Showing papers by "Blair MacIntyre published in 2004"

DART: a toolkit for rapid design exploration of augmented reality experiences

Abstract: In this paper, we describe The Designer's Augmented Reality Toolkit (DART). DART is built on top of Macromedia Director, a widely used multimedia development environment. We summarize the most significant problems faced by designers working with AR in the real world, and discuss how DART addresses them. Most of DART is implemented in an interpreted scripting language, and can be modified by designers to suit their needs. Our work focuses on supporting early design activities, especially a rapid transition from story-boards to working experience, so that the experiential part of a design can be tested early and often. DART allows designers to specify complex relationships between the physical and virtual worlds, and supports 3D animatic actors (informal, sketch-based content) in addition to more polished content. Designers can capture and replay synchronized video and sensor data, allowing them to work off-site and to test specific parts of their experience more effectively.

OSGAR: A Scene Graph with Uncertain Transformations

Abstract: An important problem for augmented reality is registration error. No system can be perfectly tracked, calibrated or modeled. As a result, the overlaid graphics are not aligned perfectly with objects in the physical world. This can be distracting, annoying or confusing. In this paper, we propose a method for mitigating the effects of registration errors that enables application developers to build dynamically adaptive AR displays. Our solution is implemented in a programming toolkit called OSGAR. Built upon OpenSceneGraph (OSG), OSGAR statistically characterizes registration errors, monitors those errors and, when a set of criteria are met, dynamically adapts the display to mitigate the effects of the errors. Because the architecture is based on a scene graph, it provides a simple, familiar and intuitive environment for application developers. We describe the components of OSGAR, discuss how several proposed methods for error registration can be implemented, and illustrate its use through a set of examples.

Presence and the Aura of Meaningful Places

Abstract: We propose the term aura to enrich the current language for designing and analyzing media experiences, especially when using augmented reality, mixed reality and ubiquitous computing technology. Aura describes the cultural and personal significance that a place (or object) holds for an individual. An MR application can exploit aura to make the user’s experience more compelling or educationally rewarding. Aura provides a necessary complement to the concepts of presence, which is commonly used to evaluate VR applications, and of place, which refers to the more generic significance of places, particularly in CSCW applications. We use the Oakland Cemetery in Atlanta, Georgia to illustrate the concept of aura. A number of research questions about the relationship of aura, presence, and place are suggested.

Automatic partitioning for prototyping ubiquitous computing applications

Abstract: A major challenge facing ubiquitous computing R&D is the difficulty of writing software for complex, distributed applications. Automatic application partitioning can help development teams rapidly prototype distributed ubiquitous computing systems.

Adapting to Registration Error in an Intent-based Augmentation System

Abstract: An ongoing research problem in augmented reality (AR) is to improve tracking and display technology in order to minimize registration errors. However, registration is not always necessary for users to understand the intent of an augmentation, especially in industrial applications where the user and the system have extensive semantic knowledge of the environment. In this chapter, we review the ideas of communicative intent developed for desktop graphical explanation systems by Seligmann and Feiner, and discuss how these approaches are the basis for our hypothesis that semantic knowledge of a scene can be used to ameliorate the effects of registration errors. We describe a set of AR visualization techniques for augmentations that adapt to changing registration errors. We first define a set of strategies that use semantic knowledge of the augmentation to enhance the augmentations with additional contextual cues. These context cues help users understand the intent of the augmentation in the presence of registration error. We then introduce algorithms that use features and feature points on objects to control these strategies in the presence of changing registration errors. Finally, these algorithms and techniques are demonstrated in four maintenance situations that challenge a user’s ability to interpret the semantics of a scene.

Automatic Partitioning: A Promising Approach to Prototyping Ubiquitous Computing Applications

Abstract: One of the main challenges facing ubiquitous computing research and development is the difficulty of writing software for complex, heterogeneous distributed applications In this paper, we evaluate automatic application partitioning as an approach to rapid prototyping of ubiquitous computing systems Our approach allows developers to largely ignore distribution issues when developing their applications, by providing tools for generating distribution code automatically, under user guidance We claim that automatic partitioning is promising for a large class of ubiquitous computing applications and discuss an example ubicomp application re-engineered using our approach

Making Tracking Technology Accessible in a Rapid Prototyping Environment

Abstract: In this paper we present an approach for exposing tracking technology in an accessible and flexible way to users of a rapid prototyping system for mixed (MR) and augmented reality (AR). Our system provides a tracking framework that alleviates the need for a high level of expertise while also presenting a model of the technology that allows for flexible modification of tracking configurations, the ability to quickly change an application from one type of tracking technology to another, and the creation of synthetic trackers for playback of prerecorded data, data fusion from multiple trackers, and wizard-of-oz applications.