Kathy Ryall

Design galleries: a general approach to setting parameters for computer graphics and animation

Image rendering maps scene parameters to output pixel values; animation maps motion-control parameters to trajectory values. Because these mapping functions are usually multidimensional, nonlinear, and discontinuous, finding input parameters that yield desirable output values is often a painful process of manual tweaking. Interactive evolution and inverse design are two general methodologies for computer-assisted parameter setting in which the computer plays a prominent role. In this paper we present another such methodology. Design GalleryTM (DG) interfaces present the user with the broadest selection, automatically generated and organized, of perceptually different graphics or animations that can be produced by varying a given input-parameter vector. The principal technical challenges posed by the DG approach are dispersion, finding a set of input-parameter vectors that optimally disperses the resulting output-value vectors, and arrangement, organizing the resulting graphics for easy and intuitive browsing by the user. We describe the use of DG interfaces for several parameter-setting problems: light selection and placement for image rendering, both standard and image-based; opacity and color transfer-function specification for volume rendering; and motion control for particle-system and articulated-figure animation. CR Categories: I.2.6 [Artificial Intelligence]: Problem Solving, Control Methods and Search—heuristic methods; I.3.6 [Computer Graphics]: Methodology and Techniques—interaction techniques; I.3.7 [Computer Graphics]: Three-Dimensional Graphics and Realism.

Gesture registration, relaxation, and reuse for multi-point direct-touch surfaces

Freehand gestural interaction with direct-touch computation surfaces has been the focus of significant research activity. While many interesting gestural interaction techniques have been proposed, their design has been mostly ad-hoc and has not been presented within a constructive design framework. In this paper, we develop and articulate a set of design principles for constructing - in a systematic and extensible manner - multi-hand gestures on touch surfaces that can sense multiple points and shapes, and can also accommodate conventional point-based input. To illustrate the generality of these design principles, a set of bimanual continuous gestures that embody these principles are developed and explored within a prototype tabletop publishing application. We carried out a user evaluation to assess the usability of these gestures and use the results and observations to suggest future design guidelines.

Exploring the effects of group size and table size on interactions with tabletop shared-display groupware

Interactive tabletops have been previously proposed and studied in the domain of co-located group applications. However, little fundamental research has been done to explore the issue of size. In this paper we identify a number of size considerations for tabletop design, and present an experiment to explore some of these issues, in particular the effects of group size and table size on the speed at which the task was performed, the distribution of work among group members, issues of shared resources, and user preference for table size. Our findings shed light on (1) how work strategies are affected by group size, (2) how social interaction varies with respect to table size, and (3) how the speed of task performance is influenced by group size but not by table size. In addition, our experiments revealed that for larger groups, designers might need to add additional vertical displays for shared information. This finding opens the door for extending single-display groupware to shared-display groupware settings that involve multiple, shared displays.

Social net: using patterns of physical proximity over time to infer shared interests

We describe Social Net, a novel interest-matching application that uses patterns of collocation, over time, to infer shared interests between users. Social Net demonstrates new possibilities and methods for using the capabilities of mobile devices equipped with RF-communications.

Tangible interaction + graphical interpretation: a new approach to 3D modeling

Construction toys are a superb medium for geometric models. We argue that such toys, suitably instrumented or sensed, could be the inspiration for a new generation of easy-to-use, tangible modeling systems—especially if the tangible modeling is combined with graphical-interpretation techniques for enhancing nascent models automatically. The three key technologies needed to realize this idea are embedded computation, vision-based acquisition, and graphical interpretation. We sample these technologies in the context of two novel modeling systems: physical building blocks that self-describe, interpret, and decorate the structures into which they are assembled; and a system for scanning, interpreting, and animating clay figures.

Living with a Tabletop: Analysis and Observations of Long Term Office Use of a Multi-Touch Table

Multi-touch tabletops have been the focus of significant recent study but, to date, few devices have moved from prototype to installed use. In this paper, we present observation and analysis of a subject who has used a direct-touch tabletop as his primary computing environment for the past 13 months, driving all manner of applications in a standard MS Windows environment. We present the results of three research instruments: a structured interview with the user, an analysis of touch and click locations when operating in desktop and tabletop modes over several days, and linguistic analysis of email composition over several months. From the product of these instruments we then report on several open avenues for research, including physical parameters, hardware limitations, touch vs. click in the WIMP, and text entry techniques.This paper proposes a novel paradigm: human-centered tabletop computing, which enhances the role of an ordinary table by projecting interactive images onto tabletop objects and the table surface at the same time. The advantage of this approach is that it utilizes tabletop objects as projection screens as well as input tools. As a result, we can change the appearance and role of each tabletop object easily and fulfill two important requirements of tabletop tangible interfaces, identifiability and versatility, which have proven difficult to satisfy simultaneously in previous systems. Our prototype, tablescape plus, achieves these functions by using two projectors and a special tabletop screen system that diffuses or transmits images selectively according to the projection orientation. This paper presents the design principle, optical design, and implementation of tablescape plus. Furthermore, we introduce several interactive applications.

Release, relocate, reorient, resize: fluid techniques for document sharing on multi-user interactive tables

Group work frequently involves transitions between periods of active collaboration and periods of individual activity. We aim to support this typical work practice by introducing four tabletop direct-manipulation interaction techniques that can be used to transition the status of an electronic document from private to group-accessible. After presenting our four techniques - release, relocate, reorient, and resize - we discuss the results of an empirical study that compares and evaluates these mechanisms for sharing documents in a co-located tabletop environment.

MultiSpace: enabling electronic document micro-mobility in table-centric, multi-device environments

Although electronic media has changed how people interact with documents, todays electronic documents and the environments in which they are used are still impoverished relative to traditional paper documents when used by groups of people and across multiple computing devices. Vertical interfaces (e.g., walls and monitors) afford a less democratic style of interaction than generally observed when people are working around a table. In this paper, we introduce MultiSpace, a research effort which explores the role of the table as a central hub to support ad hoc collaboration in a multidevice environment. The table centric approach offers new interaction techniques to provide egalitarian access and shared transport of data, supporting mobility and micromobility (Luff and Heath, 1998) of electronic content between tables and other devices. Our observations show how people use these techniques, and how tabletop technology can support and augment collaborative tasks.

Multi-user, multi-display interaction with a single-user, single-display geospatial application

In this paper, we discuss our adaptation of a single-display, single-user commercial application for use in a multi-device, multi-user environment. We wrap Google Earth, a popular geospatial application, in a manner that allows for synchronized coordinated views among multiple instances running on different machines in the same co-located environment. The environment includes a touch-sensitive tabletop display, three vertical wall displays, and a TabletPC. A set of interaction techniques that allow a group to manage and exploit this collection of devices is presented.

Building virtual structures with physical blocks

We describe a tangible interface for building virtual structures using physical building blocks. We demonstrate two applications of our system. In one version, the blocks are used to construct geometric models of objects and structures for a popular game, Quake II™. In another version, buildings created with our blocks are rendered in different styles, using intelligent decoration of the building model.