Mark Paton

Algorithm for dynamic disparity adjustment

This paper presents an algorithm for enhancing stereo depth cues for moving computer generated 3D images. The algorithm incorporates the results from an experiment in which observers were allowed to set their preferred eye separation with a set of moving screens. The data derived from this experiment were used to design an algorithm for the dynamic adjustment of eye separation (or disparity) depending on the scene characteristics. The algorithm has the following steps: (1)Determine the near and far points in the computer graphics scene to be displayed. This is done by sampling the Z buffer. (2) Scale the scene about a point corresponding to the midpoint between the observers two eyes. This scaling factor is calculated so that the nearest part of the scene comes to be located just behind the monitor. (3) Adjust an eye separation parameter to create stereo depth according to the empirical function derived from the initial study. This has the effect of doubling the stereo depth in flat scene but limiting the stereo depth for deep scenes. Steps 2 and 3 both have the effect of reducing the discrepancy between focus and vergence for most scenes. The algorithm is applied dynamically in real time with a damping factor applied so the disparities never change too abruptly.

Interactive 3D tools for pipeline route planning

With their ability to efficiently provide high-resolution bathymetry with complete coverage over wide swaths of the seafloor, multibeam sonars are increasingly becoming a standard tool for the planning of marine engineering projects such as pipelines and communication cables. In addition to high-resolution bathymetry, most modem multibeam sonar systems also provide sonar backscatter data, an indicator of surficial texture or material type. These data sets are combined with high-resolution seismic, standard sidescan and ground truth (coring or geotechnical) data to allow the marine engineer to make optimal judgments about the route of a submarine pipeline or cable. Huge volumes of data are generated by the different survey systems, often running into hundreds of megabytes. Typically this data is only available to the engineer in the form of a paper atlas with each type of data presented separately. We present a suite of software tools (the Fledermaus Toolkit) designed to present data in a three dimensional visual format, allow its interactive exploration, and to quantitatively interrogate the data within the 3-D space for geographic information and other attributes (depth, gradients, etc.). Cable and pipeline routes are planned interactively by simply drawing the route on the seabed and adjusting the route as needed. Two-dimensional and three-dimensional views of the route are simultaneously available when necessary.

Three dimensional imaging of the Belousov-Zhabotinsky reaction using magnetic resonance

The combination of 3D magnetic resonance imaging data with polygon based computer graphic display software is ideally suited to the study of the Belousov-Zhabotinsky reaction in extended volumes. In this paper we present the first true three dimensional visualization of experimental data from the Belousov-Zhabotinsky reaction. The time evolution of a twisted scroll wave like isoconcentration surface and its organizing filament are demonstrated for the manganese-catalyzed B-Z mixture. These techniques extend the experimental study of the B-Z reaction as a class of pattern-forming systems to the third dimension. The limitations of the technique are discussed.

Dealing with increasing data volumes and decreasing resources

The US Naval Oceanographic Office (NAVOCEANO) has recently updated its survey vessels and launches to include the latest generation of high-resolution multibeam and digital side-scan sonar systems, along with state-of-the-art ancillary sensors. This has resulted in NAVOCEANO possessing a tremendous ocean observing and mapping capability. However, these systems produce massive amounts of data that must be validated prior to inclusion in various bathymetry, hydrography, and imagery products. It is estimated that the amount of data to be processed will increase by an overwhelming 2000 times above present data quantities. NAVOCEANO is meeting this challenge on a number of fronts that include a series of hardware and software improvements. The key to meeting the challenge of the massive data volumes was to change the approach that required every data point to be viewed and validated. This was achieved with the replacement of the traditional line-by-line editing approach with an automated cleaning module, and an area-based editor (ABE) integrated with existing commercial off-the-shelf processing and visualization packages. NAVOCEANO has entered into two cooperative research and development agreements (CRADAs) - one with the Science Applications International Corporation (SAIC), Newport, RI, USA, and the other with Interactive Visualization Systems (IVS), Fredericton, N.B., Canada, to integrate the ABE with SAICs SABER product and IVSs Fledermaus 3D visualization product. This paper presents an overview of the new approach and data results and metrics of the effort required to process data, including editing, quality control, and product generation for multibeam data utilizing targets from digital imagery data and automated techniques.

Passive force feedback for velocity control

This paper introduces the Bungee Bat as a 3D passive force feedback device for velocity control for exploring 3D graphical environments. A qualitative study was carried out to compare a freehand velocity control device with the Bungee Bat for several navigation tasks in a graphical world consisting of a digital terrain map.