This study explores a streamlined facial data collection method for conversational contexts, addressing the limitations of existing approaches that often require extensive datasets and prioritize technical metrics over user perception and experience. We systematically investigate which facial expression data are essential for reconstructing photorealistic avatars and how they can be captured efficiently. Our research employs a two-phase methodology to identify efficient facial data collection strategies and evaluate their effectiveness. In the first phase, we conduct facial data acquisition and evaluate reconstruction performance using utterance data and emotional data. In the second phase, we carry out a comprehensive user evaluation comparing three progressive conditions: utterance only, utterance and emotional data, and a control condition involving extensive data. Findings from 24 participants engaged in simulated face-to-face conversations reveal that targeted utterance and emotional data achieve comparable levels of perceived realism, naturalness, and telepresence, while reducing training time and data usage when compared to the extensive data collection approach. These results demonstrate that targeted data inputs can enable efficient avatar face reconstruction, offering practical guidelines for real-time applications such as AR/VR telepresence and highlighting the trade-off between data quantity and perceived quality.

We present ForceCtrl, a novel 3D hand raycasting technique that enhances pointing precision based on control-display (CD) gain controlled with user-defined pinch force. We introduce a target-agnostic approach for refining raycasting precision, overcoming limitations in human motor accuracy. User-defined pinch force, detected with surface electromyography (sEMG), enables users to easily activate or deactivate CD gain during interaction. We propose three CD gain strategies and compare them through target selection and placement tasks. Our system reduces selection errors, placement jitters, and user workload, especially for distant targets in high-difficulty tasks. These results highlight the effectiveness of applying CD gain to hand raycasting and demonstrate the potential of user-defined pinch force as a robust input modality for precise hand interaction in AR/VR.

We present VRGaussianAvatar, an integrated system that enables real-time full-body 3D Gaussian Splatting (3DGS) avatars in virtual reality using only head-mounted display (HMD) tracking signals. The system adopts a parallel pipeline with a VR Frontend and a GA Backend. The VR Frontend uses inverse kinematics to estimate full-body pose and streams the resulting pose along with stereo camera parameters to the backend. The GA Backend stereoscopically renders a 3DGS avatar reconstructed from a single image. To improve stereo rendering efficiency, we introduce Binocular Batching, which jointly processes left and right eye views in a single batched pass to reduce redundant computation and support high-resolution VR displays. We evaluate VRGaussianAvatar with quantitative performance tests and a within-subject user study against image- and video-based mesh avatar baselines. Results show that VRGaussianAvatar sustains interactive VR performance and yields higher perceived appearance similarity, embodiment, and plausibility. Project page and source code are available at https://vrgaussianavatar.github.io.

We propose OFERA, a novel framework for real-time expression control of photorealistic Gaussian head avatars for VR headset users. Existing approaches attempt to recover occluded facial expressions using additional sensors or internal cameras, but sensor-based methods increase device weight and discomfort, while camera-based methods raise privacy concerns and suffer from limited access to raw data. To overcome these limitations, we leverage the blendshape signals provided by commercial VR headsets as expression inputs. Our framework consists of three key components: (1) Blendshape Distribution Alignment (BDA), which applies linear regression to align the headset-provided blendshape distribution to a canonical input space; (2) an Expression Parameter Mapper (EPM) that maps the aligned blendshape signals into an expression parameter space for controlling Gaussian head avatars; and (3) a Mapper-integrated Avatar (MiA) that incorporates EPM into the avatar learning process to ensure distributional consistency. Furthermore, OFERA establishes an end-to-end pipeline that senses and maps expressions, updates Gaussian avatars, and renders them in real-time within VR environments. We show that EPM outperforms existing mapping methods on quantitative metrics, and we demonstrate through a user study that the full OFERA framework enhances expression fidelity while preserving avatar realism. By enabling real-time and photorealistic avatar expression control, OFERA significantly improves telepresence in VR communication. A project page is available at https://ysshwan147.github.io/projects/ofera/.

As avatars have evolved from simple digital representations into extensions of our identities, they offer unprecedented opportunities for self-expression and customization beyond the physical world limitations. While virtual platforms foster new forms of identity exploration, social norms still play a crucial role in defining what is considered appropriate in these environments. In this study, we surveyed 150 participants to investigate social norms surrounding avatar modifications, examining how perspectives, contexts, and personality traits influence attitudes toward appropriateness. Our findings reveal that avatar modifications are generally viewed as more appropriate when considered from a partner's perspective, especially for changeable attributes. However, these modifications are perceived as less acceptable in professional settings such as workplaces. Additionally, individuals with high self-monitoring tendencies tend to be more resistant to changes, while those scoring higher on Machiavellianism are more accepting of changes, particularly regarding unchangeable attributes and emotional expressions. These findings provide valuable insights for platform developers and designers, highlighting the importance of implementing context-aware customization options that balance core identity elements with personality-driven preferences, thereby enhancing user experiences while respecting social norms.

Understanding gender differences in facial and spatial recognition is crucial for enhancing avatar-mediated communication. However, there remains a gap in understanding how participant gender influences perceptions of avatar facial expressions and spatial dynamics in Mixed Reality communication. Therefore, our study investigates how avatar non-verbal cues interact with gender differences to affect user experience and understanding in MR environments. To examine these complex relationships, we conducted a user study comparing the effects of various avatar facial expressions (Full, Mouth-Only, and Emotion-based) and interpersonal distances (Closer vs. Farther) on facial animation realism and social presence, with a focus on gender-balanced participant groups. Our findings revealed that female participants were particularly sensitive to the avatar’s proximity and facial expressions, reporting significantly higher perceptions of facial animation realism, copresence, message understanding, and affective understanding at farther distances compared to male participants. They also perceived higher copresence and message understanding when exposed to emotion-based facial expressions, as opposed to a mouth-only condition-a distinction not observed among male participants. Based on our findings, we advocate for avatar design strategies that accommodate gender differences in perception and preference, potentially through customizable levels of expressiveness to cater to diverse user needs and contexts.

In avatar-mediated remote communication, avatars’ facial expressions can be dynamically adjusted according to each user’s computational and device constraints, highlighting the importance of varied expressions and their impact on user perception. However, there is a lack of research on how variations in avatar facial expressions, especially when simplified, influence user perception, particularly in terms of social presence. To address this, we examine the impact of various facial expression combinations on social presence in avatar-mediated communication scenarios, ranging from informative speeches to emotional conversations. Our approach involves prioritizing avatar facial blendshape combinations using two main approaches: (1) commonly activated expressions that reflect the active facial movements observed during casual conversations, and (2) emotion-based expressions derived from Facial Action Coding System (FACS). These combinations were compared against minimal baseline and full blendshape conditions through a comprehensive study involving 32 participants. Our findings reveal that emotion-based condition achieves comparable levels of social presence and communication quality to the full condition, in both informative speeches and emotional conversations. This highlights the effectiveness of prioritizing emotion-based expressions and adopting a streamlined approach to avatar facial control. By focusing on emotional expressions while optimizing resources, this approach shows potential for enhancing the avatar-mediated communication experience, accommodating the diverse users’ contexts.

We present a novel method for avatar body generation that cumulatively updates the texture and normal map in real-time. Multiple images or videos have been broadly adopted to create detailed 3D human models that capture more realistic user identities in both Augmented Reality (AR) and Virtual Reality (VR) environments. However, this approach has a higher spatiotemporal cost because it requires a complex camera setup and extensive computational resources. For lightweight reconstruction of personalized avatar bodies, we design a system that progressively captures the texture and normal values using a single RGBD camera to generate the widely-accepted 3D parametric body model, SMPL-X. Quantitatively, our system maintains real-time performance while delivering reconstruction quality comparable to the state-of-the-art method. Moreover, user studies reveal the benefits of real-time avatar creation and its applicability in various collaborative scenarios. By enabling the production of high-fidelity avatars at a lower cost, our method provides more general way to create personalized avatar in AR/VR applications, thereby fostering more expressive self-representation in the metaverse.

In this paper, we present a prototype system for sharing a user's hand force in mixed reality (MR) remote collaboration on physical tasks, where hand force is estimated using wearable surface electromyography (sEMG) sensor. In a remote collaboration between a worker and an expert, hand activity plays a crucial role. However, the force exerted by the worker's hand has not been extensively investigated. Our sEMG-based system reliably captures the worker's hand force during physical tasks and conveys this information to the expert through hand force visualization, overlaid on the worker's view or on the worker's avatar. A user study was conducted to evaluate the impact of visualizing a worker's hand force on collaboration, employing three distinct visualization methods across two view modes. Our findings demonstrate that sensing and sharing hand force in MR remote collaboration improves the expert's awareness of the worker's task, significantly enhances the expert's perception of the collaborator's hand force and the weight of the interacting object, and promotes a heightened sense of social presence for the expert. Based on the findings, we provide design implications for future mixed reality remote collaboration systems that incorporate hand force sensing and visualization.

A critical yet unresolved challenge in designing space-adaptive narratives for Augmented Reality (AR) is to provide consistently immersive user experiences anywhere, regardless of physical features specific to a space. For this, we present a comprehensive analysis on a series of user studies investigating how the size, density, and layout of real indoor spaces affect users playing Fragments, a space-adaptive AR detective game. Based on the studies, we assert that moderate levels of traversability and visual complexity afforded in counteracting combinations of size and complexity are beneficial for narrative experience. To confirm our argument, we combined the experimental data of the studies (n=112) to compare how five different spatial complexity conditions impact narrative experience when applied to contrasting room sizes. Results show that whereas factors of narrative experience are rated significantly higher in relatively simple settings for a small space, they are less affected by complexity in a large space. Ultimately, we establish guidelines on the design and placement of space-adaptive augmentations in location-independent AR narratives to compensate for the lack or excess of affordances in various real spaces and enhance user experiences therein.

Despite the importance of avatar representation on user experience for Mixed Reality (MR) remote collaboration involving various device environments and large amounts of task-related information, studies on how controlling visual parameters for avatars can benefit users in such situations have been scarce. Thus, we conducted a user study comparing the effects of three avatars with different transparency levels (Nontransparent, Semi-transparent, and Near-transparent) on social presence for users in Augmented Reality (AR) and Virtual Reality (VR) during task-centric MR remote collaboration. Results show that avatars with a strong visual presence are not required in situations where accomplishing the collaborative task is prioritized over social interaction. However, AR users preferred more vivid avatars than VR users. Based on our findings, we suggest guidelines on how different levels of avatar transparency should be applied based on the context of the task and device type for MR remote collaboration.

This paper evaluates factors of social presence during a dynamic remote collaboration task in a technologically asymmetric Mixed Reality (MR) setting for two spatial layouts. While active movement during MR remote collaboration is afforded by how the shared 3D space is mediated and configured, studies investigating the impact of these conditions on user experience have been scarce. In a between-group study $(\mathrm{n}=48)$, a host user in Augmented Reality (AR) and a remote user in Virtual Reality (VR), both wearing Head Mounted Displays (HMDs), simultaneously moved around the shared space to find and assemble parts of a Mars exploration rover together, one group in a Peripheral layout and the other in a Scattered layout with disparate levels of spatial affordance. Results show that while VR facilitates higher co-presence and spatial presence than AR through HMDs, the Peripheral layout enables users to pay more attention to one another than the Scattered. We analyze the results and derive implications aimed at bridging the AR-VR gap in social presence for dynamic MR remote collaboration through the adaptive placement of virtual content in shared spaces.

This paper investigates how the size of virtual space and objects within it affect the threshold range of relative translation gains, a Redirected Walking (RDW) technique that scales the user’s movement in virtual space in different ratios for the width and depth. While previous studies assert that a virtual room’s size affects relative translation gain thresholds on account of the virtual horizon’s location, additional research is needed to explore this assumption through a structured approach to visual perception in Virtual Reality (VR). We estimate the relative translation gain thresholds in six spatial conditions configured by three room sizes and the presence of virtual objects (3 × 2), which were set according to differing Angles of Declination (AoDs) between eye-gaze and the forward-gaze. Results show that both size and virtual objects significantly affect the threshold range, it being greater in the large-sized condition and furnished condition. This indicates that the effect of relative translation gains can be further increased by constructing a perceived virtual movable space that is even larger than the adjusted virtual movable space and placing objects in it. Our study can be applied to adjust virtual spaces in synchronizing heterogeneous spaces without coordinate distortion where real and virtual objects can be leveraged to create realistic mutual spaces.

As quantum computers become available to the general public, the need has arisen to train a cohort of quantum programmers, many of whom have been developing classical computer programs for most of their careers. While currently available quantum computers have less than 100 qubits, quantum computing hardware is widely expected to grow in terms of qubit count, quality, and connectivity. This review aims at explaining the principles of quantum programming, which are quite different from classical programming, with straightforward algebra that makes understanding of the underlying fascinating quantum mechanical principles optional. We give an introduction to quantum computing algorithms and their implementation on real quantum hardware. We survey 20 different quantum algorithms, attempting to describe each in a succinct and self-contained fashion. We show how these algorithms can be implemented on IBM’s quantum computer, and in each case, we discuss the results of the implementation with respect to differences between the simulator and the actual hardware runs. This article introduces computer scientists, physicists, and engineers to quantum algorithms and provides a blueprint for their implementations.

Space-adaptive algorithms aim to effectively align the virtual with the real to provide immersive user experiences for Augmented Reality(AR) content across various physical spaces. While such measures are reliant on real spatial features, efforts to understand those features from the user’s perspective and reflect them in designing adaptive augmented spaces have been lacking. For this, we compared factors of narrative experience in six spatial conditions during the gameplay of Fragments, a space-adaptive AR detective game. Configured by size and furniture layout, each condition afforded disparate degrees of traversability and visibility. Results show that whereas centered furniture clusters are suitable for higher presence in sufficiently large rooms, the same layout leads to lower narrative engagement. Based on our findings, we suggest guidelines that can enhance the effects of space adaptivity by considering how users perceive and navigate augmented space generated from different physical environments.

This study investigates the effects of a virtual hand representation on the user experience including social presence during hand-based 3D remote collaboration. Although a remote hand appearance is a critical parts of a hand-based telepresence, it has been rarely studied in comparison to studies on the self-embodiment of virtual hands in a 3D environment. Thus, we conducted a user study comparing the three virtual hands models (Skeleton, Low Polygon and Realistic) while performing a remote collaborative task based on the American Sign Language (ASL) using both Augmented Reality (AR) and Virtual Reality (VR) environments. We found that the realistic type was perceived as the most sense of being together, human-like, and trustable representation. The low polygon model could also convey a clear sign and moderate level of social presence. Although the system was configured asymmetrically in AR and VR, little difference in perception was found except for the participant's mental load and message understanding. We then discuss the results and suggest design implications for future hand-based 3D telepresence systems.

This paper investigates the effect of avatar appearance on Social Presence and users' perception in an Augmented Reality (AR) telep-resence system. Despite the development of various commercial 3D telepresence systems, there has been little evaluation and discussions about the appearance of the collaborator's avatars. We conducted two user studies comparing the effect of avatar appearances with three levels of body part visibility (head & hands, upper body, and whole body) and two different character styles (realistic and cartoon-like) on Social Presence while performing two different remote collaboration tasks. We found that a realistic whole body avatar was perceived as being the best for remote collaboration, but an upper body or cartoon style could be considered as a substitute depending on the collaboration context. We discuss these results and suggest guidelines for designing future avatar-mediated AR remote collaboration systems.