THE CYBER CORNER

A Cyber Studio
Family Gathering

By Andrew Reese, START Editor

SCALEIT and TEST.3D2 are in the CYBER folder on your START disk.

This is the first of several columns intended to help you make better use of the Cyber Studio family of graphics programs from The Catalog. If you haven't used them, let me explain briefly how they fit together.

LET'S MEET THE FAMILY

At the heart of the Cyber Studio family is CAD-3D 2.0, the three-dimensional modeling tool created by Tom Hudson. With CAD-3D, you can create three-dimensional objects and, using its built-in tools, you can also move them, move the camera (the viewpoint), change the lighting and record animations.

CAD-3D animations, however, require a great deal of planning, time and extreme care. To correct this shortcoming, Hudson created a control language, called PD3DCTL in its earlier public domain form and Cyber Control in its polished commercial version. Cyber Control is a unique and specialized BASIC-like language that loads as a desk accessory on boot-up. After you load CAD-3D 2.0, you activate Cyber Control by selecting it from the Desk menu, just like any other accessory. But because of the communications pipes that Hudson built into CAD-3D, Cyber Control can "rake over" CAD-3D operations and create animations no sane human would attempt without it.

Once you have created a Cyber animation and stored it on disk, you'll often want to polish your animation. That's where Cyber Paint comes in. To my mind, it is one of the most spectacular paint and animation programs available on any microcomputer! (I also own an Amiga 2000--horrors!--so I have some basis for comparison.) Cyber Paint can load a CAD-3D/Cyber Control animation and perform all sorts of wonders on it. It also shines, however, as a stand-alone paint and 2-D animation program.

One caution in using Cyber Paint or any other animation software: Buy as much memory as your budget can afford! Animation is very memory intensive; even with 2.5 megabytes of RAM, I still occasionally see "Out of Memory" alerts when I get over-ambitious (or sloppy).

MAKING THINGS FIT

One of my first uses for the Cyber Studio family was to create animated models of a traffic accident. With that kind of real-world animation, one of the first problems I encountered was scaling several vehicles accurately to a specified universe size. In the CYBER folder on this issue's START disk, you'll find SCALEIT.CTL, the simple Cyber Control program that I created to solve the problem. SCALEIT.CTL scales an object or group in all three dimensions to whatever dimension you specify along an axis. Its accuracy is plus or minus ten percent.

"Creation"--done with DEGAS Elite and Tom
Hudson's Antialiaser. The artist set up a pal-
ette ranging from dark red to orange to white,
then airbrushed white lines on a black screen.
By repeatedly airbrushing and antialiasing the
lines, a glowing red lava effect was created.
Artwork by Jon A. Bell.

You'll also find a simple cube object called TEST.3D2 in the CYBER folder on your START disk, so you can run SCALEIT immediately to see how it works. You can use the code from SCALEIT.CTL in your own Cyber Control programs, but of course you'll have to substitute the name (and path) of the object or group you want to scale after the command "load3d."

When you examine SCALEIT.CTL, you'll see that it uses the scale command to perform simultaneous proportional scaling on an object or group in all three dimensions. You should have your object looking pretty much as you want it before you use SCALEIT. Another Cyber Control command, axisscale, will scale each dimension independently. In fact, I wrote a much more precise scaling program using axisscale and iteration factors of 99 and 101 percent. While much more precise than SCALEIT, it was cumbersome and slow.

You may want to modify SCALEIT to add independent axis scaling and to increase its accuracy. At present, SCALEIT uses scaling factors of 90 and 110 percent. Just change the variable it to whatever number you wish between the Cyber Control limits of 50 and 200 percent. Another possibility is allowing different units of measurement for the universe and object--for example miles and feet.

One other technique may require added explanation. The bounds command is used to find the minimum and maximum dimensions of the object in each dimension. After each bounds command are three expressions in the format xnow=(MAXX-MINX)/90. The Cyber universe is 9,000 units along each axis, and (MAXX-MINX) gives us the X-dimension of the object. Dividing the result by 9,000 and multiplying it by 100 (or merely dividing it by 90) gives us the percentage of the universe the object occupies. xnow, ynow and znow are the target percentages and xnew, ynew and znew are the trial percentages after each scaling. Other than these details, SCALEIT.CTL should be easy for you to understand and use. It's heavily commented and doesn't use any fancy trees or splines.

DEATH TO THE JAGGIES!

Everybody knows and hates jaggies--those stair-step edges on curved lines. In his copious free time, Tom Hudson has produced an answer to the jaggies problem. It's a desk accessory he sells directly called "The Antialiaser," and it works by filling in the jagged stair-step openings with intermediate colors (a process called anti-aliasing--hence the name). The Antialiaser can be called by Cyber Control to anti-alias a frame during recording or it can be used with Hudson's other ST triumph, DEGAS Elite, to reduce the jaggies in DEGAS art. No self-respecting ST artist or animator should be without this little wonder.

One caution, however: effective antialiasing requires that your palette have intermediate shades between the object and background colors. If your picture is too complex or your palette too diverse, you may be dissatisfied with the results. As long as the ST uses a maximum of only sixteen colors in its broadest (non-Spectrum 512) palette, however, this limitation will be a fact of life.

PRODUCTS MENTIONED

Cyber Studio, including CAD-3D 2.0, $89.95; Cyber Control, $59.95; Cyber Paint, $69.95. The Catalog, 544 Second Street, San Francisco, CA 94107, (800) 234-7001.