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Der Programmier System Generator - PSG - des Fachgebiets Praktische Informatik in Darmstadt erzeugt aus einer Sprachdefinition eine sprachspezifische Programmierumgebung. Diese besteht u. a. aus einem Editor, welcher syntaktische und semantische Fehler von Programmfragmenten, die nicht vollständig sein müssen, erkennen kann. Dem Benutzer werden per Menü Fehlerkorrekturen angeboten. Neben der freien Texteingabe besteht die Möglichkeit, den Text nur mit Hilfe von Menüs zu verfeinern. Teil dieses Editors ist die Bezeichneranalyse. Sie dient als Hilfsmittel für den Benutzer, indem für jede Stelle eines Programmfragmentes die gültigen Bezeichner ausgegeben werden können. Die Kontextanalyse setzt die Berechnung auf den von der Bezeichneranalyse erzeugten Daten auf, um semantische Fehler zu erkennen. Die bis zu dieser Arbeit verwendete Bezeichneranalyse im PSG unterstützt nur einfache Sprachkonzepte (z. B. Fortran und Pascal). Die Gültigkeitskonzepte der Bezeichner von weiterentwickelten Sprachen (z. B. Modula-2, CHILL, Ada oder Pascal-XT) sind nicht vollständig modellierbar. Wir stellen ein neues Konzept zur Definition und Berechnung der Bezeichneranalyse vor, das alle uns bekannten Sprachen mit statischer Typbindung unterstützt. Hierfür haben wir die Sprache BIS - Bezeichneridentifikationssprache - definiert. Die Methode ist verwandt mid dem Zwischencode für geordnete Attributierte Grammatiken. Für jeden Knoten des Abstrakten Syntaxbaumes wird mit Hilfe von BIS ein Code für eine abstrakte Maschine, welche die Bezeichneranalyse durchführt, geschrieben. Im Gegensatz zu herkömlichen Methoden (verkettete Symboltabellen) wird für jeden Punkt innerhalb eines Programmes for der Anfrage durch den Benutzer oder der Kontextanalyse die Menge der gültigen Bezeichner berechnet. Die Kosten für eine Anfrage sind dadurch minimal. Diese abstrakte Maschine teilt sich in zwei unabhängige Maschinen auf, zum einen in die S-Maschine, die die speziellen Operationen der Bezeichneranalyse durchführt, und zum anderen in die G-Maschine, die den Datenfluss und die Auswertung steuert. Diese Aufteilung ermöglicht den Austausch der S-Maschine durch eine andere, welche neue Anwendungsgebiete erschliesst, z. B. die eines Praeprozessors. Die G-Maschine arbeitet inkrementell; es werden nur die Codeschablonen neu ausgewertet, deren geerbten Attribute sich geändert haben. Dazu müssen die Daten, die in einer Codeschablone hinein- und hinausfliessen, abgelegt werden. Dies ergibt bei grossen Programmfragmenten eine immense Rechenzeiteinsparung auf Kosten des Speicherplatzes. Die Funktionsweise wird an einer kleinen Beispielsprache demonstriert, die zu Pascal ähnlich ist. Diese besitzt Konstrukte zum Import und Export von Daten und Datentypen zwischen Programmfragmenten. Im Prototyp kann die inkrementelle Arbeitsweise abgeschaltet werden und ermöglicht einen guten Vergleich der Verfahren.
In a virtual reality environment users are immersed in a scene with objects which might produce sound. The responsibility of a VR environment is to present these objects, but a system has only limited resources, including spatialization channels (mixels), MIDI/audio channels, and processing power. The sound spatialization resource manager controls sound resources and optimizes fidelity (presence) under given conditions. For that a priority scheme based on human psychophysical hearing is needed. Parameters for spatialization priorities include intensity calculated from volume and distance, orientation in the case of non-uniform radiation patterns, occluding objects, frequency spectrum (low frequencies are harder to localize), expected activity, and others. Objects which are spatially close together (depending on distance and direction) can be mixed. Sources that can not be spatialized can be treated as a single ambient sound source. Important for resource management is the resource assignment, i.e., minimizing swap operations, which makes it desirable to look-ahead and predict upcoming events in a scene. Prediction is achieved by monitoring objects’ speed and past evaluation values. Fidelity is contrasted for Zifferent kind of resource restrictions and optimal resource assignment based upon unlimited dynamic scene look-ahead. To give standard and comparable results, the VRML 2.0 specification is used as an application programmer interface. Applicability is demonstrated with a helical keyboard, a polyphonic MIDI stream driven animation including user interaction (user moves around, playing together with programmed notes). The developed sound spatialization resource manager gives improved spatialization fidelity under runtime constraints. Application programmers and virtual reality scene designers are freed from the burden of assigning and predicting the sound sources.
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.
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.
The PSFC, or Pioneer sound field control system, is a DSP-driven hemispherical 14-loudspeaker array, installed at the University of Aizu Multimedia Center. Collocated with a large screen rear-projection stereographic display the PSFC features realtime control of virtual room characteristics and direction of two separate sound channels, smoothly steering them around a configurable soundscape. The PSFC controls an entire sound field, including sound direction, virtual distance, and simulated environment (reverb level, room size and liveness) for each source. It can also configure a dry (DSP-less) switching matrix for direct directionalization. The PSFC speaker dome is about 14 m in diameter, allowing about twenty users at once to comfortably stand or sit near its sweet spot.
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.
The Common Lisp Interface Manager (CLIM) is used to develop graphical user interfaces for Lisp-basedapplications. With the prototype of the CLIM interface Builder (CLIB) the programmer can generate code for CLIM interactively. The developing process will be fast and less prone to errors. With this new tool, the interactive rapid prototyping reduces costs of a specification phase. Here we present the concept and first results of the prototype of CLIB.
CAD/CAM techniques are used increasingly in dentistry for design and fabrication of teeth restorations. An important issue is preserving occlusal contacts of teeth after restoration. Traditional techniques based on the use of casts with mechanical articulators require manual adjustment of occlusal surface, which becomes impractical when hard restoration materials like porcelain are used; they are also time and labor consuming. Most existing computer systems ignore completely such an articulation check, or perform the check at the level of a tooth and its immediate neighbors. We present a new mathematical model and a related user interface for global articulation simulation, developed for the Intelligent Dental Care System project. The aim of the simulation is elimination of the use of mechanical articulators and manual adjustment in the process of designing dental restorations and articulation diagnostic. The mathematical model is based upon differential topological modeling of the jawbs considered as a mechanical system. The user interface exploits metaphors that are familiar to dentists from everyday practice. A new input device designed specifically for use with articulation simulation is proposed.
Multimediale Technologien werden in der Marktforschung immer stärker eingesetzt, um flexible und kostengünstige Studien durchzuführen. Im Innovationsprozess kann dabei auf die langjährigen Erfahrungen zurückgegriffen werden, die durch den Einsatz der Computersimulation in der technischen Produktentwicklung zustande gekommen sind. In sehr frühen Phasen des Innovationsprozesses können durch Einsatz der neuen Technologien die Markteinführungskonzepte für neue Produkte getestet werden. Die Applikationen der virtuellen Realität bieten ein einzigartiges Potential, neue Produkte einschlieï‚lich des Marketingkonzeptes zu testen, ohne dass dieses Produkt bereits physisch vorhanden sein muss. Am Beispiel eines Elementes des Marketingkonzeptes, der Preispolitik, zeigt die vorliegende Studie auf, welches Potential die virtuelle Kaufsituation von Produkten bietet. Der Fokus des Projektes liegt auf der interaktiven Produktpräsentation in einer virtuellen Umgebung, die in eine Online-Befragung mit zusätzlichen Werbefilmen eingebettet ist. Visuell hochwertige 3D-Produktpräsentationen versetzen den Probanden in eine virtuelle Einkaufsumgebung, die einem realen Szenario entspricht. Die virtuellen Produkte werden in mehreren Kaufentscheidungsrunden zu unterschiedlichen Preisen angeboten. Der Preisuntersuchung geht eine Präsentation ausgewählter Werbespots sowie eine produktbezogene Befragung voraus. Im Anschluss an die virtuellen Preisentscheidungen werden die Eindrücke sowie einige Kontrollgröen abgefragt. In weitergehenden Studien dieser Art können die Wirkungen mehrerer Marketing-Instrumente zu einem Zeitpunkt untersucht werden, in dem sich die Produkte noch im Entwicklungsprozess befinden. Auf diesem Weg lassen sich auch Wettbewerbsvorteile bestehender Produkte effizienter erkennen und nutzen. Mit den hoch entwickelten Computer- und Visualisierungstechnologien ist ein mächtiges Werkzeug entstanden, das bereits für kommerzielle Präsentationen und Produktstudien eingesetzt wird. Zukünftig kann es auch in Kombination mit Internetanwendungen und klassischen Methoden der Marktforschung zu einem sehr frühen Zeitpunkt umfassende Erkenntnisse über ein Produkt liefern.
Durch den vermehrten Einsatz von multimedialen Technologien werden in der Marktforschung die Möglichkeiten der Durchführung flexibler und kostengünstiger Studien gegeben. In sehr frühen Phasen des Innovationsprozesses als Teil der Marktforschung können durch Einsatz von Virtuellen Umgebungen die Markteinführungskonzepte für neue Produkte getestet werden. Mittels Anwendungen der Virtuellen Realität können neue Produkte einschlieï‚lich des Marketingkonzeptes auch haptisch getestet werden, ohne dass dieses Produkt bereits physisch vorhanden sein muss. Informationen werden dem Benutzer in Virtuellen Umgebungen hauptsächlich visuell und ergänzend auditiv übermittelt. Verbreitete Benutzerschnittstellen sind Interaktionsgeräte wie Stylus und Wand. Durch die haptische Wahrnehmung werden Informationen menschengerechter, effektiver und intuitiver wahrgenommen. Objekte in einer virtuellen Umgebung können durch den Einsatz haptischer Interaktionsgeräte ertastet und erfühlt werden und machen dadurch eine differenziertere Beurteilung und Einschätzung durch den Benutzer eben dieser Objekte möglich. Der Fokus des vorliegenden Projektes liegt daher auf der interaktiven haptischen Produktpräsentation in einer virtuellen Einkaufsumgebung, die in Online-Befragungen mit zusätzlichen Werbefilmen eingebettet ist. Als Nebenprodukt wurde das Werkzeug Open Inventor um Knoten zur Modellierung von haptischen Szeneneigenschaften erweitert.
Virtual environment walkthrough applications are generally enhanced by a user’s interactions within a simulated architectural space, but the enhancement that stems from changes in spatial sound that are coupled with a user’s behavior are particularly important, especially within regard to creating a sense of place. When accompanied by stereoscopic image synthesis, spatial sound can immerse the user in a high-realism virtual copy of the real world. An advanced virtual environment that allow users to change realtime rendering features with a few manipulations has been shown to enable switching between different versions of a modeled space while maintaining sensory immersion. This paper reports on an experimental project in which an architectural model is being integrated into such an interactive virtual environment. The focus is on the spatial sound design for supporting interaction, including demonstrations of both the possibilities and limitations of such applications in presenting and promoting architectural designs, as well as in three-dimensional sketching.
With the virtual environment developed here, the characteristic
sound radiation patterns of musical instruments can be experienced
in real-time. The user may freely move around a musical instrument, thereby receiving acoustic and visual feedback in real-time. The perception of auditory and visual effects is intensified by the combination of acoustic and visual elements, as well as the option of user interaction. The simulation of characteristic sound radiation patterns is based on interpolating the intensities of a multichannel recording and offers a near-natural mapping of the sound radiation patterns. Additionally, a simple filter has been developed, enabling the qualitative simulation of an instrument’s characteristic sound radiation patterns to be easily implemented within real-time 3D applications. Both methods of simulating sound radiation patterns have been evaluated for a saxophone with respect to their functionality and validity by means of spectral analysis and an auditory experiment.
Virtual set environments for broadcasting become more sophisticated as well as the visual quality improves. Realtime interaction and production-specific visualization implemented through plugin mechanism enhance the existing systems like the 3DK. This work presents the integration of the Intersense IS-900 SCT camera tracking and 3D interaction into the 3DK virtual studio environment. The main goal of this work is the design of a virtual studio environment for post productions, which includes video output as well as media streaming formats such as MPEG-4. The systems allows high quality offline rendering during post production and 3D interaction by the moderator during the recording.
Virtual set environments for broadcasting become more sophisticated as well as the visual quality improves. Realtime interaction and production-specific visualization implemented through plugin mechanism enhance the existing systems like the virtual studio software 3DK. This work presents an algorithm which can dynamically manage textures of high resolution by prefetching them depending on their requirement in memory and map them on a procedural mesh in realtime. The main goal application of this work is the virtual representation of a flight over a landscape as part of weather reports in virtual studios and the interaction by the moderator.
High dynamic range environments maps based on still images or video streams are used for computer animation or interactive systems. The task of realistic light setup of scenes using captured environment maps might be eased as well as the visual quality improves. In this article, we discuss the light setting problem for virtual studio (tv) layout and system become more complex to handle this new feature of studio light capturing. The analysis of system requirements identifies the technical challenges.
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
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.
Actors in virtual studio productions are faced with the challenge that they have to interact with invisible virtual objects because these elements are rendered separately and combined with the real image later in the production process. Virtual sets typically use static virtual elements or animated objects with predefined behavior so that actors can practice their performance and errors can be corrected in the post production. With the demand for inexpensive live recording and interactive TV productions, virtual objects will be dynamically rendered at arbitrary positions that cannot be predicted by the actor. Perceptive aids have to be employed to support a natural interaction with these objects. In our work we study the effect of haptic feedback for a simple form of interaction. Actors are equipped with a custom built haptic belt and get vibrotactile feedback during a small navigational task (path following). We present a prototype of a wireless vibrotactile feedback device and a small framework for evaluating haptic feedback in a virtual set environment. Results from an initial pilot study indicate that vibrotactile feedback is a suitable non-visual aid for interaction that is at least comparable to audio-visual alternatives used in virtual set productions.
Two high dynamic range HDR environments maps based on video streams from fish-eye lens cameras are used for generating virtual lights in a virtual set renderer. The task of realistic virtual light setup of scenes using captured environment maps might be eased as well as visual quality improves. We discuss the light setting problem for virtual studio tv productions which have mixed scenes of real objects, actors, virtual objects and virtual backgrounds. Benefits of hdr interactive light control are that the real light in the studio does not have to be remodeled and the artistic impression by using the light in the studio is also captured. An analysis of system requirements identifies technical challenges. We discuss the properties of a prototype system including test production.
Markerless talent tracking is widely used for interactions and animations within virtual environments. In a virtual (tv) studio talents could be overburden by interaction tasks because camera and text require extensive attention. We take a look into animations and inter- actions within a studio, which do not require any special attention or learning. We show the generation of an artificial shadow from a talent, which ease the keying process, where separation of real shadows from the background is a difficult task. We also demonstrate animations of footsteps and dust. Furthermore, capturing talents’ height can also be used to adjust the parameters of elements in the virtual environment, like the position and scaling of a virtual display. In addition to the talents, a rigid body was tracked as placeholder for graphics, easing the interaction tasks for a talent. Two test productions show the possibilities, which subtle animations offer. In the second production, the rendering was improved (shadows, filtering, normal maps, ...) and instead of using the rigid body to move an object (a flag), the animation was only controlled by the hand’s position.
Virtual (tv) studios gain much more acceptance through improvements in computer graphics and camera tracking. Still commercial studios cannot have full interaction between actors and virtual scene because actors data are not completely digital available as well as the feedback for actors is still not sufficient. Markerless full body tracking might revolutionize virtual studio technology as it allows better interaction between real and virtual world. This article reports about using a markerless actor tracking in a virtual studio with a tracking volume of nearly 40 cubic meter enabling up to three actors within the green box. The tracking is used for resolving the occlusion between virtual objects and actors so that the Tenderer can output automatically a mask for virtual objects in the foreground in case the actor is behind. It is also used for triggering functions scripted within the Tenderer engine, which are attached to virtual objects, starting any kind of action (e.g., animation). Last but not least the system is used for controlling avatars within the virtual set. All tracking and rendering is done within a studio frame rate of 50 Hz with about 3 frames delay. The markerless actor tracking within virtual studios is evaluated by experts using an interview approach. The statistical evaluation is based on a questionnaire.
This article presents a new approach of integrating tangible user feedback in todays virtual TV studio productions. We describe a tangible multitouch planning system, enabling multiple users to prepare and customize scene flow and settings. Users can collaboratively view and interact with virtual objects by using a tangible user interface on a shared multitouch surface. The in a 2D setting created TV scenes are simultaneously rendered on an external monitor, using a production/target renderer in 3D. Thereby the user experiences a closer reproduction of a final production. Subsequently, users are able to join together the scenes into one complex plot. Within the developing process, a video prototype of the system shows the user interaction and enables early reviews and evaluations. The requirement analysis is based on expert interviews.
This paper presents a mobile approach of integrating tangible user feedback in today’s virtual TV studio productions. We describe a tangible multitouch planning system, enabling a single user to prepare and customize scene flow and settings. Users can view and interact with virtual objects by using a tangible user interface on a capacitive multitouch surface. In a 2D setting created TV scenes are simultaneously rendered as separate view using a production/target renderer in 3D. Thereby the user experiences a closer reproduction of a final production and set assets can be reused. Subsequently, a user can arrange scenes on a timeline while maintaining different versions/sequences. The system consists of a tablet and a workstation, which does all application processing and rendering. The tablet is just an interface connected via wireless LAN.
In this paper we introduce a system for tracking persons walking or standing on a large planar surface and for using the acquired data to easily configure position based interactions for virtual studio productions. The tracking component of the system, radarTRACK, is based on a laser scanner device capable of delivering interaction points on a large configurable plane. By using the device on the floor it is possible to use the delivered data to detect feet positions and derive the position and orientation of one or more users in real time. The second component of the system, named OscCalibrator, allows for the easy creation of multidimensional linear mappings between input and output parameters and the routing of OSC messages within a single modular design environment. We demonstrate the use of our system to flexibly create position-based interactions in a virtual studio environment.
A visual and spatial feedback system for orientation in virtual sets of virtual TV studios was developed and evaluated. It is based on a green proxy object, which moves around in the acting space by way of four transparent wires. A separate unit controls four winches and is connected to an engine, which renders the virtual set. A new developed plugin registers a virtual object’s position with the proxy object which imitates the virtual object’s movement on stage. This will allow actors to establish important eye contact with a virtual object and feel more comfortable in a virtual set. Furthermore, interaction with the virtual object and its proxy can be realised through a markerless actor tracking system. Several possible scenarios for user application were recorded and presented to experts in the broadcast industry, who evaluated the potential of SpiderFeedback in interviews and by questionnaires.
This paper presents an approach to integrate non-visual user feedback in today's virtual tv studio productions. Since recent studies showed that systems providing vibro-tactile feedback are not sufficient for replacing the common visual feedback, we developed an audio-based solution using an in ear headphone system, enabling a talent to move, avoid and point to virtual objects in a blue or green box. The system consists of an optical head tracking system, a wireless in ear monitor system and a workstation, which performs all application and audio processing. Using head related transfer functions, the talent gets directional and distance cues. Past research showed, that generating reflections of the sounds and simulating the acoustics of the virtual room helps the listener to conceive the acoustical feedback, we included this technique as well. In a user study with 15 participants the performance of the system was evaluated.
In this paper we describe a prototypical system for live musical performance in a virtual studio environment. The performer stands in front of the studio camera and interacts with an infrared-laser-based multi-touch device. The final TV image shows the performer interacting with a virtual screen which is augmented in front of herself. To overcome the problem of the performer not seeing this virtual screen in reality, we use a special hexagonal grid to facilitate the performer's awareness of this novel Theremin-like virtual musical instrument.
Live video broadcasting requires a multitude of professional expertise to enable multi-camera productions. Robotic systems allow the automation of common and repeated tracking shots. However, predefined camera shots do not allow quick adjustments when required due to unpredictable events. We introduce a modular automated robotic camera control and video switch system, based on fundamental cinematographic rules. The actors' positions are provided by a markerless tracking system. In addition, sound levels of actors' lavalier microphones are used to analyse the current scene. An expert system determines appropriate camera angles and decides when to switch from one camera to another. A test production was conducted to observe the developed prototype in a live broadcast scenario and served as a video-demonstration for an evaluation.
Die volumetrische Erfassung von Aushüben auf Baustellen ist ein kostenrelevanter Faktor und wird auch heute im täglichen Baustellenbetrieb oft noch in manueller Detailarbeit durchgeführt. Kostengünstige Sensoren zur Tiefenerfassung ermöglichen die halbautomatische Erfassung von Baugruben. Augmented Reality (AR) kann für diesen Prozess das nötige Feedback liefern. Vorgestellt wird ein Prototyp, bestehend aus einem Tablet mit integrierter Kamera und einem Lidar-Scanner. Es wird die Erfassung des Volumens bezüglich Nutzbarkeit und Genauigkeit mit Einsatz von AR getestet und evaluiert. Zur Bestimmung des Volumens wird unter Verwendung von Strahlen mit Unterstützung einer Grafik-Engine ein Algorithmus entwickelt. Der Algorithmus ist robust gegen nicht vollständig geschlossene Volumen. Die Bedienung, Überprüfung und Visualisierung findet durch praktischen Einsatz von AR statt.
Live-Video-Broadcasting mit mehreren Kameras erfordert eine Vielzahl von Fachkenntnissen. Robotersysteme ermöglichen zwar die Automatisierung von gängigen und wiederholten Tracking-Aufnahmen, diese erlauben jedoch keine kurzfristigen Anpassungen aufgrund von unvorhersehbaren Ereignissen. In diesem Beitrag wird ein modulares, automatisiertes Kamerasteuerungs- und Bildschnitt-System eingeführt, das auf grundlegenden kinematografischen Regeln basiert. Die Positionen der Akteure werden durch ein markerloses Tracking-System bereitgestellt. Darüber hinaus werden Tonpegel der Lavaliermikrofone der Akteure zur Analyse der aktuellen Szene verwendet. Ein Expertensystem ermittelt geeignete Kamerawinkel und entscheidet, wann von einer Kamera auf eine andere umgeschaltet werden soll. Eine Testproduktion wurde durchgeführt, um den entwickelten Prototyp in einem Live-Broadcast-Szenario zu beobachten und diente als Videodemonstration für eine Evaluierung.
Acquiring human motion data from video images plays an important role in the field of computer vision. Ground truth tracking systems require markers to create high quality motion data. But in many applications it is desired to work without markers. In recent years affordable hardware for markerless tracking systems was made available at a consumer level. Efficient depth camera systems based on Time-of-Flight sensors and structured light systems have made it possible to record motion data in real time. However, the gap between the quality of marker-based and markerless systems is high. The error sources of a markerless motion tracking pipeline are discussed and a model-based filter is proposed, which adapts depending on spatial location. The proposed method is then proven to be more robust and accurate than the unfiltered data stream and can be used to visually enhance the presence of an actor within a virtual environment in live broadcast productions.
In order to improve the interactivity between users and computers, recent technologies focus on incorporating gesture recognition into interactive systems. The aim of this article is to evaluate the effectiveness of using a Myo control armband and the Kinect 2 for recognition of gestures in order to interact with virtual objects in a weather report scenario. The Myo armband has an inertial measurement unit and is able to read electrical activity produced by skeletal muscles, which can be recognized as gestures, which are trained by machine learning. A Kinect sensor was used to build up a dataset which contains motion recordings of 8 different gestures and was also build up by a gesture training machine learning algorithm. Both input methods, the Kinect 2 and the Myo armband, were evaluated with the same interaction patterns in a user study, which allows a direct comparison and reveals benefits and limits of each technique.
The article discusses the question of “How to convey the experience in a virtual environment to third parties?” and explains the different technical implementations which can be used for live streaming and recording of a mixed reality experience. The real-world applications of our approach include education, entertainment, e- sports, tutorials, and cinematic trailers, which can benefit from our research by finding a suitable solution for their needs. We explain and outline our Mixed Reality systems as well as discuss the experience of recorded demonstrations of different VR applications, including the need for calibrated camera lens parameters based on realtime encoder values.
In this paper we describe the design of a virtual reality simulator for traditional intuitive archery. Traditional archers aim without a target figure. Good shooting results require an excellent body-eye coordination that allows the user to perform identical movements when drawing the bow. Our simulator provides a virtual archery experience and supports the user to learn and practice the motion sequence of traditional archery in a virtual environment. We use an infrared tracking system to capture the user’s movements in order to correct his movement. To provide a realistic haptic feedback a real bow is used as interaction device. Our system provides a believable user experience and supports the user to learn how to shoot in the traditional way. Following a user-centered iterative design approach we developed a number of prototypes and evaluated them for refinement in sequent iteration cycles. For illustration purposes we created a short video clip in our virtual studio about this project that presents the main ideas in an informative yet entertaining way.
Die interaktive Echtzeit 3D-Visualisierung Mobilisierung und Homing von Blutstammzellen wurde konzipiert, um ein sehr komplexes medizinisches Wissen mit den Mitteln der 3-dimensionalen Visualisierung in Echtzeit und des Internets sowie der daraus resultierenden Interaktivität aufzubereiten. Dies musste auf einer Ebene geschehen, die es hinterher auch jedem Nicht-Mediziner erlaubt, die grundlegenden biologischen und medizinischen Sachverhalte nachzuvollziehen. Das Resultat: Eine informative und didaktische Anwendung, aus einer Mischung von interaktiven 3D-Stationen und erklärenden 3D-Animationen. Diskutiert werden die Methodik der Konzeptionsphase und die Interaktionstechniken.