Traditional target-selection-based teleportation depends on the intersection of a (curved) ray with the scene's geometry, which limits navigation to points on the ground, restricting users' navigational freedom. While previous techniques exist that permit mid-air target selection, they are not optimal for transitioning between air and ground navigation, leading to inaccurate or lengthy interaction sequences. In this paper, we introduce SATOR, a new 3D teleportation technique designed to enable efficient and accurate navigation to both ground and mid-air targets by combining and enhancing previous approaches. Informed by the literature, we implemented four different parametrizations of our technique and compared them to a previously published technique that also enables both ground and mid-air target selection. Our user study with 30 participants indicates that SATOR is more efficient, accurate, and easier to use than the baseline. As a result, SATOR effectively helps users get an overview of the environment, observe features at different heights, or maneuver quickly around larger obstacles.

Target-selection-based teleportation is one of the most widely used and researched travel techniques in immersive virtual environments, requiring the user to specify a target location with a selection ray before being transported there. This work explores the influence of the maximum reach of the parabolic selection ray, modeled by different emission velocities of the projectile motion equation, and compares the resulting teleportation performance to a straight ray as the baseline. In a user study with 60 participants, we asked participants to teleport as far as possible while still remaining within accuracy constraints to understand how the theoretical implications of the projectile motion equation apply to a realistic VR use case. We found that a projectile emission velocity of $14 \frac{m}{s}$14ms (resulting in a maximal reach of $\text{21.52 m}$21.52m) offered the best trade-off between selection distance and accuracy, with an inferior performance of the straight ray. Our results demonstrate the necessity to carefully set and report the projectile emission velocity in future work, as it was shown to directly influence user-selected distance, selection errors, and controller height during selection.

The iterative design process of virtual environments commonly generates a history of revisions that each represent the state of the scene at a different point in time. Browsing through these discrete time points by common temporal navigation interfaces like time sliders, however, can be inaccurate and lead to an uncomfortably high number of visual changes in a short time. In this paper, we therefore present a novel technique called TENETvr (Temporal Exploration and Navigation in virtual Environments via Teleportation) that allows for efficient teleportation-based travel to time points in which a particular object of interest changed. Unlike previous systems, we suggest that changes affecting other objects in the same time span should also be mediated before the teleport to improve predictability. We therefore propose visualizations for nine different types of additions, property changes, and deletions. In a formal user study with 20 participants, we confirmed that this addition leads to significantly more efficient change detection, lower task loads, and higher usability ratings, therefore reducing temporal disorientation.