The 2016 Visualization Career Award goes to John Dill in recognition of major industrial and academic research advances spanning CAE/CAD, HCI, and data visualization as well as organizational leadership that helped develop the field of visual analytics.

We introduce a propagation-based parametric symbolic model approach to supporting analytic provenance. This approach combines a script language to capture and encode the analytic process and a parametrically controlled symbolic model to represent and reuse the logic of the analysis process. Our approach first appeared in a visual analytics system called CZSaw. Using a script to capture the analyst’s interactions at a meaningful system action level allows the creation of a parametrically controlled symbolic model in the form of a Directed Acyclic Graph (DAG). Using the DAG allows propagating changes. Graph nodes correspond to variables in CZSaw scripts, which are results (data and data visualizations) generated from user interactions. The user interacts with variables representing entities or relations to create the next step’s results. Graph edges represent dependency relationships among nodes. Any change to a variable triggers the propagation mechanism to update downstream dependent variables and in turn updates data views to reflect the change. The analyst can reuse parts of the analysis process by assigning new values to a node in the graph. We evaluated this symbolic model approach by solving three IEEE VAST Challenge contest problems (from IEEE VAST 2008, 2009, and 2010). In each of these challenges, the analyst first created a symbolic model to explore, understand, analyze, and solve a particular subproblem and then reused the model via its dependency graph propagation mechanism to solve similar subproblems. With the script and model, CZSaw supports the analytic provenance by capturing, encoding, and reusing the analysis process. The analyst can recall the chronological states of the analysis process with the CZSaw script and may interpret the underlying rationale of the analysis with the symbolic model.

In this paper we present a novel data structure combined with geometrically efficient techniques to simulate a "tissue peeling" method for deformable bodies. This is done to preserve the basic shape of a body in conjunction with soft-tissue deformation of multiple deformable bodies in a geometry-based model. We demonstrate our approach through haptic rendering of a virtual anatomical model for a dissection simulator that consists of surface skin along with multiple internal organs. The simulator uses multimodal cues in the form of haptic feedback to provide guidance and performance feedback to the user. The realism of the simulation is enhanced by computation of interaction forces using extrapolation techniques to send these forces back to the user via a haptic device.

Two studies evaluated linear and hierarchy+elision small‐screen display formats for clinical reasoning tasks. A controlled, quantitative study with 28 medically naive participants using a task abstracted from clinical use of laboratory results found that both display formats supported rapid and accurate decision making. Distribution of the search targets significantly affected speed, with decisions in linear format made 13% faster (4.7 sec) when all targets could be viewed on a single screen than when targets required scrolling between several screens and in hierarchical format 15% faster (5.1 sec) when all the targets were confined within one category. Performance was equivalent regardless of the relative order of the target results and data in the laboratory report. In a qualitative study, 7 physicians used the displays to perform a realistic diagnosis. Physicians were comfortable with both display formats, but preference varied with clinical experience. The 5 less experienced clinicians favored hierarchy+elision, whereas the 2 highly experienced clinicians tended to prefer the linear display.

This paper presents an initial study of an approach to reduce computational overhead in haptic rendering of physically based models. Haptic rendering refers to the notion of adding physical properties and behavior, specifically a sense of touch or force feedback, to models of objects. In this way, a user through a haptic feedback device can feel interaction forces while visually observing the objects. Physically based modeling is particularly important when representing deformable objects. In this paper, an approach based on a mass-spring damper system is used in modeling deformable objects. Deformation due to interaction forces is obtained by solving a set of differential equations, a process that is in general computationally demanding. To reduce this demand, the notion of level-of-detail in haptic rendering is introduced. Here the interplay between the graphical mesh and the haptic mesh as a function of various levels of subdivision is studied. The approach we describe is to adjust model parameters such that the user feels the same reaction force for a given deformation, regardless of the level of local subdivision.A preliminary user study with simple objects suggests there can be a local subdivision threshold such that the user cannot distinguish between global subdivision and the local subdivision introduced by the level-of-detail algorithm. This conclusion is beneficial for haptic rendering of deformable objects. Similar conclusions were obtained for haptic rendering of rigid objects. These results can be used as a guideline for other approaches to modeling deformable objects, such as finite element representations.

Computer-aided design (CAD) and 3D visualization techniques are at the heart of many engineering processes such as aircraft, ship, and automobile design. These visualization tasks require users to navigate or wayfind through complex 3D geometric models consisting of millions of parts. Despite numerous studies, it remains unclear whether large-screen displays improve user performance for such activities. We present a user study comparing standard desktop, immersive room (i.e., CAVE), and wall displays with 3D stereo/head-tracking, and mono/no head-tracking. We observed individual differences between users and found that the presence of contextual structure greatly impacted performance, suggesting that providing structure and developing interaction techniques accommodating a wide range of users yields better performance than focusing on display characteristics alone.

Tissue dissection is an important procedure in surgical simulation systems. Dissection involves cutting through and separating the tissue after a cut. In this paper, we use a surface mass-spring model to simulate virtual dissection by progressive subdivision and re-meshing. We introduce novel algorithms to generate interior structures that show the cutting result generated by the interaction between instrument and model. In addition, a novel data structure for object representation after the cutting action is proposed which allows the original soft object to be divided and a portion manipulated away. The dissection environment can support a number of user interface devices which can manipulate different representation of virtual instruments. These techniques are being integrated into a training environment for both open and minimally invasive surgery.

Originally designed as a messaging application, email is now used for a wide range of functions. Email clients however have not progressed correspondingly to support users with email management. This work describes the design of EzMail, an email visualization tool that runs in conjunction with an email client and creates a multi-view interface to assist with email management. Our primary focus is to group and visualize messages as components of threads to provide contextual information and conversational history. We have developed visualizations for individual messages, message properties, and messages in a thread. Message annotation is incorporated, along with a capability for replying simultaneously to several messages. A small user survey and a user study provided information regarding users' management of their messages and threads, and a comparative evaluation of EzMail with respect to Microsoft Outlook.

This demonstration presents the current state of an on-going team project at Simon Fraser University in developing a virtual environment for helping to train surgeons in performing laparoscopic surgery. In collaboration with surgeons, an initial set of training procedures has been developed. Our goal has been to develop procedures in each of several general categories, such as basic hand-eye coordination, single-handed and bi-manual approaches and dexterous manipulation. The environment is based on an effective data structure that offers fast graphics and physically based modeling of both rigid and deformable objects. In addition, the environment supports both 3D and 5D input devices and devices generating haptic feedback. The demonstration allows users to interact with a scene using a haptic device.

Computing devices within current work and play environments are relatively static. As the number of 'networked' devices grows, and as people and their devices become more dynamic, situations will commonly arise where users will wish to use 'that device there' instead of navigating through traditional user interface widgets such as lists. This paper describes a process for identifying devices through a pointing gesture using custom tags and a custom stylus called the gesturePen. Implementation details for this system are provided along with qualitative and quantitative results from a formal user study. As ubiquitous computing environments become more pervasive, people will rapidly switch their focus between many computing devices. The results of our work demonstrate that our gesturePen method can improve the user experience in ubiquitous environments by facilitating significantly faster interactions between computing devices.

We describe a simple technique for accurately calibrating the temporal lag in augmented and virtual environments within the Enhanced Virtual Hand Lab (EVHL), a collection of hardware and software to support research on goal-directed human hand motion. Lag is the sum of various delays in the data pipeline associated with sensing, processing, and displaying information from the physical world to produce an augmented or virtual world. Our main calibration technique uses a modified phonograph turntable to provide easily tracked periodic motion, reminiscent of the pendulum-based calibration technique of Liang, Shaw and Green. Measurements show a three-frame (50 ms) lag for the EVHL. A second technique, which uses a specialized analog sensor that is part of the EVHL, provides a "closed loop" calibration capable of sub-frame accuracy. Knowing the lag to sub-frame accuracy enables a predictive tracking scheme to compensate for the end-toend lag in the data pipeline. We describe both techniques and the EVHL environment in which they are used.

Many information structures are represented as two-dimensional networks (connected graphs) of links and nodes. Because these network tend to be large and quite complex, people often perfer to view part or all of the network at varying levels of detail. Hierarchical clustering provides a framework for viewing the network at different levels of detail by superimposing a hierarchy on it. Nodes are grouped into clusters, and clusters are themselves place into other clusters. Users can then navigate these clusters until an appropiate level of detail is reached. This article describes an experiment comparing two methods for viewing hierarchically clustered networks. Traditional full-zoom techniques provide details of only the current level of the hierarchy. In contrast, fisheye views, generated by the “variable-zoom” algorithm described in this article, provide information about higher levels as well. Subjects using both viewing methods were given problem-solving tasks requiring them to navigate a network, in this case, a simulated telephone system, and to reroute links in it. Results suggest that the greater context provided by fisheye views significantly improved user performance. Users were quicker to complete their task and made fewer unnecessary navigational steps through the hierarchy. This validation of fisheye views in important for designers of interfaces to complicated monitoring systems, such as control rooms for supervisory control and data acquistion systems, where efficient human performance is often critical. However, control room operators remained concerned about the size and visibility tradeoffs between the fine room operators remained concerned about the size and visibility tradeoffs between the fine detail provided by full-zoom techniques and the global context supplied by fisheye views. Specific interface feaures are required to reconcile the differences.

Navigatingand viewing large information spaces, such as hierarchically-organized networks from complex realtime systems, suffer the problems of viewing a large space on a small screen.Distorted-view approaches, such as fisheye techniques, have great potential to reduce these problems by representing detail within its larger context but introduce new issues of focus, transition between views and user disorientation from excessive distortion.We present a fisheye-based method which supports multiple focus points, enhances continuity through smooth transitions between views, and maintains location constraints to reduce the user's sense of spatial disorientation.These are important requirements for the representation and navigation of networked systems in supervisory control applications.The method consists of two steps: a global allocation of space to rectangular sections of the display, based on scale factors, followed by degree-of-interest adjustments.Previous versions of the algorithm relied solely on relative scale factors to assign size; we present a new version which allocates space more efficiently using a dynamically calculated degree of interest.In addition to the automatic system sizing, manual user control over the amount of space assigned each area is supported.The amount of detail shown in various parts of the network is controlled by pruning the hierarchy and presenting those sections in summary form.

In developing a mathematical representation for a surface, designers currently must use line drawing graphics to examine the curvature of a line in a plane, a two-dimensional analysis. By combining a result from differential geometry with the use of color raster graphics, the method described in this paper provides a means for the designer to examine surface curvature, a three-dimensional analysis. In particular, a formulation for the Gaussian and average curvatures is given and it is shown how these indicate the presence or absence of protrusions, hollows, etc. in a surface, i.e., how, where, and by how much the surface curves.

article Free Access Share on On the organization of a remote low cost intelligent graphics terminal Authors: John C. Dill General Motors Corporation General Motors CorporationView Profile , James J. Thomas General Motors Corporation General Motors CorporationView Profile Authors Info & Claims ACM SIGGRAPH Computer GraphicsVolume 9Issue 1Spring 1975pp 1–8https://doi.org/10.1145/964963.563733Published:01 April 1975Publication History 7citation275DownloadsMetricsTotal Citations7Total Downloads275Last 12 Months13Last 6 weeks1 Get Citation AlertsNew Citation Alert added!This alert has been successfully added and will be sent to:You will be notified whenever a record that you have chosen has been cited.To manage your alert preferences, click on the button below.Manage my AlertsNew Citation Alert!Please log in to your account Save to BinderSave to BinderCreate a New BinderNameCancelCreateExport CitationPublisher SiteeReaderPDF

Abstract A method of handling asynchronous interrupts, which are defined to be events, in a highlevel, block‐structured language is described. The language facilities are based on PL/1 conditions. The functions of an interrupt handler and its relationship with the execution time support for the language are defined and discussed. The development of the facilities being presented is also described. Solutions to design problems and implemenation details are stated. The use and benefits of the mechanism are discussed.