Software distribution and installation is a logistical issue for large enterprises. Web applications are often a good solution because users can instantly receive application updates on any device without needing special permissions to install them on their hardware. Until recently, it was not possible to create 3D multiuser virtual environment-based web applications that didn't require installing a browser plugin. However, recent web standards have made it possible. We present the Virtual World Framework (VWF), a software framework for creating 3D multiuser web applications. We are using VWF to create applications for team training and collaboration. VWF can be downloaded at http://virtual.wf.

When a virtual environment system prevents a user's avatar hand from penetrating virtual objects, the seen and felt positions of the hand separate. We propose a new method for reducing this position discrepancy as quickly as possible without introducing perceptible discrepancy between the seen and felt motion of the user's hand. We performed a user study to compare this new method to two previous methods of dealing with position discrepancy. Our method showed statistically significant improvements in user-reported naturalness and user preference and showed no loss in user performance

We investigated the ability of a user in a head-mounted display virtual environment to detect a virtual hand avatar moving at a speed different than that of the real hand. We measured discrepancy detection thresholds for each of the six cardinal directions of 3-space (left, right, up, down, toward, and away). For each of these six directions we measured two discrepancy detection thresholds: one for when the avatar hand moved more quickly than the real hand and one for when it moved more slowly. We found a trend that users are less sensitive to increases in hand avatar speed than they are to decreases. The amount the hand avatar speed can be increased without a user noticing is surprisingly large. This information is useful for techniques that require introducing hand-avatar motion discrepancy, such as a technique for recovering from the position discrepancy introduced by simulated surface constraints.

Figure 1. A participant who believes he is aiming at the virtual game board directly in front of him. Without force feedback, a head-mounted display user's avatar may penetrate virtual objects. Some virtual environment designers prevent visual interpenetration, making the assumption that prevention improves user experience. However, preventing visual avatar interpenetration causes discrepancy between visual and proprioceptive cues. We investigated users ’ detection thresholds for visual interpenetration (the depth at which they see that two objects have interpenetrated) and sensory discrepancy (the displacement at which they notice mismatched visual and proprioceptive cues). We found that users are much less sensitive to visual-proprioceptive conflict than they are to visual interpenetration. We present our plan for using this result to create a better technique for dealing with virtual object penetration.