SHREC'09 Track: Structural Shape Retrieval on Watertight Models. - J. Hartveldt; Michela Spagnuolo; Apostolos Axenopoulos; Silvia Biasotti; Petros Daras; Helin Dutagaci; Takahiko Furuya; Afzal Godil; Xiaolan Li; Athanasios Mademlis; Simone Marini; Thibault Napoléon; et al. (3DOR@Eurographics, 2009)