TY - JOUR A1 - Semmo, Amir A1 - Hildebrandt, Dieter A1 - Trapp, Matthias A1 - Döllner, Jürgen Roland Friedrich T1 - Concepts for cartography-oriented visualization of virtual 3D city models JF - Photogrammetrie, Fernerkundung, Geoinformation N2 - Virtual 3D city models serve as an effective medium with manifold applications in geoinformation systems and services. To date, most 3D city models are visualized using photorealistic graphics. But an effective communication of geoinformation significantly depends on how important information is designed and cognitively processed in the given application context. One possibility to visually emphasize important information is based on non-photorealistic rendering, which comprehends artistic depiction styles and is characterized by its expressiveness and communication aspects. However, a direct application of non-photorealistic rendering techniques primarily results in monotonic visualization that lacks cartographic design aspects. In this work, we present concepts for cartography-oriented visualization of virtual 3D city models. These are based on coupling non-photorealistic rendering techniques and semantics-based information for a user, context, and media-dependent representation of thematic information. This work highlights challenges for cartography-oriented visualization of 3D geovirtual environments, presents stylization techniques and discusses their applications and ideas for a standardized visualization. In particular, the presented concepts enable a real-time and dynamic visualization of thematic geoinformation. KW - 3D city models KW - cartography-oriented visualization KW - style description languages KW - real-time rendering Y1 - 2012 U6 - https://doi.org/10.1127/1432-8364/2012/0131 SN - 1432-8364 IS - 4 SP - 455 EP - 465 PB - Schweizerbart CY - Stuttgart ER - TY - JOUR A1 - Semmo, Amir A1 - Trapp, Matthias A1 - Jobst, Markus A1 - Döllner, Jürgen Roland Friedrich T1 - Cartography-Oriented Design of 3D Geospatial Information Visualization - Overview and Techniques JF - The cartographic journal N2 - In economy, society and personal life map-based interactive geospatial visualization becomes a natural element of a growing number of applications and systems. The visualization of 3D geospatial information, however, raises the question how to represent the information in an effective way. Considerable research has been done in technology-driven directions in the fields of cartography and computer graphics (e.g., design principles, visualization techniques). Here, non-photorealistic rendering (NPR) represents a promising visualization category - situated between both fields - that offers a large number of degrees for the cartography-oriented visual design of complex 2D and 3D geospatial information for a given application context. Still today, however, specifications and techniques for mapping cartographic design principles to the state-of-the-art rendering pipeline of 3D computer graphics remain to be explored. This paper revisits cartographic design principles for 3D geospatial visualization and introduces an extended 3D semiotic model that complies with the general, interactive visualization pipeline. Based on this model, we propose NPR techniques to interactively synthesize cartographic renditions of basic feature types, such as terrain, water, and buildings. In particular, it includes a novel iconification concept to seamlessly interpolate between photorealistic and cartographic representations of 3D landmarks. Our work concludes with a discussion of open challenges in this field of research, including topics, such as user interaction and evaluation. KW - 3D information visualization KW - 3D semiotic model KW - cartographic design KW - user interaction KW - real-time rendering Y1 - 2015 U6 - https://doi.org/10.1080/00087041.2015.1119462 SN - 0008-7041 SN - 1743-2774 VL - 52 IS - 2 SP - 95 EP - 106 PB - Routledge, Taylor & Francis Group CY - Leeds ER - TY - GEN A1 - Limberger, Daniel A1 - Gropler, Anne A1 - Buschmann, Stefan A1 - Döllner, Jürgen Roland Friedrich A1 - Wasty, Benjamin T1 - OpenLL BT - an API for Dynamic 2D and 3D Labeling T2 - 22nd International Conference Information Visualisation (IV) N2 - Today's rendering APIs lack robust functionality and capabilities for dynamic, real-time text rendering and labeling, which represent key requirements for 3D application design in many fields. As a consequence, most rendering systems are barely or not at all equipped with respective capabilities. This paper drafts the unified text rendering and labeling API OpenLL intended to complement common rendering APIs, frameworks, and transmission formats. For it, various uses of static and dynamic placement of labels are showcased and a text interaction technique is presented. Furthermore, API design constraints with respect to state-of-the-art text rendering techniques are discussed. This contribution is intended to initiate a community-driven specification of a free and open label library. KW - visualization KW - labeling KW - real-time rendering Y1 - 2018 SN - 978-1-5386-7202-0 U6 - https://doi.org/10.1109/iV.2018.00039 SP - 175 EP - 181 PB - IEEE CY - New York ER - TY - JOUR A1 - Vollmer, Jan Ole A1 - Trapp, Matthias A1 - Schumann, Heidrun A1 - Döllner, Jürgen Roland Friedrich T1 - Hierarchical spatial aggregation for level-of-detail visualization of 3D thematic data JF - ACM transactions on spatial algorithms and systems N2 - Thematic maps are a common tool to visualize semantic data with a spatial reference. Combining thematic data with a geometric representation of their natural reference frame aids the viewer’s ability in gaining an overview, as well as perceiving patterns with respect to location; however, as the amount of data for visualization continues to increase, problems such as information overload and visual clutter impede perception, requiring data aggregation and level-of-detail visualization techniques. While existing aggregation techniques for thematic data operate in a 2D reference frame (i.e., map), we present two aggregation techniques for 3D spatial and spatiotemporal data mapped onto virtual city models that hierarchically aggregate thematic data in real time during rendering to support on-the-fly and on-demand level-of-detail generation. An object-based technique performs aggregation based on scene-specific objects and their hierarchy to facilitate per-object analysis, while the scene-based technique aggregates data solely based on spatial locations, thus supporting visual analysis of data with arbitrary reference geometry. Both techniques can apply different aggregation functions (mean, minimum, and maximum) for ordinal, interval, and ratio-scaled data and can be easily extended with additional functions. Our implementation utilizes the programmable graphics pipeline and requires suitably encoded data, i.e., textures or vertex attributes. We demonstrate the application of both techniques using real-world datasets, including solar potential analyses and the propagation of pressure waves in a virtual city model. KW - Level-of-detail visualization KW - spatial aggregation KW - real-time rendering Y1 - 2018 U6 - https://doi.org/10.1145/3234506 SN - 2374-0353 SN - 2374-0361 VL - 4 IS - 3 PB - Association for Computing Machinery CY - New York ER -