1. The State Key Lab of CAD&CG, Zhejiang University, 38 Zheda Road, Hangzhou, Zhejiang Province 310027, China e-mail:
2. Department of Foreign Language, Zhejiang University of Finance and Economics, 18 Xueyuan Street, Hangzhou, Zhejiang Province 310018, China e-mail:
3. China North Vehicle Research Institute, Mailbox 969-11, Beijing 100072, China e-mail: