Yasuyuki Murai Suguru Asaoka Hiroyuki Tsuji Hisayuki Tatsumi Shinji Tokumasu Distance Field Model Concept for Space Representation. 1241-1249 2007 11 JACIII 10 http://www.fujipress.jp/finder/xslt.php?mode=present&inputfile=JACII001100100010.xml db/journals/jaciii/jaciii11.html#MuraiATTT07