摘要: Specifying the motion of an animated linked figure such that it achieves given tasks (e.g., throwing a ball into basket) and performing in realistic fashion gracefully, following physical laws as gravity) has been elusive goal for computer animators. The spacetime constraints paradigm shown to be valuable approach this problem, but suffers from computational complexity growth creatures those one would like animate. There are two sources which contribute problem: is symbolic processing animator's objective functions derived models second lies numerical optimization phase. This thesis reports on work enhance techniques both symbolically numerically significantly speed up computations. Our first contribution develop new interface with recursive evaluation scheme so time required gradient computation needed by reduced exponential optimal quadratic growth. Furthermore, method, language developed expressions can easily input, thus provides more convenient interface. Secondly, we keyframe system allows user specify few keyframes while letting determine timing, parameters may less intuitive animator, using methods. novelty user-specified used provide control over reduce problem. method advantage providing much traditional animation realism based system. Due nearly interactive complex figures. Finally hierarchical solve nonlinear variational problem arising formulation wavelets. In scheme, through generalized degrees freedom reformulated wavelet representation. means automatically add detailed only where required, minimizing number unknowns. addition, better conditioned convergence faster.