Prof. Dr. Jürgen Döllner
Amir Semmo



Tel.: +49-(0)331 5509-3909
Fax: +49-(0)331 5509-172
Room: H-2.26
Email: amir.semmo(at)hpi.de

Research Interests

Non-Photorealistic Rendering (NPR)
Real-Time Rendering & Shading
Computational Aesthetics
Cartographic Design
Virtual 3D City Models


Design and Implementation of Non-Photorealistic Rendering Techniques for 3D Geospatial Data

Semmo, Amir , University of Potsdam , 2016 .

Geospatial data has become a natural part of a growing number of information systems and services in the economy, society, and people's personal lives. In particular, virtual 3D city and landscape models constitute valuable information sources within a wide variety of applications such as urban planning, navigation, tourist information, and disaster management. Today, these models are often visualized in detail to provide realistic imagery. However, a photorealistic rendering does not automatically lead to high image quality, with respect to an effective information transfer, which requires important or prioritized information to be interactively highlighted in a context-dependent manner. Approaches in non-photorealistic renderings particularly consider a user's task and camera perspective when attempting optimal expression, recognition, and communication of important or prioritized information. However, the design and implementation of non-photorealistic rendering techniques for 3D geospatial data pose a number of challenges, especially when inherently complex geometry, appearance, and thematic data must be processed interactively. Hence, a promising technical foundation is established by the programmable and parallel computing architecture of graphics processing units. This thesis proposes non-photorealistic rendering techniques that enable both the computation and selection of the abstraction level of 3D geospatial model contents according to user interaction and dynamically changing thematic information. To achieve this goal, the techniques integrate with hardware-accelerated rendering pipelines using shader technologies of graphics processing units for real-time image synthesis. The techniques employ principles of artistic rendering, cartographic generalization, and 3D semiotics—unlike photorealistic rendering—to synthesize illustrative renditions of geospatial feature type entities such as water surfaces, buildings, and infrastructure networks. In addition, this thesis contributes a generic system that enables to integrate different graphic styles—photorealistic and non-photorealistic—and provide their seamless transition according to user tasks, camera view, and image resolution. Evaluations of the proposed techniques have demonstrated their significance to the field of geospatial information visualization including topics such as spatial perception, cognition, and mapping. In addition, the applications in illustrative and focus+context visualization have reflected their potential impact on optimizing the information transfer regarding factors such as cognitive load, integration of non-realistic information, visualization of uncertainty, and visualization on small displays.
Weitere Informationen
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  • An Interaction Framework for Level-of-Abstraction Visualization of 3D Geovirtual Environments - held at ACM SIGSPATIAL MapInteract 2014, Dallas, TX - USA (11/2014)
  • Image Filtering for Interactive Level-of-Abstraction Visualization of 3D Scenes - held at Expressive 2014, Vancouver - Canada (08/2014)
  • Evaluating the Perceptual Impact of Rendering Techniques on Thematic Color Mappings in 3D Virtual Environments - held at VMV 2013, Lugano - Switzerland (09/2013)
  • Real-Time Rendering of Water Surfaces with Cartography-Oriented Design - held at Expressive 2013, Anaheim, CA - USA (07/2013)
  • Cartography-Oriented Visualization of Virtual 3D City Models based on Level-of-Abstraction Transitions - held at HPI Research School, Potsdam - Germany (06/2012)
  • Interactive Visualization of Generalized Virtual 3D City Models using Level-of-Abstraction Transitions - held at EuroVis 2012, Vienna - Austria (06/2012)
  • Colonia3D - held at Kultur und Informatik Conference, Berlin - Germany (05/2011)
  • Ansätze zur kartographischen Gestaltung von 3D-Stadtmodellen - held at 31. Wissenschaftlich-Technische Jahrestagung der DGPF, Mainz - Germany (04/2011)
  • Automated Image-Based Abstraction of Aerial Images - held at AGILE Conference, Guimarães - Portugal (05/2010)


  • SoSe 2014: Seminar Image & Video Processing
    (with Sebastian Pasewaldt, Matthias Trapp)
  • WiSe 2013/14: Seminar Geovisualization
    (with Rico Richter)
  • SoSe 2013: Graphics Programming with OpenGL and C++
    (with Daniel Limberger, Stefan Buschmann)
  • WiSe 2012/13: Computergrafik II
    (with Daniel Limberger, Jürgen Döllner)
  • SoSe 2012: Exercises for 3D-Computergrafik I
    (with Jan Eric Kyprianidis, Matthias Trapp)
  • WiSe 2011/12: Exercises for Computergrafik II
    (with Matthias Trapp, Christine Lehmann, Jan Eric Kyprianidis)
  • WiSe 2011/12: Seminar Real-Time Rendering Techniques
    (with Rico Richter, Juri Engel)


  • ACM SIGGRAPH (2014)
  • Eurographics Conference on Visualization / EuroVis (2014)
  • IEEE Pacific Visualization (2013)
  • International Journal of Geographical Information Science (2013)
  • The Visual Computer (2012)