TY - JOUR A1 - Döllner, Jürgen Roland Friedrich T1 - Geospatial digital rights management in geovisualization N2 - Geovisualization offers powerful tools, techniques, and strategies to present, explore, analyze, and manage geoinformation. Interactive geovirtual environments such as virtual 3D maps or virtual 3D city models, however, raise the question how to control geodata usage and distribution. We present a concept for embedding digital rights in geovisualizations. It is based on geo-documents, an object-oriented scheme to specify a wide range of geo visualizations. Geo-documents are assembled by building blocks categorized into presentation, structure, interaction, animation, and Digital Rights Management (DRM) classes. DRM objects allow for defining permissions and constraints for all objects contained in geo-documents. In this way, authors of geo visualizations can control how their geo-documents are used, personalized, and redistributed by users. The strengths of the presented concept include the ability to integrate heterogeneous 2D and 3D geodata within a compact design scheme and the ability to cope with privacy, security, and copyright issues. Embedded digital rights in geovisualizations can be applied to improve the usability of geodata user interfaces, to implement publisher-subscriber communication systems for geodata, and to establish business models for geodata trading systems Y1 - 2005 SN - 0008-7041 ER - TY - BOOK A1 - Kirsch, Florian A1 - Nienhaus, Marc A1 - Döllner, Jürgen Roland Friedrich T1 - Visualizing design and spatial assembly of interactive CSG T3 - Technische Berichte des Hasso-Plattner-Instituts für Softwaresystemtechnik an der Universität Potsda Y1 - 2005 SN - 3-937786-56-2 SN - 1613-5652 VL - 7 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Nienhaus, Marc A1 - Döllner, Jürgen Roland Friedrich T1 - Depicting dynamics using principles of visual art and narration's Y1 - 2005 SN - 0272-1716 ER - TY - JOUR A1 - Paredes, E. G. A1 - Boo, M. A1 - Amor, M. A1 - Bruguera, J. D. A1 - Döllner, Jürgen Roland Friedrich T1 - Extended hybrid meshing algorithm for multiresolution terrain models JF - International journal of geographical information science N2 - Hybrid terrains are a convenient approach for the representation of digital terrain models, integrating heterogeneous data from different sources. In this article, we present a general, efficient scheme for achieving interactive level-of-detail rendering of hybrid terrain models, without the need for a costly preprocessing or resampling of the original data. The presented method works with hybrid digital terrains combining regular grid data and local high-resolution triangulated irregular networks. Since grid and triangulated irregular network data may belong to different datasets, a straightforward combination of both geometries would lead to meshes with holes and overlapping triangles. Our method generates a single multiresolution model integrating the different parts in a coherent way, by performing an adaptive tessellation of the region between their boundaries. Hence, our solution is one of the few existing approaches for integrating different multiresolution algorithms within the same terrain model, achieving a simple interactive rendering of complex hybrid terrains. KW - 3D modeling KW - 3D visualization KW - geovisualization KW - triangulated irregular networks Y1 - 2012 U6 - https://doi.org/10.1080/13658816.2011.615317 SN - 1365-8816 VL - 26 IS - 5 SP - 771 EP - 793 PB - Routledge, Taylor & Francis Group CY - Abingdon ER - TY - JOUR A1 - Delikostidis, Ioannis A1 - Engel, Juri A1 - Retsios, Bas A1 - van Elzakker, Corne P. J. M. A1 - Kraak, Menno-Jan A1 - Döllner, Jürgen Roland Friedrich T1 - Increasing the usability of pedestrian navigation interfaces by means of landmark visibility analysis JF - The journal of navigation N2 - Communicating location-specific information to pedestrians is a challenging task which can be aided by user-friendly digital technologies. In this paper, landmark visibility analysis, as a means for developing more usable pedestrian navigation systems, is discussed. Using an algorithmic framework for image-based 3D analysis, this method integrates a 3D city model with identified landmarks and produces raster visibility layers for each one. This output enables an Android phone prototype application to indicate the visibility of landmarks from the user's actual position. Tested in the field, the method achieves sufficient accuracy for the context of use and improves navigation efficiency and effectiveness. KW - Pedestrian navigation KW - Landmark visibility KW - User-centred design KW - Usability testing Y1 - 2013 U6 - https://doi.org/10.1017/S0373463313000209 SN - 0373-4633 VL - 66 IS - 4 SP - 523 EP - 537 PB - Cambridge Univ. Press CY - New York ER - TY - JOUR A1 - Richter, Rico A1 - Kyprianidis, Jan Eric A1 - Döllner, Jürgen Roland Friedrich T1 - Out-of-core GPU-based change detection in massive 3D point clouds JF - Transactions in GIS N2 - If sites, cities, and landscapes are captured at different points in time using technology such as LiDAR, large collections of 3D point clouds result. Their efficient storage, processing, analysis, and presentation constitute a challenging task because of limited computation, memory, and time resources. In this work, we present an approach to detect changes in massive 3D point clouds based on an out-of-core spatial data structure that is designed to store data acquired at different points in time and to efficiently attribute 3D points with distance information. Based on this data structure, we present and evaluate different processing schemes optimized for performing the calculation on the CPU and GPU. In addition, we present a point-based rendering technique adapted for attributed 3D point clouds, to enable effective out-of-core real-time visualization of the computation results. Our approach enables conclusions to be drawn about temporal changes in large highly accurate 3D geodata sets of a captured area at reasonable preprocessing and rendering times. We evaluate our approach with two data sets from different points in time for the urban area of a city, describe its characteristics, and report on applications. Y1 - 2013 U6 - https://doi.org/10.1111/j.1467-9671.2012.01362.x SN - 1361-1682 VL - 17 IS - 5 SP - 724 EP - 741 PB - Wiley-Blackwell CY - Hoboken ER -