In our daily lives, we are exposed to various stressors, which, even in mild forms, can lead to serious health issues when prolonged. Dance Movement Therapy (DMT) uses bodily movement as psychotherapy to improve health and well-being; however, traditional DMT requires therapists, specific setups, and physical props, limiting daily accessibility. To address this, we conducted a formative study with 10 DMT experts and developed ImmersiveDMT, a VR application that provides real-time visual and auditory feedback in response to users’ movements. A user study with 56 participants examined how visual, auditory, and audiovisual feedback affect expressive movement and stress reduction compared to a non-responsive immersive baseline. Results showed that auditory and audiovisual conditions induced significantly more expressive movement compared to baseline. Both visual and auditory feedback achieved significant stress reduction below baseline (V: 17.1%, p=.004; A: 16.6%, p=.042), while combined audiovisual feedback led to less stress reduction. This research presents a novel approach to accessible daily stress management by integrating VR and DMT, demonstrating new possibilities for self-directed mental health support.

Conventional Augmented Reality (AR) head-mounted displays (HMDs) integrate all essential components within the wearable unit, imposing limitations on weight, heat dissipation, and battery life. Beaming Displays (BDs) address these constraints by externalizing computation and projection; however, achieving reliable low-latency six-degrees-of-freedom (6-DoF) tracking remains a challenge. We present BeamStellar, a BD system that enables low-latency 6-DoF head tracking by combining a position-sensitive detector (PSD) with a spatio-temporally modulated infrared LED array mounted on passive glasses. The system integrates tracking and projection via a co-aligned optical path and performs real-time signal processing on an FPGA to minimize tracking latency. We describe the system architecture, pose reconstruction pipeline, and evaluate the pose-tracking latency of approximately 430 µs. BeamStellar provides a replicable, lightweight AR tracking platform, establishing a new paradigm for low-latency environment-based AR systems.

This paper investigates how visual texture presentation influences tactile perception when interacting with electrostatic cloth displays. We propose a visuo-haptic system that allows users to pinch and rub virtual fabrics while feeling realistic frictional sensations modulated by electrostatic actuation. Through a user study, we examined the cross-modal effects between visual roughness and perceived tactile friction. The results demonstrate that visually rough textures amplify the perceived frictional force, even under identical electrostatic stimuli. These findings contribute to the understanding of multimodal texture perception and provide design insights for haptic feedback in virtual material interfaces.

While commercial metaverse platforms offer diverse usergenerated content, they lack effective navigation assistance that can dynamically adapt to users' interests and intentions. Although previous research has investigated on-demand agents in controlled environments, implementation in commercial settings with diverse world configurations and platform constraints remains challenging. We present Navigation Pixie, an on-demand navigation agent employing a loosely coupled architecture that integrates structured spatial metadata with LLM-based natural language processing while minimizing platform dependencies, which enables experiments on the extensive user base of commercial metaverse platforms. Our cross-platform experiments on commercial metaverse platform Cluster with 99 PC client and 94 VR-HMD participants demonstrated that Navigation Pixie significantly increased dwell time and free exploration compared to fixed-route and noagent conditions across both platforms. Subjective evaluations revealed consistent on-demand preferences in PC environments versus context-dependent social perception advantages in VRHMD. This research contributes to advancing VR interaction design through conversational spatial navigation agents, establishes cross-platform evaluation methodologies revealing environment-dependent effectiveness, and demonstrates empirical experimentation frameworks for commercial metaverse platforms.

Augmented Reality (AR) glasses must be slim, lightweight, and energy-efficient to achieve widespread adoption. Beaming Displays present a promising solution by offloading active components, such as the power-supplied light engine, into the surrounding environment while leaving only passive elements, like the eyepiece, in the wearable device. However, existing approaches still struggle to achieve both a slim design and a wide tolerance for projection angles relative to the user’s head orientation. In this work, we introduce a design for light-receiving glasses using a diffractive waveguide with in-coupling and out-coupling gratings. Our approach expands the allowable range of incident angles while maintaining a compact, lightweight form factor. We developed a proof-of-concept prototype and demonstrated an incident angle tolerance of approximately 20-30 degrees range, overcoming the previous design of 5 degrees.

Gaze guidance is essential for directing user attention to specific areas of interest. However, conventional visual cues generate persistent visual noise that hinders concentration during tasks. We propose Saccaidance, a gaze-guidance method that appears only when users move their gaze. Saccaidance employs temporal additive color mixing and 480 Hz high-speed displays to shift the color phase of guidance patterns. This renders the patterns barely visible during fixation and makes them appear transiently when users move their gaze as a color-breaking effect. This intermittent gaze guidance appears only during gaze transitions, providing effective guidance without interfering with focused work or requiring eye-tracking hardware. We conducted experiments with 24 participants under four conditions that involved search tasks: an unmodified baseline, conventional explicit guidance, and our proposed method using oval and radial patterns. The results show that our approach effectively constrains the exploration area while preserving subjective naturalness. We also outline application scenarios of our method, including document highlighting.

Visual guidance (VG) plays an essential role in directing user attention in virtual reality (VR) and augmented reality (AR) environments. However, traditional approaches rely on explicit visual annotations, which often compromise visual clarity and increase user cognitive load. To address this issue, we propose an unobtrusive VG technique based on color vibration, a phenomenon in which rapidly alternating colors at frequencies above 25 Hz are perceived as a single intermediate color. Our work explores a perceptual state that exists between complete color fusion and visible flicker, where color differences remain detectable without conscious awareness of vibration. Through two experimental studies, we first identified the thresholds separating complete fusion, this intermediate perceptual state, and visible flicker by systematically varying color vibration parameters. Subsequently, we applied color vibrations with derived thresholds to natural image regions and validated their attention-guiding capabilities using eye-tracking measurements. The results demonstrate that controlled color vibration successfully directs user attention while maintaining low cognitive demand, providing an effective method for implementing unobtrusive VG in VR and AR systems.

Light Attenuation Displays (LADs), a subset of Optical See-Through Head-Mounted Displays (OST-HMDs), enable image display in bright environments by filtering incident light at the pixel level. Although recent methods have proposed single-DMD light attenuation, they do not consider additive color display and background compensation, limiting their applicability in real-world scenarios. We present FactoredSweeper, a single digital micromirror device (DMD) system that incorporates both light attenuation and addition. By synchronizing the DMD, color filter, and light source, our system generates an additive virtual image, light attenuation, and occlusion through time multiplexing. To produce the target image while compensating for the background, we optimize time-multiplexed binary DMD patterns and LED/color filter schedules using perceptually-driven non-negative matrix factorization. Simulations and prototypes demonstrate that our integrated attenuation-addition single-SLM system achieves superior dynamic range and perceptual image quality compared to conventional occlusion-capable OST-HMDs using grayscale occlusion masks.

Existing near-eye displays (NEDs) have trade-offs related to size, weight, computational resources, battery life, and body temperature. A recent paradigm, beaming display, addresses these trade-offs by separating the NED into a steering projector (SP) for image presentation and a passive headset worn by the user. However, the beaming display has issues with the projection area of a single SP and has severe limitations on the head orientation and pose that the user can move. In this study, we distribute dual steering projectors in the scene to extend the head orientation and pose of the beaming display by coordinating the dual projections on a passive headset. For cooperative control of each SP, we define a geometric model of the SPs and propose a calibration and projection control method designed for multiple projectors. We present implementations of the system along with evaluations showing that the precision and delay are 1.8 ∼ 5.7 mm and 14.46 ms, respectively, at a distance of about 1 m from the SPs. From this result, our prototype with multiple SPs can project images in the projection area ($20\ \text{mm} \times 30\ \text{mm}$) of the passive headset while extending the projectable head orientation. Furthermore, as applications of cooperative control by multiple SPs, we show the possibility of multiple users, improving dynamic range and binocular presentation.

Light Attenuation Displays (LADs) are a type of Optical See-Through Head-Mounted Display (OST-HMD) that present images by attenuating incoming light with a pixel-wise polarizing color filter. Although LADs can display images in bright environments, there is a trade-off between the number of Spatial Light Modulators (SLMs) and the color gamut and contrast that can be expressed, making it difficult to achieve both high-fidelity image display and a small form factor. To address this problem, we propose StainedSweeper, a LAD that achieves both the wide color gamut and the variable intensity with a single SLM. Our system synchronously controls a pixel-wise Digital Micromirror Device (DMD) and a nonpixel polarizing color filter to pass light when each pixel is the desired color. By sweeping this control at high speed, the human eye perceives images in a time-multiplexed, integrated manner. To achieve this, we develop the OST-HMD design using a reflective Solc filter as a polarized color filter and a color reproduction algorithm based on the optimization of the time-multiplexing matrix for the selected primary color filters. Our proof-of-concept prototype showed that our single SLM design can produce subtractive images with variable contrast and a wider color gamut than conventional LADs.

We propose HaptoFloater, a low-latency mid-air visuo-haptic augmented reality (VHAR) system that utilizes imperceptible color vibrations. When adding tactile stimuli to the visual information of a mid-air image, the user should not perceive the latency between the tactile and visual information. However, conventional tactile presentation methods for mid-air images, based on camera-detected fingertip positioning, introduce latency due to image processing and communication. To mitigate this latency, we use a color vibration technique; humans cannot perceive the vibration when the display alternates between two different color stimuli at a frequency of 25 Hz or higher. In our system, we embed this imperceptible color vibration into the mid-air image formed by a micromirror array plate, and a photodiode on the fingertip device directly detects this color vibration to provide tactile stimulation. Thus, our system allows for the tactile perception of multiple patterns on a mid-air image in 59.5 ms. In addition, we evaluate the visual-haptic delay tolerance on a mid-air display using our VHAR system and a tactile actuator with a single pattern and faster response time. The results of our user study indicate a visual-haptic delay tolerance of 110.6 ms, which is considerably larger than the latency associated with systems using multiple tactile patterns.

The tactile sensation of textiles is critical in determining the comfort of clothing. For remote use, such as online shopping, users cannot physically touch the textile of clothes, making it difficult to evaluate its tactile sensation. Tactile sensing and actuation devices are required to transmit the tactile sensation of textiles. The sensing device needs to recognize different garments, even with hand-held sensors. In addition, the existing actuation device can only present a limited number of known patterns and cannot transmit unknown tactile sensations of textiles. To address these issues, we propose Telextiles, an interface that can remotely transmit tactile sensations of textiles by creating a latent space that reflects the proximity of textiles through contrastive self-supervised learning. We confirm that textiles with similar tactile features are located close to each other in the latent space through a two-dimensional plot. We then compress the latent features for known textile samples into the 1D distance and apply the 16 textile samples to the rollers in the order of the distance. The roller is rotated to select the textile with the closest feature if an unknown textile is detected.

Occlusion is a crucial visual element in optical see-through (OST) augmented reality, however, implementing occlusion in OST displays while addressing various design trade-offs is a difficult problem. In contrast to the traditional method of using spatial light modulators (SLMs) for the occlusion mask, using photochromic materials as occlusion masks can effectively eliminate diffraction artifacts in see-through views due to the lack of electronic pixels, thus providing superior see-through image quality. However, this design requires UV illumination to activate the photochromic mate-rial, which traditionally requires multiple SLMs, resulting in a larger form factor for the system. This paper presents a compact photochromic occlusion-capable OST design using multilayer, wavelength-dependent holographic optical lenses (HOLs). Our approach employs a single digital mi-cromirror display (DMD) to form both the occlusion mask with UV light and a virtual image with visible light in a time-multiplexed man-ner. We demonstrate our proof-of-concept system on a bench-top setup and assess the appearance and contrasts of the displayed image. We also suggest potential improvements for current prototypes to encourage the community to explore this occlusion approach.

This paper introduces Retinal Homing Display, which presents focus-free stereoscopic images via retinal projection, thus eliminating the need for the user to wear additional equipment. Traditional 3D displays, typically classified as either naked-eye stereoscopic or wearable, present inherent challenges: the former involves a compromise between resolution and accurate depth perception, while the latter imposes an additional burden on the user. Our proposed display employs optical and mechanical mechanisms to converge projector light at the user’s pupil center, simultaneously tracking eye movements. This lets the user perceive focus-free, high-resolution stereoscopic images without wearable equipment. We implemented a proof-of-concept system utilizing a robotic arm and a Dihedral Corner Reflector Array (DCRA), subsequently evaluating image quality and its eyebox. Finally, we discuss the limitations of the current prototype and outline potential directions for future research.

This paper presents a low-latency Beaming Display system with a 133 μs motion-to-photon (M2P) latency, the delay from head motion to the corresponding image motion. The Beaming Display represents a recent near-eye display paradigm that involves a steerable remote projector and a passive wearable headset. This system aims to overcome typical trade-offs of Optical See-Through Head-Mounted Displays (OST-HMDs), such as weight and computational resources. However, since the Beaming Display projects a small image onto a moving, distant viewpoint, M2P latency significantly affects displacement. To reduce M2P latency, we propose a low-latency Beaming Display system that can be modularized without relying on expensive high-speed devices. In our system, a 2D position sensor, which is placed coaxially on the projector, detects the light from the IR-LED on the headset and generates a differential signal for tracking. An analog closed-loop control of the steering mirror based on this signal continuously projects images onto the headset. We have implemented a proof-of-concept prototype, evaluated the latency and the augmented reality experience through a user-perspective camera, and discussed the limitations and potential improvements of the prototype.

This work integrates Schlieren Imaging, a unique sensing modality, into Augmented Reality (AR) to explore ways to utilize invisible airflows for AR. Schlieren imaging is an imaging technique that visualizes the flow of fluids, which is normally invisible to the eyes. Theoretically, the technique can calculate the motion, pressure, temperature, and density of the airflow in our physical world. This unique, but less applied modality may expand interaction paradigms in AR and VR. We build a proof-of-concept AR system combined with Schlieren imaging that allows real airflow to affect virtual objects. The results of quantitative analyses show that our system can integrate different types of airflow with pressure values ranging from weak breathing actions to a heat gun up to 10m/s or 0.25m3/min airflow. We also showcase AR use cases including blowing out a virtual candle and a heat gun.

While presenting a photorealistic appearance plays a major role in immersion in Augmented Virtuality environment, displaying that of real objects remains a challenge. Recent developments in photogrammetry have facilitated the incorporation of real objects into virtual space. However, reproducing complex appearances, such as subsurface scattering and transparency, still requires a dedicated environment for measurement and possesses a trade-off between rendering quality and frame rate.

We present StainedView, an optical see-through display that spatially filters the spectral distribution of light to form an image with improved color fidelity. Existing light-attenuation displays have limited color fidelity and contrast, resulting in a degraded appearance of virtual images. To use these displays to present virtual images that are more consistent with the real world, we require three things: intensity modulation of incoming light, spatial color filtering with narrower bandwidth, and appropriate light modulation for incoming light with an arbitrary spectral distribution. In StainedView, we address the three requirements by cascading two phase-only spatial light modulators (PSLMs), a digital micromirror device, and polarization optics to control both light intensity and spectrum distribution. We show that our design has a 1.8 times wider color gamut fidelity (75.8% fulfillment of sRGB color space) compared to the existing single-PSLM approach (41.4%) under a reference white light. We demonstrated the design with a proof-of-concept display system. We further introduce our optics design and pixel-selection algorithm for the given light input, evaluate the spatial color filter, and discuss the limitation of the current prototype.

Spatial augmented reality (SAR) pursues realism in rendering materials and objects. To advance this goal, we propose a hybrid SAR (HySAR) that combines a projector with optical see-through head-mounted displays (OST-HMD). In an ordinary SAR scenario with co-located viewers, the viewers perceive the same virtual material on physical surfaces. In general, the material consists of two components: a view-independent (VI) component such as diffuse reflection, and a view-dependent (VD) component such as specular reflection. The VI component is static over viewpoints, whereas the VD should change for each viewpoint even if a projector can simulate only one viewpoint at one time. In HySAR, a projector only renders the static VI components. In addition, the OST-HMD renders the dynamic VD components according to the viewer's current viewpoint. Unlike conventional SAR, the HySAR concept theoretically allows an unlimited number of co-located viewers to see the correct material over different viewpoints. Furthermore, the combination enhances the total dynamic range, the maximum intensity, and the resolution of perceived materials. With proof-of-concept systems, we demonstrate HySAR both qualitatively and quantitatively with real objects. First, we demonstrate HySAR by rendering synthetic material properties on a real object from different viewpoints. Our quantitative evaluation shows that our system increases the dynamic range by 2.24 times and the maximum intensity by 2.12 times compared to an ordinary SAR system. Second, we replicate the material properties of a real object by SAR and HySAR, and show that HySAR outperforms SAR in rendering VD specular components.

We propose a hybrid SAR concept combining a projector and Optical See-Through Head-Mounted Displays (OST-HMD). Our proposed hybrid SAR system utilizes OST-HMD as an extra rendering layer to render a view-dependent property in OST-HMDs according to the viewer's viewpoint. Combined with view-independent components created by a static projector, the viewer can see richer material contents. Unlike conventional SAR systems, our system theoretically allows unlimited number of viewers seeing enhanced contents in the same space while keeping the existing SAR experiences. Furthermore, the system enhances the total dynamic range, the maximum intensity, and the resolution of perceived materials. With a proof-of-concept system that consists of a projector and an OST-HMD, we qualitatively demonstrate that our system successfully creates hybrid rendering on a hemisphere object from five horizontal viewpoints. Our quantitative evaluation also shows that our system increases the dynamic range by 2.1 times and the maximum intensity by 1.9 times compared to an ordinary SAR system.

Typical personal fabrication using a laser cutter allows objects to be created from raw material and the engraving of existing objects. Current methods to precisely align an object with the laser is a difficult process due to indirect manipulations. In this paper, we propose a marker-based system as a novel paradigm for direct interactive laser cutting on existing objects. Our system, MARCut, performs the laser cutting based on tangible markers that are applied directly onto the object to express the design. Two types of markers are available; hand constructed Shape Markers that represent the desired geometry, and Command Markers that indicate the operational parameters such as cut, engrave or material.

This paper proposes a remote welding robot manipulation system by using multi-view images. After an operator specifies two-dimensional path on images, the system transforms it into three-dimensional path and displays the movement of the robot by overlaying graphics with images. The accuracy of our system is sufficient to weld objects when combining with a sensor in the robot. The system allows the non-expert operator to weld objects remotely and intuitively, without the need to create a 3D model of a processed object beforehand.