Volume Visualizations

The Volume tool allows you to quickly visualize volume data. The example in this section uses variables that you enter on the command line.

Note
If you currently have variables open in the Variables view, you may want to reset your session so that only these new variables will display. To reset, click the Reset button () at the top right of the command line.

Make sure you are viewing the IDL Visualize Perspective. (Click the Visualize button (

) in the upper right of the Workbench.)

Enter the code the command line (or click on the code below):

RESTORE, FILEPATH('clouds3d.dat', SUBDIRECTORY=['examples', 'data'])

Two variables, CLOUDS and RAIN, appear in the Variables View.

In the Variables View, click on the first variable in the list (CLOUDS).

Hold down the Shift key and click the last variable in the list (RAIN).

With the variables all selected, drag and drop them on the Volume tool:

An iVolume window opens, displaying the data:

In this display, it's difficult to see much information about the data. For example, which parts are clouds and which parts are rain?

Enhancing the Display

To better understand the data, manipulate the data display to show the rain data more prominently.

From the menu, select Operations → Volume → Internal Volume.

The Internal Volume Value Selector dialog appears.

At the top of the dialog, select Volume 1 from the pull-down list. In the slider Mesh quality: % of original surface, move the slider to the left to 10, as shown:

Click OK.

The display now displays the rain data clearly:

Manipulating Volume Visualizations

Once you have visualized an image, you can perform many different kinds of operations on it, including:

Using the Volume Panel to view and modify regions of interest, pixel value, location, and scale, edit the palette, etc. (see Using the Volume Panel)

Modifying properties such as adding colorbars, axes, resampling, filtering, contouring, and surfacing (see Volume Properties)

Manipulating the visualization by rotating, scaling, flipping, inverting, zooming, adding annotations, etc. (see Manipulating the Volume Display)

Changing operations such as cropping, or viewing statistics or a histogram (see iVolume Tool Operations)

Using the iTools Procedural Interface to add a variety of annotations.

For more information, please refer to Working with Images and Manipulating the Display in the iTools User Guide.