Catálogo de publicaciones - libros

We propose a distributed computing framework for network- optimized visualization and steering of real-time scientific simulations and computations executed on a remote host, such as workstation, cluster or supercomputer. Unlike the conventional “batch” simulations, this system enables: (i) monitoring of an on-going remote computation using visualization tools, and (ii) on-line specification of simulation parameters to interactively steer remote computations. Using performance models for transport channels and visualization modules, we develop a dynamic programming method to optimize the realization of the visualization pipeline over a wide-area network to maximize the frame rate. We present experimental results to illustrate the effectiveness of this system.

An improved 6DOF electromagnetic tracking algorithm is proposed. It utilizes the scattering parameters, which are about the transmitter coils, the receiver coils and the involved circuits, to determine the pose and orientation information of the target. Compared with the traditional algorithm which takes the system parameters as same in all the three directions, it is more accordant to the nature of the current tracking device. And it also simplifies the system hardware design. The experimental results prove the algorithm is valid and can improve the accuracy of the system.

A framework of collaborative system based on multi-stereo vision for a shared mixed reality (MR) application is described in this paper. The traditional immersive VR system usually separates the users from the real environment and mainly provides CG-generated space. Recently an alternative approach is through Mixed Reality, which allows user to manipulate objects in a combined environment of the real world objects and virtual space. We propose a framework of shared mixed reality environment to show a real world object with a stereo view and natural operating interface for the separated users. In this paper we mainly describe the sketch of the system and the structure of each functional part and their implementation approaches.

In this paper, we illustrate an augmented reality toolkit that can be used to develop edutainment materials with 3-dimensional graphics and video images. It is based on SEDRIS(Synthetic Environment Data Representation and Interchange Specification) and represents a complete range of real world object attributes. The toolkit manipulates and integrates 3-dimensional graphics objects and video. The virtual environment data structure allows object attributes to be visualized and interactively manipulated in the toolkit.

Augmented Reality (AR) and Tangible User Interface (TUI) have been proven to provide intuition to human computer interface with richness of a tactile sense. Recent implementations in that field, however, have inherited a 2D Graphical User Interface (GUI) scheme and work as isolated systems. Consequently, the systems are limited in supporting intuitive interfaces and various applications. This paper presents an AR-based tangible interaction system for table-top interaction environments. A projector displays information or graphical images on the table through back-projection. Two cameras on and under the table track the tangible objects which are attached with ARToolKit markers and that are used as interaction tools. Furthermore, a Augmentation Display beside the table shows graphical objects combined with the real table. The system shares the object tracking information of the object as context through the vr-UCAM [8]. Moreover, we also present a scheme of tracking smoothing based on a tracking prediction using Kalman Filter. As an application, the ARTable is integrated with Responsive Multimedia System (RMS), a storytelling system [3,4]. The proposed system is applicable to a wide range of usages such as virtual reality and augmented reality applications.

A multi-modal virtual reality application that aims to investigate the effect of olfaction on learning, retention, and recall of complex 3D structures such as organic molecules, is presented. Students interact with molecules in either desktop or immersive configuration. In the latter case, visual immersion is achieved through the use of a large rear-projected stereoscopic screen. In both configurations motion parallax is provided using a camera-based head tracking technique. Both desktop and large-scale fan-based devices that allow real-time smell diffusion are used.

This paper proposes a prototype of an optical tracking system based on a single camera, and presents a design of the active infrared optical tracker to improve the stability of the tracking. Moreover, a method based on Virtual Visual Servoing (VVS) is utilized to compute the pose of the device to be tracked. With the proposed method, the pose computation can be considered as the dual problem of visual servoing, thus an accurate and robust result can be obtained. The proposed system can be regarded as a 6-DOF controller and can be widely applied in the fields of entertainment, education and industry, etc.

In this paper, we propose a computer interaction method for a game. The game is played by using finger shadow cast by a projector to move a ball rendered by a computer. We use a camera to track the movement of the finger shadow. A simple algorithm to move this ball was developed, which depends on the position of the shadow in the camera picture.

The algorithm consist of three parts: the recognition of the shadow, the calculation of the ball by using transformation matrices, and the recognition of the collision between the ball and the shadow and consequential the direction of the ball-movement.

Interactions that provide motivating activities, and perform mutual feedback truly in human-scale spaces, were not suggested in any studies. In this paper, we propose and implement a haptic interaction system that realizes reciprocal reactions. This system is composed of a wire-driven haptic interface and an immersive virtual environment. It enables user to do visual and force feedback in a human-scale interaction spaces. And the virtual human performs intuitive response to changes of user’s action. Based on the framework, we implemented a haptic interaction, , that a user can play the virtual human with one’s feeling of contacting real ball. Furthermore we introduce the system’s extended function that virtual human imitates user’s effective styles acquired by a on-line motion capture, and then reflects them on his behavioral structure. It will be a practical way to produce various motion patterns during playing, and to evolve both behaviors.

A source-less attitude measurement system and robust heading self-calibration method for virtual surgery navigation is presented. The proposed system includes three accelerometers and three magnetometers to measure the gravity field and the geomagnetic filed to calculate the attitude. During the heading calibration procedure, both the magnetic field and gravity field are measured in all three axes with a set of combinations of attitudes. The set of measurements of magnetometer triad are first selected by random sampling consensus (RANSAC), and then are used to fit an ellipsoid to remove the hard iron error, finally the measurements of the magnetometer triad without the hard iron error and the measurements of accelerometer triad are rearranged to a set of equations to solve the soft iron matrix. Compared with other existing calibration method, the proposed calibration method does not require heading reference. Experimental results show the effectiveness of the proposed method and its potential application in virtual surgery navigation.