Abstract of: Locomotion in immersive virtual environments

Abstract:

Changing the viewpoint is one of the basic interaction tasks in virtual environments (VEs). In traditional desktop setups the viewpoint is moved gradually by mouse, keyboard or joystick input. Using the same technique in immersive setups, where nearly the complete field of view is stimulated by the VE, is likely to cause motion sickness on users because of a conflict between their visual and vestibular senses. Ideally the user would physically walk around in the VE but this is limited to the tracking space of the setup. So in this paper I survey virtual locomotion techniques for immersive VEs proposed in the literature. Since there is a large variety of immersive VE setups I narrow the scope down to locomotion techniques for setups using only an Head Mounted Display and motion controllers since these have recently become broadly available consumer hardware. To compare the different techniques, I classify the locomotion techniques into a taxonomy and point out quality criteria. In the end I conclude with a recommendation of locomotion techniques for exemplary applications.

Punctuation Game

We live in the era of Big Data with storage and transmission capacity measured not just in terabytes but in petabytes (where peta- denotes a quadrillion or a thousand trillion). Data collection is constant and even insidious with every click and every “like” stored somewhere for something. This book reminds us that data is anything but “raw”; that we shouldn’t think of data as a natural resource but as a cultural one, which needs to be generated, protected, and interpreted. The book’s essays describe eight episodes in the history of data from the predigital to the digital. Together they address such issues as the ways that different kinds of data and different domains of inquiry are mutually defining how data are variously “cooked” in the processes of their collection and use *and conflicts over what can or can’t be “reduced” to data. Contributors discuss the intellectual history of data as a concept, describe early financial modeling and some unusual sources for astronomical data, discover the prehistory of the database in newspaper clippings and index cards, and consider contemporary “dataveillance” of our online habits as well as the complexity of scientific data curation.

* I have no idea where the following part of the sentence belongs to.


During succession, ecosystem development occurs, but in the long term absence of catastrophic disturbance a decline phase eventually follows. We studied six long term chronosequences in Australia, Sweden, Alaska, Hawaii, and New Zealand. For each, the decline phase was associated with a reduction in tree basal area and an increase in the substrate nitrogen to phosphorus ratio; indicating increasing phosphorus limitation over time. These changes were often associated with reductions in litter decomposition rates (phosphorus release from litter and biomass) and activity of decomposer microbes. Our findings suggest that the maximal biomass phase reached during succession cannot be maintained in the long term absence of major disturbance and that similar patterns of decline occur in forested ecosystems spanning the tropical temperate and boreal zones.


Facebook’s Graph API is an API for accessing objects and connections in Facebook’s social graph. To give some idea of the enormity of the social graph underlying Facebook, it was recently announced that Facebook has 901 million users  and the social graph consists of many types beyond just users. Until recently, the Graph API provided data to applications in only a JSON format. In 2011 an effort was undertaken to provide the same data in a semantically enriched RDF format containing Linked Data URIs. This was achieved by implementing a flexible and robust translation of the JSON output to a Turtle output. This paper describes the associated design decisions, the resulting Linked Data for objects in the social graph, and known issues.

Homework – Research, References, and Citation

Here I will present my top 5 references for my research topic “Locomotion in immersive virtual environments”. Note that this is only a small selection of the interesting titles (about 50) I found until now. Additionally, I have not read all of them in depth yet, so their value for my project is not perfectly clear.

Side note:
The terms “locomotion”-, “travel”- and “motion”- techniques may be used synonymously. They are generic terms for an interaction technique used in a virtual environment to change the viewpoint of the user (in a natural way).

[1]     Bowman, D. a., Koller, D., and Hodges, L. F. Travel in immersive virtual environments: an evaluation of viewpoint motion control techniques. In IEEE 1997 Annual International Symposium on Virtual Reality, 45–52. DOI=10.1109/VRAIS.1997.583043.

This article provides a taxonomy of motion techniques and compares some selected ones. Thus it may give valuable guidelines on how to generally compare motion techniques.

[2]     Harm, D. L. 2002. Motion sickness neurophysiology, physiological correlates, and treatment. In Handbook of virtual environments. Design, implementation, and applications, K. M. Stanney, Ed. Human factors and ergonomics. Lawrence Erlbaum Associates, Mahwah, NJ, 637–661.

The handbook for virtual environments gives in depth information on designing virtual environments. This particular chapter covers the causes of motion sickness and possible treatments. These information may help to understand how to avoid motion sickness when moving in an immersive virtual environment.

[3]     Laura Lynn Arns. 2002. A new taxonomy for locomotion in virtual environments.

This Phd. Thesis may not be the best quality resource (grey literature) but it seems to provide in depth information on the design as well as a taxonomy of locomotion techniques. References in this thesis might also lead to higher quality resources.

[4]     Riecke, B. E. 2010. Compelling Self-Motion Through Virtual Environments without Actual Self-Motion – Using Self-Motion Illusions (“ Vection ”) to Improve User Experience in VR. Virtual Reality, 149–176.

To make the user believe he is moving, while he is actually not, is one of the main challenges for locomotion in a virtual environment. This article provides an in depth discussion on how to use (visually induced) self-motion illusions, so called “vection” exactly for this purpose.

[5]     Steed, A. and Bowman, D. A. 2013. Displays and Interaction for Virtual Travel. In Human Walking in Virtual Environments, F. Steinicke, Y. Visell, J. Campos and A. Lécuyer, Eds. Springer New York, New York, NY, 147–175. DOI=10.1007/978-1-4419-8432-6_7.

The book “Human Walking in Virtual Environments” contains guidelines and approaches to enable (natural) walking in VR. I chose especially this chapter because it gives a general overview on the required hardware for input and output as well as an outline on travel techniqurs suited for immersive virtual environments. You may recognize the second author (D. A. Bowman) from the first entry of my list. He is one of the main authors in the field of human computer interaction.