Nan Zhang 0011 Wei Hong Arie E. Kaufman Dual Contouring with Topology-Preserving Simplification Using Enhanced Cell Representation. 505-512 2004 conf/visualization/2004 IEEE Visualization http://csdl.computer.org/dl/proceedings/vis/2004/8788/00/87880505.pdf db/conf/visualization/visualization2004.html#ZhangHK04