The main piece of software used in performing the visualisations was AVS 5, and the networks used are discussed and presented in detail in Section 3.1. All the animations were performed in AVS 5, which generated individual frame files for each animation. These frame files were then composited into SGI movie files and Quicktime movie files using the SGI makemovie utility. The image files created by AVS 5 were converted into the intermediate SGI RGB file format using the mica batch image conversion utility.
The specific settings found to be best for makemovie were either SGI movies using JPEG compression, or Quicktime movies using Compact Video (also known as Cinepak) compression. These movies have the best compression ratios (that is, produce the smallest files) whilst preserving good image quality and frame rates. The Quicktime Cinepak movies, in particular, are suitable for publication on the World Wide Web, as Quicktime Cinepak is a common format with wide support.
The time-based animations, presented in Sections 2.1 and 2.2, have frame rates of 2 frames per second. The animations with time as an additional visualisation dimension, presented in Sections 2.3 and 2.4, have frame rates of 5 frames per second. These rates were chosen as they show the animations with enough speed to appear smooth, yet slow enough to examine detail and thus are not too fast. However, fast, overview animations are useful for seeing the ``bigger picture'' of the animation, and frame rates of 10 frames per second for the time-based animations and 20 frames per second for the remaining animations have proved valuable.
The SGI utility moviemaker was found to be grossly too unstable for practical use, and so as a result all titles and other context was added in AVS 5 at the image generation stage, rather than at the movie creation stage.
In addition, small awk scripts were written to generate the many repetitive AVS field files required, as detailed in Section 3.1.