Kai Ye Kun Zhou Zhigeng Pan Yiying Tong Baining Guo Low Distortion Shell Map Generation. 203-208 2007 VR http://doi.ieeecomputersociety.org/10.1109/VR.2007.352482 conf/vr/2007 db/conf/vr/vr2007.html#YeZPTG07