We present the Finger-Mounted Extending Rod, a wearable device that transforms fingers into virtual tools by modulating fingertip mass distribution. We employ linear actuators on fingers that extend or retract metal rods according to their poses, generating rotational inertia while redirecting the hand to natural grip postures. Through three user studies, we evaluate (1) finger pose embodiment under visual redirection and tool matching via inertia tensor similarity, (2) perception of tool length and rotational inertia, and (3) VR tool interaction experience. Results show that 10 of 15 finger poses maintained embodiment, exhibiting inertia tensor similarities of 0.936–0.991 with their matched tools and yielding perceived inertia amplifications of 4.19–10.45×; moreover, aligning inertia tensors to virtual tools enhanced immersion, realism, and enjoyment compared to misaligned or no-device conditions across six VR scenarios. We conclude by discussing how the system renders virtual tools through the fingers and enhances their perception with inertia modulation.

Accessing real-world objects during immersive virtual reality (VR) experiences remains challenging, as current cross-reality systems often rely on predefined interaction steps, tracking devices/markers, or fixed object setups. They also lack support for personalized object recall, where users can add, remove, or modify real-world items blended into the virtual environment (VE). Many head-mounted displays (HMDs) include passthrough technology to switch between virtual and real worlds, but it often disrupts immersion by requiring a full shift from virtual to real. Thus, maintaining an optimal balance between virtuality and reality is difficult. To address these challenges, we developed SelfBlending, a framework that uses AI-based hand tracking to let users label physical objects through freehand gestures, then blends the selected item into the VE using object recognition, enabling interaction with the relevant real-world object. SelfBlending was evaluated against two common interaction conditions: the default passthrough feature in VR HMDs and the conventional approach of physically removing the HMD to access real-world objects. Results from seated, single-object interactions with tabletop-placed items showed that SelfBlending enhanced user experience by boosting presence, supporting efficient physical interaction, and improving cross-reality continuity. It also enabled selective interaction with real objects while minimizing the disruption of VR experience.

In-car VR applications typically synchronize virtual motion with real vehicle movement to minimize visual-vestibular mismatch. However, this approach limits virtual movement to directions in which the vehicle can physically move, typically restricting the experience to horizontal motion. This study introduces a method to expand the range of virtual motion by simulating vertical movement, leveraging vehicle acceleration to induce a vertical pitch illusion via manipulation of gravitoinertial perception. We conducted a two-phase study evaluating (1) optimal vertical gain values for maximizing perceptual realism in a controlled environment and (2) user experience factors such as motion sickness and presence in an on-road VR flight simulation under realistic driving conditions. Our findings show that users tend to prefer vertical gains that exceed theoretically valid mappings, and highlight the importance of aligning virtual motion with perceived inertial cues to enhance the realism and coherence of vertical motion in in-car VR applications.