Ivan Poupyrev

Virtual object manipulation on a table-top AR environment

We address the problems of virtual object interaction and user tracking in a table-top augmented reality (AR) interface. In this setting there is a need for very accurate tracking and registration techniques and an intuitive and useful interface. This is especially true in AR interfaces for supporting face to face collaboration where users need to be able to easily cooperate with each other. We describe an accurate vision-based tracking method for table-top AR environments and tangible user interface (TUI) techniques based on this method that allow users to manipulate virtual objects in a natural and intuitive manner. Our approach is robust, allowing users to cover some of the tracking markers while still returning camera viewpoint information, overcoming one of the limitations of traditional computer vision based systems. After describing this technique we describe its use in prototype AR applications.

The go-go interaction technique: non-linear mapping for direct manipulation in VR

The Go-Go immersive interaction technique uses the metaphor of interactively growing the user’s arm and non-linear mapping for reaching and manipulating distant objects. Unlike others, our technique allows for seamless direct manipulation of both nearby objects and those at a distance.

The MagicBook - moving seamlessly between reality and virtuality

Little work has so far been done to add environmental aspects into VRML architectural models. These observations led us to develop a software package named VREnhancer to address this problem. With ...The MagicBook project is an early attempt to explore how we can use a physical object to smoothly transport users between reality and virtuality. Young children often fantasize about flying into the pages of a fairy tale and becoming part of the story. The MagicBook project makes this fantasy a reality using a normal book as the main interface object. People can turn the pages of the book, look at the pictures, and read the text without any additional technology. However, if a person looks at the pages through an augmented reality display, they see 3D virtual models appearing out of the pages. The models appear attached to the real page so users can see the augmented reality scene from any perspective by moving themselves or the book. The virtual content can be any size and is animated, so the augmented reality view is an enhanced version of a traditional 3D pop-up book.

Ambient touch: designing tactile interfaces for handheld devices

This paper investigates the sense of touch as a channel for communicating with miniature handheld devices. We embedded a PDA with a TouchEngineTM --- a thin, miniature lower-power tactile actuator that we have designed specifically to use in mobile interfaces (Figure 1). Unlike previous tactile actuators, the TouchEngine is a universal tactile display that can produce a wide variety of tactile feelings from simple clicks to complex vibrotactile patterns. Using the TouchEngine, we began exploring the design space of interactive tactile feedback for handheld computers. Here, we investigated only a subset of this space: using touch as the ambient, background channel of interaction. We proposed a general approach to design such tactile interfaces and described several implemented prototypes. Finally, our user studies demonstrated 22% faster task completion when we enhanced handheld tilting interfaces with tactile feedback.

The MagicBook: a transitional AR interface

Abstract The MagicBook is a Mixed Reality interface that uses a real book to seamlessly transport users between Reality and Virtuality. A vision-based tracking method is used to overlay virtual models on real book pages, creating an Augmented Reality (AR) scene. When users see an AR scene they are interested in they can fly inside it and experience it as an immersive Virtual Reality (VR). The interface also supports multi-scale collaboration, allowing multiple users to experience the same virtual environment either from an egocentric or an exocentric perspective. In this paper we describe the MagicBook prototype, potential applications and user feedback.

Egocentric Object Manipulation in Virtual Environments: Empirical Evaluation of Interaction Techniques

The acceptance of virtual environment (VE) technology requires scrupulous optimization of the most basic interactions in order to maximize user performance and provide efficient and enjoyable virtual interfaces. Motivated by insufficient understanding of the human factors design implications of interaction techniques and tools for virtual interfaces, this paper presents results of a formal study that compared two basic interaction metaphors for egocentric direct manipulation in VEs, virtual hand and virtual pointer, in object selection and positioning experiments. The goals of the study were to explore immersive direct manipulation interfaces, compare performance characteristics of interaction techniques based on the metaphors of interest, understand their relative strengths and weaknesses, and derive design guidelines for practical development of VE applications.

Tactile interfaces for small touch screens

We present the design, implementation, and informal evaluation of tactile interfaces for small touch screens used in mobile devices. We embedded a tactile apparatus in a Sony PDA touch screen and enhanced its basic GUI elements with tactile feedback. Instead of observing the response of interface controls, users can feel it with their fingers as they press the screen. In informal evaluations, tactile feedback was greeted with enthusiasm. We believe that tactile feedback will become the next step in touch screen interface design and a standard feature of future mobile devices.

Gummi: a bendable computer

Gummi is an interaction technique and device concept based on physical deformation of a handheld device. The device consists of several layers of flexible electronic components, including sensors measuring deformation of the device. Users interact with this device by a combination of bending and 2D position control. Gummi explores physical interaction techniques and screen interfaces for such a device. Its graphical user interface facilitates a wide range of interaction tasks, focused on browsing of visual information. We implemented both hardware and software prototypes to explore and evaluate the proposed interaction techniques.Our evaluations have shown that users can grasp Gummis key interaction principles within minutes. Gummi demonstrates promising possibilities for new interaction techniques and devices based on flexible electronic components.

A framework and testbed for studying manipulation techniques for immersive VR

Developing virtual realit y (VR) applications which enable actual work over a period of time requires optimization of the most basic interactions, such as object manipulation, so that the immersed participant can concentrate on higher-level tasks rather than on low-level motor activities. This paper presents a framework and experimental testbed for studies of VR object manipulation techniques. The framework provides a systematic task analysis of immersive manipulation and suggests a user-specific nonEuclidean system for the measurement of VR spatial relationships. The Virtual Reality Manipulation Assessment Testbed (VRMAT) is a practical implementation of the framework and is a flexible tool allowing in-depth experimental studies of immersive manipulation. Pilot studies have been conducted to evaluate this framework and testbed and to establish a baseline for further development.

Actuation and tangible user interfaces: the Vaucanson duck, robots, and shape displays

In the last decade, the vision of future interfaces has shifted from virtual reality to augmented and tangible user interfaces (UI) where virtual and physical (or bits and atoms) co-exist in harmony. Recently, a growing number of designers and researchers have been taking the next logical step: creating interfaces where physical, tangible elements are not merely dynamically coupled to the digital attributes and information, but are themselves dynamic, self-reconfigurable devices that can change their physical properties depending on the state of the interfaces, the user, or the environment.A combination of the actuation, self-configuration, and tangibility can expand and enhance the design of tangible interfaces. In this paper, we present an overview of the use of actuation in user interfaces and discuss the rationality of building actuated interfaces. We then discuss actuated interfaces in detail based on our experience designing Lumen shape displays. Work on actuated interfaces is still in its infancy, projects are few and far between, so we consider this paper an invitation to discussion and hope it can help stimulate further research in this area.