Facility Vulnerability with VISAC

Contour Viewer

The contour viewer is the main way to access grid data. A grid is a set of QuickBlast points all calculated with the same weapon and calculational parameters. The locations are evenly spaced in two or three dimensions. Navigation is done with the mouse or using the menu options. This viewer is also used to select one of the QuickBlast points from one of the grids for a VISAC 'QuickBlast from Grids' incident.

Navigation

The viewer contains a single section view of the facility: front, top or side. The bounding box of the view is shown on the left hand side panel, as well as the value of the cut plane that the view is in. For top views, both the absolute height (elevation above sea level) and the relative height (above ground level) are shown. The user can set the extent of the view showing by changing the bounding box parameters, and then pushing the 'Redraw' button. The value of the cut plane can be set by moving the slider bar or typing in the value. Zooming is done with the mouse (press the mouse button at one corner of your desired zoom area, drag to the opposite corner, then release) or using the 'Scene' menu, the 'Camera' option, and then either 'Zoom In' or 'Zoom Out'.

Figure 10. An example of a grid of large truck bomb QuickBlast calculations for a fictitious nuclear power plant.

Data Display

The default view is to show all of the points from all of the grids, and to color-code them by the probability of one of the major consequences determined for the facility. This produces a contour map of the consequence probability. Note that the walls and components are shown in levels of gray so that that they are not mistaken for the color contours representing the consequence level. The data display is controlled by the 'Data Select' tab.

Data can be restricted in several ways: first, the user can select just one or a few of the grids to work with. Second, the user can decide to either

• show all of the calculated points for each selected grid for one selected aspect (a major consequence of damage), or
• show only the points from the selected grids whose outcomes meet some set of criteria.

Selecting 'All calculated points by Grid/Aspect' in the 'Display Type' box lets the user pick which aspect to use for all of the selected grids. Select one of the aspects, then which consequence. Return to the image by selecting the 'Contour Plot' tab and then select 'Redraw'.

Selecting 'Selected points based on Outcome' in the 'Display Type' box allows the user to go through each aspect and specify which points to display. For each aspect, the user can pick one consequence and then set upper and lower limits on that consequence's probability. Only those points which fall in between the limits will be shown. When all of the aspects that you wish to be included have been set, return to the image by selecting the 'Contour Plot' tab and then select 'Redraw'.

Standard Features

As the mouse is moved around the image, the status bar below the image shows the coordinates (usually feet), the name of the region, and the material code for the region. For detailed models, the names of critical components and their damage probabilities will also be displayed. For basic models, the building name will be displayed.

The 'File' menu allows the geometry to be exported or the current image to be saved.

• 'Export Geometry' option - writes out the geometry information in a variety of formats, including BRL-CAD, WaveFront and Unreal Tournement.
• 'Save Image as JPEG' - creates a *.jpeg file for the current view.
• 'Copy Image to Clipboard' - copies the current image to the system clipboard, which can then be pasted into other programs, such as MS Word.

Contour Viewer Features

The menu 'Scene', option 'Camera', option 'Default View' will set the bounding box and the cut plane to show the center of the volume defined by all of the selected grids.

There are also several menu options under the 'Scene' menu which allow the user to change the view of the plant. These include which view (Top, Front, Side) and what type of render style to use (Filled or Edges). The user can also decide to show or not the blast points with black dots ('Scene', 'Blast Data', 'Blast Points') and decide to use color or black and white contours ('Scene', 'Blast Data', 'Colors').

Also, as the mouse is moved around the facility, a display at the bottom of the viewer reports the coordinates, the geometry region name, the material code, and the building name (or the basic event name if the region is a critical component).

Clicking on a blast point will bring up the BlastWave Viewer which shows a contour plot of the blast overpressure (in air) for that blast point.

Selecting a Blast Point

To pick a blast point for a VISAC 'QuickBlast from Grids' incident, simply click on one of the displayed blast points. A small dialog will be displayed, asking if you first wish to see the blast overpressure (in air) map using the BlastWave Viewer. If you select 'No' in this dialog or after you close the BlastWave window, a second dialog will ask if this is the point you wish to use in the incident. If it is, select 'Yes'. If not, select 'No' and pick the point you wish to use in the incident.

Three Dimensional Contour Plots

Work is currently ongoing to create a useful 3D view of the contour data. Several of our test modules are available to be used from the 'File' menu, '3d Viewer' option. All of these tend to be slow and memory intensive, and may result "Out of Memory" errors for large sets of grid data. These should be used with caution as they are still under development.

Oak Ridge National Laboratory, 2004

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