Scalable Resource and QoS Brokering Mechanisms for Massively Multiplayer Online Games

Multiplayer online games have become an increasingly integral part of online entertainment. With advances in social media, the number of players of these games is increasing at a very rapid rate, which in some cases has been observed to be exponential. This is when resource becomes a concern. In this thesis, I investigated several challenges in developing and maintaining multiplayer games such as hotspots, genrespeci c limitations, unpredictable quality of service and rigidity in resource availability. I showed that these issues can be solved by adopting mechanisms for separation of resource concerns from functional concerns and coordination of resources. To support resource coordination, I divided the ownership of resources among three partiesgame owner, resource owner and game player. I developed the CyberOrgs-MMOG API, which supports Massively Multiplayer Online Game (MMOG) platforms capable of resource sharing among multiple peers, through mechanisms for acquiring these resources dynamically. I showed that dynamic acquisition of resources can solve the resource questions mentioned above. The API was evaluated using a 2D game with up to 250 simulated players. I also showed, how the game's responsiveness can be dynamically adjusted in a scalable way. This thesis presents the design and implementation of the CyberOrgs-MMOG API, interfaces provided to the interacting agents representing di erent parties. I integrated a 2D multiplayer game with the API and evaluated the mechanisms supported by the API

Broken World

Broken World is a non-violent, non-competitive MMO set in an expansive post-fuel world with an emphasis on building a community. The art style is drawn from the real world, using low-poly models. The game is built upon a unique peer-to-peer networking model, which allows for a low-resource server. It also features a terrain rendering system that utilizes PNGs to store landscape data efficiently. Along with the game, a suite of custom development tools were built to allow developers to insert game content quickly. Post-development, the game and its related technologies were evaluated for their effectiveness

Passage à l'échelle pour les mondes virtuels

Virtual worlds attract millions of users and these popular applications --supported by gigantic data centers with myriads of processors-- are routinely accessed. However, surprisingly, virtual worlds are still unable to host simultaneously more than a few hundred users in the same contiguous space.The main contribution of the thesis is Kiwano, a distributed system enabling an unlimited number of avatars to simultaneously evolve and interact in a contiguous virtual space. In Kiwano we employ the Delaunay triangulation to provide each avatar with a constant number of neighbors independently of their density or distribution. The avatar-to-avatar interactions and related computations are then bounded, allowing the system to scale. The load is constantly balanced among Kiwano's nodes which adapt and take in charge sets of avatars according to their geographic proximity. The optimal number of avatars per CPU and the performances of our system have been evaluated simulating tens of thousands of avatars connecting to a Kiwano instance running across several data centers, with results well beyond the current state-of-the-art.We also propose Kwery, a distributed spatial index capable to scale dynamic objects of virtual worlds. Kwery performs efficient reverse geolocation queries on large numbers of moving objects updating their position at arbitrary high frequencies. We use a distributed spatial index on top of a self-adaptive tree structure. Each node of the system hosts and answers queries on a group of objects in a zone, which is the minimal axis-aligned rectangle. They are chosen based on their proximity and the load of the node. Spatial queries are then answered only by the nodes with meaningful zones, that is, where the node's zone intersects the query zone.Kiwano has been successfully implemented for HybridEarth, a mixed reality world, Manycraft, our scalable multiplayer Minecraft map, and discussed for OneSim, a distributed Second Life architecture. By handling avatars separately, we show interoperability between these virtual worlds.With Kiwano and Kwery we provide the first massively distributed and self-adaptive solutions for virtual worlds suitable to run in the cloud. The results, in terms of number of avatars per CPU, exceed by orders of magnitude the performances of current state-of-the-art implementations. This indicates Kiwano to be a cost effective solution for the industry. The open API for our first implementation is available at \url{http://kiwano.li}.La réalité mixe, les jeux en ligne massivement multijoueur (MMOGs), les mondes virtuels et le cyberespace sont des concepts extrêmement attractifs. Mais leur déploiement à large échelle reste difficile et il est en conséquence souvent évité.La contribution principale de la thèse réside dans le système distribué Kiwano, qui permet à un nombre illimité d'avatars de peupler et d'interagir simultanément dans un même monde contigu. Dans Kiwano nous utilisons la triangulation de Delaunay pour fournir à chaque avatar un nombre constant de voisins en moyenne, indépendamment de leur densité ou distribution géographique. Le nombre d'interactions entre les avatars et les calculs inhérents sont bornés, ce qui permet le passage à l'échelle du système.La charge est repartie sur plusieurs machines qui regroupent sur un même nœud les avatars voisins de façon contiguë dans le graphe de Delaunay. L'équilibrage de la charge se fait de manière contiguë et dynamique, en suivant la philosophie des réseaux pair-à-pair (peer-to-peer overlays). Cependant ce principe est adapté au contexte de l'informatique dématérialisée (cloud computing).Le nombre optimal d'avatars par CPU et les performances de notre système ont été évalués en simulant des dizaines de milliers d'avatars connectés à la même instance de Kiwano tournant à travers plusieurs centres de traitement de données.Nous proposons également trois applications concrètes qui utilisent Kiwano : Manycraft est une architecture distribuée capable de supporter un nombre arbitrairement grand d'utilisateurs cohabitant dans le même espace Minecraft, OneSim, qui permet à un nombre illimité d'usagers d'être ensemble dans la même région de Second Life et HybridEarth, un monde en réalité mixte où avatars et personnes physiques sont présents et interagissent dans un même espace: la Terre

A Framework for Turn-Based Local Multiplayer Games

Mobile devices are present in people’s everyday lives and have gone from being a tool used purely to communicate. Currently they are also used as a means to entertain, by listening to music, watching videos or playing games. When it comes to games, these can be played alone (single player games) or with other people (multiplayer games), from strangers to family and friends. Local multiplayer games are a popular choice because they connect groups of physically close people to play and allow them to interact. However, there are some concerns to address. Local multiplayer games connect de vices but that alone isn’t enough to ensure correct game play. These games need to distribute the game state between the devices and solve the issues that ensue from that. These involve matching players, managing game state (making sure players get the cur rent state in a reasonable time frame, in order for the next moves to be performed), dealing with player inflow and outflow, among other problems. To reliably handle the aforementioned issues, in this thesis we propose Peppermint, a framework and runtime system to program local multiplayer games on the mobile edge. It was developed on top of Basil GardenBed, a data storage and dissemination system for the mobile edge developed at NOVA LINCS, that provides communication between devices. On the other hand, the challenges stemming from the games’ execution will be addressed by our framework, which are validated by the development and evaluation of one game according to a set of functional metrics. The results obtained during testing of our framework, mostly in a simulated setting, show that the framework is able to create and store matches, letting players join, leave and play in them. It will also discard the generated data when the match ends, so that the network doesn’t end up being cluttered with data that isn’t being accessed anymore. These characteristics constitute a framework has a set of core features that can be expanded in future work.Os dispositivos móveis estão presentes no dia-a-dia das pessoas e deixaram de ser apenas utilizados para comunicar. Presentemente são também usados como meio de entreteni mento, ao permitirem ouvir música, ver vídeos ou jogar jogos. Em relação a jogos, estes podem ser apenas para um jogador, ou podem ser jogados por várias pessoas (jogos mul tijogador), desde desconhecidos a família e amigos. Os jogos multijogador locais são uma escolha popular porque permitem que grupos de pessoas próximas fisicamente se juntem e interajam. No entanto, existem problemas a resolver. Os jogos multijogador locais conectam dis positivos mas apenas isso não é suficiente para garantir a sua correcção. Os jogos necessi tam de distribuir o seu estado entre os dispositivos e resolver as questões que decorrem disso. Estas envolvem agrupar jogadores, gerir o estado do jogo (ao garantir que os joga dores recebem o estado mais recente atempadamente, para que os próximos movimentos possam ser efectuados), lidar com o fluxo de jogadores, entre outros problemas. Para resolver os problemas mencionados, nesta tese apresentamos Peppermint, uma infraestrutura e sistema de execução para implementar jogos multijogador locais em dispositivos ligados a uma rede na mobile edge. Foi desenvolvido sobre o sistemaBasil GardenBed, um sistema de armazenamento e disseminação de dados na mobile edge de senvolvido no NOVA LINCS, que fornece comunicação entre dispositivos. Por outro lado, os desafios resultantes da execução dos jogos são endereçados pela nossa infraestrutura, validados pelo desenvolvimento e avaliação de um jogo de acordo com um conjunto de métricas relativas ao seu funcionamento. Os resultados, predominantemente obtidos em ambiente simulado, mostram que a infraestrutura permite criar e armazenar partidas, deixando outros jogadores entrar, sair e jogar. Também elimina os dados criados quando estas terminam, para que a rede não fique preenchida com dados que já não serão acedidos. Tudo isto forma uma infraestrutura com um conjunto de características básicas que podem ser expandidas em trabalho futuro

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