GRAPHICS

3D or Not 3D

A Look at Graphics in ST Gameware

by Andy Eddy

Computer games have come a long way since the early Pong days. This evolution, beginning with coin-operated arcade contests, has brought home computer playware to a level that still garners a major share of products sold. But looking over the period of time—a short lifespan, to say the least—that computer games have been around, it's obvious that people's tastes lean towards impatience.

These days there are a ton of companies creating gameware for personal computers; some have been around for a while, and others are simply spare-time endeavors sparking garage-based development of home-brewed products. To be successful, the bottom line is that you have to keep moving ahead, bringing about new features to pique the end-users' attentions. Anything short of that will spell disaster to the company's long-term survival.

But it's gotten to a stage where everyone who comes out with an entertainment product appears to have the phrase "3-D graphics" attached to it. We'll see how that may be something of a misstatement, as well as how developments in entertainment software have brought us to the present era.

In the Beginning....

While the layout of the game itself holds a lot of weight in a product's market success, you can boil most of them down into similar categories of structure: shootouts (either space- or earth-bound), driving contests (sometimes mixed with the shooting genre), traditional board games, adventures and sports. Predominately, what sets one piece of software apart from the next is how it's graphically represented. Even these can be broken down into categories, geometrically speaking.

The first games to appear on the scene were what we'll call a two-dimensional playfield with one-dimensional movement; Pong and Space Invaders are examples of this basic layout. Simple left-right or up-down movement—limited to one axis, if you refer to the screen as an X-Y graph—is all that you can manage.

The next generation brought us games like Asteroids and Missile Command. These went a step further by allowing two-dimensional movement in a two-dimensional playfield. Your on-screen counterpart isn't limited in its range of movement—both X and Y axes can be traveled freely. In fact, Asteroids takes it a jump beyond this with its "wraparound" universe. In other words, the borders of the screen were no longer like a wall to the player. This succeeded in adding more tension and required stronger peripheral vision from the player.

Lastly, the final leap in programming is what we'll term three-dimensional movement in a three-dimensional play-field. Of course, it must be explained for clarity's sake that this three-dimensional universe—using the X, Y and Z (depth) axes at one—is sensory only. Though we'll mention the few deviations to the rule in a moment, the games we're talking about now are "simulated" in their 3-D effect, simply because a standard monitor screen is only two-dimensional. "2-D plus" or "2½-D" are more accurate ways of terming these graphic representations.

There are two different ways of creating the perception of 3-D in a 2-D medium. Looking at a TV program shows the first way: The program was filmed on a 3-D stage, and the viewer relates to the perspective of objects on the screen and and how they interact with each other (i.e., size relationships and whether objects move in front of or behind others).

There are many good examples of the success of this method, but perhaps the easiest way to tie this in with computer gaming is Player/Missile Graphics. Through this, you can set players, missiles and playfields, as well as program how they interact with each other. In essence, this creates a situation similar to the TV show example above, giving the "illusion" of depth.

Space Quest and others in the Sierra On-Line "3-D Animated Adventure" series demonstrate a similar use of this type of process to create the imagery on-screen. They're called 3-D adventures, but you're perceiving the effect because the onscreen characters can move in front and in back of, jump over and crawl under objects, as well as climb fences and trees, or fall into holes, just like television.

The second method was first displayed in Battlezone, that point-of-view (POV) display. You get the feeling that you're actually sitting in the vehicle (you don't, as in other games, see your character onscreen), and all objects appear accurately scaled in size to the distance you are from them. Also, as you move around an object, your perspective changes so you can see a different side of that object.

This brought about a breakthrough of sorts. Previous contests depicted your character on the screen (as well as those characters around you), and you subsequently controlled it in accordance with the threats you saw on the screen. POV games give you a whole different feedback to react to, as you can't see all that's around you unless you manipulate your character into a position that allows that view.

To bring this up to date, games like Starglider (Firebird Licensees) and ST-Wars (Miles Computing) take the basic line-drawing structure of Battlezone and give the user a strong dose of seemingly realistic motion and action. As an avid player of entertainment software, I know that the best test of a product's 3-D imagery is to note how you react to playing the game; in my case, I find that the docking silos of Starglider have me ducking to avoid hitting my head on top. Sure, I know it's a game, but in the heat of battle I find myself getting into it as if it were real life.

On the Horizon

Given the memory size/capability and processing speed of the ST—to be further enhanced by the blitter when it becomes available—vector graphics can give way to solid construction of on-screen objects, as witnessed by ST-Wars and Harrier Strike Mission (also by Miles). This spells the future of computer gaming, as the last few years have brought us great leaps in graphic technology. I'm sure that the next few years will be similar, especially if recent creations dictate the path of progress along those lines.

The strides that computer manufacturers and software developers have taken to give us the latest and greatest has resulted in some pretty wild concoctions. For realism, old and new 3-D technology has been utilized in various manners to that end.

In the old category, you can look back as far as the '40s and '50s to the introduction of two-color 3-D movies. While they fell out of favor, particularly when an increase in technology in this field brought about the advent of color 3-D movies (using polarized lenses), a resurgence of the two-color effect came about recently as some of these ancient films were shown on TV stations across the country, giving viewers at home what they previously had to travel to theaters to see.

Bringing that up to date, Wanderer (Pyramide Software, marketed in the U.S. by Paradox) utilizes this two-color effect to bring about a realistic vector-graphic space shootout with depth. Again, the test of this was when I was demonstrating the game for a few friends. When one of the enemy ships dipped off the bottom of the screen, a couple of us tried to look "into" the monitor as if it were a window, thinking that by moving our perspective, we'd be able to see the object below the field of vision that the screen provided. For those interested in experiencing this effect, there is a downloadable demo version of Wanderer in the "Applications for the ST" section of the Analog SIG on Delphi.

It's quite simple to build this effect: Two distinct images are put on the screen, one in red and the other in blue. Putting on a pair of glasses (with one red lens and one blue lens) gives each eye a different view by virtue of the lenses filtering out the image of their respective color. If the two views are properly shifted and the color matching between the glasses and image is good, the brain assembles the incoming data where it is perceived as a realistic 3-D image. The limitations to this technique are sufficient, though. You're restricted onscreen to using only the two colors that are instrumental in forming the effect, and eyestrain can be fairly heavy with long gaming sessions.

Now Tektronix, a strong, high-end graphics terminal producer, through their LC Technologies division, has brought a new twist to the creation of realistic 3-D or, more aptly described, stereo graphics. The StereoTek glasses, as they are called, use high-speed liquid-crystal shutters (LCS) as lenses encased in plastic frames. The benefit to this is that similar to liquid crystal watches and video displays, when they aren't activated, the lenses are basically transparent, which is less annoying to your eyes. When they are under the ST's control with compatible software, the stereo effect can be amazing.

Of course, this article is dealing with the proliferation of 3-D entertainment software, and the potential for that is great. At the time of this writing (mid-June), Antic already had a StereoTek-compatible version of Wanderer ready for release, as well as a Space Invaders/Galaxians-type of contest called Shoot-The-Moon in nearly completed form.

On the third-party software front, Shelbourne Software (makers of ST Pool) were displaying a beta version of their upcoming 3-D Breakthru at the Summer CES (Consumer Electronics Show). Slated for September release, this game is a variation of the original Breakout with one exception: Your paddle hits the ball "into" the monitor at a wall of bricks at the end of a hallway. To open the product to as many people as possible, the game will have a function key toggle for switching between normal and stereo play modes. The game is stunning in both modes—especially in stereo—and should be popular, laving the groundwork for Shelbourne's name becoming better known to Atari users. They also stated to me their intentions to support StereoTek users with future releases.

Along with Shelbourne's efforts, Gary Yost, marketing director for The Catalog, informed me that Rainbird Software was almost finished with a conversion of StarGlider to the glasses. Though I haven't yet seen a pre-release of the new version, Yost confirmed that it may lose a portion of its original innovative effects—like the memory-hogging, digitized music at the game's start—to allow the cramming of the stereo routines into a standard ST.

In addition, the ever-present programming wizard, Tom Hudson, was one of the first to have his hands on this product outside the Tektronix staff. Among other things, he plans to convert his popular Livewire game (a Tempest-like contest for the 8-bit line originally published in ANALOG'S issue 12), to the ST and have it playable with the StereoTek glasses. Other manufacturers are looking into using this innovative product with their future game development, depending on how the glasses sell. If the current sales indicate anything—Yost claims over 500 pairs were sold in the first month they were offered—more developers will be following suit.

This technology takes gameware years into the future, all the while making it easier for programmers to utilize it in their efforts. And with the ST in the forefront of graphics creation, you can bet that we in the Atari community will be among the first to witness any other groundbreaking innovations.