The Microsoft Kinect for Xbox 360 (“Kinect”) provides a convenient and inexpensive depth sensor and, with the Microsoft software development kit, a skeleton tracker (Figure 2). These have great potential to be useful as virtual environment (VE) control interfaces for avatars or for viewpoint control. In order to determine its suitability for our applications, we devised and conducted tests to measure standard performance specifications for tracking systems. We evaluated the noise, accuracy, resolution, and latency of the skeleton tracking software. We also measured the range in which the person being tracked must be in order to achieve these values.

Multivariate visualization techniques have attracted great interest as the dimensionality of data sets grows. One premise of such techniques is that simultaneous visual representation of multiple variables will enable the data analyst to detect patterns amongst multiple variables. Such insights could lead to development of new techniques for rigorous (numerical) analysis of complex relationships hidden within the data. Two natural questions arise from this premise: Which multivariate visualization techniques are the most effective for high-dimensional data sets? How does the analysis task change this utility ranking? We present a user study with a new task to answer the first question. We provide some insights to the second question based on the results of our study and results available in the literature. Our task led to significant differences in error, response time, and subjective workload ratings amongst four visualization techniques. We implemented three integrated techniques (Data-driven Spots, Oriented Slivers, and Attribute Blocks), as well as a baseline case of separate grayscale images. The baseline case fared poorly on all three measures, whereas Datadriven Spots yielded the best accuracy and was among the best in response time. These results differ from comparisons of similar techniques with other tasks, and we review all the techniques, tasks, and results (from our work and previous work) to understand the reasons for this discrepancy.

In collaborative augmented reality (AR) missions, much georegistered information is collected and sent to a command and control center. This paper describes the concept and prototypical implementation of a mixed reality (MR) based system that integrates georegistered information from AR systems and other sources on a virtual globe. The application can be used for a command and control center to monitor the field operation where multiple AR users are engaging in a collaborative mission. Google Earth is used to demonstrate the system, which integrates georegistered icons, live video streams from field operators or surveillance cameras, 3D models, and satellite or aerial photos into one MR environment.

Properly perceived stereo display is often assumed to be vital in augmented reality (AR) displays used for close distances, echoing the general understanding from the perception literature. However, the accuracy of the perception of stereo in head-worn AR displays has not been studied greatly. We conducted a user study to elicit the precision of stereo perception in AR and its dependency on the size and contrast of the stimulus. We found a strong effect of contrast on the disparity users desired to make a virtual target verge at the distance of a real reference object. We also found that whether the target began behind or in front of the reference in a method of adjustments protocol made a significant difference. The mean disparity in the rendering that users preferred had a strong linear relationship with their IPD. We present our results and infer stereoacuity thresholds.

We tested users' depth perception of virtual objects in our mobile augmented reality (AR) system in both indoor and outdoor environments using a depth matching task. The indoor environment is characterized by strong linear perspective cues; we attempted to re-create these cues in the outdoor environment. In the indoor environment, we found an overall pattern of underestimation of depth that is typical for virtual environments and AR systems. However, in the outdoor environment, we found that subjects overestimated depth. In addition, our synthetic linear perspective cues met with a measure of success, leading users to reduce their estimate of the depth of distant objects. We describe the experimental procedure, analyze the data, present the results of the study, and discuss the implications for mobile, outdoor AR systems.

We conducted a user study of the effect of registration error on performance of tracking distant objects in augmented reality. Categorizing error by types that are often used as specifications, we hoped to derive some insight into the ability of users to tolerate noise, latency, and orientation error. We used measurements from actual systems to derive the parameter settings. We expected all three errors to influence userspsila ability to perform the task correctly and the precision with which they performed the task. We found that high latency had a negative impact on both performance and response time. While noise consistently interacted with the other variables, and orientation error increased user error, the differences between ldquohighrdquo and ldquolowrdquo amounts were smaller than we expected. Results of userspsila subjective rankings of these three categories of error were surprisingly mixed. Users believed noise was the most detrimental, though statistical analysis of performance refuted this belief. We interpret the results and draw insights for system design.

A virtual environment for interactive molecular dynamics simulation has been designed and implemented at the Fraunhofer Institute for Computer Graphics. Different kinds of virtual reality devices are used in the environment for immersive display and interaction with the molecular system. A parallel computer is used to simulate the physical and chemical properties of the molecular system dynamically. A high‐speed network exchanges data between the simulation program and the modeling program. Molecular dynamics simulation virtual environment provides scientists with a powerful tool to study immersively the world of molecules. The dynamic interaction between an AIDS antiviral drug and reverse transcriptase enzyme is illustrated in the paper.