SMS:Contour Options

3D view of color filled contours

At a glance

• Visualize scalar datasets
• Linear, color filled or both at the same time
• Variable level of transparency
• Full control of ranges and colors
• Precision control for labels and legends

SMS can generate contours from a scalar dataset. Contour display is enabled using in the Display Options dialog. Unique contour display options can be set for each module that uses scalar datasets. Contour options can also be set for an individual dataset.

The module contour options can be edited by:

• The menu command Data | Contour Options. The data menu is available in most modules. See Module Specific Menus for more information.
• Opening the Display Options dialog
• The Contour Options Macro File:Contour Options.bmp

The dataset specific contour options for an individual dataset can be edited by:

• Right-click on the dataset in the Project Explorer and choose Dataset Contour Options. This will open a dialog where a user can define dataset specific contour options. If wanting to go back to using the module contour options, right-click on the dataset in the Project Explorer and choose Clear Dataset Contour Options.

Data Range

The name, minimum value, and maximum value for the active time step of the dataset are shown. These values are sometimes useful when choosing an appropriate contour interval.

A minimum and maximum contour value can be specified, restricting the contours interval which will be shown. If the range is not specified, SMS will automatically choose a range based on the minimum and maximum value for the active time step.

Contour Interval

The contour interval is user controlled. Options include:

• Number of Contours – Specify the number of contours to use. SMS will automatically determine the value for each interval based on the specified range or dataset range.
• Specified Interval – Specify the interval to use for contours. SMS will automatically determine the number of contours needed based on the specified range or dataset range.
• Specified Values – Specify the number of contours to use and interval.

The items in the upper right section of the Contour Options dialog control the display of a contour legend and the option to accentuate some of the contours. If the Show Color Legend option is selected, and the contours are not being displayed as a single color, a legend of colors and corresponding data set values is displayed in a corner of Graphics Window. For color filled contours, this legend is a vertical strip of colors with text labels for the contour levels. If the contours are being displayed as linear segments or cubic splines, the legend is displayed as a series of contour level values and a line drawn in the color corresponding to that level. The size, location, label and font for the legend are set using the Legend Options dialog. If the user enters the title "DS" for the legend title, the name of the current dataset is used. If the user enters "DS:TS" the current dataset and time step are used as the title.

The options in the middle of the right side of the dialog control how the contours are computed and displayed. Three contouring methods are available:

• The default method is Normal Linear Contours and causes the contours to be displayed as piece-wise linear strings.
• If using the Color fill between contours method, the same linear contour strings are computed, but the regions between adjacent contour lines is filled with a solid color.
• If using the Cubic Spline Contours method, the contours are computed in strings and drawn as cubic splines. Drawing the contours as splines can cause the contours to appear smoother. Occasionally, loops appear in the splines or the splines cross neighboring contour splines. These problems can sometimes be fixed by adding tension to the splines. A tension factor greater than zero causes the cubic spline to be blended with or converge to a linear spline based on the same set of points. A tension factor of unity causes the cubic spline to coincide with the linear spline.

In the lower right corner of the Contour Options dialog, two buttons allow the user to specify the contour colors and the contour labeling options.

Contour Labels

File:Contour Label.jpg

Contour Label Options dialog

The Contour Label Opts command in the Data menu is used to access the Contour Labels Options dialog which can be used to set the label color, font, spacing, size, etc. The dialog may also be invoked through the Contour Options dialog.

Labels can be added to contours one of two ways:

1. The upper left portion of the Contour Label Options dialog controls the generation of automatically spaced contour labels. The user can toggle the generation of automatic contour labels on or off. If the toggle is on, the user also specifies which contours should be labeled and the distance along the contour between labels.
2. In some modules, contour or function labels can be added manually to an image by selecting the Contour Labels tool in the Tool Palette and clicking on the mesh or grid where a label is desired. If the Place on contours option in the upper right portion of the Contour Label Options dialog is selected, the label is moved to the closest contour and the contour is labeled there. If the Place under cursor option is selected, the label shows the value of the point at the click location and is placed there. This option is useful to post data set value labels in regions where there are no contours. Contour labels can be deleted by holding down the SHIFT key while clicking on a label.

The bottom portion of the Contour Label Options dialog control how the labels appear. On the left side, the user can control how many digits of accuracy are desired. The default will match the contour legend. On the right side, the user can select a color and font for the label. For labels on contours, the user may also specify that the contour be oriented to lie along the contour.

Contour Legend Options

File:Contout Legend.jpg

Contour Legend Options dialog

The Contour Legend Options controls the formatting and location of a displayed legend. If a contour dataset exists and is displayed, the legend will be shown if the Legend check box on the Contour Display Options dialog is checked. This window is accessed only from the Legend Options button on the Contour Display Options page of the Display Options dialog.

The Formatting section includes fields for the Title and Units displayed with the legend, a Font selection button for text style, and Height and Width fields for legend size.

Since contour datasets can be displayed for multiple modules at the same time and, therefore, multiple contour legends can be displayed, the Title field can include keywords for convenient labeling. The following title keywords are case sensitive:

• "MODULE" – will be replaced with the title of the contour dataset's module
• "DS" – will be replaced with the name of the currently selected contour dataset
• "DS:TS" – will be replaced with the name of the currently selected contour dataset followed by the current time step

A title of "MODULE DS:TS" is best since it will automatically update as contour dataset selection changes.

The Units field includes the single case sensitive keyword of "DEFAULT", which will be replaced with the velocity units of meters per second (m/s) or feet per sceond (ft/s) based on the current coordinate system's horizontal units.

The Location section includes a combo box for specifying the location of the displayed legend. The locations include:

• Top left corner
• Bottom left corner
• Top right corner
• Bottom right corner
• Screen location – specify the location based on screen precentages
• World location – specify the coordinate location

Related Topics

• Color Ramps
• Display Options