Figure 1: Original illustration visualizing the process of this research: Each puzzle piece represents an integral part of the board game creation process, and the aim of this work is to discover the way the pieces connect with each other.

Physics-based hand interaction in VR has been extensively explored, but almost none of the solutions are usable. The only exception is CLAP, a custom soft body simulation offering realistic and smooth hand interaction in VR. Even CLAP, however, imposes constraints on virtual hand and object behavior. We introduce HPTK+, a software solution that utilizes the physics engine NVIDIA PhysX. Benefiting from the engine’s maturity and integration with game engines, we aim to enable more general and free-hand interactions in virtual environments. We conducted a user study with 27 participants comparing the interactions supported by both libraries. Results indicate an overall preference for CLAP, but no significant differences in other measures or performance, except variance. These findings provide insights into the libraries’ suitability for specific tasks. Additionally, we highlight HPTK+’s exclusive support for diverse interactions, positioning it as an ideal candidate for further research in physics-based VR interactions.

Continuous artificial locomotion in VR typically involves users selecting their direction using controller input, with the forward direction determined by the Head, Hands, or less commonly, the Hip. The effects of these different sources on user experience are under-explored, and Feet have not been used as a direction source. To address these gaps, we compared these direction sources, including a novel Feet-based technique. A user study with 22 participants assessed these methods in terms of performance, preference, motion sickness, and sense of presence. Our findings indicate high levels of presence and minimal motion sickness across all methods. Performance differences were noted in one task, where the Head outperformed the Hand. The Hand method was the least preferred, feeling less natural and realistic. The Feet method was found to be more natural than the Head and more realistic than the Hip. This study enhances understanding of direction sources in VR locomotion and introduces Feet-based direction as a viable alternative.

Virtual grasping is one of the most common and important interactions performed in a Virtual Environment (VE). Even though there has been substantial research using hand tracking methods exploring different ways of visualizing grasping, there are only a few studies that focus on handheld controllers. This gap in research is particularly crucial, since controllers remain the most used input modality in commercial Virtual Reality (VR). Extending existing research, we designed an experiment comparing three different grasping visualizations when users are interacting with virtual objects in immersive VR using controllers. We examine the following visualizations: the Auto-Pose (AP), where the hand is automatically adjusted to the object upon grasping; the Simple-Pose (SP), where the hand closes fully when selecting the object; and the Disappearing-Hand (DH), where the hand becomes invisible after selecting an object, and turns visible again after positioning it on the target. We recruited 38 participants in order to measure if and how their performance, sense of embodiment, and preference are affected. Our results show that while in terms of performance there is almost no significant difference in any of the visualizations, the perceived sense of embodiment is stronger with the AP, and is generally preferred by the users. Thus, this study incentivizes the inclusion of similar visualizations in relevant future research and VR experiences.