David J. Cowperthwaite

3-dimensional pliable surfaces: for the effective presentation of visual information

A fundamental issue in user interface design is the effective use of available screen space, commonly referred to as the screen real estate problem. This paper presents a new distortion-based viewing tool for exploring large information spaces through the use of a three-dimensional pliable surface. Arbitrarily-shaped regions (foci) on the surface may be selected and pulled towards or pushed away from the viewer thereby increasing or decreasing the level of detail contained within each region. Furthermore, multiple foci are smoothly blended together such that there is no loss of context. The manipulation and blending of foci is accomplished using a fairly simple mathematical model based on gaussian curves. The significance of this approach is that it utilizes precognitive perceptual cues about the three-dimensional surface to make the distortions comprehensible, and allows the user to interactively control the location, shape, and extent of the distortion in very large graphs or maps.

Graph Folding: Extending Detail and Context Viewing into a Tool for Subgraph Comparisons

It is a difficult problem to display large, complex graphs in a manner which furthers comprehension. A useful approach is to expand selected sections (foci) of the graph revealing details of subgraphs. If this expansion is maintained within the context of the entire graph, information is provided about how subgraphs are embedded in the overall structure. Often it is also desirable to realign these foci in order to facilitate the visual comparison of subgraphs. We have introduced a distortion-based viewing tool, three-dimensional pliable surface (3DPS) [1], which allows for multiple arbitrarily-shaped foci on a surface that can be manipulated by the viewer to control the level of detail contained within each region. This paper extends 3DPS to include the repositioning of foci so as to bring together spatially separated regions for the purpose of comparison while retaining the effect of detail in context viewing. The significance of this approach is that it utilizes precognitive perceptual cues about the three-dimensional surface to make the distortions comprehensible, and allows the user to interactively control the location, shape, and extent of the distortion in very large graphs.

Distortion viewing techniques for 3-dimensional data

As the use of 3D information presentation becomes more prevalent, the need for effective viewing tools grows accordingly. Much work has been done in developing tools for 2D spaces which allow for detail in context views. We examine the extension of such 2D methods to 3D and explore the limitations encountered in accessing internal regions of the data with these methods. We then describe a novel solution to this problem of internal access with the introduction of a distortion function which creates a clear line of sight to the focus revealing sections previously obscured. The distortion is symmetric about the line of sight and is smoothly integrated back into the original 3D layout.

Visual access for 3D data

ABSTRACTWe describe a novel solution to the problem of occlusion inviewing three-dimensional data. A distortion function is usedto clear a line of sight to previously obscured interior ele-ments.KeywordsDistortion viewing, 3D interactionINTRODUCTIONThere is accumulating evidence [1] supporting the idea thatthree-dimensional representations of data are advantageous.Unlike 2D techniques, 3D viewing encounters a fundament-al problem in the display of information in that it is possiblefor an object of interest to be partially or wholly occluded byother objects. Current solutions provide access to such inter-nal details through the use of cutting planes, layer removal,fly-through, and transparency. However, such techniques re-sult in the loss of contextual information.The recent desire to integrate knowledge and experiencefrom the field of cognitive science into the design of user in-terfaces and new interaction paradigms has led to an appre-ciation of the importance of presenting data within its con-text [3, 4]. Our goal is to allow interactive access to 3D in-formation spaces while maintaining context. This is achievedby providing a viewer aligned visual access distortion whichclears a line of sight to the object of interest, permitting ex-amination from all angles.VISUAL ACCESS DISTORTIONThe problem of occlusion arises when objects lie on or nearthe line of sight, between the viewpoint and the focus. Thesolution is to move data objects away from the line of sightwhere necessary, clearing a path to the focus. A distortion isapplied radially about the line of sight, displacing data itemsin gradually decreasing amounts as their distance from theline of sight increases (Figure 1). Here the scale and hue ofthe focal node have been adjusted to distinguish it from thefield.

Tardis: a visual exploration environment for landscape dynamics

This paper presents the creation of a visual environment for exploring landscape patterns and changes to such patterns over time. Dynamic landscape patterns can involve both spatial and temporal complexity. Exploration of spatio-temporal landscape patterns should provide the ability to view information at different scales to permit navigation of a vast amount of information in a manner that facilitates comprehension rather than confusion. One way of achieving this goal is to support selection, navigation and comparison of progressively refined segments of time and space. We have entitled this system Tardis after the time machine of Dr. Who, to emphasize the exploration of time dependent data and because our use of elastic presentation has the effect of providing more internal space than the external volume suggests. Of special concern in this research is the extent of the data and its inter- relationships that need to be understood over multiple scales, and the challenge inherent in implementing viewing methods to facilitate understanding.

Case study: visual access for landscape event based temporal data

As ecological awareness increases there has been a shift towards more integrated forest management. Accurate modeling of future states of forested landscapes will allow better planning for safeguarding our forest resource for future generations. We present an initial exploration into providing visual access to information generated by SELES (Spatially Explicit Landscape Event Simulator). We explore the application of our visual access distortion technique to a block of temporal data created from a sequence of landscape event based information. This type of access extends the possibilities of visual exploration for temporal and spatial interrelations in a data set.

Multi-scale viewing

As the ability to accumulate and generate very high resolution image data explodes so does the need for appropriate access tools. We present a multi-scale or detail in context viewing tool for image data.