REDUCING LATENCY IN A VIRTUAL REALITY-BASED TRAINING APPLICATION

Overall latency is the elapsed time from input of human motion to the immediate response of the input in the display. Apparently, latency is one of the most frequently cited shortcomings of current Virtual Reality (VR) applications. To compensate latency, previous prediction mechanisms insert a complex mathematical algorithm, which may not be appropriate for complex virtual training applications. More complex VR simulations most likely will impose greater computation burdens and resulted in the increase of latencies. In order to overcome latency problem, this research is an attempt to suggest a new prediction algorithm based on heuristic that could be used to develop a more effective and general system for virtual training applications. The heuristic-based predictor provides a platform to utilize the heuristic power of human along with the algorithmic power, geometry accuracy of motion-planning programs and biomechanical laws of human. Heuristic algorithm is an important module widely used for humanoid robots and avatars in VR systems. However, to the best of the researcher's knowledge, the heuristic approach has not been used as a single prediction algorithm for compensating latency in virtual training systems. In order to find out whether the new prediction algorithm is acceptable and possibly could reduce latency, a fast synchronization squash-game simulation was selected as a study source. This research analyzed the latencies of all subcomponents of this system and designed prediction algorithm that allows high-speed interaction. In measuring the performance on various prediction methods, this research also makes a comparison in real tasks among 1) the heuristic-based prediction, 2) the Grey system prediction and 3) the one without prediction using different sample rates. Findings indicated that heuristic-based algorithm is an accurate prediction method to compensate latency in virtual training. Apparently, heuristic-based prediction and Grey system prediction are significantly better than the one without prediction. When heuristic-based prediction and Grey system prediction were compared, heuristic-based prediction was in fact a better predictor. Overall findings indicated that heuristicbased prediction is efficient, robust and easier to implement

Measuring Digital System Latency from Sensing to Actuation at Continuous 1 Millisecond Resolution

This thesis describes a new method for measuring the end-to-end latency between sensing and actuation in a digital computing system. Compared to previous work, which generally measures the latency at 16-33 ms intervals or at discrete events separated by hundreds of ms, our new method measures the latency continuously at 1 millisecond resolution. This allows for the observation of variations in latency over sub 1 s periods, instead of relying upon averages of measurements. We have applied our method to two systems, the ?rst using a camera for sensing and an LCD monitor for actuation, and the second using an orientation sensor for sensing and a motor for actuation. Our results show two interesting ?ndings. First, a cyclical variation in latency can be seen based upon the relative rates of the sensor and actuator clocks and bu?er times; for the components we tested the variation was in the range of 15-50 Hz with a magnitude of 10-20 ms. Second, orientation sensor error can look like a variation in latency; for the sensor we tested the variation was in the range of 0.5-1.0 Hz with a magnitude of 20-100 ms. Both of these ?ndings have implications for robotics and virtual reality systems. In particular, it is possible that the variation in apparent latency caused by orientation sensor error may have some relation to \u27simulator sickness\u27

From presence to consciousness through virtual reality

Immersive virtual environments can break the deep, everyday connection between where our senses tell us we are and where we are actually located and whom we are with. The concept of 'presence' refers to the phenomenon of behaving and feeling as if we are in the virtual world created by computer displays. In this article, we argue that presence is worthy of study by neuroscientists, and that it might aid the study of perception and consciousness

A Dose of Reality: Overcoming Usability Challenges in VR Head-Mounted Displays

We identify usability challenges facing consumers adopting Virtual Reality (VR) head-mounted displays (HMDs) in a survey of 108 VR HMD users. Users reported significant issues in interacting with, and being aware of their real-world context when using a HMD. Building upon existing work on blending real and virtual environments, we performed three design studies to address these usability concerns. In a typing study, we show that augmenting VR with a view of reality significantly corrected the performance impairment of typing in VR. We then investigated how much reality should be incorporated and when, so as to preserve users’ sense of presence in VR. For interaction with objects and peripherals, we found that selectively presenting reality as users engaged with it was optimal in terms of performance and users’ sense of presence. Finally, we investigated how this selective, engagement-dependent approach could be applied in social environments, to support the user’s awareness of the proximity and presence of others

Evaluation of optimisation techniques for multiscopic rendering

A thesis submitted to the University of Bedfordshire in fulfilment of the requirements for the degree of Master of Science by ResearchThis project evaluates different performance optimisation techniques applied to stereoscopic and multiscopic rendering for interactive applications. The artefact features a robust plug-in package for the Unity game engine. The thesis provides background information for the performance optimisations, outlines all the findings, evaluates the optimisations and provides suggestions for future work. Scrum development methodology is used to develop the artefact and quantitative research methodology is used to evaluate the findings by measuring performance. This project concludes that the use of each performance optimisation has specific use case scenarios in which performance benefits. Foveated rendering provides greatest performance increase for both stereoscopic and multiscopic rendering but is also more computationally intensive as it requires an eye tracking solution. Dynamic resolution is very beneficial when overall frame rate smoothness is needed and frame drops are present. Depth optimisation is beneficial for vast open environments but can lead to decreased performance if used inappropriately