@incollection{RattayGeigerHerderetal.2007, author = {Rattay, Oliver and Geiger, Christian and Herder, Jens and Goebbels, Gernot and Nikitin, Igor}, title = {Zweih{\"a}ndige Interaktion in VR-Umgebungen}, series = {Augmented \& Virtual Reality in der Produktentstehung}, volume = {209}, booktitle = {Augmented \& Virtual Reality in der Produktentstehung}, editor = {Gausemeier, J{\"u}rgen and Grafe, Michael}, publisher = {Heinz Nixdorf Institut, Universit{\"a}t Paderborn}, address = {Paderborn}, isbn = {978-3-939350-28-6}, pages = {315 -- 332}, year = {2007}, abstract = {Einfach benutzbare VR-Anwendungen erfordern andere Interaktionstechniken als konventionelle Desktop-Anwendungen mit Maus, Tastatur und Desktop-Metapher zur Verf{\"u}gung stellen. Da solche Ans{\"a}tze in Konzeption und Realisierung deutlicher komplexer sind, m{\"u}ssen diese mit Sorgfalt ausgew{\"a}hlt werden. Folgt man der Argumentation, dass VR eine nat{\"u}rliche Interaktion mit virtuellen Objekten erm{\"o}glicht, so f{\"u}hrt dies fast zwangsl{\"a}ufig zu zweih{\"a}ndigen Interaktionstechniken f{\"u}r virtuelle Umgebungen, da Benutzer in realen Umgebungen gewohnt sind, fast ausschlie{\"i}‚lich zweih{\"a}ndig zu agieren. In diesem Beitrag geben wir eine {\"U}bersicht {\"u}ber den Stand der Technik im Bereich zweih{\"a}ndiger Interaktion, leiten Anforderungen an eine Entwicklung zweih{\"a}ndiger Interaktionstechniken in VR ab und beschreiben einen eigenen Ansatz. Dabei geht es um die zweih{\"a}ndige Interaktion bei der Simulation flexibler biegeschlaffer Bauteile (z. B. Schlauchverbindungen).}, language = {de} } @article{Herder1999, author = {Herder, Jens}, title = {Visualization of a Clustering Algorithm of Sound Sources based on Localization Errors}, series = {Journal of the 3D-Forum Society}, volume = {13}, journal = {Journal of the 3D-Forum Society}, number = {3}, pages = {66 -- 70}, year = {1999}, abstract = {A module for soundscape monitoring and visualizing resource management processes was extended for presenting clusters, generated by a novel sound source clustering algorithm. This algorithm groups multiple sound sources together into a single representative source, considering localization errors depending on listener orientation. Localization errors are visualized for each cluster using resolution cones. Visualization is done in runtime and allows understanding and evaluation of the clustering algorithm.}, language = {en} } @inproceedings{Herder1999, author = {Herder, Jens}, title = {Visualization of a Clustering Algorithm of Sound Sources based on Localization Errors}, series = {Second International Conference on Human and Computer}, booktitle = {Second International Conference on Human and Computer}, address = {Aizu-Wakamatsu}, pages = {1 -- 5}, year = {1999}, abstract = {A module for soundscape monitoring and visualizing resource management processes was extended for presenting clusters, generated by a novel sound source clustering algorithm. This algorithm groups multiple sound sources together into a single representative source, considering localization errors depending on listener orientation. Localization errors are visualized for each cluster using resolution cones. Visualization is done in runtime and allows understanding and evaluation of the clustering algorithm.}, language = {en} } @inproceedings{MyszkowskiHerderKuniietal.1996, author = {Myszkowski, Karol and Herder, Jens and Kunii, Tosiyasu L. and Ibusuki, Masumi}, title = {Visualization and analysis of occlusion for human jaws using a "functionally generated path"}, series = {IS\&T/SPIE Symp. on Electronic Imaging, Visual Data Exploration and Analysis III}, booktitle = {IS\&T/SPIE Symp. on Electronic Imaging, Visual Data Exploration and Analysis III}, publisher = {The International Society for Optical Engineering}, address = {San Jose}, doi = {10.1117/12.234684}, pages = {360 -- 367}, year = {1996}, abstract = {Dynamic characteristics of occlusion during lower jaw motion are useful in the diagnosis of jaw articulation problems and in computer-aided design/manufacture of teeth restorations. The Functionally Generated Path (FGP), produced as a surface which envelops the actual occlusal surface of the moving opponent jaw, can be used for compact representation of dynamic occlusal relations. In traditional dentistry FGP is recorded as a bite impression in a patient's mouth. We propose an efficient computerized technique for FGP reconstruction and validate it through implementation and testing. The distance maps between occlusal surfaces of jaws, calculated for multiple projection directions and accumulated for mandibular motion, provide information for FGP computation. Rasterizing graphics hardware is used for fast calculation of the distance maps. Real-world data are used: the scanned shape of teeth and the measured motion of the lower jaw. We show applications of FGP to analysis of the occlusion relations and occlusal surface design for restorations.}, language = {en} } @inproceedings{MyszkowskiOkunevaHerderetal.1997, author = {Myszkowski, Karol and Okuneva, Galina and Herder, Jens and Kunii, Tosiyasu L. and Ibusuki, Masumi}, title = {Visual Simulation of the Chewing Process for Dentistry}, series = {Visualization \& Modeling}, booktitle = {Visualization \& Modeling}, editor = {Earnshaw, Rae A. and Huw, Jones and John, Vince}, publisher = {Academic Press}, address = {London}, isbn = {0-12-227738-4}, pages = {419 -- 438}, year = {1997}, abstract = {CAD/CAM techniques are increasingly used in dentistry for the design and fabrication of teeth estorations. Important concerns are the correction of articulation problems that existed before treatment and the prevention of treatment-generated problems. These require interactive evaluation of the occlusal surfaces of teeth during mastication. Traditional techniques based on the use of casts with mechanical articulators require manual adjustment of occlusal surfaces, which becomes impractical when hard restoration materials like porcelain are used; they are also time and labor consuming and provide little visual information. We present new visual tools and a related user interface for global articulation simulation, developed for the Intelligent Dental Care System project. The aim of the simulation is visual representation of characteristics relevant to the chewing process. The simulation is based on the construction of distance maps, which are visual representations of the distributions of the distances of points in a tooth to the opposite jaw. We use rasterizing graphics hardware for fast calculation of the distance maps. Distance maps are used for collision detection and for the derivation of various characteristics showing the distribution of load on the teeth and the chewing capability of the teeth. Such characteristics can be calculated for particular positions of the jaws; cumulative characteristics are used to describe the properties of jaw movement. This information may be used for interactive design of the occlusal surfaces of restorations and for jaw articulation diagnosis. We also demonstrate elements of a user interface that exploit metaphors familiar to dentists from everyday practice.}, language = {en} } @inproceedings{MyszkowskiOkunevaHerderetal.1995, author = {Myszkowski, Karol and Okuneva, Galina and Herder, Jens and Kunii, Tosiyasu L. and Ibusuki, Masumi}, title = {Visual Simulation of the Chewing Process for Dentistry}, series = {Visualization \& Modelling, International Conf., 5-7 December, 1995}, booktitle = {Visualization \& Modelling, International Conf., 5-7 December, 1995}, address = {Leeds}, year = {1995}, abstract = {CAD/CAM techniques are increasingly used in dentistry for the design and fabrication of teeth restorations. Important concerns are the correction of articulation problems that existed beforetreatment and the prevention of treatment-generated problems. These require interactive evaluation of the occlusal surfaces of teeth during mastication. Traditional techniques based on the use of casts with mechanical articulators require manual adjustment of occlusal surfaces, which becomes impractical when hard restoration materials like porcelain are used; they are also time and labor consuming and provide little visual information. We present new visual tools and a related user interface for global articulation simulation, developed for the Intelligent Dental Care System project. The aim of the simulation is visual representation of characteristics relevant to the chewing process. The simulation is based on the construction of distance maps, which are visual representations of the distributions of the distances of points in a tooth to the opposite jaw. We use rasterizing graphics hardware for fast calculation of the distance maps. Distance maps are used for collision detection and for the derivation of various characteristics showing the distribution of load on the teeth and the chewing capability of the teeth. Such characteristics can be calculated for particular positions of the jaws; cumulative characteristics are used to describe the properties of jaw movement. This information may be used for interactive design of the occlusal surfaces of restorations and for jaw articulation diagnosis. We also demonstrate elements of a user interface that exploit metaphors familiar to dentists from everyday practice.}, language = {en} } @inproceedings{AytenHerderVonolfen2010, author = {Ayten, H{\"u}seyin and Herder, Jens and Vonolfen, Wolfgang}, title = {Visual Acceptance Evaluation of Soft Shadow Algorithms for Virtual TV Studios}, series = {HC '10 Proceedings of the 13th International Conference on Humans and Computers}, booktitle = {HC '10 Proceedings of the 13th International Conference on Humans and Computers}, publisher = {University of Aizu Press}, address = {Aizu-Wakamatsu}, pages = {66 -- 71}, year = {2010}, abstract = {Shadows in computer graphics are an important rendering aspect for spatial objects. For realtime computer applications such as games, it is essential to represent shadows as accurate as possible. Also, various tv stations work with virtual studio systems instead of real studio sets. Especially for those systems, a realistic impression of the rendered and mixed scene is important. One challenge, hence, is the creation of a natural shadow impression. This paper presents the results of an empirical study to compare the performance and quality of different shadow mapping methods. For this test, a prototype studio renderer was developed. A percentage closer filter (pcf) with a number of specific resolutions is used to minimize the aliasing issue. More advanced algorithms which generate smooth shadows like the percentage closer soft shadow (pcss) method as well as the variance shadow maps (vsm) method are analysed. Different open source apis are used to develop the virtual studio renderer, giving the benefit of permanent enhancement. The Ogre 3D graphic engine is used to implement the rendering system, benefiting from various functions and plugins. The transmission of the tracking data is accomplished with the vrpn server/client and the Intersense api. The different shadow algorithms are compared in a virtual studio environment which also casts real shadows and thus gives a chance for a direct comparison throughout the empirical user study. The performance is measured in frames per secon}, language = {en} } @inproceedings{KlapdohrWoeldeckeMarinosetal.2010, author = {Klapdohr, Monika and W{\"o}ldecke, Bj{\"o}rn and Marinos, Dionysios and Herder, Jens and Geiger, Christian and Vonolfen, Wolfgang}, title = {Vibrotactile Pitfalls: Arm Guidance for Moderators in Virtual TV Studios}, series = {HC '10 Proceedings of the 13th International Conference on Humans and Computers}, booktitle = {HC '10 Proceedings of the 13th International Conference on Humans and Computers}, publisher = {University of Aizu Press}, address = {Aizu-Wakamatsu}, pages = {72 -- 80}, year = {2010}, abstract = {For this study, an experimental vibrotactile feedback system was developed to help actors with the task of moving their arm to a certain place in a virtual tv studio under live conditions. Our intention is to improve interaction with virtual objects in a virtual set, which are usually not directly visible to the actor, but only on distant displays. Vibrotactile feedback might improve the appearance on tv because an actor is able to look in any desired direction (camera or virtual object) or to read text on a teleprompter while interacting with a virtual object. Visual feedback in a virtual studio lacks spatial relation to the actor, which impedes the adjustment of the desired interaction. The five tactors of the implemented system which are mounted on the tracked arm give additional information like collision, navigation and activation. The user study for the developed system shows that the duration for reaching a certain target is much longer in case no visual feedback is given, but the accuracy is similar. In this study, subjects reported that an activation signal indicating the arrival at the target of a drag \& drop task was helpful. In this paper, we discuss the problems we encountered while developing such a vibrotactile display. Keeping these pitfalls in mind could lead to better feedback systems for actors in virtual studio environments.}, language = {en} } @incollection{HerderWoerzbergerJuttneretal.2005, author = {Herder, Jens and W{\"o}rzberger, Ralf and Juttner, Carsten and Twelker, Uwe}, title = {Verwendung von Grafikkarten-Prozessoren (GPUs) f{\"u}r eine interaktive Produktvisualisierung in Echtzeit unter Verwendung von Shadern und Videotexturen}, series = {Augmented and Virtual Reality in der Produktentstehung}, volume = {167}, booktitle = {Augmented and Virtual Reality in der Produktentstehung}, editor = {Gausemeier, J{\"u}rgen and Grafe, Michael}, publisher = {Heinz Nixdorf Institut, Universit{\"a}t Paderborn}, address = {Paderborn}, pages = {23 -- 36}, year = {2005}, abstract = {Die Visualisierung von Produkten in Echtzeit ist in vielen Bereichen ein hilfreicher Schritt, um potentiellen Kunden eine Vorstellung vom Einsatzgebiet und einen {\"U}berblick {\"u}ber die finale Anwendung zu erlauben. In den letzten Jahren haben neue Technologien in der Grafikkartenindustrie dazu gef{\"u}hrt, dass fr{\"u}her nur auf teuren Grafikworkstations verf{\"u}gbare M{\"o}glichkeiten nun auch mit relativ kosteng{\"u}nstigen Karten, welche f{\"u}r den Einsatz in Standard-PCs konzipiert wurden, realisierbar sind. Es wird an einem Modellentwurf des Innenraums des People Cargo Movers gezeigt, wie die Beleuchtung innerhalb einer Echtzeitvisualisierung durch Shader realisiert werden kann. Als Lichtquelle wird dabei eine Landschaftsaufnahme herangezogen, welche als eine von mehreren Videotexturen eingebunden wurde. Außerdem werden real im virtuellen Studio gefilmte Personen im Innenraum gleicherma{\"i}‚en {\"u}ber Videotexturen dargestellt und ebenfalls durch die Landschaft beleuchtet.}, language = {de} } @article{HerderWoerzbergerTwelkeretal.2002, author = {Herder, Jens and W{\"o}rzberger, Ralf and Twelker, Uwe and Albertz, Stefan}, title = {Use of Virtual Environments in the Promotion and Evaluation of Architectural Designs}, series = {Journal of the 3D-Forum Society}, volume = {16}, journal = {Journal of the 3D-Forum Society}, number = {4}, pages = {117 -- 122}, year = {2002}, abstract = {Virtual environments can create a realistic impression of an architectural space during the architectural design process, providing a powerful tool for evaluation and promotion during a project's early stages. In comparison to pre-rendered animations, such as walkthroughs based on CAD models, virtual environments can offer intuitive interaction and a more life like experience. Advanced virtual environments allow users to change realtime rendering features with a few manipulations, switching between different versions while still maintaining sensory immersion. This paper reports on an experimental project in which architectural models are being integrated into interactive virtual environments, and includes demonstrations of both the possibilities and limitations of such applications in evaluating, presenting and promoting architectural designs.}, language = {en} }