WPDFD Issue #4 - July 01, 1998
I suppose I'm pretty lucky. Not so long ago, a National lottery was introduced in the UK with weekly jackpots of eight million pounds or more. The chances of winning this jackpot are zillions to one but I thought that I would be clever and write a little computer program to improve my chances. Being a crazy designer and virtually number-dyslexic, my thinking was more mystical than scientific.
Choosing an animation technique to use on a Web page is primarily a trade-off between quality and file size. It also depends very much on how much effort the designer is prepared to put into producing it in the first place. Ok, we are not talking about Disney epics here, we are looking at ways to attract the eye in a basically static medium. The simplest animation technique is the animated GIF used mostly for banner ads.
Shockwave is a plug-in that displays Macromedia Director movies within a Web browser. Director has been around for quite some time and has always been a favourite with multimedia producers. Not only does it handle 2D animation in a very intuitive way, its scripting language, 'Lingo', gives extensive control for manipulating 'sprites', sound channels and for general interactivity and navigation. Although 'Shocked' files are compressed very efficiently, they still tend to be on the 'heavy' side compared to other Web animation techniques.
Adobe Macromedia Flash is based on 'vector' graphics. Instead of having to retrieve every individual pixel in an image, as you do with the bitmaps used in GIFs and JPEGs, vectors describe shapes as a set of coordinates. For a simple rectangle, for instance, you only need the coordinates of two opposite corners - just four numbers, and maybe a few more to provide the fill and border colors. So, file sizes are very small indeed.
Java animation can be virtually anything you want it to be but has been considerably more difficult to produce until recently. One of the features of Director 6.5 is that, as well as Shockwave, it can export animations as Java applets complete and ready to run without any special plug-ins. Most of my experience with Java has been bad. On a Mac, or with Windows NT, it is either pitifully slow, doesn't work or crashes the computer.
Animation adds a new dimension to Web pages but it isn't easy to do well. The designer has to consider how a graphic will change over time and has to be able to relate each drawing to the ones before and after. Traditional cell animation is done by tracing new positions on a piece of tracing paper or transparent film because each layer holds a image that has only marginally changed from the previous one.