中文摘要：

E-mail： zhaoyong@cad.zju.edu.cn, Yong Zhao received his B.S. degree in computational mathematics from Qingdao University in 2004. He is currently a Ph.D. candidate in State Key Lab of CAD ＆ CG, Zhejiang University, majoring in computer graphics. His research interests include digital geometry processing and computational geometry. E-mail： xgliu@cad.zju.edu.cn, Xin-Guo Liu received his B.S. and Ph.D. degrees in 1995 and 2001 from the Department of Applied Mathematics, Zhejiang University. He is currently in State Key Lab of CAD ＆ CG, and is a professor of the School of Computer Science, Zhejiang University. His research interests include digital geometry processing, real-time rendering, and virtual reality. E-mail：peng@cad.zju.edu.cn, Qun-Sheng Peng graduated from Beijing Mechanical College in 1970 and received his Ph.D. degree from the Department of Computing Studies, University of East Anglia, UK in 1983. He is currently a professor of computer graphics in Zhejiang University, and is a senior member of CCF. His research interests include digital geometry processing, scientific visualization, realistic image synthesis, bio-molecule graphics and virtual reality. E-mail： bao@cad.zju.edu.cn ,Hu-Jun Bao received his B.S. and Ph.D. degrees in 1987 and 1993 from the Department of Applied Mathematics, Zhejiang University. He is currently the director of State Key Lab of CAD ＆ CG, and is also the principal investigator of the virtual reality project sponsored by Ministry of Science and Technology of China. His research interests in-clude digital geometry processing, field-based surface modeling, real-time rendering, realistic image synthesis and virtual reality.