Wayne Piekarski

ARQuake: the outdoor augmented reality gaming system

cially available affordable wearable computers and head-mounted displays (HMDs), it is possible to develop augmented reality entertainment applications suitable for an outdoor environment. We extended an existing desktop game and developed it into the ARQuake system [4], one of the first systems that allows users to play augmented reality games outdoors—allowing them to move in the physical world, and at the same time experience computer-generated graphical monsters and objects. The game we extended was Quake from id Software (see www.idsoftware.com), a firstperson-perspective, shoot-em-up game initially released in 1996. In Quake, the player runs around a virtual world, shooting at monsters, collecting objects, and completing objectives. The game is desktop-based, with the user interacting with it using a monitor, keyboard, and mouse. Although the game is relatively old, the graphics engine is very powerful and runs on a wide range of computing hardware. Recently, id Software released the source code for Quake, making it possible for enthusiasts and researchers to modify the game for their own purposes. Augmented reality (AR) is the process of overlaying and aligning computer-generated images over a user’s view of the physical world. Using a transparent HMD placed on the user’s head, an internal half-silvered mirror combines images from an LCD display with the user’s vision of the world (see Figure 1). By combining this display technology with a wearable computer, it is possible for the user to walk outdoors and visualize graphical objects that are not normally visible. A comprehensive survey article [1] discusses most aspects of this research area. Wayne Piekarski and Bruce Thomas

ARQuake: an outdoor/indoor augmented reality first person application

This paper presents an outdoor/indoor augmented reality first person application ARQuake we have developed. 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 architecture for a low cost, moderately accurate six degrees of freedom tracking system based on GPS, digital compass, and fiducial vision-based tracking. Usability issues such as monster selection, colour, and input devices are discussed. A second application for AR architectural design visualisation is presented.

First Person Indoor/Outdoor Augmented Reality Application: ARQuake

Abstract: This paper presents a first person outdoor/indoor augmented reality application ARQuake that we have developed. 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 architecture for a low cost, moderately accurate six degrees of freedom tracking system based on GPS, digital compass, and fiducial vision-based tracking. Usability issues such as monster selection, colour, input devices, and multi-person collaboration are discussed.

Tinmith-Metro: new outdoor techniques for creating city models with an augmented reality wearable computer

This paper presents new techniques for capturing and viewing on site 3D graphical models for large outdoor objects. Using an augmented reality wearable computer, we have developed a software system, known as Tinmith-Metro. Tinmith-Metro allows users to control a 3D constructive solid geometry modeller for building graphical objects of large physical artefacts, for example buildings, in the physical world. The 3D modeller is driven by a new user interface known as Tinmith-Hand, which allows the user to control the modeller using a set of pinch gloves and hand tracking. These techniques allow user to supply their AR renderers with models that would previously have to be captured with manual, time-consuming, and/or expensive methods.

Interactive augmented reality techniques for construction at a distance of 3D geometry

This paper presents a series of new augmented reality user interaction techniques to support the capture and creation of 3D geometry of large outdoor structures, part of an overall concept we have named construction at a distance. We use information about the users physical presence, along with hand and head gestures, to allow the user to capture and create the geometry of objects that are orders of magnitude larger than themselves, with no prior information or assistance. Using augmented reality and these new techniques, users can enter geometry and verify its accuracy in real time. This paper includes a number of examples showing objects that have been modelled in the physical world, demonstrating the usefulness of the techniques.

Integrating virtual and augmented realities in an outdoor application

This paper explores interconnecting outdoor AR systems with a VR system to achieve collaboration in both domains simultaneously. We envisage multiple mobile users of wearable AR systems interacting with a stationary VR facility via a wireless network. An application in simulated combat training is described, where the AR users are soldiers with wearable computers, and the VR system is located at a command and control centre. For soldiers, AR provides enhanced information about the battlefield environment, which may include the positions and attributes of simulated entities for the purpose of training outdoors at low cost. At the same time a complete picture of the battlefield, including real and simulated troops and vehicles, is available via the VR system. As soldiers move about, their GPS and digital compass hardware provide the remote VR user and other AR users with the means to track their position in real-time. We describe a working system based on our modular Tinmith-II wearable computer, which interacts with a combat simulator to create a synthetic battle environment for safe training and monitoring.

Glove Based User Interaction Techniques for Augmented Reality in an Outdoor Environment

This paper presents a set of pinch glove-based user interface tools for an outdoor wearable augmented reality computer system. The main form of user interaction is the use of hand and head gestures. We have developed a set of augmented reality information presentation techniques. To support direct manipulation, the following three selection techniques have been implemented: two-handed framing, line of sight and laser beam. A new glove-based text entry mechanism has been developed to support symbolic manipulation. A scenario for a military logistics task is described to illustrate the functionality of this form of interaction.

An object-oriented software architecture for 3D mixed reality applications

This paper presents a new software architecture for 3D mixed reality applications, named Tinmith-evo5. Currently there are a limited number of existing toolkits for the development of 3D mixed reality applications, each optimized for particular feature but at the detriment of others. Complex interactive user interfaces and applications require extensive supporting infrastructure, and can be hampered by inadequate support. The Tinmith-evo5 architecture is optimised to develop mobile augmented reality and other interactive 3D applications on portable platforms with limited resources. This architecture is implemented in C++ with an object-oriented data flow design, an object store based on the Unix file system model, and uses other ideas from existing previous work.

Measuring ARTootKit accuracy in long distance tracking experiments

This paper presents the results from an experiment which was performed to test the ARToolKit and the accuracy of its tracking over large distances of 1 to 3 metres. We used ARToolKit to extract the position of a camera pointed at a fiducial marker, and compared these values to physical measurements to quantify the accuracy of the tracking. The results indicate that the error in position increases with the distance from the target, and that the error also varies in X and Y in phase opposition when orbiting around the pattern. We suggest further experiments to perform and the creation of filters which could reduce at least 75% of the errors detected in this initial experiment.

Using ARToolKit for 3D hand position tracking in mobile outdoor environments

This paper describes how, we have used the ARToolKit to perform three degree of freedom tracking of the hands, in world coordinates, which is used to interact with a mobile outdoor augmented reality computer. Since ARToolKit generates matrices in camera coordinates, if errors occur during the calibration process, it is difficult to extract out real world coordinates. We discuss the problem of making ARToolKit generate world coordinates, and the solutions we developed to meet the requirements for our tracking system.