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Simulating eye movements for virtual humans or avatars can improve social experiences in virtual reality (VR) games, especially when wearing head mounted displays. While other researchers have already demonstrated the importance of simulating meaningful eye movements, we compare three gaze models with different levels of fidelity regarding realism: (1) a base model with static fixation and saccadic movements, (2) a proposed simulation model that extends the saccadic model with gaze shifts based on a neural network, and (3) a user's real eye movements recorded by a proprietary eye tracker. Our between-groups design study with 42 subjects evaluates impact of eye movements on social VR user experience regarding perceived quality of communication and presence. The tasks include free conversation and two guessing games in a co-located setting. Results indicate that a high quality of communication in co-located VR can be achieved without using extended gaze behavior models besides saccadic simulation. Users might have to gain more experience with VR technology before being able to notice subtle details in gaze animation. In the future, remote VR collaboration involving different tasks requires further investigation.
Integration of Multi-modal Cues in Synthetic Attention Processes to Drive Virtual Agent Behavior
(2017)
Simulations and serious games require realistic behavior of multiple intelligent agents in real-time. One particular issue is how attention and multi-modal sensory memory can be modeled in a natural but effective way, such that agents controllably react to salient objects or are distracted by other multi-modal cues from their current intention. We propose a conceptual framework that provides a solution with adherence to three main design goals: natural behavior, real-time performance, and controllability. As a proof of concept, we implement three major components and showcase effectiveness in a real-time game engine scenario. Within the exemplified scenario, a visual sensor is combined with static saliency probes and auditory cues. The attention model weighs bottom-up attention against intention-related top-down processing, controllable by a designer using memory and attention inhibitor parameters. We demonstrate our case and discuss future extensions.
Populating virtual worlds with intelligent agents can drastically improve a user's sense of presence. Applying these worlds to virtual training, simulations, or (serious) games, often requires multiple agents to be simulated in real time. The process of generating believable agent behavior starts with providing a plausible perception and attention process that is both efficient and controllable. We describe a conceptual framework for synthetic perception that specifically considers the mentioned requirements: plausibility, real-time performance, and controllability. A sample implementation will focus on sensing, attention, and memory to demonstrate the framework's capabilities in a real-time game engine scenario. A combination of dynamic geometric sensing and false coloring with static saliency information is provided to exemplify the collection of environmental stimuli. The subsequent attention process handles both bottom-up processing and task-oriented, top-down factors. Behavioral results can be influenced by controlling memory and attention The example case is demonstrated and discussed alongside future extensions.
This paper presents the implementation and evaluation of a computer vision task on a Field Programmable Gate Array (FPGA). As an experimental approach for an application-specific image-processing problem, it provides results about gained performance and precision compared with similar solutions on General Purpose Processor (GPP) architectures. The problem of detecting Binary Large OBjects (BLOBs) in a continuous video stream and computation of their center points has been addressed. Most existing solutions are realized on GPP platforms, where resolution of image material and sequential processing define the performance barrier. FPGA based approaches perform implemented algorithms as fast as hardware circuits and in addition offer parallelization abilities. The evaluation compares precision and performance gain against similar approaches on GPP platforms. The paper discusses different concepts for BLOB detection and shows the implementation of one common method for BLOB detection, including design problems and performance evaluation.
This paper presents the implementation and evaluation of a computer vision problem on a Field Programmable Gate Array (FPGA). This work is based upon previous work where the feasibility of application specific image processing algorithms on a FPGA platform have been evaluated by experimental approaches. This work coveres the development of a BLOB detection system on an Altera Development and Education II (DE2) board with a Cyclone II FPGA in Verilog. It detects binary spatially extended objects in image material and computes their center points. Bounding Box and Center-of-Mass have been applied for estimating center points of the BLOBs. The results are transmitted via a serial interface to the PC for validation of their ground truth and further processing. The evaluation compares precision and performance gains dependent on the applied computation methods.
The objective of the FIVIS project is to develop a bicycle simulator which is able to simulate real life bicycle ride situations as a virtual scenario within an immersive environment. A sample test bicycle is mounted on a motion platform to enable a close to reality simulation of turns and balance situations. The visual field of the bike rider is enveloped within a multi-screen visualisation environment which provides visual data relative to the motion and activity of the test bicycle. That means the bike rider has to pedal and steer the bicycle as a usual bicycle, while the motion is recorded and processed to control the simulation. Furthermore, the platform is fed with real forces and accelerations that have been logged by a mobile data acquisition system during real bicycle test drives. Thus, using a feedback system makes the movements of the platform match to the virtual environment and the reaction of the driver (e.g. steering angle, step rate).
GL-Wrapper for Stereoscopic Rendering of Standard Applications for a PC-based Immersive Environment
(2007)
Realism and plausibility of computer controlled entities in entertainment software have been enhanced by adding both static personalities and dynamic emotions. Here a generic model is introduced which allows the transfer of findings from real-life personality studies to a computational model. This information is used for decision making. The introduction of dynamic event-based emotions enables adaptive behavior patterns. The advantages of this new model have been validated with a four-way crossroad in a traffic simulation. Driving agents using the introduced model enhanced by dynamics were compared to agents based on static personality profiles and simple rule-based behavior. It has been shown that adding an adaptive dynamic factor to agents improves perceivable plausibility and realism. It also supports coping with extreme situations in a fair and understandable way.
Grailog embodies a systematics to visualize knowledge sources by graphical elements. Its main benefit is that the resulting visual presentations are easier to read for humans than the original symbolic source code. In this paper we introduce a methodology to handle the mapping from Datalog RuleML, serialized in XML, to an SVG representation of Grailog, also serialized in XML, via eXtensible Stylesheet Language Transformations (XSLT) 2.0/XML; the SVG is then rendered visually by modern Web browsers. This initial mapping is realized to target Grailog's "fully node copied" normal form. Elements can thus be translated one at a time, separating the fundamental Datalog-to-SVG translation concern from the concern of merging node copies for optimal (hyper)graph layout and avoiding its high computational complexity in this online tool. The resulting open source Grailog Knowledge-Source Visualizer (Grailog KS Viz) supports Datalog RuleML with positional relations of arity n>1. The on-the-fly transformation was shown to run on all recent major Web browsers and should be easy to understand, use, and extend.
Developing applications for Field Programmable Gate Array (FPGA) devices utilizes Computer Aided Design (CAD) flows. The transition from a high level Verilog hardware description to the optimized structure of programmed soft logic blocks and routing structure includes stages such as Verilog synthesis, hardware mapping, logical synthesis, packing, placement and routing. The VTR CAD flow is a collaborative project consisting of Odin II (University of New Brunswick), ABC (University of California, Berkeley) and VPR (University of Toronto), which offers an FPGA CAD flow for research and experimentation purposes. This paper describes developments in the visualization and simulation modules of Odin II, the first stage of the CAD flow. The contributions include new netlist visualization possibilities as well as an extended netlist simulator capable of simulating circuits with multiple clocks and providing extended generic structure simulation abilities. This results in the possibility to explore and simulate a larger set of new FPGA architectures and evaluate them using the VTR flow.
In interactive multi-screen visualization environments, every output device has to be constantly supplied with video information. Such visualization environments often use large projection screens, which require high resolution visualization data. An efficient approach to master this challenge is to distribute the workload to multiple low-cost computer systems. Nowadays’ game consoles are very powerful and specialized for interactive graphics applications; therefore they are well suited to be applied for computational expensive rendering purposes in real-time applications. The proposed solution (dXNA) has been developed on Microsoft’s XNA Game Studio. It supports interactive distributed rendering on multiple Xbox 360 and PC setups. Application logic synchronization and network session management are completely handled by dXNA. The interface of dXNA is similar to XNA Game Studio’s interface, which allows for efficient porting of existing projects. It has been proven that dXNA is an efficient and lightweight solution for distributed rendering for interactive multi-screen visualization environments.
Connect6 is a member of the k-in-a-row games family and attracts attention through its fairness and game complexity. Several very good strategies for Connect6 exist. In this paper we improve an already existing threat-based hardware design, which only evaluates the actual allocation of the game board. This strategy calculates a best move and waits until it wins or loses in the next two moves after the actual state. Our new proposed strategies think ahead and try to advance the player into a better position for the subsequent moves. We implemented three strategies with different winning chances, but all with clear advantages against the original strategy. This could be achieved without a much longer time for calculation and without the need of much more memory capacity. The implementations are validated on an Altera DE2 board, which contains a Cyclone II field-programmable gate array.
Inventory design in games is crucial when it comes to managing in-game items efficiently. In multi-user settings, an additional goal is to support awareness concerning a coplayer’s inventory and his/her available actions. Especially in virtual reality (VR), presence and immersion are vital aspects of the experience, suggesting real-world metaphors for interface design. The presented work examines two basic inventory paradigms: an abstract menu-based inventory and a metaphoric virtual belt. Both systems are implemented in a serious game prototype for paramedic training in VR, then evaluated in a between-group design study with paramedic trainees inexperienced in VR technology. While both solutions offer comparable usability and presence scores, the results suggest future optimization.
"Visual Computing" (VC) fasst als hochgradig aktuelles Forschungsgebiet verschiedene Bereiche der Informatik zusammen, denen gemeinsam ist, dass sie sich mit der Erzeugung und Auswertung visueller Signale befassen. Im Fachbereich Informatik der FH Bonn-Rhein-Sieg nimmt dieser Aspekt eine zentrale Rolle in Lehre und Forschung innerhalb des Studienschwerpunktes Medieninformatik ein. Drei wesentliche Bereiche des VC werden besonders in diversen Lehreinheiten und verschiedenen Projekten vermittelt: Computergrafik, Bildverarbeitung und Hypermedia-Anwendungen. Die Aktivitäten in diesen drei Bereichen fließen zusammen im Kontext immersiver virtueller Visualisierungsumgebungen.
Für die prototypische Erstellung von Virtual Reality (VR) Szenen auf Grundlage realer Umgebungen bieten sich Daten aus aktuellen Panorama-Kameras an. Diese Daten eignen sich jedoch nicht unmittelbar für die Integration in eine Game Engine. Wir stellen daher ein projektionsbasiertes Verfahren vor, mit dem Bilder und Videos im Fischaugenformat, wie sie z.B. die 360 Kamera Ricoh Theta erstellt, ohne Konvertierung in Echtzeit mit Hilfe der Unity Game Engine visualisiert werden können. Es wird weiterhin gezeigt, dass ein Panoramabild mit diesem Verfahren leicht manuell um grobe Tiefeninformation erweitert werden kann, sodass bei einer Darstellung in VR ein grober räumlicher Eindruck der Szene für einfach prototypische Umsetzungen ermöglicht wird.
Interactive Distributed Rendering of 3D Scenes on Multiple Xbox 360 Systems and Personal Computers
(2012)
In interactive visualization environments which use a multiple screen setup, every output device has to be supplied frequently with video information. Such virtual environments often use large projection screens, which require high resolution video data. When increasing scene complexity, it can become a challenge to equip a single computer with graphics hardware powerful enough for the task. An efficient approach is to distribute the workload to multiple low-cost computer systems such as game consoles. Nowadays' game consoles are very powerful and specialized for interactive graphics applications, therefore they are suitable to being used for rendering purposes. A framework has been developed that builds on Microsoft's XNA Game Studio. It enables for interactive distributed rendering on multiple Xbox 360 systems and PCs. Tasks such as game logic synchronization, network session management are fully handled by the framework. A game built with it can focus mostly on its own implementation. The framework's structure follows that of the XNA Game Studio, which allows porting existing game projects quickly. Our evaluation showed that the framework is a lightweight solution which leaves almost the full CPU time to the actual game.
For almost all modern means of transportation (car, train, airplane) driving simulators exist that provide realistic models of complex traffic situations under defined laboratory conditions. For many years, these simulators have been successfully used for drivers’ training and education and have considerably contributed to the overall road safety. Unfortunately, there is no such advanced system for the bicycle, although the number of bike accidents has been increasing against the common trend during the last decade. Hence the objective of this project is to design a real bicycle simulator that is able to generate any desired traffic situation within an immersive visualization environment. For this purpose the bike is mounted onto a motion platform with six degrees of freedom that enables a close-to-reality simulation of external forces acting on the bike. This system is surrounded by three projection walls displaying a virtual scenario.
Work on real-time hand-gesture recognition for SAVI (stereo active vision interface) is presented. Based on the detection of frontal faces, image regions near the face are searched for the existence of skin-tone blobs. Each blob is evaluated to determine if it is a hand held in a standard pose. A verification algorithm based on the responses of elongated oriented filters is used to decide whether a hand is present or not. Once a hand is detected, gestures are given by varying the number of fingers visible. The hand is segmented using an algorithm which detects connected skin-tone blobs in the region of interest, and a medial axis transform (skeletonization) is applied. Analysis of the resulting skeleton allows detection of the number of fingers visible, thus determining the gesture. The skeletonization is sensitive to strong shadows which may alter the detected morphology of the hand. Experimental results are given indicating good performance of the algorithm.
Maintaining orientation in an environment with non-Earth gravity (1 g) is critical for an astronaut's operational performance. Such environments present a number of complexities for balance and motion. For example, when an astronaut tilts due to ascending or descending an inclined plane on the moon, the gravity vector will be tilted correctly, but the magnitude will be different from on earth. If this results in a mis-perceived tilt, then that may lead to postural and perceptual errors, such as mis-perceiving the orientation of oneself or the ground plane and corresponding errors in task judgment.
We present a multi-user virtual reality (VR) setup that aims at providing novel training tools for paramedics that enhances current learning methods. The hardware setup consists of a two-user fullscale VR environment with head-mounted displays for two interactive trainees and one additional desktop pc for one trainer participant. The software provides a connected multi-user environment, showcasing a paramedic emergency simulation with focus on anaphylactic shock, a representative scenario for critical medical cases that happen too rare to eventually occur within a regular curricular term of vocational training. The prototype offers hands-on experience on multi-user VR in an applied scenario, generating discussion around current state and future development concerning three important research areas: (a) user navigation, (b) interaction, (c) level of visual abstraction, and (d) level of task abstraction.
In this work, we automatically distinguish the efficient high elbow pose from dropping one in pulling phase of front crawl stroke in front view amateurly recorded videos. This task is challenging due to the aquatic environment and missing depth information. We predict the pull’s efficiency through multiclass svm and random forest classifiers given arms key positions and angles as the feature set. We evaluate our approach over a labeled dataset of video frames taken from 25 members of masters’ swim club at Ryerson University with different levels of expertise and physiological characteristics. Our results show the effectiveness of our approach with random forest classifier, yielding 67% accuracy.
