Development of a Physics-Aware Dead Reckoning Mechanism for Distributed Interactive Applications

Distributed Interactive Applications (DIAs) are a class of software that allow geographically remote users to interact within a shared virtual environment. Many DIAs seek to present a rich and realistic virtual world to users, both on a visual and behavioural level. A relatively recent addition to virtual environments (both distributed and single user) to achieve the latter has been the simulation of realistic physical phenomena between objects in the environment. However, the application of physics simulation to virtual environments in DIAs currently lags that of single user environments. This is primarily due to the unavailability of entity state update mechanisms which can maintain consistency in such physics-rich environments. The difference is particularly evident in applications built on a peer-to-peer architecture, as a lack of a single authority presents additional challenges in synchronising the state of shared objects while also presenting a responsive simulation. This thesis proposes a novel state maintenance mechanism for physics-rich environments in peer-to-peer DIAs composed of two parts: a dynamic authority scheme for shared objects, and a physics-aware dead reckoning model with an adaptive error threshold. The first part is intended to place a bound on the overall inconsistency present in shared objects, while the second is implemented to minimise the instantaneous inconsistency during users’ interactions with shared objects. A testbed application is also described, which is used to validate the performance of the proposed mechanism. The state maintenance mechanism is implemented for a single type of physicsaware application, and demonstrates a marked improvement in consistency for that application. However, several flexible terms are described in its implementation, as well as their potential relevance to alternative applications. Finally, it should be noted that the physics-aware dead reckoning model does not depend on the authority scheme, and can therefore be employed with alternative authority scheme

Aesthetically driven design of network based multi-user instruments.

Digital networking technologies open up a new world of possibilities for music making, allowing performers to collaborate in ways not possible before. Network based Multi-User Instruments (NMIs) are one novel method of musical collaboration that take advantage of networking technology. NMIs are digital musical instruments that exist as a single entity instantiated over several nodes in a network and are performed simultaneously by multiple musicians in realtime. This new avenue is exciting, but it begs the question of how does one design instruments for this new medium? This research explores the use of an aesthetically driven design process to guide the design, construction, rehearsal, and performance of a series of NMIs. This is an iterative process that makes use of a regularly rehearsing and performing ensemble which serves as a test-bed for new instruments, from conception, to design, to implementation, to performance. This research includes details of several NMIs constructed in accordance with this design process. These NMIs have been quantitatively analysed and empirically tested for the presence of interconnectivity and group influence during performance as a method for measuring group collaboration. Furthermore qualitative analyses are applied which test for the perceived e ectiveness of these instruments during real-world performances in front of live audiences. The results of these analyses show that an aesthetically driven method of designing NMIs produces instruments that are interactive and collaborative. Furthermore results show that audiences perceive a measurable impression of interconnectivity and liveness in the ensemble even though most of the performers in the ensemble are not physically present

Virtual Reality Games for Motor Rehabilitation

This paper presents a fuzzy logic based method to track user satisfaction without the need for devices to monitor users physiological conditions. User satisfaction is the key to any product’s acceptance; computer applications and video games provide a unique opportunity to provide a tailored environment for each user to better suit their needs. We have implemented a non-adaptive fuzzy logic model of emotion, based on the emotional component of the Fuzzy Logic Adaptive Model of Emotion (FLAME) proposed by El-Nasr, to estimate player emotion in UnrealTournament 2004. In this paper we describe the implementation of this system and present the results of one of several play tests. Our research contradicts the current literature that suggests physiological measurements are needed. We show that it is possible to use a software only method to estimate user emotion

Consensus Based Networking of Distributed Virtual Environments

Distributed Virtual Environments (DVEs) are challenging to create as the goals of consistency and responsiveness become contradictory under increasing latency. DVEs have been considered as both distributed transactional databases and force-reflection systems. Both are good approaches, but they do have drawbacks. Transactional systems do not support Level 3 (L3) collaboration: manipulating the same degree-of-freedom at the same time. Force-reflection requires a client-server architecture and stabilisation techniques. With Consensus Based Networking (CBN), we suggest DVEs be considered as a distributed data-fusion problem. Many simulations run in parallel and exchange their states, with remote states integrated with continous authority. Over time the exchanges average out local differences, performing a distribued-average of a consistent, shared state. CBN aims to build simulations that are highly responsive, but consistent enough for use cases such as the piano-movers problem. CBN's support for heterogeneous nodes can transparently couple different input methods, avoid the requirement of determinism, and provide more options for personal control over the shared experience. Our work is early, however we demonstrate many successes, including L3 collaboration in room-scale VR, 1000's of interacting objects, complex configurations such as stacking, and transparent coupling of haptic devices. These have been shown before, but each with a different technique; CBN supports them all within a single, unified system

Комп’ютерні мережі як апаратна платформа для проектування онлайн-ігор

Робота публікується згідно наказу ректора від 29.12.2020 р. №580/од "Про розміщення кваліфікаційних робіт вищої освіти в репозиторії НАУ". Керівник проекту: к.т.н., доцент Надточій Василь ІвановичComputer networking is a branch of computer science, telecommunication and computer engineering and its was influenced by a wide range of the technologies and historical events. A computer network provides new ways of communications by means of diverse technologies, such as online chats and messengers, electronic mail, voice and video calls. Network users are able to share resources such as data, files and other types of information. Authorized participants of the network can gain access to the stored information on other computers, resources provided by the devices or perform some tasks with the help of distributed computing across the network.Комп’ютерні мережі - це галузь обчислювальної техніки, телекомунікацій та обчислювальної техніки, на яку вплинули широкий спектр технологій та історичні події. Комп’ютерна мережа забезпечує нові способи спілкування за допомогою різноманітних технологій, таких як онлайн-чати та месенджери, електронна пошта, голосові та відеодзвінки. Користувачі мережі можуть обмінюватися такими ресурсами, як дані, файли та інші типи інформації. Уповноважені учасники мережі можуть отримати доступ до інформації, що зберігається на інших комп'ютерах, ресурсах, що надаються пристроями, або виконувати деякі завдання за допомогою розподілених обчислень по мережі

MediaSync: Handbook on Multimedia Synchronization

This book provides an approachable overview of the most recent advances in the fascinating field of media synchronization (mediasync), gathering contributions from the most representative and influential experts. Understanding the challenges of this field in the current multi-sensory, multi-device, and multi-protocol world is not an easy task. The book revisits the foundations of mediasync, including theoretical frameworks and models, highlights ongoing research efforts, like hybrid broadband broadcast (HBB) delivery and users' perception modeling (i.e., Quality of Experience or QoE), and paves the way for the future (e.g., towards the deployment of multi-sensory and ultra-realistic experiences). Although many advances around mediasync have been devised and deployed, this area of research is getting renewed attention to overcome remaining challenges in the next-generation (heterogeneous and ubiquitous) media ecosystem. Given the significant advances in this research area, its current relevance and the multiple disciplines it involves, the availability of a reference book on mediasync becomes necessary. This book fills the gap in this context. In particular, it addresses key aspects and reviews the most relevant contributions within the mediasync research space, from different perspectives. Mediasync: Handbook on Multimedia Synchronization is the perfect companion for scholars and practitioners that want to acquire strong knowledge about this research area, and also approach the challenges behind ensuring the best mediated experiences, by providing the adequate synchronization between the media elements that constitute these experiences

An Information-Theoretic Framework for Consistency Maintenance in Distributed Interactive Applications

Distributed Interactive Applications (DIAs) enable geographically dispersed users to interact with each other in a virtual environment. A key factor to the success of a DIA is the maintenance of a consistent view of the shared virtual world for all the participants. However, maintaining consistent states in DIAs is difficult under real networks. State changes communicated by messages over such networks suffer latency leading to inconsistency across the application. Predictive Contract Mechanisms (PCMs) combat this problem through reducing the number of messages transmitted in return for perceptually tolerable inconsistency. This thesis examines the operation of PCMs using concepts and methods derived from information theory. This information theory perspective results in a novel information model of PCMs that quantifies and analyzes the efficiency of such methods in communicating the reduced state information, and a new adaptive multiple-model-based framework for improving consistency in DIAs. The first part of this thesis introduces information measurements of user behavior in DIAs and formalizes the information model for PCM operation. In presenting the information model, the statistical dependence in the entity state, which makes using extrapolation models to predict future user behavior possible, is evaluated. The efficiency of a PCM to exploit such predictability to reduce the amount of network resources required to maintain consistency is also investigated. It is demonstrated that from the information theory perspective, PCMs can be interpreted as a form of information reduction and compression. The second part of this thesis proposes an Information-Based Dynamic Extrapolation Model for dynamically selecting between extrapolation algorithms based on information evaluation and inferred network conditions. This model adapts PCM configurations to both user behavior and network conditions, and makes the most information-efficient use of the available network resources. In doing so, it improves PCM performance and consistency in DIAs

Microworld Writing: Making Spaces for Collaboration, Construction, Creativity, and Community in the Composition Classroom

In order to create a 21st century pedagogy of learning experiences that inspire the engaged, constructive, dynamic, and empowering modes of work we see in online creative communities, we need to focus on the platforms, the environments, the microworlds that host, hold, and constitute the work. A good platform can build connections between users, allowing for the creation of a community, giving creative work an engaged and active audience. These platforms will work together to build networks of rhetorical/creative possibilities, wherein students can learn to cultivate their voices, skills, and knowledge bases as they engage across platforms and genres. I call on others to make, mod, or hack other new platforms. In applying this argument to my subject, teaching writing in a college composition class, I describe Microworld Writing as a genre that combines literary language practice with creativity, performativity, play, game mechanics, and coding. The MOO can be an example of one of these platforms and of microworld writing, in that it allows for creativity, user agency, and programmability, if it can be updated to have the needed features (virtual world, community, accessibility, narrativity, compatibility and exportability). I offer the concept of this MOO-IF as inspiration for a collaborative, community-oriented Interactive Fiction platform, and encourage people to extend, find, and build their own platforms. Until then and in addition, students can be brought into Microworld Writing in the composition classroom through interactive-fiction platforms, as part of an ecology of genre experimentation and platform exercise

Virtutopia: A Framework for Virtual Environments

Virtutopia is a framework for the design and maintenance of persistent virtual online worlds. In this project we designed, implemented and evaluated a proposed architecture for the first stage of Virtutopia. The initial architecture provides capabilities for networking, defining objects and behaviors, receiving user input and rendering output. The outcome is a network system, utilizing a hybrid client-server peer-to-peer architecture, combined with a 3D client interface capable of interacting with other clients in the virtual world