1. Computer Science and Engineering, Beihang University, China
2. Computer Science and Engineering, Beihang University, China and Zhongguancun Laboratory, China and State Key Laboratory of Virtual Reality Technology and Systems, China
3. Computer Science and Engineering, Beihang University, China and Zhongguancun Laboratory, China
4. Beihang University, China
5. Beihang University, China and Zhongguancun Laboratory, China