“…For instance, space can be modelled using primitive instancing (Foley et al, 1995;Kada, 2007), constructive solid geometry (Requicha & Voelcker, 1977) or various boundary representation approaches (Muller & Preparata, 1978;Guibas & Stolfi, 1985;Lienhardt, 1994), among others. Time can be modelled on the basis of snapshots (Armstrong, 1988;Hamre, Mughal & Jacob, 1997), space-time composites (Peucker & Chrisman, 1975;Chrisman, 1983), events (Worboys, 1992;Peuquet, 1994;Peuquet & Duan, 1995), or a combination of all of these (Abiteboul & Hull, 1987;Worboys, Hearnshaw & Maguire, 1990;Worboys, 1994;Wachowicz & Healy, 1994). Scale is usually modelled based on independent datasets at each scale (Buttenfield & DeLotto, 1989;Friis-Christensen & Jensen, 2003;Meijers, 2011b), although approaches to combine them into single datasets (Gröger et al, 2012) or to create progressive and continuous representations also exist (Ballard, 1981;Jones & Abraham, 1986;Günther, 1988;Van Oosterom, 1990;Filho et al, 1995;Rigaux & Scholl, 1995;Plümer & Gröger, 1997;Van Oosterom, 2005).…”