Classic Computer Magazine Archive ANTIC VOL. 6, NO. 2 / JUNE 1987



Design your own computerized cartoons

Reviewed by Matthew G. Loveless
START Consulting Editor

A faint light glows amidst a starry background. It darts playfully from side to side, then pauses mysteriously, pulsating slowly as if deciding what to do next-a lonely force in an empty universe. Flash! The screen brightens momentarily, shooting beams of stormy light from behind an imaginary horizon. A corporate logo appears in the maelstrom and moves forward, rotating, growing as it comes closer. The camera tilts downward, showing the Lincoln Memorial as the logo floats high above. The stars brighten and the logo fades, leaving the landmark structure alone under the night sky.

A new 15-second TV spot? The latest Lucasfilm magic created on a $50,000 graphics workstation? The sequel to Tron? No, none of the above. Try an Atari ST running the impressively powerful Aegis Animator ST. Full-scale, high-level computer animation has finally arrived for the Atari.

The Aegis Animator was first implemented on the Commodore Amiga over a year ago. When that version was finished, Jim Kent, the program author and now a SYSOP on the ST section of Byte's BIX, wasted no time translating it to the Atari. The Amiga version has been heralded as one of the finest low-cost animation systems ever available. In fact, professional animator Overton Lloyd used it in a new music video by Parliament called "Do you want shake with your fries?" And, the Danny Elfman-led group Oingo Boingo plays a taped Animator sequence on a giant screen while they perform at their concerts. Animator ST has all the features of the Amiga version, plus a few extra niceties thrown in for good measure. And, lest we Atari owners feel second best, William Volk of Aegis claims the Atari not only produces a sharper picture, but that metamorphic animations actually run faster on the ST.

Animator ST requires a color monitor and only runs in low-resolution. It comes on a single-sided disk with a 100 + page spiral-bound instruction manual, and it is not copy-protected. The Animator will run on a 512K machine, but Aegis recommends a megabyte or more for complex animations. I tried it on a standard 520ST and found enough memory to create sophisticated animations. But I was limited in my cut and paste abilities in the storyboard. It is certainly workable in a 1/2 megabyte, but dreams of five- and ten-minute animations are a powerful incentive for a memory upgrade.

There is no provision for using the animations within your own programs. You need either the animator itself or the PLAYER.PRG program. PLAYER.PRG is supplied on the program disk and Aegis lets you distribute it freely, so you can create your own animations and give them out with the Player. For those readers who wish to see what Animator ST can do before buying, you can download PLAYER.PRG from CompuServe or GEnie along with some sample animations. My personal favorite is the pyramid animation. The program starts you on an empty workspace with a GEM menu-bar at the top. In the center of the screen is a Fast Menu. The Fast Menu is a movable GEM-like window with icons you can point to and select. Each icon represents a function available in the animator. Most functions are available from either the Fast Menu or the menu bar, but some are exclusive to one or the other. At first I found the Fast Menu quick and convenient, but as soon as I got more than a couple of objects spread across screen, it became bulky and clumsy, constantly getting in the way of my work. (The Fast Menu takes up a full 1/5 of the usable screen area.) However, it is movable (even off the screen) and it can be easily disabled. I usually turn the Fast Menu on or off depending on the functions I'm using. If I'm doing a lot of disk access and color changes, I'll use the Fast Menu. If I'm manipulating polygons or cels, I'll stick to the drop-downs. Animator ST offers three types of animation: metamorphic, cel, and cyclic. Metamorphic (often just referred to as morphic) animation allows the manipulation and transformation of two-dimensional polygons in a quasi-3D perspective. Cel animation, a term which comes from studio cartoon animators who did much of their work on transparent celluloid, allows the planar movement of color pictures which you can extract from NEOchrome or DEGAS. Cyclic animation allows you to cycle groups of colors, like the color cycling features of NEOchrome and DEGAS Elite. Combined, these three types of animation can produce stunning artwork, seductive sales demonstrations, or even. . . a music video.

Every animation is built up from key frames, the atomic units of your sequence. In traditional hand-drawn animation, a professional illustrator would sketch key frames, the portions of the animation representative of the overall movement. Then an assistant (often an apprentice animator) would perform the mechanical process of drawing the in-between sequences. The animator, for example, might draw two key frames, one with Mickey's arm bent at the elbow and one with his arm outstretched. The assistant (or tweener) would draw the intermediate positons between bent and outstretched. This process was called tweening. When the full sequence was filmed and played back, the motion of the arm would appear smooth and continuous.

All three types of animation (morphic, cel, and cyclic) within Animator ST utilize some form of tweening. You create a key frame, deciding which type of objects should appear, where they should appear, and what color they should be. Then you decide how the objects should move or transform. Animator ST interpolates the intermediate frames and produces a smooth animation. For example, if I wanted to make a shooting star, I could create the star in the upper left hand corner and make that the first key frame. Then I could move the star to the lower right corner of the screen in a large arc, rotate it around its center a couple of times, shrink it to the size of one pixel, fade its color to black, and make the result the second key frame. When I play this back, the star begins bright in the upper left corner. Then it arcs downward while, simultaneously, shrinking, rotatating, and fading to nothingness -all in about a minute's worth of work. Tweens, as the sequences of one key frame to the next are called, determine the speed of the animation. The length of a tween is set in 60ths of a second (the color video refresh rate) and this setting determines how long the tween will last. In other words, a tween length of 60 will last one second. This means whatever transformations which are destined to happen, going from one key frame to the next, will take exactly one second. If you decrease the time of a tween, the same amount of activity must now happen in a shorter period of time, hence the events in this tween will occur at a faster rate. The faster you make a tween the coarser the animation becomes (less time to calculate) but the less your eye misses the smoothness (it's happening so fast).

This is a nice feature in the sense that everything can be synchronized with a real-time clock; you'll always know when an event will occur relative to another event and there's no guessing involved. However, the more objects you have on the screen and the more you animate them, the chunkier the animation becomes as Animator ST sacrifices smoothness for time. It's a trial and error process to find the delicate mix of speed and complexity which makes a slick animation. Fortunately, if you are taping, you can halve the global speed (thereby buying Animator ST more number-crunching time) and double the tape playback rate for an overall smoother production.

(JNL Technologies manufactures the Monitor Box composite video generator for the ST, which allows any ST, with or without RF output, to hook directly into a tape machine. For more information, contact Jeremy Berger
at (516) 536-3969.-ANTIC ED.)

The single most distinctive aspect of Animator ST is its metamorphic animation. The metamorphic animation is based on single-color polygons, either filled or unfilled. You create a polygon by defining its vertices. A line has two, a square has four, and the Atari Fuji logo might have twenty.

Once you have created a polygon and set it in a key frame, you can move and transform it in a variety of ways. You can rotate it around an axis in any three dimensions, make it shrink or grow, or move it across the screen. You can transform the fundamental shape of the polygon by adding or deleting vertices, stretching the endpoints, or folding edges over one another. You can even mix various forms of movement. For example, while moving laterally across the screen, you can rotate the top half of a polygon, while shrinking the lower half. The combinations are practically limitless.

Objects behave as if they were in a quasi-3-dimensional universe. The Z-dimension is faked (no real-time floating point math here!) and the objects are still two-dimensional. But you can still realize some stunning perspective effects. The Z-coordinate also determines whether one polygon should appear in front of another, allowing you to prioritize your images.

The best way to think of a cel in Animator ST is as rectangular cutout from a DEGAS or NEOchrome screen, because that's exactly where they come from. You make a eel by pulling up a full screen picture and drawing a rubber-box around the area you wish to use. Once you have a eel defined, you can use it in your animations. I found the cel animation rather "vanilla," almost as if it were added to the program as an afterthought.

It's cumbersome to define cel images, difficult to position them when you pull them into an animation, and limited in the amount of things you can do with them. For example, you can't resize a eel, nor can you change it once you cut it out of a picture without going through a rigamarole of pasting it, saving the screen out, and loading DEGAS or NEOehrome. The turnaround time on building eels into your animation is frustratingly slow, that is, compared to metamorphic animation. Additionally, the manual suggests that you can animate a eel by manually drawing successive images and then deleting and replacing the eel with a new one every tween-good luck. (To Aegis's credit, they do supply just such an animation on the Animator disk.)

However, with all that said, the eel features of Animator ST are better than most available eel-type animators and certainly no worse. I find I use eels for images which don't require sophisticated movement or require a lot of color and a high degree of detail. For example, the Lincoln Memorial mentioned in the first paragraph was a eel. It's a complex image, which couldn't have been created realistically with just polygons, and I only needed to move it vertically an inch or so. It's just a shame eels aren't as easy to use as the program's other features.

The final type of animation, cyclic, is nothing new to most Atari users. It's merely rotating palette registers. If you've played with the color cycling feature of NEOchrome or DEGAS Elite, you'll find it familiar. The idea is the same, only the approach is a little different. First, you determine the number of iterations you want the range of colors to cycle during any given tween. This means if you have an animation where you want a static image in the background to cycle, you must manually set the number of cycles for each tween or build the cycling into a strip. If you change the speed of the tween, you may have a bit of trouble readjusting your cycling. Second, the cycling doesn't just do a palette rotate, it actually fades one color into its neighboring color. This makes for a smoother transition but effects you designed in one of the paint programs can end up looking strange.

Editing animations is cumbersome. You're probably better off planning carefully than going back and fixing mistakes. For example, there is no easy way to insert or delete a key frame and the undo feature has a very short memory. This is very frustrating because something which should be an easy fix may take ten or more minutes of trial and error as you scrap everything and start over.

The cutting and pasting abilities of the storyboard, however, are very nice. You can pull out of an animation and enter the storyboard, a mode where you have six mini-screens, each one of which can hold a different animation. You can then cut and paste between animations. Beware, though, without lots of memory, you won't be able to do much editing on large animations. But, if you do run out of memory, Animator ST will do its best to maintain the integrity of the system and save off your current work into several smaller files.

Animations are saved out as scripts. A script is a text file which describes every action and every tween within your animation. You can load it into an editor, such as 1ST Word, and modify particular parameters and achieve special effects you can't create from within the Animator itself. This capability makes the animator one of the most powerful systems available, allowing you to customize and edit your animations much like professional animation systems allow. I spend almost as much time editing script files with my word processor as I do working within Animator ST.

High-level animation has finally
arrived for the Atari. Animator ST
has all the features of the Amiga
version, pIus a few niceties
thrown in for good measure.
The Atari not only produces a
sharper picture, but metamorphic
animations run faster on the ST.

Animation segments can be saved out as strips, also. A strip is a portion of an animation sequence which cannot run alone because it is designed to be mixed into another animation. With this feature, you can loop a common sequence continually or a fixed number of times, and you can mix animations of varying tween arrangements without worrying about how a time change in one will affect the other. My most successful animations were built up from strips. Unfortunately, I didn't pick up on this technique until I had been using the product for quite awhile-the documentation says very little about using strips effectively.

There isn't much to say about the Art Pak, except that it's a collection of predrawn cels, backdrops, and NEOchrome screens, for those of us who aren't accomplished artists. It comes on a double-sided disk. Customers who only have single-sided drives can transfer the files with the help of a friend or a dealer, or they can exchange their double-sided disk for two single-sided ones directly through Aegis.

The art was done by Jim Sax, the well-known computer artist whose work can be seen in the Defender of the Crown CinemaWare game. Art Pak contains a variety of animals from cheetas to elephants, a sampling of buildings from small houses to high rise office buildings, airplanes, cars, and various other objects to play with. Some of the artwork is of dubious usefulness (like a six-inch motorcycle rider), but others I found use for right away (the Lincoln memorial, for example). For the more casual user, Art Pak could be a fun addition to Animator ST

Animator ST has some minor weaknesses and a few nonfatal bugs, but overall it's a slick program. Perhaps its biggest flaw is that it is limited to the ST: I find myself wanting another 500 colors, a higher resolution display, and a faster CPU.

In the proper hands, Animator ST can produce artwork of symphonic proportions. But like a musical instrument, it is difficult to master. Not only do you need some creative impetus, you also need a practiced control of the tools. It's not just a matter of putting tab A into slot B, then pushing a few buttons. Creating a good, original animation is a grueling, albeit rewarding, process. Expect to put in some work.

For the average person, Animator ST is an expensive toy. For the professional, it's a powerful tool. For people like me, the closet artists, it's an indispensable addition to our software libraries.

I just wonder when Jim Kent will start working on version two. I already have my wish list. Are you listening, Aegis?
(For those of you interested in seeing more of Jim Kent's work, see his program Flicker in issue #5 of START The ST Quarterly, on sale June 1. Flicker is a combination drawing and animation program which will enable you to duplicate some of Animator ST's  simpler capabilities. Flicker is also compatible with DEGAS, DEGAS Elite and NEOchrome.-ANTIC ED.)

Aegis Animator ST
Art Pak ST
Aegis Development
2115 Pico Boulevard
Santa Monica, CA 90405
(213) 392-9972
Animator ST $79.95
Art Pak ST $29.95