COMPUTER
GRAPHICS

You ain't seen nothin' yet!
by Robert de Marrais

New Mona

I am sitting in a dark room, next to a U-shaped table. At work in the hollow of the U is Rob Haimes, coordinator of M.I.T.'s Visible Language Workshop. To his left is a computer terminal with keyboard and highresolution video monitor; to his right, a digitizing tablet that creates images on the screen when navigated Ouija-fashion by an elaborate rolling "mouse" controller. Above the tablet is a "menu screen" TV, hooked up with the terminal and mouse, and straight ahead is a button-studded joystick control box.
    "Which will it be?" Rob asks.
    I have three choices. A quick trip through the Page Layout system convinces me that it can do paste-up and mechanicals for books or magazines; it can even do "greeking," that preliminary laying out of textless "filler" print in a specified type style. Page Management is the second choice: once you have a printable page, you want to fit it into a publishable text; this system allows for thirty-two finished pages plus thirty-two pages of "scratch space" for alternate layouts.
    I decide to take an in-depth tour of option three: Graphics Tools. It takes a couple of seconds for the picture to emerge, then da Vinci's favorite model, Mona Lisa, smiles pleasantly on the screen. The illusion convinces, and for good reason. As Rob points out, each image is 512 dots square, and each dot, or pixel, is 24 bits of color deep. This means you can mix up to 16 million different shades and hues, allowing for virtually limitless variation of opacity.
    To show me how easy it is to get the hang of things ("It takes about two hours to get used to physically," I'm assured), Rob casually throws graphics "windows" over Mona's face, lifting off clones of her eyes, nose and cleavage, and idly strewing bouquets of anatomy in sinuously overlaid streaks that quickly heap up to form a "Mona totem pole." Then, jockeying levels of transparency while he shifts background colors and gray scales, Rob dips down for some dot-by-dot foraging to snag the subtler colorations. Transferring these to charcoal sticks, he starts smudging up Mona's hands until they take on a granular "dishpan" consistency.
    My astonishment at the speed and beauty-and apparent nonchalance-of constructing the "totem pole" must be obvious because now Rob decides to one-up himself and modularize it. In an instant, Mona's upper face is peering down on a Gothic archway of totem-pole pillars. A few more sequences of ghost-image pullout and color infusion, and I'm nearly beside myself: "Stop, that's exquisite! Can you print it?"
    "Well, let's name it first," Rob suggests. He pulls two different typefaces from disk and wields them to print New Mona in the upper left.

Computer-Assisted Imaging
The system Rob uses was built for about $1 million, though it could be rebuilt now at perhaps a fifth that cost. Two of its main programmers have left to set up their own company to mass-produce facsimiles of the system for as low as $50,000.
    Such sophisticated equipment is at the heart of the computerized graphics revolution spreading throughout industrial applications. With computer-assisted design (CAD) you can use a computer screen as a faster-than-thou draftsman's table, assembling dots, lines and surfaces with electronic ease. Cut-and-paste, the old nemesis of industrial designers, architects and art directors, is suddenly obsolete thanks to the computer's graphics editing ability. In computer-assisted manufacture (CAM), the computer can simulate and test the inner workings of complicated machine assemblies or electronic circuits, then actually produce final production drawings, plans or blueprints.
    Already, CAD/CAM computer graphics can be viewed outside the computer labs on six-figure work stations in high-level industrial design shops. A consortium of architects, for example, planning plumbing, wiring and material stress-and-strain patterns for a new factory or building, can create an image of the complex bit by modularized bit on-screen. Or maybe a robotics team will employ CAD/CAM to duplicate the grip and many movements of the hundreds of interconnected components that make up the human hand.
    Common to all these design systems-and to the ones you'll be buying less than a decade from now for your kids at Christmas-are levels of progressively more sensual capacities. Most unlike day-to-day vision (unless you're a mild-mannered reporter from the Daily Planet) is their ability to perceive and surgically operate on nested levels of structuring. Mobile "x-ray windows" of variable size can be shifted across your monitor surface as fast as you can move a stylus across a digitizing tablet. As they pass over a structure, the windows peel back one or more layers of imagistic "skin" and let you probe and poke within to play with the tinkertoy-like skeleton of "wire-frame" drawings that support these gossamer solids. Complementary to this, you can build up from the most simple graphic primitives, combining, excising, transplanting or cloning lines and surfaces with virtual instantaneity, to create highly stratified "real" objects.
    In one display seen on a monitor at ComputerVision, a pioneering graphics firm, the sun rises over an architectural model of a factory (guts viewable through x-ray windows, from different approaches, speeds and angles) in what could pass for a Technicolor movie sequence. As the day progresses, shadows shift and shorten, disappearing at noon, lengthening again until dusk; when the sun sets, the streetlights come on, casting shadows of their own.
     All of which points to the most sensual capacity of such sophisticated screen shows: the vivid depiction of texture, color and optical subtleties like "specularity" (e.g., the highlight glints on shiny surfaces). Ironically, it is these "secondary qualities," the most sought out in advanced design work, that were dismissed by Galileo and his contemporary Scientific Revolutionaries as "subjective."
    But more than this, the new graphics allow for an unprecedented, nonformalist style of mental work-one that can result in radical economies of thought. Watching Larry Hare, a top programmer at ComputerVision, show off his latest creations, I noticed a recurring 3-D logo-like motif in a doorknob shape at the top center of the screen. As Larry flitted through his spur-of-the-moment noodlings, the multicolored mosaic went through subtle changes in hue and edge relationship. Larry explained that this was his "debugging program": instead of sorting through pages of tedious abstract code to track down errors after the fact, his trained eye can keep tabs on the color shifts of his jigsaw mandala and instantly detect any "glitches" in his program work. "Once you've been doing graphics for a while," he added, "nothing less immediate will ever satisfy you."

Apple World graphics program

Graphics Come Home
How frustrating for home computer owners that such marvelous graphics capabilities are not yet accessible. "Studio shoot" rearrangement, for example, conjures up notions of an interior decorating revolution, the ultimate software answer to "How would that couch look in the parlor?" questions. As for the chance to mix colors and textures without easels, pigments or collagist's scissors, the creative possibilities seem endlessand beyond reach.
    Despair, however, is inappropriate. Multiple xray window graphics can already be created on the screen of the Apple Macintosh (though only in black and white, since color takes a lot more memory). As for remodeling your living room, take a look at Paul Lutus' classic Apple World program, written when its rustic author wanted to do some sweatless shuffling of the contents of his Oregon cabin. With the new video disk's ability to store full-resolution color images on LP-like platters, and with to-and-fro access between disk and home computer, the capacity for Lutus-style maneuvers with trunkfuls of furnishings is not far off.
    For artwork pure and simple, the limitations of even top-of-the-line home computers can be sidestepped to a startling extent thanks to some recent off-the-shelf software packages. A major breakthrough came in 1982 with a trio of floppy disks from Mark Pelczarski's Penguin Software. The Graphic Magician is aimed at programmers who want to put professional-quality graphics into their own programming efforts and allows for the combination of up to thirty-two independent multicolored shapes: just draw them, and give them starting points and paths, and the software does the rest-letting you control animated objects with a joystick.
    Penguin's Complete Graphics System II and Special Effects are aimed at artistically inclined nonprogrammers. One reviewer pointed out that with the latter program, which costs only $39.95, "the Apple computer comes very close to emulating mainframe computer graphics systems costing as much as $250,000." When the two programs are used together, you can draw, edit and manipulate 3-D objects in perspective without having to calculate coordinates. You can also paint directly on-screen from a palette of 108 colors, using an array of 96 differently textured brushes-all with just a joystick or Apple Graphics Tablet. You can mix text with graphics and change fonts, type sizes, spacing. You can create "shape tables" of objects to be stored, retrieved, combined and changed at will. The video monitor quality resolution of a ComputerVision system is lacking, as are the enormous storage capacity and speed, but you probably don't need all this-and in any case you'll most likely have it by the late eighties.

The MovieMaker program

    Among other innovations in home computer graphics is Movie Maker, a simple animation package for Apples, Ataris and Commodore 64s. Developed by Interactive Picture Systems (IPS), the program allows you to create moving figures and backgrounds shape by shape, then put them in motion to musical accompaniment. It may require some effort to master, but this software can produce smooth, colorful animation that would be the envy of sophisticated graphics terminals. Using Movie Maker's routines, IPS has also developed a dance program that allows you to block out and choreograph original dance sequences on your home computer screen.
    We can only wonder where else tomorrow's supergraphics will take us as the sophisticated laboratory terminals relinquish their powers to smaller, less expensive machines. But with breakthroughs like easy graphics and simple animation, the CAD/CAM revolution is surely just a step away from our homes.

CREATING SCREEN IMAGES
Long before there were personal computers, graphics images were projected on laboratory cathode ray tubes (CRTs) of the kind found in oscilloscopes. You needed a computer to define the shape and a digital-to-analog converter to send signals to the CRT, moving its electron beam to a point plotted on x, y axes proportional to the amplitudes of its input signals. This process was called "stroke" or vector graphics, wherein a number of such points were joined up in connect-the-dots fashion.
    Now that TV sets are ubiquitous, "raster scanning," the image-sweeping technique used in picture tubes, is standard fare for home computer monitors. Here the CRT beam is deflected in a weaving pattern that sweeps across the screen and down, the way your eyes move when you read successive lines in a book.
    The signals sent by broadcasting stations to home television sets contain special synchronized pulses used by the TV circuitry to get in step with the transmission. These sweep-triggering beats come in horizontal and vertical varieties, and between them come the pulses that contain the actual video information. On a typical TV tube, this information takes up 512 lines, with up to twice that number of dots being defined on each.
    Substitute "computer" for "broadcasting station," and you get the idea. With proper synchronization, requiring time chains, clocks, multiplexers and other hardware on a video circuit board, any point on the screen's x, y plane can be addressed and made to hold a dot. Each dot, or "pixel," remains visible for only an instant before its place is usurped by a new dot, by a clone of itself or by nothing at all. What you actually see is a grainy dot-matrix.
    Pixels are typically addressible not as mere points, but as "stacks" made up of binary options on each level. A byte that is only three bits deep allows for two times two times two (eight) possible messages-enough to encode primitive color information since there is room for three primaries and their complements-plus, say, high and low intensity. An Atari computer (still the best graphics system you can buy for under $5,000 as I write this) allows for up to four colors simultaneously, plus eight levels of brightness for each.
    In computerdom, "a picture is worth a thousand words" is an understatement. Addressing each of the tens of thousands of pixels on the screen thirty times each second consumes huge amounts of memory. Hence there's a need for tricks and shortcuts, some of which are standardized. The most familiar is the ASCII character set, the agreed-upon dot-matrix encoding of the standard alphanumerical characters found on your typewriter keys. And in the works is a convention known as NAPLPS (for North American Presentation Level Protocol Syntax and pronounced "naplips"). Already in use in Canada, NAPLPS allows vector graphics "building blocks," with specified colors, to be transmitted efficiently, rapidly and over long distances via modem hookups to telephone lines.

R.DE M.


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