Dr. Sisi Zlatanova is a seniour researcher and lecturer at the GISt section, Delft University of Technology, The Netherlands (since 2000). She graduated as a surveyor at the University of Architecture, Civil Engineering and Geodesy (UACG), Sofia, Bulgaria in 1983 and obtained her PhD degree on 3D GIS for urban modelling at the Graz University of Technology, Graz, Austria in 2000. She worked as a software programmer at the Central Cadastre in Sofia, Bulgaria (1984-1989), an assistant-professor at UACG, Sofia, Bulgaria (1989-1995) and a researcher at the International Institute for Geo-information Science and Earth Observation (ITC), Enschede, The Netherlands (1995-1999). Her research interests are in 3D GIS: 3D object reconstruction, 3D data structures and databases, 3D spatial relationships and 3D visualisation.