Modeling of soft 3-dimensional objects and volume-conserving deformations of such objects by an external force
Isamu Mizuno, Yohei Iwasaki, Toyohisa Kaneko, Shigeru Kuriyama · Systems and Computers in Japan · 2005
This paper sets forth a method for creating models of soft 3-dimensional objects that are capable of describing the deformations that are easily produced in these objects by various external forces. In addition to virtual objects such as spheres and cubes, the authors have attempted to model the facial region of the human head. Their technique for modeling soft objects is to represent them by networks of springs and masses (i.e., by a spring network model). Using CT images to guide them, the authors construct a spring network model by first partitioning the head region with a tetrahedral mesh, and then using the bubble-mesh method to generate a close-packed structure that specifies the initial positions of the nodes. This procedure ensures that the springs all have almost the same length. In simulating the deformation, the response of the soft object is modeled by incorporating both a spring force and a volume-conserving force. Physical phenomena such as reaction forces arising from mutual contact between the surfaces of soft objects, such as hands with faces, and normal counterforces, are well described in the calculations. After verifying that deformations owing to contact between a sphere and a cube are well described, they developed their model of the human head and used it to simulate the effects of external forces exerted by a model hand. It was confirmed that the simulated deformations of the virtual head and hand that accompanied contact between them conserved volumes well. In addition, by introducing frictional forces, it was possible to simulate the deformations that accompany physical actions such as pushing up and tugging at lips, thereby confirming the effectiveness of the simulation method. © 2005 Wiley Periodicals, Inc. Syst Comp Jpn, 36(13): 23–34, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.20325