@inproceedings{18136,
  abstract     = {{We present a parallel algorithm for the rendering of complex three-dimensional scenes. The algorithm runs across heterogeneous architectures of PC-clusters consisting of a visualization-node, equipped with a powerful graphics adapter, and cluster nodes requiring weaker graphics capabilities only. The visualization-node renders a mixture of scene objects and simplified meshes (Reliefboards). The cluster nodes assist the visualization-node by asynchronous computing of Reliefboards, which are used to replace and render distant parts of the scene. Our algorithm is capable of gaining significant speedups if the cluster's nodes provide weak graphics adapters only. We trade the number of cluster nodes off the scene objects' image quality.}},
  author       = {{Fischer, Matthias and Jähn, Claudius and Suess, Tim}},
  booktitle    = {{Eurographics Symposium on Parallel Graphics and Visualization (EGPGV)}},
  pages        = {{43--51}},
  publisher    = {{The Eurographics Association}},
  title        = {{{Asynchronous Parallel Reliefboard Computation for Scene Object Approximation}}},
  doi          = {{10.2312/EGPGV/EGPGV10/043-051}},
  year         = {{2010}},
}

@inproceedings{18289,
  abstract     = {{Many professional cluster systems consist of nodes with different hardware configurations. Such heterogeneous environments require different load-balancing techniques than homogenous environments. The c-load-collision-protocol is able to achieve good results for data-management purposes. Using this protocol, we propose a way for load-balancing in interactive rendering environments. For this work, we implemented a parallel rendering system and took different picking strategies into account to compare the results. The advantage of our approach compared to other approaches is that we group the available nodes of a cluster into two different categories, based on the hardware abilities. Some nodes are used solely for rendering, while others serve as secondary storage and to assist the former ones by performing auxiliary calculations.}},
  author       = {{Suess, Tim and Wiesemann, Timo and Fischer, Matthias}},
  booktitle    = {{2010 IEEE Fifth International Conference on Networking, Architecture, and Storage}},
  isbn         = {{9781424481330}},
  pages        = {{448 -- 456}},
  title        = {{{Evaluation of a c-Load-Collision-Protocol for Load-Balancing in Interactive Environments}}},
  doi          = {{10.1109/nas.2010.52}},
  year         = {{2010}},
}

@inbook{18290,
  abstract     = {{Typischerweise sind die Knoten eines PC-Clusters nicht mit leistungsfähigen Grafikkarten ausgestattet. Dennoch bieten Cluster-Betreiber einige wenige Rechenknoten an, die mit Highend-Grafikkarten ausgestattet sind, um beispielsweise eine PowerWall zu betreiben. Wenn zwischen diesen unterschiedlichen Knotentypen ein schnelles Netzwerk existiert, kann die Bilderzeugung durch die Knoten mit schwacher Grafikkarte beschleunigt werden. Dabei können die unterschiedlichen Knotentypen unterschiedliche Aufgabe bearbeiten. In einem solchen heterogenen System, müssen die unterschiedlichen entstehenden Lasten auf andere Weise verteilt werden, als in einem System, bei dem alle Knoten gleich ausgestattet sind. Wir präsentieren in dieser Arbeit Lastbalancierungsmechanismen, die in einem parallelen Out-of-Core-Renderingsystem für heterogene PC-Cluster eingesetzt werden.
}},
  author       = {{Suess, Tim and Wiesemann, Timo and Fischer, Matthias}},
  booktitle    = {{Augmented & Virtual Reality in der Produktentstehung}},
  pages        = {{39--52}},
  title        = {{{Gewichtetes c-Collision-Protokoll zur Balancierung eines parallelen Out-of-Core-Renderingsystems}}},
  year         = {{2010}},
}

@inbook{16505,
  abstract     = {{We present an approach for real-time rendering of complex 3D scenes consisting of millions of polygons on limited graphics hardware. In a preprocessing step, powerful hardware is used to gain fine granular global visibility information of a scene using an adaptive sampling algorithm. Additively the visual influence of each object on the eventual rendered image is estimated. This influence is used to select the most important objects to display in our approximative culling algorithm. After the visibility data is compressed to meet the storage capabilities of small devices, we achieve an interactive walkthrough of the Power Plant scene on a standard netbook with an integrated graphics chipset.}},
  author       = {{Eikel, Benjamin and Jähn, Claudius and Fischer, Matthias}},
  booktitle    = {{Advances in Visual Computing}},
  isbn         = {{9783642172885}},
  issn         = {{0302-9743}},
  title        = {{{Preprocessed Global Visibility for Real-Time Rendering on Low-End Hardware}}},
  doi          = {{10.1007/978-3-642-17289-2_60}},
  year         = {{2010}},
}

@inproceedings{18138,
  abstract     = {{Modern companies are nowadays confronted with an increasing demand of multiple products, where they need to perform more flexible every day. Cost-intensive decisions are to be confirmed in short times, in order to minimize risks and secure efficient production programs as well as material flows. Tools for this digital planning via simulation methods are one well established possibility to receive decision support. Nevertheless, the creation of the necessary simulation models is a complicated and error-prone process, where complexity of modeling, validation and verification depends on the used tool and its functionalities. This paper presents implemented concepts for an innovative user support in his tasks of verification and validation of simulation models during the execution of a simulation run. Time-intensive procedures like stopping simulation, parameterization and restarting within the problem analysis are simplified. So the user is able to focus on the real problem solving task.}},
  author       = {{Laroque, Christoph and Fischer, Matthias and Dangelmaier, Wilhelm}},
  booktitle    = {{European Simulation and Modelling Conference (ESM 2009)}},
  publisher    = {{EUROSIS-ETI}},
  title        = {{{Concepts for Model Verification and Validation during Simulation Runtime}}},
  year         = {{2009}},
}

@inbook{18291,
  author       = {{Suess, Tim and Fischer, Matthias and Huber, Daniel and Laroque, Christoph  and Dangelmaier, Wilhelm}},
  booktitle    = {{Augmented & Virtual Reality in der Produktentstehung}},
  pages        = {{111----126}},
  publisher    = {{Verlagsschriftenreihe des Heinz Nixdorf Instituts, Paderborn}},
  title        = {{{Ein System zur aggregierten Visualisierung verteilter Materialflusssimulationen}}},
  volume       = {{252}},
  year         = {{2009}},
}

@inproceedings{18346,
  abstract     = {{For a fixed virtual scene (=collection of simplices) S and given observer
position p, how many elements of S are weakly visible (i.e. not fully occluded
by others) from p? The present work explores the trade-off between query time
and preprocessing space for these quantities in 2D: exactly, in the approximate
deterministic, and in the probabilistic sense. We deduce the EXISTENCE of an
O(m^2/n^2) space data structure for S that, given p and time O(log n), allows
to approximate the ratio of occluded segments up to arbitrary constant absolute
error; here m denotes the size of the Visibility Graph--which may be quadratic,
but typically is just linear in the size n of the scene S. On the other hand,
we present a data structure CONSTRUCTIBLE in O(n*log(n)+m^2*polylog(n)/k)
preprocessing time and space with similar approximation properties and query
time O(k*polylog n), where k<n is an arbitrary parameter. We describe an
implementation of this approach and demonstrate the practical benefit of the
parameter k to trade memory for query time in an empirical evaluation on three
classes of benchmark scenes.}},
  author       = {{Fischer, Matthias and Hilbig, Matthias and Jähn, Claudius and Meyer auf der Heide, Friedhelm and Ziegler, Martin}},
  booktitle    = {{Proc. 25th European Workshop on Computational Geometry}},
  pages        = {{203--206}},
  title        = {{{Planar Visibility Counting}}},
  year         = {{2009}},
}

@inproceedings{17416,
  abstract     = {{In this paper we present a system for the simultaneous visualization of several parallel executed simulation replications. By aggregating the scenes of multiple similar simulations into one single scene it is possible to make a visual statistical analysis of a set of discrete event simulations as well as to easily compare different system parameterizations. The aim of our system is to enhance the model analysis, verification and validation process in terms of speed and ease. The parallel execution of several simulations of complex models and the visualization of these cannot be done on one computer, thus a parallel approach is necessary. Our system uses a thin-client and multiple processors on a PC-cluster. The rendering and the simulation execution are done on processors of the cluster. The client is used only for the visualization of the images transmitted by the cluster and for user interaction.
}},
  author       = {{Suess, Tim and Huber, Daniel and Fischer, Matthias and Laroque, Christoph and Dangelmaier, Wilhelm}},
  booktitle    = {{IEEE International Symposium on Parallel and Distributed Processing with Applications}},
  isbn         = {{9780769534718}},
  title        = {{{A System for Aggregated Visualization of Multiple Parallel Discrete Event Simulations}}},
  doi          = {{10.1109/ispa.2008.30}},
  year         = {{2008}},
}

@inproceedings{17868,
  abstract     = {{The paper describes an approach for an aggregated animation of a simulation experiment in an interactive 3D environment, visualizing multiple, distributed simulation runs. Although the general approach of a 3-dimensional visualization of material flow simulation helps to understand the dynamic behavior of a system better as well as faster, it remains unclear, how typical the animated simulation represents the model, if there is a stochastic influence for even some parameters. By the integrated visualization of multiple distributed simulation runs, this uncertainty can be solved, which will be shown in this paper for a typical simulation study of a queuing system. }},
  author       = {{Dangelmaier, Wilhelm and Fischer, Matthias and Huber, Daniel and Laroque, Christoph and Suess, Tim}},
  booktitle    = {{2008 Winter Simulation Conference}},
  isbn         = {{9781424427079}},
  pages        = {{2012--2020}},
  title        = {{{Aggregated 3D-visualization of a distributed simulation experiment of a queuing system}}},
  doi          = {{10.1109/wsc.2008.4736296}},
  year         = {{2008}},
}

@inproceedings{18139,
  abstract     = {{This paper describes a method for the animation of a large number of objects within a dynamic 3D visualization of a material flow simulation model. It uses key-frame based animation. The number of animated objects may grow constantly in complex simulation models, which might lead to an amount of animations that is too big to be computed in real-time. By the use of a dynamic adjustment, the presented algorithm prefers important animations. Less relevant animations are updated rarely, whereby the selection itself is taken by multiple indicators, e.g. the visible size of the animated object on the screen, in order to keep a good optical impression. Dependent on the computing power of the computer, the algorithm controls the animations in such a way, that the fluid visualization of a large number of objects is still possible. Though the algorithm is to be used within a material flow simulator, it is moreover implemented in a specific animation editor, which allows the design and control of animation schemes. It supports the use of grouping to allow the creation of hierarchical structures for complex animations in a fast and easy manner. The evaluation of the algorithm is proven by a test scene, consisting of tens of thousands animated objects. }},
  author       = {{Laroque, Christoph and Fischer, Matthias and Dangelmaier, Wilhelm and Eikel, Benjamin}},
  booktitle    = {{Industrial Simulation Conference (ISC 2008)}},
  pages        = {{306--310}},
  publisher    = {{EUROSIS-ETI}},
  title        = {{{Dynamic Control of Animation Schemes for the Efficient 3D-Visualization of Material Flow Simulations}}},
  year         = {{2008}},
}

@inproceedings{18141,
  abstract     = {{Dieser Artikel beschreibt eine Methode zur Animation einer großen Anzahl von Objekten zur dynamischen 3D-Visualisierung eines Simulationsmodells mittels der Materialflusssimulation auf Basis von Schlüsselbildern. Die Anzahl zu animierender Objekte ist in komplexen Modellen zu groß, um alle Animationen flüssig darzustellen. Dynamisch abgestuft wählt das entwickelte Verfahren gezielt wichtige Animationen aus, weniger relevante Animationen werden entsprechend seltener animiert. Die Selektion der Animationen erfolgt nach der projizierten Größe der Objekte auf das Ausgabegerät, um einen guten optischen Eindruck beizubehalten. Angepasst an die Leistungsfähigkeit des Rechners wird das Verfahren so geregelt, dass die Visualisierung einer hohen Anzahl von Objekten in Echtzeit möglich bleibt. Das Verfahren ist in einem Editor prototypisch implementiert, mit dem Schlüsselbilder für Objekte erzeugt werden können. Das Gruppieren von Objekten wird erlaubt, so dass eine Hierarchie von Bewegungspfaden definierbar ist. Die Evaluierung der Methode wird mittels Testszenen durchgeführt, die aus mehreren zehntausend animierten Objekten bestehen.}},
  author       = {{Laroque, Christoph and Fischer, Matthias and Eikel, Benjamin}},
  booktitle    = {{Augmented & Virtual Reality in der Produktentstehung}},
  pages        = {{193----206}},
  publisher    = {{Verlagsschriftenreihe des Heinz Nixdorf Instituts, Paderborn}},
  title        = {{{Regelung von Animationen in Simulationen von  hochdynamischen Fabrikszenen }}},
  volume       = {{232}},
  year         = {{2008}},
}

@unpublished{16465,
  abstract     = {{For a fixed virtual scene (=collection of simplices) S and given observer
position p, how many elements of S are weakly visible (i.e. not fully occluded
by others) from p? The present work explores the trade-off between query time
and preprocessing space for these quantities in 2D: exactly, in the approximate
deterministic, and in the probabilistic sense. We deduce the EXISTENCE of an
O(m^2/n^2) space data structure for S that, given p and time O(log n), allows
to approximate the ratio of occluded segments up to arbitrary constant absolute
error; here m denotes the size of the Visibility Graph--which may be quadratic,
but typically is just linear in the size n of the scene S. On the other hand,
we present a data structure CONSTRUCTIBLE in O(n*log(n)+m^2*polylog(n)/k)
preprocessing time and space with similar approximation properties and query
time O(k*polylog n), where k<n is an arbitrary parameter. We describe an
implementation of this approach and demonstrate the practical benefit of the
parameter k to trade memory for query time in an empirical evaluation on three
classes of benchmark scenes.}},
  author       = {{Fischer, Matthias and Hilbig, Matthias and Jähn, Claudius and Meyer auf der Heide, Friedhelm and Ziegler, Martin}},
  booktitle    = {{arXiv:0810.0052}},
  title        = {{{Planar Visibility Counting}}},
  year         = {{2008}},
}

@inproceedings{18347,
  abstract     = {{The validation of material flow models as well as the selection of promising strategies for the generation of a successful experiment plan is a time-consuming process. A new approach is presented, which supports the simulation expert in his working process by giving him the opportunity to modify the simulated simulation run and afterwards compare the effects of his modification with the original setting, online and in one user interface, implemented by switching the visualizations between the simulation runs or opening up to 5 parallel 3D windows. The method developed therefore clones existing simulation runs online and allows the navigation within these existing simulation runs. The method has been implemented and is validated by a test model, which describes in detail the new working process of a modeler. New research questions are derived from this work, which will define following working steps.
}},
  author       = {{Fischer, Matthias and Laroque, Christoph  and Huber, Daniel  and Krokowski, Jens  and Mueck, Bengt  and Kortenjan, Michael  and Aufenanger, Mark and  Dangelmaier, Wilhelm}},
  booktitle    = {{European Simulation and Modelling Conference (ESM 2007)}},
  pages        = {{499----505}},
  title        = {{{Interactive Refinement of a Material Flow Simulation Model by Comparing Multiple Simulation Runs in one 3D Environment}}},
  year         = {{2007}},
}

@inproceedings{18349,
  author       = {{Dangelmaier, Wilhelm and  Laroque, Christoph  and Fischer, Matthias}},
  booktitle    = {{Augmented & Virtual Reality in der Produktentstehung}},
  pages        = {{95--110}},
  publisher    = {{Verlagsschriftenreihe des Heinz Nixdorf Instituts, Paderborn}},
  title        = {{{Ein ganzheitlicher Ansatz zur immersiven 3D-Materialflusssimulation innerhalb der Digitalen Fabrik}}},
  volume       = {{209}},
  year         = {{2007}},
}

@inproceedings{7970,
  abstract     = {{We consider the problem of exploring an unknown environment using a swarm of autonomous robots with collective behavior emerging from their local rules. Each robot has only a very restricted view on the environment which makes cooperation difficult. We introduce a software system which is capable of simulating a large number of such robots (e.g. 1000) on highly complex terrains with millions of obstacles. Its main purpose is to easily integrate and evaluate any kind of algorithm for controlling the robot behavior. The simulation may be observed in real-time via a visualization that displays both the individual and the collective progress of the robots. We present the system design, its main features and underlying concepts.}},
  author       = {{Arens, Stephan and Buss, Alexander and Deck, Helena and Dynia, Miroslaw and Fischer, Matthias and Hagedorn, Holger and Isaak, Peter and Kutylowski, Jaroslaw and Meyer auf der Heide, Friedhelm and Nesterow, Viktor and Ogiermann, Adrian and Stobbe, Boris and Storm, Thomas and Wachsmuth, Henning}},
  booktitle    = {{Proceedings of the 4th International Symposium on Autonomous Minirobots for Research and Edutainment}},
  pages        = {{215--222}},
  publisher    = {{Heinz Nixdorf Institut, University of Paderborn}},
  title        = {{{Smart Teams: Simulating Large Robotic Swarms in Vast Environments}}},
  year         = {{2007}},
}

@inproceedings{18351,
  abstract     = {{In this paper the ideas of a new research project are presented. The material flow simu- lator d3FACT insight shall manage multiple parallel and time synchronous simulations to grand the power of real-time visualization in combination with statistical analysis. This research is issued to overcome the conflict of simulation run repetition for a good statistical basis and real-time immersive visualization. A side effect will be the reduc- tion of time needed for simulation experiments. The planned simulation tool has the feature of triggered cloning, i.e., the user can decide during runtime to clone a set of simulations after changing parameters to preserve the original system. The simulations will be aggregated by visualization and statistics. The rendering is planned to overlay several simulations using effects like inking and transparency. Simulation data will be aggregated with statistical functions and diagrams.}},
  author       = {{Dangelmaier, Wilhelm  and Huber, Daniel  and Laroque, Christoph  and Aufenanger, Mark and Fischer, Matthias and Krokowski, Jens and Kortenjan, Michael}},
  booktitle    = {{Simulation and Visualization 2006 (SimViS)}},
  pages        = {{79--88}},
  publisher    = {{SCS European Publishing House}},
  title        = {{{d³FACT insight goes parallel - Aggregation of multiple simulations}}},
  year         = {{2006}},
}

@phdthesis{25226,
  author       = {{Fischer, Matthias}},
  publisher    = {{Verlagsschriftenreihe des Heinz Nixdorf Instituts, Paderborn}},
  title        = {{{Design, Analysis, and Evaluation of Data Structure for Distributed Virtual Environments}}},
  volume       = {{164}},
  year         = {{2005}},
}

@phdthesis{17413,
  author       = {{Fischer, Matthias}},
  isbn         = {{3-935433-73-5}},
  publisher    = {{Verlagsschriftenreihe des Heinz Nixdorf Instituts, Paderborn}},
  title        = {{{Design, analysis, and evaluation of a data structure for distributed virtual environments}}},
  volume       = {{164}},
  year         = {{2005}},
}

@article{17414,
  abstract     = {{Nowadays companies operate in a difficult environment: the dynamics of innovations increase and product life cycles become shorter. Furthermore products and the corresponding manufacturing processes get more and more complex. Therefore, companies need new methods for the planning of manufacturing systems. One promising approach in this context is digital factory/virtual productionthe modeling and analysis of computer models of the planned factory with the objective to reduce time and costs. For the modeling and analysis various simulation methods and programs have been developed. They are a highly valuable support for planning and visualizing the manufacturing system. But there is one major disadvantage: only experienced and long trained experts are able to operate with these programs. The graphical user interface is very complex and not intuitive to use. This results in an extensive and error-prone modeling of complex simulation models and a time-consuming interpretation of the simulation results.

To overcome these weak points, intuitive and understandable manmachine interfaces like augmented and virtual reality can be used. This paper describes the architecture of a system which uses the technologies of augmented and virtual reality to support the planning process of complex manufacturing systems. The proposed system assists the user in modeling, the validation of the simulation model, and the subsequent optimization of the production system. A general application of the VR- and AR-technologies and of the simulation is realized by the development of appropriate linking and integration mechanisms. For the visualization of the arising 3D-data within the VR- and AR-environments, a dedicated 3D-rendering library is used.}},
  author       = {{Dangelmaier, Wilhelm and Fischer, Matthias and Gausemeier, Jürgen and Grafe, Michael and Matysczok, Carsten and Mueck, Bengt}},
  issn         = {{0166-3615}},
  journal      = {{Computers in Industry}},
  pages        = {{371--383}},
  title        = {{{Virtual and augmented reality support for discrete manufacturing system simulation}}},
  doi          = {{10.1016/j.compind.2005.01.007}},
  year         = {{2005}},
}

@inproceedings{17415,
  author       = {{Fischer, Matthias and Mueck, B. and Mahajan, K. and Kortenjan, M. and Laroque, C. and Dangelmaier, W.}},
  booktitle    = {{Proceedings of the Winter Simulation Conference}},
  isbn         = {{0780395190}},
  title        = {{{Multi-User Support and Motion Planning of Humans and Humans Driven Vehicles in Interactive 3D Material Flow Simulations}}},
  doi          = {{10.1109/wsc.2005.1574470}},
  year         = {{2005}},
}

