This pap er presents an outdoor/indoor augmented re- ality first person applic ationAR(2uake we have developal. ARQuake is an extension of the desktop game Quake, and as such we are investigating how to convert a desktop first person application into an outdoor/indoor mobile augmented reality application. We present an archire cture for a low cost, moderately accurate six degrees of freedom tracking system based on GP$, digital compass, and fiducial vision-based tracking. Usability issues such as monster selection, colour, and input devies are discussed. A second application for AR architectural design visualisation is presented.

Near-field virtual reality allows users to interact with virtual objects within arm's reach of the user. Environments for near-field VR are well suited for direct precise interaction by taking advantage of the user's hand-eye co-ordination.

Homogenous Virtual Environments evolved into Mixed Environments thanks to recent Augmented Reality techniques. [Ye have done research on novel interaction techniques in virtual environments exploiting the usage of 3D virtual space. [Ye will briefly present our Augmented Reality set-up for mixed reality experiments and we will analyze two distinct mixed environment case studies, and present two new interaction techniques where we use virtual humans as mediators between the real and virtual world.

In this paper we present a new framework in Augmented Reality context for rapid evaluation of prototypes before manufacture. The design of such prototypes is a time consuming process, leading to the need of previous evaluation in realistic interactive environments. We have extended the definition of modelling object geometry with modelling object behaviour being able to evaluate them in a mixed environment. Such enhancements allow the development of tools and methods to test object behaviour, and perform interactions between real virtual humans and complex real and virtual objects. We propose a framework for testing the design of objects in an augmented reality context, where a virtual human is able to perform evaluation tests with an object composed of real and virtual components. In this paper our framework is described and a case study is presented. Keywords: Augmented Reality, Object Behaviour, Virtual Humans, Prototyping, Human Factors. 1. INTRODUCTION With emerge of new tech...

. For some years, we have been able to integrate virtual humans into virtual environments. As the demand for Augmented Reality systems grows, so will the need for these synthetic humans to coexist and interact with humans who live in the real world. In this paper, we use the example of a checkers game between a real and a virtual human to demonstrate the integration of techniques required to achieve a realistic-looking interaction in real-time. We do not use cumbersome devices such as a magnetic motion capture system. Instead, we rely on purely image-based techniques to address the registration issue, when the camera or the objects move, and to drive the virtual human's behavior. 1 Introduction Recent developments in Virtual Reality and Human Animation have led to the integration of Virtual Humans into synthetic environments. We can now interact with them and represent ourselves as avatars in the Virtual World [4]. Fast workstations make it feasible to animate them in realtime...

Through interactive augmented virtuality we provide the ability to interactively explore a remote space inside a virtual environment. This paper presents a tool and technique that can be used to create such virtual worlds that are augmented by video textures taken of real world objects. The system constructs and updates, in near real-time, a representation of the user-defined salient and relevant features of the real world. This technique has the advantage of constructing a virtual world that contains the relevant video-data of the real world, while maintaining the flexibility of a virtual world. The virtual-real world representation is not dependent on physical location and can be manipulated in a way not subject to the temporal, spatial, and physical constraints found in the real world. Another advantage is that spatializing the video-data may afford more intuitive examination. Keywords Augmented Virtuality, Teleoperation, Collaborative Virtual Environments, Video Textures, Environ...

A crucial aspect in the implementation of an augmented reality (AR) system is determining its accuracy. The accuracy of a system determinies the applications it can be used for. The aim of our research is measuring the overall accuracy of an arbitrary AR system. Once measurements of a system are made, they can be analyzed for structure and used to track down sources of error. From the analysis it may also be possible to improve the methods used to calibrate and register the virtual to the real.

Tracking has proven a difficult problem to solve accurately without limiting the user or the application. Vision-based systems have shown promise, but are limited by occlusion of the landmarks. We introduce a new approach to vision-based tracking using structured light to generate landmarks. The novel aspect of this approach is the system need not know the 3D locations of landmarks. This implies that motion within the field of view of the camera does not disturb tracking as long as landmarks are reflected off any surface into the camera. This dissertation specifies an algorithm which tracks a camera using structured light. A simulator demonstrates excellent performance on user motion data from an application currently limited by inaccurate tracking. Further analysis reveals directions for implementation of the system, theoretical limitations, and potential extensions to the algorithm. The term augmented reality (AR) has been given to applications that merge computer graphics with ima...

Most pose (3D position and 3D orientation) tracking methods using vision require a priori knowledge about the environment and correspondences between 3D environment features and 2D images. This environmental information is difficult to acquire accurately for large working volumes or may not be available at all, especially for outdoor environments. As a result, most pose tracking methods using vision are designed for small indoor working spaces. We track the pose of a moving camera from 2D images of the world. The pose of a camera is tracked through two 5 degree-of-freedom (DOF) motion estimations, which requires only 2D-to-2D correspondences. Therefore, the presented method can be applied to varied working space sizes including outdoor environments. 1.

This paper addresses the problem of accurately tracking the 3D motion of a monocular camera in a known 3D environment and dynamically estimating the 3D camera location. For that purpose we propose a fully automated landmarkbased camera calibration method and initialize a motion estimator, which employes extended Kalman filter techniques to track landmarks and to estimate the camera location at any given time. The implementation of our approach has been proven to be efficient and robust and our system successfully tracks in real-time at approximately 10 Hz. We show tracking results of various augmented reality scenarios. 1