Takashi Kanai Hiromasa Suzuki Fumihiko Kimura 3D geometric metamorphosis based on harmonic map. 97-104 1997 conf/pg/1997 Pacific Conference on Computer Graphics and Applications http://doi.ieeecomputersociety.org/10.1109/PCCGA.1997.626179 db/conf/pg/pg1997.html#KanaiSK97