16.1.8 Manipulating Scalar Fields

Interactivity is an important feature available in all of these data visualization techniques. A visualization system becomes dramatically more useful if the data set can be manipulated by the viewer, especially in real-time.

Some important interaction features include:

1. 3D manipulation of the data space The viewer should be able to rotate, scale, and zoom the data space. This makes it possible to clarify the relationship between data points, especially for 3D data fields.
2. Isolate a subset of the data The ability to zoom in and clip a subregion of the data set is important for analyzing the data as a series of smaller pieces. Allowing the user to simplify the scene by subsetting the data makes it possible to tag the subset with additional information without incurring excessive clutter.
3. Picking/Selecting data values Being able to pick a data value or small set of values is an important feature. The user can query a point, getting its exact value, without cluttering the entire scene with unnecessary details.