Dead Reckoning for Distributed Network Online Games

Online networked games are becoming increasingly popular. One type of network architecture used in these games is a distributed network architecture, where players send periodic updates to each other and each player must locally reconstruct the position of their opponents in between these updates. In this work, we assume a car model for the players, as errors in this type of network are most pronounced when players have high speeds. We are interested in decreasing this update frequency in order to conserve bandwidth. We are also interested in investigating issues that arise when these locally replicated opponents need to interact and collide with objects in the environment. In this thesis we decompose the replication problem into two components: first, we must predict the position of our opponents by extrapolating from the received updates, then we must create a smooth trajectory from these predicted positions that appears believable to the player. We introduce a neural network based approach to solving the prediction portion that outperforms the current state of the art. We then propose a neural network based approach and an approach based on a path tracking controller for mobile robots to generate smooth trajectories. We present results to compare these approaches and show that the path tracking approach performs better than both the neural network approach and the established state of the art approaches. We also investigate collisions between replicated opponents and the environment. This is a complex problem, so for simplicity we are only examining collisions with static obstacles. Collisions can vary dramatically based on small changes in impact point and angle, and so we want to be able to predict collisions based on the predicted position of the opponent because that is theoretically our best estimate of the true position of our opponent. We propose a neural network based approach to this problem, which is able to predict the collision response of a vehicle colliding with a static obstacle. We present results that show this method has potential to outperform the current best practice, but we also discuss several implementation issues that must be addressed

Effects of Local Latency on Games

Video games are a major type of entertainment for millions of people, and feature a wide variety genres. Many genres of video games require quick reactions, and in these games it is critical for player performance and player experience that the game is responsive. One of the major contributing factors that can make games less responsive is local latency — the total delay between input and a resulting change to the screen. Local latency is produced by a combination of delays from input devices, software processing, and displays. Due to latency, game companies spend considerable time and money play-testing their games to ensure the game is both responsive and that the in-game difficulty is reasonable. Past studies have made it clear that local latency negatively affects both player performance and experience, but there is still little knowledge about local latency’s exact effects on games. In this thesis, we address this problem by providing game designers with more knowledge about local latency’s effects. First, we performed a study to examine latency’s effects on performance and experience for popular pointing input devices used with games. Our results show significant differences between devices based on the task and the amount of latency. We then provide design guidelines based on our findings. Second, we performed a study to understand latency’s effects on ‘atoms’ of interaction in games. The study varied both latency and game speed, and found game speed to affect a task’s sensitivity to latency. Third, we used our findings to build a model to help designers quickly identify latency-sensitive game atoms, thus saving time during play-testing. We built and validated a model that predicts errors rates in a game atom based on latency and game speed. Our work helps game designers by providing new insight into latency’s varied effects and by modelling and predicting those effect

Cloud Services Brokerage for Mobile Ubiquitous Computing

Recently, companies are adopting Mobile Cloud Computing (MCC) to efficiently deliver enterprise services to users (or consumers) on their personalized devices. MCC is the facilitation of mobile devices (e.g., smartphones, tablets, notebooks, and smart watches) to access virtualized services such as software applications, servers, storage, and network services over the Internet. With the advancement and diversity of the mobile landscape, there has been a growing trend in consumer attitude where a single user owns multiple mobile devices. This paradigm of supporting a single user or consumer to access multiple services from n-devices is referred to as the Ubiquitous Cloud Computing (UCC) or the Personal Cloud Computing. In the UCC era, consumers expect to have application and data consistency across their multiple devices and in real time. However, this expectation can be hindered by the intermittent loss of connectivity in wireless networks, user mobility, and peak load demands. Hence, this dissertation presents an architectural framework called, Cloud Services Brokerage for Mobile Ubiquitous Cloud Computing (CSB-UCC), which ensures soft real-time and reliable services consumption on multiple devices of users. The CSB-UCC acts as an application middleware broker that connects the n-devices of users to the multi-cloud services. The designed system determines the multi-cloud services based on the user's subscriptions and the n-devices are determined through device registration on the broker. The preliminary evaluations of the designed system shows that the following are achieved: 1) high scalability through the adoption of a distributed architecture of the brokerage service, 2) providing soft real-time application synchronization for consistent user experience through an enhanced mobile-to-cloud proximity-based access technique, 3) reliable error recovery from system failure through transactional services re-assignment to active nodes, and 4) transparent audit trail through access-level and context-centric provenance