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.

This article explores the synergistic interaction among the geometric field of view (GFOV), proprioceptive interaction and multimodal feedback in a virtual environment. We hypothesise that, with proprioceptive interaction and multimodal feedback, the GFOV can be set larger than its reference value originally set to give similar distance perception when viewed with a given physical field of view of a head mounted display. This in turn would help a user carry out a task more effectively with the increased visibility. We tested our hypothesis with an experiment to measure the user's change in distance perception according to different values of egocentric GFOV and task/feedback conditions (15 subjects). Our experimental results have shown that, when coupled with proprioceptive interaction, the GFOV could be increased up to 170% of the reference without introducing change in user's distance perception. When additional visual and tactile feedback was introduced, the GFOV could be increased up to 200%. The results offer a useful guideline for designing multimodal interfaces for close range spatial tasks in virtual environments. In addition, it demonstrates one way to overcome the inadequacy of the narrow physical fields of view often found in most general purpose head mounted displays.

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 bead's sectional shape is mathematical modeled, and a height map is generated according to this numerical equation, which is used for generating the bead's mesh data using its height information. Finally, virtual weld beads are visualized in real-time according to the accurately simulated results from user's input motion.

Mobile computing devices are getting popular as a platform for augmented reality (AR) application, and efficient interaction methods for mobile AR environments are considered necessary. Recently, touch interfaces are getting popular and drawing attention as a future standard interface on mobile computing devices. However, accurate touch interactions are not that easy in mobile AR environments where users tend to move and viewpoints easily get shaky. In this paper, the authors suggest a new interaction method for handheld mobile AR environments, named 'Freeze-Set-Go'. The proposed interaction method lets users to 'freeze' the real world view tentatively, and continue to manipulate virtual entities within the AR scene. According to the user experiment, the proposed method turns out to be helping users to interact with mobile AR environments using touch interfaces in a more accurate and comfortable way.

In this paper, we introduce a method for design evaluation of mobile devices using virtual reality based prototypes. For this, we present technologies for a classification of design parameters and for visualizing mobile devices with high quality 3D data. Also, we describe an implementation method for natural simulation and interaction of product functions.

We present a virtual reality (VR) system that simulates the situation of ship block spray painting. The system was developed under demands from ship building industry for training purpose. We designed an immersive stereo display platform, a realistic spray painting rendering technique and intuitive user interface to match with the real working environment. The system is currently under user-test in the ship building company with receiving positive responses.