Social uses of virtual reality, such as collaborative virtual environments (CVEs), are showing significant increases in general adoption. In these CVEs, it is desirable for users to feel a high level of presence, which can increase collaboration effectiveness. This study investigated the effect of facial realism on presence in CVEs. Facial realism was implemented through including eye- and mouth-tracked facial expressions in an avatar representation. A controlled within-dyad experiment was performed, consisting of a dyadic interaction between participants in a CVE. We found no significant difference between a Static Face condition and either Eye Tracked or Full Tracked (eye- and mouth) facial expression conditions. Some individual items on the questionnaire were significant or marginally significant, suggesting some positive impact on the assessment of partner reactions in the Full Tracked condition, compared to Static Face. Participants also reported a lower feeling of correspondence between virtual experiences and their physical body in the Full Tracked and Eye Tracked conditions. Some evidence has been found that this experiment warrants repetition with changes discussed in this paper, which may yield significant differences with a higher sample size.

Lag in Virtual Reality can be devastating to the enjoyment of participants. This paper reduces the lag in a physics system by implementing a subset of the architecture proposed by Loren Peitso and Don Brutzman. This subset contains an event based physics system together with a networking system. The collision system of the physics system has been heavily reduced in size, as to speedup development of the architecture.

This architecture seems promising and handles predictable cases with almost no noticeable lag. This architecture does not handle external events well, as the lag is noticeable. The `healing' process for unexpected external events should be researched further to make this architecture viable.

Effective text input in VR is an ongoing problem with no best-agreed-upon solution. One effective solution for this is a word-gesture keyboard implemented in VR. These keyboards work by matching the user-drawn gestures to predefined gestures of all words that connect consecutive letters of the word with straight lines. We investigate matching the user input with gestures comprising of Bézier curves. We found a small improvement in writing speed and a reduction in errors while writing. The method of using complex curves for matching gestures seems promising with many possible ways for further extension.

Virtual Reality's uniquely immersive nature can facilitate skill transfer between an instructor and a student. Through the use of statically transparent ghost instructors that are superimposed on the student avatar, the student can learn skills by observing the ghost instructor's movements from a first-person perspective.

This paper aims to investigate the effect that changing the transparency values of the ghost avatar based on student performance has on learning and retaining skills. A small-scale user study has been conducted to contrast these dynamically and statically transparent ghost instructors. While the group taught by statically transparent ghost instructors displayed better performance improvement between training trials, the performance drop between the training and test trials was much smaller for the group taught by dynamically transparent ghost instructors.