{"responseHeader":{"status":0,"QTime":3,"params":{"q":"{!q.op=AND}id:\"97677\"","hl":"true","hl.simple.post":"","hl.fragsize":"5000","fq":"!embargo_tdt:[NOW TO *]","hl.fl":"ocr_t","hl.method":"unified","wt":"json","hl.simple.pre":""}},"response":{"numFound":1,"start":0,"docs":[{"file_name_t":"Cohen-Spacetme_Control.pdf","thumb_s":"/33/8c/338cbd22ca4cce5a124015784a9cb8f8bd023e01.jpg","oldid_t":"compsci 5790","setname_s":"ir_computersa","restricted_i":0,"format_t":"application/pdf","modified_tdt":"2016-04-27T00:00:00Z","file_s":"/25/49/2549b807f2323eb587c802133e586ed2b0c67077.pdf","title_t":"Page 51","ocr_t":"37 allow constraints and objectives to be general second order differential equations. Both provide local control of the curve maintaining the sparseness of the Jacobian matrix of constraint derivatives with respect to the state variables and so lead to efficient algorithms, and intuitive responses to constraint impositions. The variation diminishing properties of the B-spline and the cubic vs. quintic functions should give the B-spline formulation some advantages in the optimization process. The B-spline approximation and Hermite interpolation both lend themselves to \"refinement\"; however, if only uniform B-splines are used, refinement must be carried out evenly across a DOF function. Uniform cubic B-splines and the quintic Hermite formulations are explored and compared. 4.1.4 Active Constraints and Objectives The other components of a window are an objective function and the constraint functions that are active during the timespan of the window, and have some dependence on DOF within the window. The constraint functions cut across the timelines of the window, specifying relationships between DOF that should be maintained. These may be relationships that should always be maintained, such as physical constraints, or they may be functions that are active only at a particular point in time or in a range of times. The latter include constraints that specify a particular location or velocity for the creature at a particular point in time. The objective function may depend on any subset of the state variables. 4.2 Spacetime Windows and Their Implications in Optimization and Control Focusing attention on subregions of the full spacetime of an animation through the use of spacetime windows will, in general, lead to suboptimal solutions to the spacetime constraints problem. There are, however, a number of advantages afforded by the use of spacetime windows to warrant their use. These include:","id":97677,"created_tdt":"2016-04-27T00:00:00Z","parent_i":97747,"_version_":1642982591110840320}]},"highlighting":{"97677":{"ocr_t":[]}}}