Optimizing Design With Extensive Simulation Data: A Case Study of Designing a Vacuum-Assisted Biopsy Tool.

Design by Dragging (DBD) [1] is a virtual design tool, which displays three-dimensional (3D) visualizations of many simulation results obtained by sampling a large design space and ties this visual display together with a new user interface. The design space is explored through mouse-based interactions performed directly on top of the 3D data visualizations. Our previous study [1] introduced the realization of DBD with a simplistic example of biopsy needle design under a static bending force. This paper considers a realistic problem of designing a vacuum-assisted biopsy (VAB) needle that brings in more technical challenges to include dynamic tissue reaction forces, nonlinear tissue deformation, and progressive tissue damage in an integrated visualization with design suggestions. The emphasis is placed on the inverse design strategy in DBD, which involves clicking directly on a stress (or other output field parameter) contour and dragging it to a new (usually preferable) position on the contour. Subsequently, the software computes the best fit for the design variables for generating a new output stress field based on the user input. Three cases demonstrated how the inverse design can assist users in intuitively and interactively approaching desired design solutions. This paper illustrates how virtual prototyping may be used to replace (or reduce reliance on) purely experimental trial-and-error methods for achieving optimal designs.

Design by dragging: an interface for creative forward and inverse design with simulation ensembles.

We present an interface for exploring large design spaces as encountered in simulation-based engineering, design of visual effects, and other tasks that require tuning parameters of computationally-intensive simulations and visually evaluating results. The goal is to enable a style of design with simulations that feels as-direct-as-possible so users can concentrate on creative design tasks. The approach integrates forward design via direct manipulation of simulation inputs (e.g., geometric properties, applied forces) in the same visual space with inverse design via 'tugging' and reshaping simulation outputs (e.g., scalar fields from finite element analysis (FEA) or computational fluid dynamics (CFD)). The interface includes algorithms for interpreting the intent of users' drag operations relative to parameterized models, morphing arbitrary scalar fields output from FEA and CFD simulations, and in-place interactive ensemble visualization. The inverse design strategy can be extended to use multi-touch input in combination with an as-rigid-as-possible shape manipulation to support rich visual queries. The potential of this new design approach is confirmed via two applications: medical device engineering of a vacuum-assisted biopsy device and visual effects design using a physically based flame simulation.

Toward Mixed Method Evaluations of Scientific Visualizations and Design Process as an Evaluation Tool.

In this position paper we discuss successes and limitations of current evaluation strategies for scientific visualizations and argue for embracing a mixed methods strategy of evaluation. The most novel contribution of the approach that we advocate is a new emphasis on employing design processes as practiced in related fields (e.g., graphic design, illustration, architecture) as a formalized mode of evaluation for data visualizations. To motivate this position we describe a series of recent evaluations of scientific visualization interfaces and computer graphics strategies conducted within our research group. Complementing these more traditional evaluations our visualization research group also regularly employs sketching, critique, and other design methods that have been formalized over years of practice in design fields. Our experience has convinced us that these activities are invaluable, often providing much more detailed evaluative feedback about our visualization systems than that obtained via more traditional user studies and the like. We believe that if design-based evaluation methodologies (e.g., ideation, sketching, critique) can be taught and embraced within the visualization community then these may become one of the most effective future strategies for both formative and summative evaluations.

Interactive slice WIM: navigating and interrogating volume data sets using a multisurface, multitouch VR interface.

We present Interactive Slice World-in-Miniature (WIM), a framework for navigating and interrogating volumetric data sets using an interface enabled by a virtual reality environment made of two display surfaces: an interactive multitouch table, and a stereoscopic display wall. The framework addresses two current challenges in immersive visualization: 1) providing an appropriate overview+detail style of visualization while navigating through volume data, and 2) supporting interactive querying and data exploration, i.e., interrogating volume data. The approach extends the WIM metaphor, simultaneously displaying a large-scale detailed data visualization and an interactive miniature. Leveraging the table+wall hardware, horizontal slices are projected (like a shadow) down onto the table surface, providing a useful 2D data overview to complement the 3D views as well as a data context for interpreting 2D multitouch gestures made on the table. In addition to enabling effective navigation through complex geometries, extensions to the core Slice WIM technique support interacting with a set of multiple slices that persist on the table even as the user navigates around a scene and annotating and measuring data via points, paths, and volumes specified using interactive slices. Applications of the interface to two volume data sets are presented, and design decisions, limitations, and user feedback are discussed.