UDMV15: Eurographics Workshop on Urban Data Modelling and Visualisation
Permanent URI for this collection
Browse
Browsing UDMV15: Eurographics Workshop on Urban Data Modelling and Visualisation by Subject "Graphics data structures and data types"
Now showing 1 - 2 of 2
Results Per Page
Sort Options
Item 5D Multi-Purpose Land Information System(The Eurographics Association, 2015) Ioannidis, Charalabos; Verykokou, Styliani; Soile, Sofia; Potsiou, Chryssy; Filip Biljecki and Vincent TourreThe complexity of modern urban environments has led to the introduction of 3D Land Information Systems (LISs), which tend to replace traditional 2D LIS architectures for the purposes of urban planning and regeneration, land administration, real estate management and civil development. Both the need for 3D visualization of the geometry of buildings in various time instances through the years and the need for acquisition of 3D models in various levels of detail (LoDs), which not only fulfill the requirements of the various users but also they speed up the visualization process, are obvious. Thus, additional dimensions, that is, for time and scale, need to be supported by a modern LIS. This paper introduces a 5D modelling pipeline that may be adopted by a multi-purpose LIS for the selective creation of 3D models of an urban area in various time instances and at various LoDs, enriched with cadastral and other spatial data. The methodology is based on automatic change detection algorithms for spatial-temporal analysis of the spatial changes that took place in subsequent time periods, using image orientation, dense image matching and structure from motion algorithms; the procedure requires photogrammetric stereo plotting, implements procedural modelling and relies on the availability of overlapping aerial and terrestrial imagery, ground control points and cadastral information. Finally, an application based on the proposed methodology in an urban area in Greece is presented and the future work is discussed.Item Automatic Semantic-preserving Conversion Between OBJ and CityGML(The Eurographics Association, 2015) Biljecki, Filip; Arroyo Ohori, Ken; Filip Biljecki and Vincent TourreWe investigate the automatic conversion between two substantially different formats used in 3D city models: the ubiquitous but semantically poor Wavefront OBJ and the semantically rich but less used OGC standard CityGML. We elaborate on their differences and on the challenges involved in their conversion, such as the inference of semantics in an OBJ file for their use in CityGML, and the storage of these semantics back in OBJ. We implement two software prototypes: a conversion of 3D building models from CityGML to OBJ (CityGML2OBJs), and one from OBJ to CityGML (OBJ2CityGML). By presenting both methods and implementations, we aim at increasing the availability of CityGML datasets and the possibility to create them in powerful 3D modelling software.