1. Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
2. State Key Laboratory of Virtual Reality Technology and Systems and Beijing Advanced Innovation Center for Biomedical Engineering, Beihang University, Beijing, China
3. Department of Robotics Engineering and Department of Computer Science, Worcester Polytechnic Institute, Worcester, MA, USA
4. Department of Mathematics and Theories, Peng Cheng Laboratory, Shenzhen, Guangdong Province, China