Data-Driven Animation of Skin Deformations

Carnegie Mellon University, Pittsburgh PA

Investigators

Abstract

Data-driven Animation of Skin Deformations Optical motion capture has been used very successfully to create compelling human animations for entertainment applications; however, it provides only a much simplified version of what we would see if we were to view a person actually performing those actions. The data contain the motion of the skeleton but miss such visually important effects as the bulging of muscles and the jiggling of flesh. The current state of the art uses 40-60 markers to approximate the rigid body motion of 15-22 segments. To the extent possible, the markers are placed on joint axes and bony landmarks so that they can more easily be used to find the motion of an idealized skeleton. The investigators are taking a different approach to motion capture and use a very large set of markers (approximately 350-500) placed on the muscular and fleshy parts of the body to capture not only the motion of the skeleton but also the motion of the surface of the skin. Models of skin and muscle deformations will have long term applications in such fields as computer animation, video games, surgical planning, humanoid robotics, and bioengineering. The investigators are using captured data to construct dynamic models of the deformations seen in human motion parameterized by joint angle, velocity, and torque. Those models are used to generalize captured data to new motions and new subjects with a similar body type. The investigators have been able to accurately reconstruct the motion of the surface of the body by applying the three-dimensional trajectories for this dense marker set to a subject-specific polygonal model. They are exploring a number of different approaches to generalize this data ranging from simple statistical dynamic models to relatively accurate anatomical models with parameters identified from the data.