Funding for this research was provided by:
National Natural Science Foundation of China (No.61572450 61303150)
the Fundamental Research Funds for the Central Universities (WK2350000002)
the Open Funding Project of State Key Laboratory of Virtual Reality Technology and Systems, Beihang University (No. BUAA-VR-16KF-12)
Natural Science Foundation of Anhui Province (1708085QF138)
the Open Funding Project of State Key Lab of Novel Software Technology, Nanjing University (KFKT2016B08)