Multiplayer, online computer games often distribute game-object state to client machines in order to improve game scalability and responsiveness. Network latency and jitter are concerns in this context, although the impact is reduced by the use of predictive techniques such as dead reckoning. These techniques, however, introduce consistency concerns for important and hard to predict behaviours, such as object collisions. In these cases a centralized authority or client/server architecture is typically used to ensure strong consistency, limiting game scalability. In this work we propose a motion-lock protocol for distributed game collision detection and resolution. The motion-lock protocol improves performance of motion prediction by giving stations time to communicate and agree on the detected collisions. This reduces the divergence of object states and post-collision trajectories. Offline and online simulation results show the motion-lock protocol is able to maintain strong consistency in collision count and reduces post-collision deviation with a small sacrifice of 3-4% in responsiveness of player controls. Qualitatively, the visual result of the collision response is greatly improved. With the motion-lock protocol, multiplayer online games can offload basic collision detection and resolution to game clients, increasing scalability without overly sacrificing consistency. / Multijoueurs, des jeux informatiques en ligne distribuent souvent tat du jeu-objet aux ordinateurs clients afin d'amliorer l'extensibilit de jeu et ractivit. Temps de latence et la gigue sont des proccupations dans ce contexte, bien que l'impact est rduit par l'utilisation de techniques de prdiction, comme dead reckoning. Ces techniques, toutefois, d'introduire des proccupations importantes pour la cohrence et difficile prdire les comportements, tels que les collisions d'objets. Dans ces cas, l'architecture d'une autorit centralise ou client/serveur est gnralement utilis pour assurer la cohrence forte, limiter l'volutivit jeu. Dans cette texte, nous proposons un protocole de motion-lock pour la dtection de collision jeu distribu et de la rsolution. Le motion-lock protocole amliore les performances de prdiction de mouvement en donnant stations temps de communiquer et de s'entendre sur les collisions dtectes. Cela rduit la divergence des tats de lobjet et trajectoires post-collision. Les rsultats de simulation en mode den ligne et hors ligne montrent le protocole motion-lock est en mesure de maintenir la cohrence forte du nombre de collisions et rduit l'cart aprs la collision avec un petit sacrifice de 3-4% de la ractivit des commandes du lecteur. Qualitativement, le rsultat visuel de la raction de collision est grandement amliore. Avec le protocole de motion-lock, les jeux multijoueurs en ligne peut dcharger la dtection de collision et la rsolution de base aux clients de jeu, ce qui augmente l'volutivit sans trop sacrifier la cohrence.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.94952 |
| Date | January 2010 |
| Creators | Chen, Ching Ling Tom |
| Contributors | Clark Verbrugge (Internal/Supervisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | French |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science (School of Computer Science) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | Electronically-submitted theses. |
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