Three-Dimensional Graphics Will Add Realism To Computing

We live in a dynamic, three-dimensional world but the images we see on paper, television and movie screens are flat.

They often appear somewhat three-dimensional, especially when displaying photographs, but this is an illusion of perspective and shading.

Computer screens are flat, too, and unlike TV and movie screens, they usually look quite flat. Exceptions include the toolbar buttons and other on-screen controls that tend to appear slightly raised from the screen surface, thanks to the way they are shaded.

But the shading of toolbar buttons only hints at what is to come.

Over the next few years threedimensional graphics will transform the face of popular computing. Among other things, today’s twodimensional desktop metaphor, in which a PC user looks straight down on a flat desktop that has documents and tools on it, is likely to give way to a three-dimensional metaphor. You may be able to move around to all sides of a desk or open a drawer to look for something.

Three-dimensional graphics will make computers more useful, entertaining and natural because the images that computers will convey will more closely approximate the real world.

Providing this kind of on-screen realism requires a lot of computer horsepower which hardware companies are rushing to provide. A variety of PC add-in cards that accelerate 3-D graphics are about to hit the market.

Within two or three years the typical personal computer will have 3-D-graphics capabilities roughly equivalent to those of high-end computer workstations that today cost 10 times as much or more.

A text-only document may not be changed much by 3-D graphics but charts and animations will be. Software used by architects and engineers to design threedimensional objects will be dramatically improved. Homeowners will be able to use computers to design decks or gardens, or even to figure out how to rearrange livingroom furniture.

Over the centuries people have found ingenious ways to give the impression of three-dimensionality on paper. Since the Renaissance, paintings have tended to include perspective. Artists shade objects to simulate contours. Map-makers may represent terrain by depicting mountains and valleys, or by including the shapes and heights of buildings to give a map the qualities of an aerial photograph.

Thanks to recent astonishing increases in computing power, TV and movie screens are now filled with three-dimensional images created by artists. Synthetic 3-D scenery, fashioned electronically through the use of software, now bombards us in commercials, television shows and movies.

Words that appear to be carved from shiny metal spin across our television screens. Cars morph into trucks. Sportscasts open with fancy graphics that almost envelope us.

As viewers our point-of-view often floats in three-dimensional space so that we seem to travel through and around objects such as corporate logos, automobile engines and television-station call letters.

Motion pictures such as “Jurassic Park” take the 3-D art form to impressive lengths, yielding images that appear to be captured from real life rather than from the imaginations of artists. I’m quite taken in by the dinosaurs in “Jurassic Park,” even though I know they were created on computers.

Three-dimensional modeling and rendering allows persuasive simulations of the real world because the artist controls the form, texture, light, shadow, perspective and motion in a scene. An artist first creates a 3-D model of an object, which exists only mathematically, and then asks the computer to render the model as it would appear from a specific vantage, thereby creating a two-dimensional image.

To model a red brick, the artist might draw on the computer screen a rectangular cross-section defining the width and height of the brick, and then indicate (by “extruding” the rectangular cross-section) how long he wants the brick to be. The result is a three-dimensional box, perfectly smooth on all sides.

Since bricks don’t have smooth sides, the artist could introduce imperfections and apply a deep red color. More likely he would simply wrap a photograph of the face of a real brick around the six sides of the model. This technique is called texture-mapping.

The computer can then “see” the brick from any position and snap a picture. This creates a twodimensional rendering - a snapshot - that can be displayed on a screen. To simulate motion, the artist defines a trajectory and tells the camera to snap pictures repeatedly while following it.

Of course, not many people are modeling mere bricks. Real-world models are sometimes extremely intricate. Companies are springing up to meet the surging demand for high-end 3-D for movies, television and multimedia.

The firms range from big players such as Industrial Light & Magic and Digital Domain, all the way down to small shops such as Cyan and Raster Ranch.

These companies use expensive workstations that may take several hours or days to render sequences that take only seconds to play back. But by the next decade, inexpensive PCs will render animated scenes in real-time.

When this happens, entertainment will be affected profoundly. Interactive games will have all the realism of “Jurassic Park.” If you want to battle frighteningly realistic dinosaurs right on your computer screen, you’ll have the chance.

In fact, if you want to design the dinosaurs yourself and then battle them, you’ll have that chance too.

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