Animation under Unix remains an awkward process; PCs (running Windows) & Macs are much better at this. Still, it can be done, even without buying expensive software. Generally the easiest way is to create a series of frames that you want to string together to form a movie. These frames could be produced by a drawing package (like POV-Ray, described below) and/or a plotting package (for example, in sm you could output to device blackgif to create a GIF image of a plot). The frames should be numbered consecutively and left-padded with zeroes, e.g. frame001.gif, frame002.gif, etc. for easy manipulation. The file format is largely dictated by the movie-making package you choose. For example, mpeg_encode accepts a handful of formats and has a provision to convert from an unsupported format to a supported one. Conversely, ppm2fli supports only PPM format (``portable pixmap'') and gifsicle supports only GIFs. If you need to keep the frames as well as the movie, the best strategy is to use compressed formats for the frames. Otherwise, use PPM for maximum flexibility. The Netpbm package contains lots of graphics conversion and processing utilities. These are available on the department machines (e.g. man pbm pgm ppm pnm to get listings of most of the utilities). Also check out:
http://netpbm.sourceforge.net/for the latest source. Another popular conversion tool is ImageMagick:
http://www.imagemagick.org/(in particular, check out the convert command, which comes standard these days in many Linux implementations.) You can use xv or display to view graphics files in a window.