Yi-Hsing Tseng, a professor of geomatics at the National Cheng Kung University in Taiwan gave people at the 28th ACRS a view inside a complex but highly detailed 3 D model of the campus. The model contains details of the topography of the site, and the roads, buildings, sculptures, and trees, as well as photo-realistic surfaces. To create the model, they used a great number of existing data sources. These included topographic maps, vertical digital aerial photography from a Vexcel camera, an airborne laser scanner (ADS40) and a terrestrial scanner (Optech Ilris 3D). All the data from these sources was registered to the national grid, which had been used to create the topo maps. Tseng then assigned portions of the model to the data, as appropriate. For instance, the airborne laser scanner was used to create a digital terrain model of the site. Photogrammetry was used to create a rough model of the buildings, augmented by laser ranging from the ground and street level photography to create a fine model.