TY  - THES
A1  - Trapp, Matthias
T1  - Analysis and exploration of virtual 3D city models using 3D information lenses
N2  - This thesis addresses real-time rendering techniques for 3D information lenses based on the focus & context metaphor. It analyzes, conceives, implements, and reviews its applicability to objects and structures of virtual 3D city models. In contrast to digital terrain models, the application of focus & context visualization to virtual 3D city models is barely researched. However, the purposeful visualization of contextual data of is extreme importance for the interactive exploration and analysis of this field. Programmable hardware enables the implementation of new lens techniques, that allow the augmentation of the perceptive and cognitive quality of the visualization compared to classical perspective projections. A set of 3D information lenses is integrated into a 3D scene-graph system: • Occlusion lenses modify the appearance of virtual 3D city model objects to resolve their occlusion and consequently facilitate the navigation. • Best-view lenses display city model objects in a priority-based manner and mediate their meta information. Thus, they support exploration and navigation of virtual 3D city models. • Color and deformation lenses modify the appearance and geometry of 3D city models to facilitate their perception. The presented techniques for 3D information lenses and their application to virtual 3D city models clarify their potential for interactive visualization and form a base for further development.
N2  - Diese Diplomarbeit behandelt echtzeitfähige Renderingverfahren für 3D Informationslinsen, die auf der Fokus-&-Kontext-Metapher basieren. Im folgenden werden ihre Anwendbarkeit auf Objekte und Strukturen von virtuellen 3D-Stadtmodellen analysiert, konzipiert, implementiert und bewertet. Die Focus-&-Kontext-Visualisierung für virtuelle 3D-Stadtmodelle ist im Gegensatz zum Anwendungsbereich der 3D Geländemodelle kaum untersucht. Hier jedoch ist eine gezielte Visualisierung von kontextbezogenen Daten zu Objekten von großer Bedeutung für die interaktive Exploration und Analyse. Programmierbare Computerhardware erlaubt die Umsetzung neuer Linsen-Techniken, welche die Steigerung der perzeptorischen und kognitiven Qualität der Visualisierung im Vergleich zu klassischen perspektivischen Projektionen zum Ziel hat. Für eine Auswahl von 3D-Informationslinsen wird die Integration in ein 3D-Szenengraph-System durchgeführt: • Verdeckungslinsen modifizieren die Gestaltung von virtuellen 3D-Stadtmodell- Objekten, um deren Verdeckungen aufzulösen und somit die Navigation zu erleichtern. • Best-View Linsen zeigen Stadtmodell-Objekte in einer prioritätsdefinierten Weise und vermitteln Meta-Informationen virtueller 3D-Stadtmodelle. Sie unterstützen dadurch deren Exploration und Navigation. • Farb- und Deformationslinsen modifizieren die Gestaltung und die Geometrie von 3D-Stadtmodell-Bereichen, um deren Wahrnehmung zu steigern. Die in dieser Arbeit präsentierten Techniken für 3D Informationslinsen und die Anwendung auf virtuelle 3D Stadt-Modelle verdeutlichen deren Potenzial in der interaktiven Visualisierung und bilden eine Basis für Weiterentwicklungen.
KW  - Virtuelles 3D Stadtmodell
KW  - 3D Linsen
KW  - Shader
KW  - Echtzeitanwendung
KW  - virtual 3D city model
KW  - 3D lenses
KW  - shader
KW  - real-time application
Y1  - 2007
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-13930
ER  - 
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  - Kyprianidis, Jan Eric
A1  - Döllner, Jürgen Roland Friedrich
T1  - Interactive visualization of generalized virtual 3D city models using level-of-abstraction transitions
JF  - Computer graphics forum : journal of the European Association for Computer Graphics
N2  - Virtual 3D city models play an important role in the communication of complex geospatial information in a growing number of applications, such as urban planning, navigation, tourist information, and disaster management. In general, homogeneous graphic styles are used for visualization. For instance, photorealism is suitable for detailed presentations, and non-photorealism or abstract stylization is used to facilitate guidance of a viewer's gaze to prioritized information. However, to adapt visualization to different contexts and contents and to support saliency-guided visualization based on user interaction or dynamically changing thematic information, a combination of different graphic styles is necessary. Design and implementation of such combined graphic styles pose a number of challenges, specifically from the perspective of real-time 3D visualization. In this paper, the authors present a concept and an implementation of a system that enables different presentation styles, their seamless integration within a single view, and parametrized transitions between them, which are defined according to tasks, camera view, and image resolution. The paper outlines potential usage scenarios and application fields together with a performance evaluation of the implementation.
Y1  - 2012
U6  - https://doi.org/10.1111/j.1467-8659.2012.03081.x
SN  - 0167-7055
VL  - 31
IS  - 3
SP  - 885
EP  - 894
PB  - Wiley-Blackwell
CY  - Hoboken
ER  - 
TY  - THES
A1  - Trapp, Matthias
T1  - Interactive rendering techniques for focus+context visualization of 3D geovirtual environments
T1  - Interaktive Rendering-Techniken für die Fokus-&-Kontext-Visualisierung von geovirtuellen 3D-Umgebungen
N2  - This thesis introduces a collection of new real-time rendering techniques and applications for focus+context visualization of interactive 3D geovirtual environments such as virtual 3D city and landscape models. These environments are generally characterized by a large number of objects and are of high complexity with respect to geometry and textures. For these reasons, their interactive 3D rendering represents a major challenge. Their 3D depiction implies a number of weaknesses such as occlusions, cluttered image contents, and partial screen-space usage. To overcome these limitations and, thus, to facilitate the effective communication of geo-information, principles of focus+context visualization can be used for the design of real-time 3D rendering techniques for 3D geovirtual environments (see Figure). In general, detailed views of a 3D geovirtual environment are combined seamlessly with abstracted views of the context within a single image. To perform the real-time image synthesis required for interactive visualization, dedicated parallel processors (GPUs) for rasterization of computer graphics primitives are used. For this purpose, the design and implementation of appropriate data structures and rendering pipelines are necessary. The contribution of this work comprises the following five real-time rendering methods: • The rendering technique for 3D generalization lenses enables the combination of different 3D city geometries (e.g., generalized versions of a 3D city model) in a single image in real time. The method is based on a generalized and fragment-precise clipping approach, which uses a compressible, raster-based data structure. It enables the combination of detailed views in the focus area with the representation of abstracted variants in the context area. • The rendering technique for the interactive visualization of dynamic raster data in 3D geovirtual environments facilitates the rendering of 2D surface lenses. It enables a flexible combination of different raster layers (e.g., aerial images or videos) using projective texturing for decoupling image and geometry data. Thus, various overlapping and nested 2D surface lenses of different contents can be visualized interactively. • The interactive rendering technique for image-based deformation of 3D geovirtual environments enables the real-time image synthesis of non-planar projections, such as cylindrical and spherical projections, as well as multi-focal 3D fisheye-lenses and the combination of planar and non-planar projections. • The rendering technique for view-dependent multi-perspective views of 3D geovirtual environments, based on the application of global deformations to the 3D scene geometry, can be used for synthesizing interactive panorama maps to combine detailed views close to the camera (focus) with abstract views in the background (context). This approach reduces occlusions, increases the usage the available screen space, and reduces the overload of image contents. • The object-based and image-based rendering techniques for highlighting objects and focus areas inside and outside the view frustum facilitate preattentive perception. The concepts and implementations of interactive image synthesis for focus+context visualization and their selected applications enable a more effective communication of spatial information, and provide building blocks for design and development of new applications and systems in the field of 3D geovirtual environments.
N2  - Die Darstellung immer komplexerer raumbezogener Information durch Geovisualisierung stellt die existierenden Technologien und den Menschen ständig vor neue Herausforderungen. In dieser Arbeit werden fünf neue, echtzeitfähige Renderingverfahren und darauf basierende Anwendungen für die Fokus-&-Kontext-Visualisierung von interaktiven geovirtuellen 3D-Umgebungen – wie virtuelle 3D-Stadt- und Landschaftsmodelle – vorgestellt. Die große Menge verschiedener darzustellender raumbezogener Information in 3D-Umgebungen führt oft zu einer hohen Anzahl unterschiedlicher Objekte und somit zu einer hohen Geometrie- und Texturkomplexität. In der Folge verlieren 3D-Darstellungen durch Verdeckungen, überladene Bildinhalte und eine geringe Ausnutzung des zur Verfügung stehenden Bildraumes an Informationswert. Um diese Beschränkungen zu kompensieren und somit die Kommunikation raumbezogener Information zu verbessern, kann das Prinzip der Fokus-&-Kontext-Visualisierung angewendet werden. Hierbei wird die für den Nutzer wesentliche Information als detaillierte Ansicht im Fokus mit abstrahierter Kontextinformation nahtlos miteinander kombiniert. Um das für die interaktive Visualisierung notwendige Echtzeit-Rendering durchzuführen, können spezialisierte Parallelprozessoren für die Rasterisierung von computergraphischen Primitiven (GPUs) verwendet werden. Dazu ist die Konzeption und Implementierung von geeigneten Datenstrukturen und Rendering-Pipelines notwendig. Der Beitrag dieser Arbeit umfasst die folgenden fünf Renderingverfahren. • Das Renderingverfahren für interaktive 3D-Generalisierungslinsen: Hierbei wird die Kombination unterschiedlicher 3D-Szenengeometrien, z. B. generalisierte Varianten eines 3DStadtmodells, in einem Bild ermöglicht. Das Verfahren basiert auf einem generalisierten Clipping-Ansatz, der es erlaubt, unter Verwendung einer komprimierbaren, rasterbasierten Datenstruktur beliebige Bereiche einer 3D-Szene freizustellen bzw. zu kappen. Somit lässt sich eine Kombination von detaillierten Ansichten im Fokusbereich mit der Darstellung einer abstrahierten Variante im Kontextbereich implementieren. • Das Renderingverfahren zur Visualisierung von dynamischen Raster-Daten in geovirtuellen 3D-Umgebungen zur Darstellung von 2D-Oberflächenlinsen: Die Verwendung von projektiven Texturen zur Entkoppelung von Bild- und Geometriedaten ermöglicht eine flexible Kombination verschiedener Rasterebenen (z.B. Luftbilder oder Videos). Somit können verschiedene überlappende sowie verschachtelte 2D-Oberflächenlinsen mit unterschiedlichen Dateninhalten interaktiv visualisiert werden. • Das Renderingverfahren zur bildbasierten Deformation von geovirtuellen 3D-Umgebungen: Neben der interaktiven Bildsynthese von nicht-planaren Projektionen, wie beispielsweise zylindrischen oder sphärischen Panoramen, lassen sich mit diesem Verfahren multifokale 3D-Fischaugen-Linsen erzeugen sowie planare und nicht-planare Projektionen miteinander kombinieren. • Das Renderingverfahren für die Generierung von sichtabhängigen multiperspektivischen Ansichten von geovirtuellen 3D-Umgebungen: Das Verfahren basiert auf globalen Deformationen der 3D-Szenengeometrie und kann zur Erstellung von interaktiven 3D-Panoramakarten verwendet werden, welche beispielsweise detaillierte Absichten nahe der virtuellen Kamera (Fokus) mit abstrakten Ansichten im Hintergrund (Kontext) kombinieren. Dieser Ansatz reduziert Verdeckungen, nutzt den zur Verfügung stehenden Bildraum in verbesserter Weise aus und reduziert das Überladen von Bildinhalten. • Objekt-und bildbasierte Renderingverfahren für die Hervorhebung von Fokus-Objekten und Fokus-Bereichen innerhalb und außerhalb des sichtbaren Bildausschnitts, um die präattentive Wahrnehmung eines Benutzers besser zu unterstützen. Die in dieser Arbeit vorgestellten Konzepte, Entwürfe und Implementierungen von interaktiven Renderingverfahren zur Fokus-&-Kontext-Visualisierung sowie deren ausgewählte Anwendungen ermöglichen eine effektivere Kommunikation raumbezogener Information und repräsentieren softwaretechnische Bausteine für die Entwicklung neuer Anwendungen und Systeme im Bereich der geovirtuellen 3D-Umgebungen.
KW  - 3D Computer Grafik
KW  - Interaktives Rendering
KW  - Fokus-&-Kontext Visualisierung
KW  - 3D Computer Graphics
KW  - Interactive Rendering
KW  - Focus+Context Visualization
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-66824
ER  - 
TY  - JOUR
A1  - Pasewaldt, Sebastian
A1  - Semmo, Amir
A1  - Trapp, Matthias
A1  - Döllner, Jürgen
T1  - Multi-perspective 3D panoramas
JF  - International journal of geographical information science
N2  - This article presents multi-perspective 3D panoramas that focus on visualizing 3D geovirtual environments (3D GeoVEs) for navigation and exploration tasks. Their key element, a multi-perspective view (MPV), seamlessly combines what is seen from multiple viewpoints into a single image. This approach facilitates the presentation of information for virtual 3D city and landscape models, particularly by reducing occlusions, increasing screen-space utilization, and providing additional context within a single image. We complement MPVs with cartographic visualization techniques to stylize features according to their semantics and highlight important or prioritized information. When combined, both techniques constitute the core implementation of interactive, multi-perspective 3D panoramas. They offer a large number of effective means for visual communication of 3D spatial information, a high degree of customization with respect to cartographic design, and manifold applications in different domains. We discuss design decisions of 3D panoramas for the exploration of and navigation in 3D GeoVEs. We also discuss a preliminary user study that indicates that 3D panoramas are a promising approach for navigation systems using 3D GeoVEs.
KW  - multi-perspective visualization
KW  - panorama
KW  - focus plus context visualization
KW  - 3D geovirtual environments
KW  - cartographic design
Y1  - 2014
U6  - https://doi.org/10.1080/13658816.2014.922686
SN  - 1365-8816
SN  - 1362-3087
VL  - 28
IS  - 10
SP  - 2030
EP  - 2051
PB  - Routledge, Taylor & Francis Group
CY  - Abingdon
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  - JOUR
A1  - Buschmann, Stefan
A1  - Trapp, Matthias
A1  - Döllner, Jürgen Roland Friedrich
T1  - Animated visualization of spatial-temporal trajectory data for air-traffic analysis
JF  - The Visual Computer
N2  - With increasing numbers of flights worldwide and a continuing rise in airport traffic, air-traffic management is faced with a number of challenges. These include monitoring, reporting, planning, and problem analysis of past and current air traffic, e.g., to identify hotspots, minimize delays, or to optimize sector assignments to air-traffic controllers. To cope with these challenges, cyber worlds can be used for interactive visual analysis and analytical reasoning based on aircraft trajectory data. However, with growing data size and complexity, visualization requires high computational efficiency to process that data within real-time constraints. This paper presents a technique for real-time animated visualization of massive trajectory data. It enables (1) interactive spatio-temporal filtering, (2) generic mapping of trajectory attributes to geometric representations and appearance, and (3) real-time rendering within 3D virtual environments such as virtual 3D airport or 3D city models. Different visualization metaphors can be efficiently built upon this technique such as temporal focus+context, density maps, or overview+detail methods. As a general-purpose visualization technique, it can be applied to general 3D and 3+1D trajectory data, e.g., traffic movement data, geo-referenced networks, or spatio-temporal data, and it supports related visual analytics and data mining tasks within cyber worlds.
KW  - Spatio-temporal visualization
KW  - Trajectory visualization
KW  - 3D visualization
KW  - Visual analytics
KW  - Real-time rendering
Y1  - 2016
U6  - https://doi.org/10.1007/s00371-015-1185-9
SN  - 0178-2789
SN  - 1432-2315
VL  - 32
SP  - 371
EP  - 381
PB  - Springer
CY  - New York
ER  - 
TY  - GEN
A1  - Limberger, Daniel
A1  - Scheibel, Willy
A1  - Trapp, Matthias
A1  - Döllner, Jürgen Roland Friedrich
T1  - Mixed-projection treemaps
BT  - a novel approach mixing 2D and 2.5D treemaps
T2  - 21st International Conference Information Visualisation (IV)
N2  - This paper presents a novel technique for combining 2D and 2.5D treemaps using multi-perspective views to leverage the advantages of both treemap types. It enables a new form of overview+detail visualization for tree-structured data and contributes new concepts for real-time rendering of and interaction with treemaps. The technique operates by tilting the graphical elements representing inner nodes using affine transformations and animated state transitions. We explain how to mix orthogonal and perspective projections within a single treemap. Finally, we show application examples that benefit from the reduced interaction overhead.
KW  - Information Visualization
KW  - Overview plus Detail
KW  - Treemaps
KW  - 2.5D Treemaps
KW  - Multi-perspective Views
Y1  - 2017
SN  - 978-1-5386-0831-9
U6  - https://doi.org/10.1109/iV.2017.67
SN  - 2375-0138
SP  - 164
EP  - 169
PB  - Institute of Electrical and Electronics Engineers
CY  - Los Alamitos
ER  - 
TY  - GEN
A1  - Stojanovic, Vladeta
A1  - Trapp, Matthias
A1  - Richter, Rico
A1  - Döllner, Jürgen Roland Friedrich
T1  - A service-oriented approach for classifying 3D points clouds by example of office furniture classification
T2  - Web3D 2018: Proceedings of the 23rd International ACM Conference on 3D Web Technology
N2  - The rapid digitalization of the Facility Management (FM) sector has increased the demand for mobile, interactive analytics approaches concerning the operational state of a building. These approaches provide the key to increasing stakeholder engagement associated with Operation and Maintenance (O&M) procedures of living and working areas, buildings, and other built environment spaces. We present a generic and fast approach to process and analyze given 3D point clouds of typical indoor office spaces to create corresponding up-to-date approximations of classified segments and object-based 3D models that can be used to analyze, record and highlight changes of spatial configurations. The approach is based on machine-learning methods used to classify the scanned 3D point cloud data using 2D images. This approach can be used to primarily track changes of objects over time for comparison, allowing for routine classification, and presentation of results used for decision making. We specifically focus on classification, segmentation, and reconstruction of multiple different object types in a 3D point-cloud scene. We present our current research and describe the implementation of these technologies as a web-based application using a services-oriented methodology.
KW  - Indoor Models
KW  - 3D Point Clouds
KW  - Machine
KW  - Learning
KW  - BIM
KW  - Service-Oriented
Y1  - 2018
SN  - 978-1-4503-5800-2
U6  - https://doi.org/10.1145/3208806.3208810
SP  - 1
EP  - 9
PB  - Association for Computing Machinery
CY  - New York
ER  - 
TY  - GEN
A1  - Reimann, Max
A1  - Klingbeil, Mandy
A1  - Pasewaldt, Sebastian
A1  - Semmo, Amir
A1  - Trapp, Matthias
A1  - Döllner, Jürgen Roland Friedrich
ED  - Sourin, A Sourina
T1  - MaeSTrO: A Mobile App for Style Transfer Orchestration using Neural Networks
T2  - International Conference on Cyberworlds (CW)
N2  - Mobile expressive rendering gained increasing popularity among users seeking casual creativity by image stylization and supports the development of mobile artists as a new user group. In particular, neural style transfer has advanced as a core technology to emulate characteristics of manifold artistic styles. However, when it comes to creative expression, the technology still faces inherent limitations in providing low-level controls for localized image stylization. This work enhances state-of-the-art neural style transfer techniques by a generalized user interface with interactive tools to facilitate a creative and localized editing process. Thereby, we first propose a problem characterization representing trade-offs between visual quality, run-time performance, and user control. We then present MaeSTrO, a mobile app for orchestration of neural style transfer techniques using iterative, multi-style generative and adaptive neural networks that can be locally controlled by on-screen painting metaphors. At this, first user tests indicate different levels of satisfaction for the implemented techniques and interaction design.
KW  - non-photorealistic rendering
KW  - style transfer
Y1  - 2018
SN  - 978-1-5386-7315-7
U6  - https://doi.org/10.1109/CW.2018.00016
SP  - 9
EP  - 16
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  - 
TY  - JOUR
A1  - Stojanovic, Vladeta
A1  - Trapp, Matthias
A1  - Richter, Rico
A1  - Döllner, Jürgen Roland Friedrich
T1  - Service-oriented semantic enrichment of indoor point clouds using octree-based multiview classification
JF  - Graphical Models
N2  - The use of Building Information Modeling (BIM) for Facility Management (FM) in the Operation and Maintenance (O&M) stages of the building life-cycle is intended to bridge the gap between operations and digital data, but lacks the functionality of assessing the state of the built environment due to non-automated generation of associated semantics. 3D point clouds can be used to capture the physical state of the built environment, but also lack these associated semantics. A prototypical implementation of a service-oriented architecture for classification of indoor point cloud scenes of office environments is presented, using multiview classification. The multiview classification approach is tested using a retrained Convolutional Neural Network (CNN) model - Inception V3. The presented approach for classifying common office furniture objects (chairs, sofas and desks), contained in 3D point cloud scans, is tested and evaluated. The results show that the presented approach can classify common office furniture up to an acceptable degree of accuracy, and is suitable for quick and robust semantics approximation - based on RGB (red, green and blue color channel) cubemap images of the octree partitioned areas of the 3D point cloud scan. Additional methods for web-based 3D visualization, editing and annotation of point clouds are also discussed. Using the described approach, captured scans of indoor environments can be semantically enriched using object annotations derived from multiview classification results. Furthermore, the presented approach is suited for semantic enrichment of lower resolution indoor point clouds acquired using commodity mobile devices.
KW  - Semantic enrichment
KW  - 3D point clouds
KW  - Multiview classification
KW  - Service-oriented
KW  - Indoor environments
Y1  - 2019
U6  - https://doi.org/10.1016/j.gmod.2019.101039
SN  - 1524-0703
SN  - 1524-0711
VL  - 105
PB  - Elsevier
CY  - San Diego
ER  - 
TY  - GEN
A1  - Trapp, Matthias
A1  - Döllner, Jürgen Roland Friedrich
ED  - Banissi, E Ursyn
T1  - Interactive Close-Up Rendering for Detail plus Overview Visualization of 3D Digital Terrain Models
T2  - 2019 23rd International Conference Information Visualisation (IV)
N2  - This paper presents an interactive rendering technique for detail+overview visualization of 3D digital terrain models using interactive close-ups. A close-up is an alternative presentation of input data varying with respect to geometrical scale, mapping, appearance, as well as Level-of-Detail (LOD) and Level-of-Abstraction (LOA) used. The presented 3D close-up approach enables in-situ comparison of multiple Regionof-Interests (ROIs) simultaneously. We describe a GPU-based rendering technique for the image-synthesis of multiple close-ups in real-time.
KW  - Terrain Visualization
KW  - Detail plus Overview
KW  - Close-Up
KW  - Coordinated and Multiple Views
Y1  - 2019
SN  - 978-1-7281-2838-2
SN  - 978-1-7281-2839-9
U6  - https://doi.org/10.1109/IV.2019.00053
SN  - 2375-0138
SN  - 1550-6037
SP  - 275
EP  - 280
PB  - Inst. of Electr. and Electronics Engineers
CY  - Los Alamitos
ER  - 
TY  - JOUR
A1  - Reimann, Max
A1  - Klingbeil, Mandy
A1  - Pasewaldt, Sebastian
A1  - Semmo, Amir
A1  - Trapp, Matthias
A1  - Döllner, Jürgen Roland Friedrich
T1  - Locally controllable neural style transfer on mobile devices
JF  - The Visual Computer
N2  - Mobile expressive rendering gained increasing popularity among users seeking casual creativity by image stylization and supports the development of mobile artists as a new user group. In particular, neural style transfer has advanced as a core technology to emulate characteristics of manifold artistic styles. However, when it comes to creative expression, the technology still faces inherent limitations in providing low-level controls for localized image stylization. In this work, we first propose a problem characterization of interactive style transfer representing a trade-off between visual quality, run-time performance, and user control. We then present MaeSTrO, a mobile app for orchestration of neural style transfer techniques using iterative, multi-style generative and adaptive neural networks that can be locally controlled by on-screen painting metaphors. At this, we enhance state-of-the-art neural style transfer techniques by mask-based loss terms that can be interactively parameterized by a generalized user interface to facilitate a creative and localized editing process. We report on a usability study and an online survey that demonstrate the ability of our app to transfer styles at improved semantic plausibility.
KW  - Non-photorealistic rendering
KW  - Style transfer
KW  - Neural networks
KW  - Mobile devices
KW  - Interactive control
KW  - Expressive rendering
Y1  - 2019
U6  - https://doi.org/10.1007/s00371-019-01654-1
SN  - 0178-2789
SN  - 1432-2315
VL  - 35
IS  - 11
SP  - 1531
EP  - 1547
PB  - Springer
CY  - New York
ER  - 
TY  - GEN
A1  - Florio, Alessandro
A1  - Trapp, Matthias
A1  - Döllner, Jürgen Roland Friedrich
T1  - Semantic-driven Visualization Techniques for Interactive Exploration of 3D Indoor Models
T2  - 2019 23rd International Conference Information Visualisation (IV)
N2  - The availability of detailed virtual 3D building models including representations of indoor elements, allows for a wide number of applications requiring effective exploration and navigation functionality. Depending on the application context, users should be enabled to focus on specific Objects-of-Interests (OOIs) or important building elements. This requires approaches to filtering building parts as well as techniques to visualize important building objects and their relations. For it, this paper explores the application and combination of interactive rendering techniques as well as their semanticallydriven configuration in the context of 3D indoor models.
KW  - Building Information Models
KW  - BIM
KW  - Industry Foundation Classes
KW  - IFC
KW  - Interactive Visualization
KW  - Real-time Rendering
Y1  - 2019
SN  - 978-1-7281-2838-2
SN  - 978-1-7281-2839-9
U6  - https://doi.org/10.1109/IV.2019.00014
SN  - 2375-0138
SN  - 1550-6037
SP  - 25
EP  - 30
PB  - Inst. of Electr. and Electronics Engineers
CY  - Los Alamitos
ER  - 
TY  - GEN
A1  - Trapp, Matthias
A1  - Döllner, Jürgen Roland Friedrich
T1  - Real-time Screen-space Geometry Draping for 3D Digital Terrain Models
T2  - 2019 23rd International Conference Information Visualisation (IV)
N2  - A fundamental task in 3D geovisualization and GIS applications is the visualization of vector data that can represent features such as transportation networks or land use coverage. Mapping or draping vector data represented by geometric primitives (e.g., polylines or polygons) to 3D digital elevation or 3D digital terrain models is a challenging task. We present an interactive GPU-based approach that performs geometry-based draping of vector data on per-frame basis using an image-based representation of a 3D digital elevation or terrain model only.
KW  - Geometry Draping
KW  - Geovisualization
KW  - GPU-based Real-time Rendering
Y1  - 2019
SN  - 978-1-7281-2838-2
SN  - 978-1-7281-2839-9
U6  - https://doi.org/10.1109/IV.2019.00054
SN  - 2375-0138
SN  - 1550-6037
SP  - 281
EP  - 286
PB  - Inst. of Electr. and Electronics Engineers
CY  - Los Alamitos
ER  - 
TY  - JOUR
A1  - Söchting, Maximilian
A1  - Trapp, Matthias
T1  - Controlling image-stylization techniques using eye tracking
JF  - Science and Technology Publications
N2  - With the spread of smart phones capable of taking high-resolution photos and the development of high-speed mobile data infrastructure, digital visual media is becoming one of the most important forms of modern communication. With this development, however, also comes a devaluation of images as a media form with the focus becoming the frequency at which visual content is generated instead of the quality of the content. In this work, an interactive system using image-abstraction techniques and an eye tracking sensor is presented, which allows users to experience diverting and dynamic artworks that react to their eye movement. The underlying modular architecture enables a variety of different interaction techniques that share common design principles, making the interface as intuitive as possible. The resulting experience allows users to experience a game-like interaction in which they aim for a reward, the artwork, while being held under constraints, e.g., not blinking. The co nscious eye movements that are required by some interaction techniques hint an interesting, possible future extension for this work into the field of relaxation exercises and concentration training.
KW  - Eye-tracking
KW  - Image Abstraction
KW  - Image Processing
KW  - Artistic Image Stylization
KW  - Interactive Media
Y1  - 2020
SN  - 2184-4321
PB  - Springer
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Scheibel, Willy
A1  - Trapp, Matthias
A1  - Limberger, Daniel
A1  - Döllner, Jürgen Roland Friedrich
T1  - A taxonomy of treemap visualization techniques
JF  - Science and Technology Publications
N2  - A treemap is a visualization that has been specifically designed to facilitate the exploration of tree-structured data and, more general, hierarchically structured data. The family of visualization techniques that use a visual metaphor for parent-child relationships based “on the property of containment” (Johnson, 1993) is commonly referred to as treemaps. However, as the number of variations of treemaps grows, it becomes increasingly important to distinguish clearly between techniques and their specific characteristics. This paper proposes to discern between Space-filling Treemap TS, Containment Treemap TC, Implicit Edge Representation Tree TIE, and Mapped Tree TMT for classification of hierarchy visualization techniques and highlights their respective properties. This taxonomy is created as a hyponymy, i.e., its classes have an is-a relationship to one another: TS TC TIE TMT. With this proposal, we intend to stimulate a discussion on a more unambiguous classification of treemaps and, furthermore, broaden what is understood by the concept of treemap itself.
KW  - Treemaps
KW  - Taxonomy
Y1  - 2020
PB  - Springer
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Isailović, Dušan
A1  - Stojanovic, Vladeta
A1  - Trapp, Matthias
A1  - Richter, Rico
A1  - Hajdin, Rade
A1  - Döllner, Jürgen Roland Friedrich
T1  - Bridge damage
BT  - detection, IFC-based semantic enrichment and visualization
JF  - Automation in construction : an international research journal
N2  - Building Information Modeling (BIM) representations of bridges enriched by inspection data will add tremendous value to future Bridge Management Systems (BMSs). This paper presents an approach for point cloud-based detection of spalling damage, as well as integrating damage components into a BIM via semantic enrichment of an as-built Industry Foundation Classes (IFC) model. An approach for generating the as-built BIM, geometric reconstruction of detected damage point clusters and semantic-enrichment of the corresponding IFC model is presented. Multiview-classification is used and evaluated for the detection of spalling damage features. The semantic enrichment of as-built IFC models is based on injecting classified and reconstructed damage clusters back into the as-built IFC, thus generating an accurate as-is IFC model compliant to the BMS inspection requirements.
KW  - damage detection
KW  - building information modeling
KW  - 3D point clouds
KW  - multiview classification
KW  - bridge management systems
Y1  - 2020
U6  - https://doi.org/10.1016/j.autcon.2020.103088
SN  - 0926-5805
SN  - 1872-7891
VL  - 112
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - GEN
A1  - Söchting, Maximilian
A1  - Trapp, Matthias
T1  - Controlling image-stylization techniques using eye tracking
T2  - Postprints der Universität Potsdam : Reihe der Digital Engineering Fakultät
N2  - With the spread of smart phones capable of taking high-resolution photos and the development of high-speed mobile data infrastructure, digital visual media is becoming one of the most important forms of modern communication. With this development, however, also comes a devaluation of images as a media form with the focus becoming the frequency at which visual content is generated instead of the quality of the content. In this work, an interactive system using image-abstraction techniques and an eye tracking sensor is presented, which allows users to experience diverting and dynamic artworks that react to their eye movement. The underlying modular architecture enables a variety of different interaction techniques that share common design principles, making the interface as intuitive as possible. The resulting experience allows users to experience a game-like interaction in which they aim for a reward, the artwork, while being held under constraints, e.g., not blinking. The co nscious eye movements that are required by some interaction techniques hint an interesting, possible future extension for this work into the field of relaxation exercises and concentration training.
T3  - Zweitveröffentlichungen der Universität Potsdam : Reihe der Digital Engineering Fakultät - 7 
KW  - eye-tracking
KW  - image abstraction
KW  - image processing
KW  - artistic image stylization
KW  - interactive media
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-524717
IS  - 7
ER  -