Figure 1: VRCreatIn is a virtual reality (VR) 3D content creation solution that supports the process of 3D scene creation (a) starting from ideation and going beyond to modeling (c), lighting, and texturing (a, d).It is based on a design space focusing on in-situ interaction for unconstrained 3D mid-air and constrained 2D surface-based interaction using pen and tablet (b).

Remote tutoring has gained significant traction due to technological advances, primarily relying on video-conferencing tools. However, these tools are not specifically designed for tutoring. Positive tutoring experiences rely on interaction with and immediate feedback from the tutor. Moreover, traditional methods like writing, reading, and drawing in physical spaces enhance learning outcomes. Integrating these methods with physical materials and digital remote guidance could improve remote learning experiences. A technology that enables this integration is spatial augmented reality (SAR), which utilizes projection to integrate digital content into the physical world. This work introduces a Spatial Augmented Reality (SAR) remote tutoring tool that enables augmented annotations and projected video streams. We conducted a between-subject lab study (N=18) comparing learning experiences in remote tutoring between standard video conferencing tools and the introduced Spatial Augmented Reality (SAR) tool. Qualitative analysis revealed the Spatial Augmented Reality (SAR) system's benefits over video conferencing, specifically immediate feedback, in-situ annotations, improved interactivity, and enhanced social presence.

Object manipulation in 3D space, meaning translating, rotating, and scaling, is ubiquitous in virtual reality (VR), and several interaction techniques have been developed in the past to optimize the task performance and usability. However, preliminary research indicates that individual spatial abilities also have an impact. Yet, it was never investigated if users’ spatial abilities influence VR object manipulation. We assessed this in a user study (N=66) using 21 manipulation tasks defined in a Fitts’ law-related approach. As interaction techniques, we chose gizmos for simultaneously manipulating 1 and 3 degrees of freedom (DOF) and a handle bar metaphor for 7 DOF. Higher spatial abilities resulted in significantly shorter task completion time and more targeted manipulations, while task accuracy was unaffected. However, an optimized interaction technique could compensate individual disadvantages. We propose seven guidelines on spatial abilities in interaction technique design and research to personalize and improve VR applications.

Pair-learning is beneficial for learning outcome, motivation, and social presence, and so is virtual reality (VR) by increasing immersion, engagement, motivation, and interest of students. Nevertheless, there is a research gap if the benefits of pair-learning and VR can be combined. Furthermore, it is not clear which influence it has if only one or both peers use VR. To investigate these aspects, we implemented two types of VR pair-learning systems, a symmetric system with both peers using VR and an asymmetric system with one using a tablet. In a user study (N=46), the symmetric system statistically significantly provided higher presence, immersion, player experience, and lower intrinsic cognitive load, which are all important for learning. Symmetric and asymmetric systems performed equally well regarding learning outcome, highlighting that both are valuable learning systems. We used these findings to define guidelines on how to design co-located VR pair-learning applications, including characteristics for symmetric and asymmetric systems.

Players can get stuck in video games, which impedes their process to their goal and results in unfavorable outcomes like negative emotions, impediments of flow, and obstacles for learning. Currently, it is not easily possible to assess if a player is stuck, as no widely accepted definition of "being stuck" in games exists. We conducted 13 expert interviews and a systematic literature review with 104 relevant papers selected from 4022 candidates. We present a definition of "being stuck" that conceptualizes the state as a continuum and contextualize it within related concepts. Our stuck continuum can be applied to regulate the player's stuck level. We propose a taxonomy of measures that are useful for the detection of the level of stuckness and discuss the effectiveness of countermeasures. Our stuck concept is crucial for game developers creating an optimal player experience in games.

Sketching in virtual reality (VR) enhances perception and understanding of 3D volumes, but is currently a challenging task, as spatial input devices (e.g., tracked controllers) do not provide any scaffolding or constraints for mid-air interaction. We present VRSketchIn, a VR sketching application using a 6DoF-tracked pen and a 6DoF-tracked tablet as input devices, combining unconstrained 3D mid-air with constrained 2D surface-based sketching. To explore what possibilities arise from this combination of 2D (pen on tablet) and 3D input (6DoF pen), we present a set of design dimensions and define the design space for 2D and 3D sketching interaction metaphors in VR. We categorize prior art inside our design space and implemented a subset of metaphors for pen and tablet sketching in our prototype. To gain a deeper understanding which specific sketching operations users perform with 2D and which with 3D metaphors, we present findings of usability walkthroughs with six participants.