Learning Two-Person Interaction Models for Responsive Synthetic Humanoids

Imitation learning is a promising approach for generating life-like behaviors of virtual humans and humanoid robots. So far, however, imitation learning has been mostly restricted to single agent settings where observed motions are adapted to new environment conditions but not to the dynamic behavior of interaction partners. In this paper, we introduce a new imitation learning approach that is based on the simultaneous motion capture of two human interaction partners. From the observed interactions, low-dimensional motion models are extracted and a mapping between these motion models is learned. This interaction model allows the real-time generation of agent behaviors that are responsive to the body movements of an interaction partner. The interaction model can be applied both to the animation of virtual characters as well as to the behavior generation for humanoid robots.

Connecting Interactive Arts and Virtual Reality with Enaction

This paper reports on a Virtual Reality theater experiment named Il était Xn fois, conducted by artists and computer scientists working in cognitive science. It offered the opportunity for knowledge and ideas exchange between these groups, highlighting the benefits of collaboration of this kind. Section 1 explains the link between enaction in cognitive science and virtual reality, and specifically the need to develop an autonomous entity which enhances presence in an artificial world. Section 2 argues that enactive artificial intelligence is able to produce such autonomy. This was demonstrated by the theatrical experiment, "Il était Xn fois" (in English: Once upon Xn time), explained in section 3. Its first public performance was in 2009, by the company Dérézo. The last section offers the view that enaction can form a common ground between the artistic and computer science areas.

Application of Time-Delay Estimation to Mixed Reality Multisensor Tracking

Spatial tracking is one of the most challenging and important parts of Mixed Reality environments. Many applications, especially in the domain of Augmented Reality, rely on the fusion of several tracking systems in order to optimize the overall performance. While the topic of spatial tracking sensor fusion has already seen considerable interest, most results only deal with the integration of carefully arranged setups as opposed to dynamic sensor fusion setups. A crucial prerequisite for correct sensor fusion is the temporal alignment of the tracking data from several sensors. Tracking sensors are typically encountered in Mixed Reality applications, are generally not synchronized. We present a general method to calibrate the temporal offset between different sensors by the Time Delay Estimation method which can be used to perform on-line temporal calibration. By applying Time Delay Estimation on the tracking data, we show that the temporal offset between generic Mixed Reality spatial tracking sensors can be calibrated. To show the correctness and the feasibility of this approach, we have examined different variations of our method and evaluated various combinations of tracking sensors. We furthermore integrated this time synchronization method into our UBITRACK Mixed Reality tracking framework to provide facilities for calibration and real-time data alignment.

Virtual Reality as a Support Tool for Ergonomic-Style Convergence

The competitive industrial context compels companies to speed-up every new product design. In order to keep designing products that meet the needs of the end user, a human centered concurrent product design methodology has been proposed. Its setting up is complicated by the difficulties of collaboration between experts involved inthe design process. In order to ease this collaboration, we propose the use of virtual reality as an intermediate design representation in the form of light and specialized immersive convergence support applications. In this paper, we present the As Soon As Possible (ASAP) methodology making possible the development of these tools while ensuring their usefulness and usability. The relevance oft his approach is validated by an industrial use case through the design of an ergonomic-style convergence support tool.

Collision Detection: Broad Phase Adaptation from Multi-Core to Multi-GPU Architecture

We present in this paper several contributions on the collision detection optimization centered on hardware performance. We focus on the broad phase which is the first step of the collision detection process and propose three new ways of parallelization of the well-known Sweep and Prune algorithm. We first developed a multi-core model takes into account the number of available cores. Multi-core architecture enables us to distribute geometric computations with use of multi-threading. Critical writing section and threads idling have been minimized by introducing new data structures for each thread. Programming with directives, like OpenMP, appears to be a good compromise for code portability. We then proposed a new GPU-based algorithm also based on the "Sweep and Prune" that has been adapted to multi-GPU architectures. Our technique is based on a spatial subdivision method used to distribute computations among GPUs. Results show that significant speed-up can be obtained by passing from 1 to 4 GPUs in a large-scale environment.

Comparison of 2D and 3D GUI Widgets for Stereoscopic Multitouch Setups

Recent developments in the area of interactive entertainment have suggested to combine stereoscopic visualization with multi-touch displays, which has the potential to open up new vistas for natural interaction with interactive three-dimensional (3D) applications. However, the question arises how the user interfaces for system control in such 3D setups should be designed in order to provide an effective user experience. In this article we introduce 3D GUI widgets for interaction with stereoscopic touch displays. The design of the widgets was inspired to skeuomorphism and affordances in such a way that the user should be able to operate the virtual objects in the same way as their real-world equivalents. We evaluate the developed widgets and compared them with their 2D counterparts in the scope of an example application in order to analyze the usability of and user behavior with the widgets. The results reveal differences in user behavior with and without stereoscopic display during touch interaction, and show that the developed 2D as well as 3D GUI widgets can be used effectively in different applications.

Estimating Gesture Accuracy in Motion-Based Health Games

This manuscript details a technique for estimating gesture accuracy within the context of motion-based health video games using the MICROSOFT KINECT. We created a physical therapy game that requires players to imitate clinically significant reference gestures. Player performance is represented by the degree of similarity between the performed and reference gestures and is quantified by collecting the Euler angles of the player's gestures, converting them to a three-dimensional vector, and comparing the magnitude between the vectors. Lower difference values represent greater gestural correspondence and therefore greater player performance. A group of thirty-one subjects was tested. Subjects achieved gestural correspondence sufficient to complete the game's objectives while also improving their ability to perform reference gestures accurately.

Entwicklung eines Versuchsfelds für große Systeme intelligenter Behälter

Im Rahmen dieses Artikels werden aktuelle Forschungsarbeiten zum Einsatz von Energy-Harvesting und Ultra-Low-Power-Geräten in Materialflusssystemen beschrieben. Ein besonderes Augenmerk wird auf die inBin-Plattform, das Energy-Harvesting und deren Auswirkungen auf die Leistungsverfügbarkeit gelegt. Dazu werden die Hardwareplattform und Architektur der inBin-Plattform sowie der Aufbau eines Versuchsfelds detailliert erläutert. Des Weiteren wird ein Ansatz zur Modellierung und Simulation von Systemen mit einer großen Anzahl von inBin-Plattformen vorgestellt. Darüber hinaus werden die Ergebnisse zweier simulierter Szenarien und mögliche Folgen für die Planung zukünftiger Materialflusssysteme betrachtet.

Simulating Wind and Warmth in Virtual Reality: Conception, Realization and Evaluation for a CAVE Environment

Wind and warmth sensations proved to be able to enhance users' state of presence in Virtual Reality applications. Still, only few projects deal with their detailed effect on the user and general ways of implementing such stimuli. This work tries to fill this gap: After analyzing requirements for hardware and software concerning wind and warmth simulations, a hardware and also a software setup for the application in a CAVE environment is proposed. The setup is evaluated with regard to technical details and requirements, but also - in the form of a pilot study - in view of user experience and presence. Our setup proved to comply with the requirements and leads to satisfactory results. To our knowledge, the low cost simulation system (approx. 2200 Euro) presented here is one of the most extensive, most flexible and best evaluated systems for creating wind and warmth stimuli in CAVE-based VR applications.

A Comparative Evaluation of Three Skin Color Detection Approaches

Skin segmentation is a challenging task due to several influences such as unknown lighting conditions, skin colored background, and camera limitations. A lot of skin segmentation approaches were proposed in the past including adaptive (in the sense of updating the skin color online) and non-adaptive approaches. In this paper, we compare three skin segmentation approaches that are promising to work well for hand tracking, which is our main motivation for this work. Hand tracking can widely be used in VR/AR e.g. navigation and object manipulation. The first skin segmentation approach is a well-known non-adaptive approach. It is based on a simple, pre-computed skin color distribution. Methods two and three adaptively estimate the skin color in each frame utilizing clustering algorithms. The second approach uses a hierarchical clustering for a simultaneous image and color space segmentation, while the third approach is a pure color space clustering, but with a more sophisticated clustering approach. For evaluation, we compared the segmentation results of the approaches against a ground truth dataset. To obtain the ground truth dataset, we labeled about 500 images captured under various conditions.

Influence of Comfort on 3D Selection Task Performance in Immersive Desktop Setups

Immersive virtual environments (IVEs) have the potential to afford natural interaction in the three-dimensional (3D) space around a user. However, interaction performance in 3D mid-air is often reduced and depends on a variety of ergonomics factors, the user's endurance, muscular strength, as well as fitness. In particular, in contrast to traditional desktop-based setups, users often cannot rest their arms in a comfortable pose during the interaction. In this article we analyze the impact of comfort on 3D selection tasks in an immersive desktop setup. First, in a pre-study we identified how comfortable or uncomfortable specific interaction positions and poses are for users who are standing upright. Then, we investigated differences in 3D selection task performance when users interact with their hands in a comfortable or uncomfortable body pose, while sitting on a chair in front of a table while the VE was displayed on a headmounted display (HMD). We conducted a Fitts' Law experiment to evaluate selection performance in different poses. The results suggest that users achieve a significantly higher performance in a comfortable pose when they rest their elbow on the table.

Jacob van Ruisdaels Buiten-Ansichten

In den Buiten-Ansichten Jacob van Ruisdaels zeigt sich eine einmalige Verbindung von Architektur und Naturkonzept in der niederländischen Malerei des 17. Jahrhunderts. Die Darstellung von luxuriösen Landvillen wird in eine illusionistische Landschaft gesetzt, die in ihrem Wildnischarakter den realen barocken Garten negiert. Ruisdael spielt bewusst mit der assoziativen Wirkung von Buiten- und Garten-Architektur, die durch ihre Übertragung in die Wildnis ihrer Funktion enthoben werden. Gleichzeitig erhält die Landschaft durch ihre Gruppierung um die Architektur eine Aufwertung zum Garten. Die dabei entstehenden Parallelen zur Gartenkunst des 18. Jahrhunderts, machen Ruisdael zu einem visionären Künstler seiner Zeit.

Einfügen als Kulturtechnik

Der Architekt und Pritzker-Preisträger von 2012 Wang Shu und seine Frau Lu Wenyu setzen traditionelle chinesische Baukultur neu um. Das kommt insbesondere im Fügen alter und neuer Materialien nach tradierten Handwerksregeln zum Ausdruck. Das theoretische wie praktische Interesse am lokalen Handwerk führen sie unter anderem auf die Beschäftigung mit den chinesischen Literati zurück. Auf diese Weise widersetzen sie sich der heute vorherrschenden Ökonomie im chinesischen Baugewerbe. Sie aktualisieren nicht nur das traditionelle chinesische Handwerk, sondern setzen sich auch für eine Nachhaltigkeit ein, in welcher die zeitliche Entwicklung im Zusammenhang mit bestimmten Erfahrungsräumen gesehen wird. Mittels Improvisationen und Handwerk lassen Wang Shu und Lu Wenyu die alten kulturellen Traditionen mit spezifischen Ästhetiken in einem neuen Licht einer anderen gegenwärtigen Moderne wieder aufscheinen.

Raumspinnen

In der Architektur ist der Raum das primäre Gestaltungsmedium. Um Raum in der Gestaltungslehre zu erfahren und diesen in ein räumliches Denken zu überführen, eignet sich der reale Raum am besten, um ihn zu definieren, zu gliedern und ihn letztlich zu gestalten. Das Erleben im Maßstab 1:1 ist ein physisches Erleben, das in seiner Wirkungsweise der Körperlichkeit, Empfindung und Wahrnehmung des Menschen unmittelbar entspricht und dadurch beste Voraussetzungen schafft, um ihn in späteren abstrakten Gestaltungsstrategien anzuwenden.

Aufzüge

Die architekturgeschichtliche Arbeit endet nicht mit dem bauzeitlichen Nar­rativ, jede spätere Modernisierung wird mit der Zeit ebenfalls geschichtlich. Am Beispiel einer profanen Bauaufgabe – der nachträglich installierten Aufzugsanlagen in den Wohnbauten des Roten Wien – wird gezeigt, wie diese nicht dazugehörigen, stets irritierenden Supplemente wesentlich zum his­torischem Verständnis sowohl der Architektur als auch der Wohnbaupolitik beitragen. Die Aufzüge, die über keinen historischen Platz und über keine originäre Form verfügen, erweisen sich in der retrospektiven Betrachtung als widerspenstiges, sperriges Supplement. Der Stil und die Konstruktion der Aufzugsschächte veränderten sich im Laufe der Zeit mehrfach. Standardisierte Profilbauglasanbauten wurden um 1980 zu massiven, dekorierten Schächten. Um 1990 gestalteten Architekten eine Reihe von Liften als fein abgestimmte Interpretationen des Historischen. Und aktuelle Ganzglasanlagen eignen sich neue Bereiche an: die Bürgersteige.