masterarbeit.pdf

Abstract

The fields of Augmented and Virtual Reality have seen a flurry of development in recent years, both in entertainment and more serious areas of research such as medical, educational or commercial applications. The technology has matured to a point where even many end-users own a Head-Mounted Device and frequently use it for both AR and VR software, while web cams make AR applications available to anyone with access to a desktop computer. While hardware and software seem to have entered a stable phase of only incremental improvements, the new, three-dimensional user interfaces needed to interact with fully three-dimensional applications are still immature compared to the decades of research and development that have lead to modern two-dimensional user interfaces.

Tasks such as navigating a three-dimensional space, working with a three-dimensional model or even just interacting with a list of data points are often hampered by a rudimentary, unergonomic 3D interface or a two-dimensional interface projected into three dimensions. While many attempts have been made to create new and better interfaces, these are mostly independent efforts with little connection to each other and often not documented publicly if at all. This thesis aims to begin to rectify this situation by documenting the current state of the art in visible 3D User Interfaces. The documentation will consist of a collection and classification of existing interface solutions and the tasks they were created to achieve, and an evaluation of how well-suited they are to achieving their specific task.

Results

Due to the classification schemes which are commonly used in current literature failing to capture the entirety of the possible 3D user interfaces, there is a necessity to either develop a new scheme or expand one of the current schemes using knowledge gained from other works and our own results. As the work in 3D User Interfaces: Theory and Practice is still considered the standard work on the subject, their overall classification scheme serves as the base for the expanded scheme. Thus, the overall classification of user interfaces in this work is by basic interface tasks. LaViola et al. identify three sets of basic tasks, Selection and Manipulation, Travel and Wayfinding and System Control. However, these tasks fail to capture all possible tasks documented in prior literature. To accommodate the additional tasks found by Sherman et al. in Understanding Virtual Reality, this work adds the tasks Communication, and Collaboration and, as they are related very closely, group them into a single class. The following paragraphs will give an overview of how the classifications discussed in this work are applied to the overall tasks defined.

Selection And Manipulation

Selection and manipulation techniques are grouped in their chapter according to the task metaphors found by LaViola et al.. However, as there are many graphical aids in the selection and manipulation process which are not specific to a certain metaphor, they are discussed separately from the techniques in their own section.

Travel And Wayfinding

Travel metaphors are grouped into their respective metaphors, however only brief discussion will be given to metaphors such as walking which contain little to no visual elements. Wayfinding aids are grouped into the categories defined for them by Sherman et al., though categories which did not appear in their work but were defined by LaViola et al. will also be discussed. While it would be possible to divide these categories into user-centric and environment-centric aids, this distinction was not made by Sherman et al. and for the sake of congruency will not be made in this work either.

System Control And Menus

As this work is focused on the visible aspects of user interaction, voice and gesturecommands are discussed only if they are used in conjunction with a notable visual component, such as a menu, thus reducing system control to the two classes of menus and tools. As symbolic input which is not inputted using a keyboard is inputted using  graphical menus, surveying and classifying graphical menus according to the taxonomy developed by Dachselt et al. covers both possible symbolic input methods and menus.

Communication And Collaboration

Communication methods are split based on synchronicity and then classified into the categories developed by Sherman et al. while the visual aspects of shared environments are classified based on the type of shared environment they are used in.

The actual survey of interface elements, classified according to this classification system and grouped into even more detailed sub-classes, can be found in the PDF of the full thesis. linked on this page.

Conclusion

Virtual and Augmented Reality will become an even larger part of industrial, medical, educational, and consumer entertainment applications. As their importance grows, so does the importance of 3D Human-computer-Interaction (HCI) research, as the quality and efficiency of user interfaces are almost entirely responsible for the quality of the user experience and efficiency of the usage of an application. While games and entertainment are predicted by many to be the "killer app" which will lead to widespread adoption of 3D user interfaces~\parencite{LaViola:2263157} and a surge in the development of new techniques and technologies, efficiency is perhaps the most important property of 3D user interfaces for industrial or medical purposes. This makes it likely that the development of applications for these fields may lead to new discoveries regarding the design of 3D user interfaces for efficiency.

This thesis aimed to explore the current state-of-the-art, survey and evaluate past and present developments and classify them. To this end evaluation methods and criteria were discussed and an informal evaluation method was decided on, which consisted of comparing each technique discussed to those trying to fulfill the same task and discussing their advantages and disadvantages, giving special attention to the evaluation criteria found in research on user interface evaluation. Using classification methods and taxonomies developed in several related surveys, a new classification system was created by merging several task-based and metaphor-based classification systems. This new classification system was used as a basic hierarchy of interaction tasks and possible solutions which was then expanded with examples, discussions and evaluations of these solutions.

While we believe our survey and discussion to be as comprehensive as the scope of this thesis allowed, each implementation of a solution may contain details or small changes unique to its specific application and each task and class of solutions discussed warrants further exploration, especially in light of ongoing development. Additionally, we believe the classification system presented in this work to be suitable as a base for a catalog or database of possible UI solutions, which could then serve as a base for further research such as comparative qualitative analysis of the efficiency of different solutions.

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