Computergraphic modeling and analysis II: three-dimensional reconstruction and interactive analysis.

The analysis of human motion can be advanced by analyzing motion not only numerically, but also graphically. A new system is presented for the computergraphic analysis of human motion in three-dimensional space. The system allows the three-dimensional reconstruction, visualization, manipulation, and graphic editing of digitized movement trajectories. An entire sequence of the positions of the arm in three-dimensional space can be displayed simultaneously, or the actual motion can be recreated in real time. Along with the reconstruction of the spatial path, the temporal characteristics of the movement can be concurrently displayed. Graphic procedures for interactively examining couplings between spatial and temporal aspects of trajectories were developed. Finally, based on digitized trajectories, stimuli can be generated and sequenced in real time for studies of the perception of motion. In conjunction with new methods of three-dimensional movement tracking, the computergraphic methods presented here offer new approaches to the analysis of human movement and its underlying neural control.