Rieko Kadobayashi

Path drawing for 3D walkthrough

This paper presents an interaction technique for walkthrough in virtual 3D spaces, where the user draws the intended path directly on the scene, and the avatar automatically moves along the path. The system calculates the path by projecting the stroke drawn on the screen to the walking surface in the 3D world. Using this technique, the user can specify not only the goal position, but also the route to take and the camera direction at the goal with a single stroke. A prototype system is tested using a displayintegrated tablet, and experimental results suggest that the technique can enhance existing walkthrough techniques.

3D viewpoint-based photo search and information browsing

We propose a new photo search method that uses three-dimensional (3D) viewpoints as queries. 3D viewpoint-based image retrieval is especially useful for searching collections of archaeological photographs,which contain many different images of the same object. Our method is designed to enable users to retrieve images that contain the same object but show a different view, and to browse groups of images taken from a similar viewpoint. We also propose using 3D scenes to query by example, which means that users do not have the problem of trying to formulate appropriate queries. This combination gives users an easy way of accessing not only photographs but also archived information.

Design and evaluation of gesture interface of an immersive walk-through application for exploring cyberspace

The authors have developed an application of a full-body, noncontact gesture interface for exploring cyberspace that provides immersive walk-through and information accessing capabilities. The VisTA-walk system is designed for use at museum exhibitions where easy, durable, and pleasurable user interface is preferable. It uses a large projection screen for immersive cyberspace presentation. VisTA-walk allows the user to walk through virtual villages by taking physical steps and to retrieve information on objects displayed in the scene by pointing at them. They carefully designed the interface of VisTA-walk with a simple video-based gesture recognition module, providing it with a minimal but comprehensive set of gestures as its vocabulary. The mouse and gesture-based interfaces are compared through subjective experimentation on walk through capability for ease of use and degree of immersiveness. The immersiveness achieved by the combined use of the large screen and gesture interaction is comprehensively evaluated.

3D Model Annotation from Multiple Viewpoints for Croquet

This paper explores ways by which multiple authors can annotate 3D models from multiple viewpoints in a 3D collaborative environment, with particular reference to the environment provided by Croquet. We deal with two types of viewpoint: the conceptual viewpoint and the physical viewpoint. Our approach is to exploit the portal, which is a notable feature of Croquet, in order to achieve our goal. We can assume that a physical viewpoint is expressed by the position and orientation of a portal. To provide a method for annotation based on the conceptual viewpoint, we developed a new portal called an interactor. The design and our preliminary implementation are discussed

Annotation authoring in collaborative 3D virtual environments

To be generally useful for collaborative research and learning, immersive virtual 3D spaces must include intuitive content creation and annotation tools. We describe some initial work to enhance one such environment (Croquet) for use in a broad range of collaborative applications. Annotations in virtual spaces may include features such as comments on objects in the environment, guided tours through the virtual space, and a history mechanism so that the evolution of objects or portions of the space can be replayed and examined. In general terms, an annotation is simply a relationship between one object and another and we examine several methods of displaying these relationships. To extend annotations across communities, the system architecture supports naming and packaging object and meta-information and integration of content into a shared digital repository. By distributing to users the power to create, edit, store, and retrieve objects and annotations, we promote development and re-use of meaningful content. Such systems can have great utility for the development of virtual environments for learning and research.

Personalizing Museum Exhibition by Mediating Agents

We have proposed Meta-Museum as a new knowledge sharing environment where experts and novices can communicate with each other with agent support. Museum exhibitions are thought to be well organized representations of the expert knowledge of curators, but they are just one example of structures of knowledge among many possibilities, given to museum visitors in a one-sided way. Therefore, traditional museum exhibitions can hardly meet the vast requirements of general visitors who possess a variety of interests. In this paper, we propose agents to mediate between curators and visitors, so that both sides can convey their interests and knowledge to one another and gain a better understanding. These mediating agents visualize the semantic relations of displays as a two-dimensional spatial structure based on the viewpoints of the curators and visitors separately, and then together. The structures reflect the interests of the visitors, while maintaining the knowledge of the curators.

Automatic 3d blogging to support the collaborative experience of 3d digital archives

Digital archives that include 3D CG models of, for example, art works and archaeological sites are now commonly created for a wide range of purposes. Unlike traditional museums where people can visit in a group, access to digital archives and browsing of their contents are solitary activities. Thus, users cannot as easily gain a deep understanding of the contents and are less likely to truly enjoy the contents. We therefore propose a method to support collaborative experiencing of 3D digital archives related to cultural heritages. To achieve this goal, we developed a system that enables automatic blogging of annotations made to 3D content. The annotations a user makes to the 3D content of archives while “walking” through them are automatically converted into a blog on a web page. Users experiences, through annotations expressing their impressions, opinions, suggestions, and so on, are converted into content, which can then be used by subsequent users as a reference or guide when browsing the archives.

Evaluation of mediating agents that personalize museum exhibitions

Despite having the potential to provide a knowledge sharing environment among experts (e.g. curators) and novices (e.g. museum visitors), traditional museums do not generally function in this way. The biggest problem is the lack of an efficient way for both experts and visitors to represent and exchange their knowledge, interests, and viewpoints, which would allow visitors to examine the exhibitions in a customized manner. Therefore, we have proposed mediating agents between experts and visitors to personalize museum exhibitions based on the needs of the visitor in order to enhance their understanding of the exhibitions. This personalization process can be considered asynchronous collaborative work by curators and visitors through the help of mediating agents. In this paper, we evaluate the mediating agents with a subjective experiment from the visitors point of view. The results show that the mediating agents are effective in personalizing museum exhibitions.

Collaborative Guidance System Using Multi-gaze History and Shared Photograph Collection

In this paper, we propose a collaborative guidance system which provides information extracted from a shared photo collection based on a users context. The users gaze history is used to determine the users situation in the real world. In our proposed system, we use a photograph viewpoint logging (PVL) system, which was previously developed to record the real world as photographs with viewpoint information (based on the photographers position and direction of gaze). In the prototype of the PVL system, a user terminal consisting of a mobile phone with an attached motion sensor, a GPS sensor, and a notebook PC is used for logging the position and orientation of the mobile phone. Based on the PVL system, we design the collaborative guidance system by using a multi-gaze history and the shared photograph collection. After a user takes two or three photographs consecutively, the collaborative guidance system provides useful and well-processed content based on the user situation.

The Group Mapping for Developing Collaborative 3D Blog System

This paper proposes a group mapping mechanism for a 3D blog system that enables system to more systematically and effectively support collaboration on the Internet. The 3D blog system enables users to interact with a 3D model, annotate any spot on the model, and publish the annotations in a blog entry along with viewpoint information, making it easier for the user to communicate with other people and share interests, ideas, and questions about 3D models. The 3D blog system uses the viewpoint information to detect similar entries and automatically creates TrackBack links to enable users to easily find people who may have similar interests. However, there is no way to group similar interests in the 3D blog system. Therefore, we propose a group mapping mechanism that dynamically categorizes the similar entries in different users blogs. This collaborative 3D blog system is expected to promote the emergence of communities of people who share interests and to support communication in those communities.