All movies were made on a Macintosh. For each movie, the electric and magnetic fields were calculated numerically from first principles, at each location of interest. A computer program, written in the cT language, performed the calculations, and generated wireframe representations of the objects and field vectors. The wireframe representations were exported to a 3D rendering program, where surfaces were applied and the images were rendered. The challenging part was selecting the locations where the field would be displayed, so the images would be informative, but not incomprehensibly cluttered.
In cases where the camera "flies through" a static field configuration,
wireframe models were exported in DXF format to Specular Infini-D. In Infini-D, surfaces were created and applied,
lighting was set, and a camera path was constructed. QuickTime movies were generated
through the animation option. Usually Phong shading was used, with medium anti-aliasing.
Fog was added to increase sense of depth. Adobe Premiere was
often used to assemble several clips into a single movie.
In cases where fields are changing dynamically with time, each frame of the movie had to
be computed and rendered separately. For these movies (moving proton, stretching dipole,
radiation from an accelerated charge, and traveling electromagnetic wave), Persistence of Vision (POVRAY), a freeware
Ray Tracing program, was used. The cT program generated a complete POV scene description
(in the POV scene description language) for each frame, and exported it to a file. The POV
files were batch rendered on a Power Mac; these movies required 15-40 hours of Power Mac
time to render (not counting all the initial trials). The resultant PICTs were assembled
into a QuickTime movie using MooVer (a free utility available with POV).
All of the movies were initially compressed using the Animation CODEC. Most of them were
then recompressed using Cinepak (in Adobe Premiere) to reduce data rates to about 250 K/s
or less, to make it possible to play them directly from a CD.