Deformation model of a human face based on measurements

This paper proposes a method for simulating a soft object in a virtual space. We employ a spring mass network to represent a human face, which is an example of a soft object. A bubble mesh algorithm is applied to CT data to obtain a network whose nodes are approximately equally spaced. For connecting bubble centers we devised a technique employing a Voronoi diagram. Softness is represented by a spring network model with springs assigned to edges connecting adjacent nodes. The spring constant is determined experimentally so that the measured softness is equal to the softness of a virtual object in terms of the relation between force and displacement. The nonlinearity of a spring is set at 80% of its depth, read from the CT data. A force feedback system using PHANToM was implemented in order to allow a sensation of virtually feeling and pushing a soft object. © 2003 Wiley Periodicals, Inc. Syst Comp Jpn, 34(8): 33–41, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10320