Curriculum Vitae

Dipl.-Inf. (Univ.) Klaus Engel

Mailing address:
University of Stuttgart
Visualization and Interactive Systems Group (VIS)
Breitwiesenstraße 20-22
70565 Stuttgart

Faculty of Computer Science
Visualization and Interactive Systems Group (VIS)
Breitwiesenstraße 20-22
70565 Stuttgart
Room: 1.116
Research Web-Page:
Phone: +49-(0)711-7816 208
Fax:     +49-(0)711-7816 340







Best Paper Award:
K. Engel, M. Kraus, and T. Ertl
"High-Quality Pre-Integrated Volume Rendering Using Hardware-Accelerated Pixel Shading"
In Proc. Eurographics/SIGGRAPH Workshop on Graphics Hardware 2001

Best Paper Award:
C.Resk-Salama, K.Engel, M.Bauer, G.Greiner, T.Ertl
"Interactive Volume Rendering on Standard PC Graphics Hardware Using Multi-Textures and Multi-Stage-Rasterization"
In Proc. Eurographics/SIGGRAPH Workshop on Graphics Hardware 2000

Scientific Interests



(from an interactive graphics point of view)


My fascination for computer graphics started back in 1985 with the first Commodore64 computer. I started programming the C64 with first programs and soon discovered assembler-programming to utililize the graphics chip of the C64. This graphics chip, the VIC-II (Video Interface Controller) had some great graphics capabilities, a 14 bit address bus, 16 colors, hardware sprites and  rasterline interrupt requests. I had my first "scientific success" by discovering the double buffering algorithm for smooth scrolling (unfortunately somebody else had discovered it before ;-) )and developed my first computer game "Deneb", a so-called "shoot-em-up" game in the style of the wellknown game "Uridium", that i sold to C64 disk magazine "Magic Disk" in 1987. I also programmed lots of graphics demos and shop window advertising.

A big step forward in interactive computer graphics was the Commodore Amiga Computer in 1988 with it's custom graphics coprocessor "copper" and animation coprocessor "blitter". For me, it was the first contact with 3D graphics. I implemented my first ray-tracer and although the graphics coprocessors had pure 2D graphics capabilities, the first interactive polygonal 3D graphics was possible. I implemented several graphics demos in 68000 assembler to exploit all the possibilities of the hardware for 2D and 3D graphics.


In 1989 in got my general qualification for university entrance. Before starting my academic career, i had to complete a year of military service at the German Federal Armed Forces. In November 1990 i began studying computer science at University of Würzburg. I finished my undergraduate studies at the University of Würzburg in 1993 with a pre-degree in computer science and started graduate studies at the University of Erlangen-Nuremberg. My major subject at the University of Erlangen-Nuremberg was computer graphics at the Computer Graphics Group at the University of Erlangen (Prof. Dr. Hans-Peter Seidel, Prof. Dr. Thomas Ertl). First experiences with Silicon Graphics graphics hardware and GL  followed. My main interests were interative computer graphics and visualization. This was also the time of the first consumer graphics boards, so i used the 3DFX Voodoo board, followed by a NVidia Riva128 graphics board for 3D programming at home. I finished my graduate  with the master of science (`Diplom'), at the Department of Computer Science of the University of Erlangen-Nuremberg in 1997 with the thesis "Conception and Implementation of JAVA-based Visualization-Components for Embedded Systems". The thesis was part of a project of four students and the company 3SOFT GmbH. We developed a toolset for accessing embedded systems via a embedded HTTP server and JAVA applets (the ProWeb Toolset). The project was a big success, so SUN sponsored a booth for the project at the JavaOne conference 1997. We demonstrated how to control a remote coffee maker und video camera with a web-browser by accessing the embedded HTTP server of the device. We also had a booth an a paper at the 6th World Wide Web Conference '97 in Santa Clara.


In May 1997 i started as a computer engineer at 3SOFT GmbH and worked as a consultant for the  Kodak AG. Computer graphics was purely a hobby during that time. I worked on a system for semi-automatic software tests.


So the fascination for computer graphics brought me back to the university. In January 1998 i joined the Visualization Group of Prof. Dr. Ertl at the Computer Graphics Group of the University of Erlangen and got sponsored by the German Research Foundation in the project "ChemVis". The ChemVis project is one of 23 research projects in the strategic research initiative "V3D2" ("Distributed Processing and Exchange of Digital Documents") of the German Research Foundation (Deutsche Forschungsgemeinschaft DFG). The main goal of the "ChemVis" project is chemical visualization on the Internet with embedded dynamic and interactive high-end graphics in digital documents for the visualization of complex factual relationships.  In this context we propose the development of an Internet standard orientated system for the embedding of dynamic visualizations in digital documents in the field of chemistry. We aim to show with prototypical examples that such a system facilitates the understanding of complex chemical phenomena easier than static 3D scenes or videos. For example, important chemical effects depend on 3D geometry, time scale and field effects and therefore is difficult to depict by a few static viewpoints. The coupling and realtime manipulation of 3D visualizations, by user-initiated change of graph attributes, space/time parameters and other influencing factors,  enable a new quality and density of information. Such kind of information visualization is able to keep pace with the complexity of current research. Several models of scene manipulation shall highlight a wide range of uses and requirements of these dynamic scenarios. 3D graphics hardware played an important role in that project, because we are certain that visualization of complex data requires maximum interactivity, which is only possible with the support of specialized graphics hardware. Another important aspects in the project was to provide access to interactive visualizations with any rastergraphics capable device. The basic idea is find strategies to provide maximum interactivity by utilizing local or remote graphics hardware capabilities. Another important direction for research are adaptive and progressive multi-resolution algorithms to work on different resolutions of the data and to reduce the complexity before geometry is send to the graphics hardware.

We were certain from the beggining, that consumer graphics hardware would soon catch up with professional hardware. As that happened very soon and consumer graphics hardware got flexible and progammable, we looked for methods to optimize interativity and quality by using those new capabilities. We published two papers on the "Siggraph/Eurographics Workshop on Graphics Hardware" in 2000 and 2001, that show how to employ the newest features of programmable low-cost graphics hardware for interactive, high-quality volume visualization.
By the end of 2001 in will finish my PhD. thesis with the title "Strategies and Algorithms for Distributed Volume-Visualization on different Hardware-Architectures".


I see bright prospects for computer graphics hardware in the future. Computer graphics is ideally suited for parallization, which can be realized very efficiently in specialized computer graphics hardware. I believe, that more parallel pipelines with flexible programmability will provide new effects and more convincing sceneries in entertainment applications as well as new insights for science by providing interactive visualizations of complex data. Mobile 3D graphics is one of the key markets of the future. Computer games, education and science applications will be available on the desktop as well as on many mobile devices. 3D Computer graphics will be more realistic and convincing by employing physical simulations, more realistic light models and more complex scenes.
My personal future lies hopefully in the computer graphics field. I am interested in developing new ideas and improvements to provide high quality programmable hardware, both for the entertainment and professional market. I also like experimenting with graphics hardware to open up new fields of application, to use graphics hardware in a way, the people who designed it never have thought about.
The availability of such graphics hardware to everybody and everywhere will provide new possibilities for entertainment, education and science and enhance the value of electronic devices dramatically.

Courses and Tutorials

Joe Michael Kniss, Christof Rezk-Salama, Markus Hadwiger, Klaus Engel
High-Quality Volume Graphics on Consumer PC Hardware
Siggraph 2002 course #42

T. Ertl, D. Weiskopf, M. Kraus, K. Engel, M. Weiler, M. Hopf, S. Röttger, C. Rezk-Salama
Tutorial4: Programmable Graphics Hardware for Interactive Visualization
Eurographics 2002 Full-Day Tutorial


K. Engel, T. Ertl
Interactive High-Quality Volume Rendering with Flexible Consumer Graphics Hardware
Eurographics 2002 STAR (state-of- the-art) Report (to appear)

D. Weiskopf, K. Engel, and T. Ertl
"Volume Clipping via Per-Fragment Operations in Texture-Based Volume Visualization"
IEEE Visualization, 2002 (to appear)

K. Engel, M. Kraus, and T. Ertl
"High-Quality Pre-Integrated Volume Rendering Using Hardware-Accelerated Pixel Shading"
In  Eurographics / SIGGRAPH Workshop on Graphics Hardware '01 (best paper award)

K. Engel, D. Weiskopf, M. Hopf, T. Ertl
"Hardware Accelerated Simulation and Rendering Based on Pixel Shading"
Unterhaltungs Software Forum (USF) 2001

P. Hastreiter, K. Engel, G. Soza, M.Bauer, M. Wolf, O.Ganslandt, R. Fahlbusch, G.Greiner, Ch. Nimsky
"Remote Analysis for Brain Shift Compensation"
In Proc. of The Fourth International Conference on Medical Image Computing and Computer-Assisted Intervention, 2001

Bernd F. Tomandl, Peter Hastreiter, Christof Rezk-Salama, Klaus Engel, Thomas   Ertl, Walter J. Huk, Ramin Naraghi, Oliver Ganslandt, and Christopher Nimsky
"Local and Remote Visualization Techniques for Interactive Direct Volume Rendering in Neuroradiology"
RadioGraphics 2001

F. Oellien, W. D. Ihlenfeldt, K. Engel, and T. Ertl
"Multi-Variate Interactive Visualization of Data from Digital Laboratory Notebooks"
ECDL: Workshop Generalized Documents , 2001

K.Engel, F.Oellien, W.D.Ihlenfeldt, T.Ertl
"Client-Server-Strategien zur Visualisierung komplexer Struktureigenschaften in digitalen Dokumenten der Chemie"
IT+TI 6/2000 Informationstechnik und Technische Informatik

C.Resk-Salama, K.Engel, M.Bauer, G.Greiner, T.Ertl
"Interactive Volume Rendering on Standard PC Graphics Hardware Using Multi-Textures and Multi-Stage-Rasterization"
In Proc. Eurographics/SIGGRAPH Workshop on Graphics Hardware 2000 (best paper award)

K. Engel, P.Hastreiter, B. Tomandl, K.Eberhardt, T.Ertl
"Combining Local and Remote Visualization Techniques for Interactive Volume Rendering in Medical Applications"
IEEE Visualization, 2000

K. Engel, Ove Sommer, T.Ertl
"A Framework for Interactive Hardware-Accelerated Remote 3D-Visualization"
Data Visualization 2000, Springer Computer Science, 2000

K. Engel, Ruediger Westermann, T.Ertl
"Isosurface Extraction Techniques for Web-based Volume Visualization"
IEEE Visualization, 1999

F.Oellien, W.D. Ihlenfeldt, K.Engel, T.Ert
"Chemische Visualisierung und Datenintegration im Internet"
Neue Medien in Forschung und Lehre, Ein Workshop im Rahmen der 29.Jahrestagung der Gesellschaft fuer Informatik (Informatik 99)

K.Engel, O.Sommer, C.Ernst, T.Ertl
"Remote 3D Visualization using Image-Streaming Techniques"
International Symposium on Intelligent Multimedia and Distance Education, 1999

K.Engel, T.Ertl
"Texture-based Volume Visualization for Multiple Users on the World Wide Web"
5th Eurographics Workshop on Virtual Environments, 1999

W.D. Ihlenfeldt, K.Engel
"Visualizing Chemical Data on the Internet - Data-Driven and Interactive Graphics"
Computers and Graphics, Vol.22, No.6, Elsevier Science Ltd., 1999

K.Engel, R.Grosso, T.Ertl
"Progressive Isosurfaces on the Web"
IEEE Visualization - Late Breaking Hot Topics, 1998

Klaus Engel
"Conception and Implementation of JAVA-based Visualization-Components for Embedded Systems"
Diploma-Thesis, 1997

Klaus Engel
"Design and Implementation of a Requirements Inspection and Validation Editor (RIVALE)"
Klaus Engel
Pre-Diploma-Thesis, 1995


Tübingen, Germany, 2001: Interative High-Quality Volume Rendering on Flexible Consumer Graphics Hardware, Graphiktag 2001

Los Angeles, USA, 2001: Siggraph/Eurographics Graphics Hardware Workshop on Graphics Hardware 2001, High-Quality Pre-Integrated Volume Rendering Using Hardware-Accelerated Pixel Shading (best paper award)

Chicago, USA, 2000: Interactive High-Quality Volume Visualization on Desktop PCs, Radiological Society of North America

Göttingen, Germany, 2000: ChemVis - Internet-based Visualization of Chemical Data, V3D2 Symposium 2000

Dagstuhl, Germany, 2000: Client-Server Strategies for Interactive Web-based 3D Visualization, Dagstuhl-Tagung Hierarchische Ansätze in der Computergraphik

Salt Lake City, USA, 2000:  Combining Local and Remote Rendering Techniques for Interactive Volume Rendering in Medical Applications, IEEE Visualization 2000

San Francisco, USA, 1999: Isosurface Extraction Techniques for Web-based Volume Visualization, IEEE Visualization

Baden-Baden, Germany, 1999: Remote 3D Visualization using Image-Streaming Techniques, Int. Symposium on Intelligent Multimedia and Distance Education

Wien, Austria, 1999: Texture-based Volume Visualization for Multiple Users on the World Wide Web, 5th Eurographics Workshop on Virtual Environments

Bad Dürkheim, Germany, November 15-17 1998: Visualization of Chemical Volume Datasets on the WWW, 13th CIC-Workshop

Hannover, Germany, June 22-26 1998: Progressive Iso-Surfaces on the Web, Computer Graphics International '98

Raleigh-Durham, USA, 1998: Progressive Iso-Surfaces on the Web, IEEE Visualization

Munich, Germany, May 1998: PROLET: Progressive Iso-surface Applet, V3D2 Opening Workshop