Elements of Visualization

When a scientist comes to us for help in presenting data, we first determine how the visualization is going to be used. The technique we recommend depends partly on whether the visualization is to be used as part of a presentation or as an analysis tool. A very-high-quality static image or video animation is more costly to generate, but it may be better suited for use in a conference or as part of a presentation for future funding of a project. A simple, inexpensive image or animation may be the best solution for a researcher who needs to analyze data from multiple computer simulations. We also ask a prospective user to identify, if possible, the most important phenomenon he or she wants to observe or show. We can then tune the visualization to highlight that aspect of the science.
Consider a materials science problem of finding the area of the highest density of electrical charges within a three-dimensional (3D) volume. One way to simplify the process of looking into a volume is to break the problem down into a series of two-dimensional (2D) slices running along one of the axes of the volume. Each slice of the volume shows the charge density as a color contour map within that slice. The original volume can be represented by an outline of a rectangular box. The series of images generated by visualizing a perspective view of this box with each of the slices correctly oriented within the box produces an animation.

Another method of visualizing data in three dimensions is to generate isosurfaces. An isosurface is a surface generated by connecting all data in the volume that have the same value. In groundwater contamination modeling, a 3D volume of concentrations can be simplified by generating isosurfaces of different contaminant concentrations.