Yongwan Kim

Analysis on virtual interaction-induced fatigue and difficulty in manipulation for interactive 3D gaming console

As typical games become interactive 3D games, users may feel fatigued and may have difficulty manipulating virtual objects with current interactive 3D technologies such as Nintendo Wii, MS Kinect and the PS3 3D display. In this paper, we analyze factors about interaction fatigue and manipulation difficulty. For an analysis on factors, we categorize various interactions into two types of interaction scenarios: object manipulation and 3D UI selection. From our analysis, we presented the design factors related to finger extension motion for grasping, early extension for grasping/selection, haptic sensation, erroneous trials, and head motion for 3D perception. Game developers can apply induced design factors to their interactive 3D game contents.

Physically based grasping and manipulation method using pre-contact grasping quality measure

While the human hand is the most natural tool for interacting with objects, hand interaction with virtual objects is still a challenging research field. We recognize that common hand interaction involves two separate stages with different aspects: One is the robustness of grasping, and the other is the dexterity of manipulation after grasping a virtual object. In this paper, we address virtual hand interaction by decoupling these two aspects and propose strategic simulation algorithms for two different stages. As for the initial grasping, a quality measure-based grasping algorithm is applied for robustness, and the manipulation is simulated by physically based methods to meet the requirements of dexterity. We conducted experiments to evaluate the effectiveness of our proposed method under different display environments -- monoscopic and stereoscopic. From the 2-way ANOVA test, we were able to show that the proposed scheme that separates a pre-contact grasping phase and a post-contact manipulation phase gives us the robustness of grasping quality and dexterity of tool operation. Furthermore, we demonstrate various assembly manipulations of the relatively complex models using our interaction scheme.

Virtual Reality Based Welding Training Simulator with 3D Multimodal Interaction

In this paper, we present a prototype Virtual Welding Simulator, which supports interactive training of welding process by using multimodal interface that can deliver realistic experiences. The goal of this research is to overcome difficult problems by using virtual reality technology in training tasks where welding is treated as a principal manufacturing process. The system design and implementation technical issues are described including real-time simulation and visualization of welding bead, providing realistic experience through 3D multimodal interaction, presenting visual training guides for novice workers, and visual and interactive interface for training assessments. According to the results from an initial user study, the prototype VR based simulator system appears to be helpful for training welding tasks, especially in terms of providing visual training guides and instant training assessment.

Visualization of virtual weld beads

In this paper, we present a visualization method of weld beads for a welding training under virtual environments. To represent virtual beads, a bead shape is defined according to the datasets which consist of bead width, height, angle, penetration acquired from real welding operations. A curve equation of beads sectional shape is mathematical modeled, and a height map is generated according to this numerical equation, which is used for generating the beads mesh data using its height information. Finally, virtual weld beads are visualized in real-time according to the accurately simulated results from users input motion.

Interactive panoramic VR system to expand spatialness and depth of 3D zone using see-through HMD glasses

In this paper, we propose a panoramic 3D display system to expand 3D spatialness and depth zone of 3D flat displays using see-through HMD glasses. For our purpose, we install circular passive filters in front of see-through glasses and also IR-LED markers for head tracking. Using these hardwares, we separately render a view region of each virtual camera with respect to 1:1 scale matching and divide its own 3D comfortable zone. Finally, we demonstrate expandable 3D virtual golf content with self-guidance.

Welding representation for training under VR environments

In this paper, we present a virtual training system which realistically represents the situation of real welding. First of all, we built a database about welding outputs such as the shape of bead which is the deposit outcome resulting from inputs of real welding conditions and operations. Second, we performed an analysis of relations between input variables and output variables, and the major and minor factors influencing on the welding shape were classified. Finally, we designed an estimation process of outputs by various inputs such as users movement, and constructed the method of graphical representation for real-time visualization from heuristic sources. Additionally, we also installed a welding simulator for a teacher and trainees, which can support not only a variety of welding situations but prompt evaluation of results and educational guide by optimal welding conditions.

6DOF Whole-Hand Haptic Interaction System Based on Hybrid Grasping Approach

Although haptic interaction which provides direct touch sensation is the most natural way of interacting with VR environment, existing haptic solutions are not yet fully satisfying due to the interaction problems such as the hand penetration, frictionlessness, lack of visual feedback, and so on. Among these problems, the hand penetration problem which is an effect sinking into a virtual object is the most visually distracting artifact in grasping, and it is mainly caused by the incomplete physical capabilities of haptic devices and poor grasping manipulation. To address this problem, we have developed a realistic haptic interaction system, which consists of the new 6DOF whole-hand hardware combined with a glove-type device, and propose a hybrid grasping method which intelligently uses both heuristic and physics-based approach.

The impact of avatar-owner visual similarity on body ownership in immersive virtual reality

In this paper we report on an investigation of the effects of a self-avatars visual similarity to a users actual appearance, on their perceptions of the avatar in an immersive virtual reality (IVR) experience. We conducted a user study to examine the participants sense of body ownership, presence and visual realism under three levels of avatar-owner visual similarity: (L1) an avatar reconstructed from real imagery of the participants appearance, (L2) a cartoon-like virtual avatar created by a 3D artist for each participant, where the avatar shoes and clothing mimic that of the participant, but using a low-fidelity model, and (L3) a cartoon-like virtual avatar with a pre-defined appearance for the shoes and clothing. Surprisingly, the results indicate that the participants generally exhibited the highest sense of body ownership and presence when inhabiting the cartoon-like virtual avatar mimicking the outft of the participant (L2), despite the relatively low participant similarity. We present our experiment and main findings, also, discuss the potential impact of a self-avatars visual differences on human perceptions in IVR.

Two-stage articulated hand interaction for virtual assembly simulation

Virtual assembly simulation which refers to the verification process of digital mockup in product development lifecycle is one of the most promising topics in virtual reality applications. In the virtual assembly simulation, inaccurate hand interaction is an obstacle to natural hand interaction with virtual environments. The crucial interaction problems include unrealistic hand motion such as penetration and frictionlessness, lack of visual feedback and limited accuracy in hardwares. In this paper, we present the delicate hand interaction system which intelligently uses both heuristic and physics-based approach using a new glove device.

VR Planning Toolkit to Simulate Physical and Virtual Configurations: A Case Study of an Indoor VR Roller Coaster Augmenting Experience

This paper proposes a novel VR planning toolkit to simulate physical configurations of the actual space such as physical sensors of users surrounding space (e.g. tracking sensors, IoT devices, muscle interfaces, exoskeletons) in advance, and simultaneously create a VR content mixed for the configured environment. This toolkit provides guidelines for configurations of real and virtual spaces at the same time, and allows the user to bridging two spaces that need to be simulated. As a case study of our proposed VR planning toolkit, we have developed a prototype to test indoor VR roller coaster, and applied it as a usage scenario that can be experienced.