FEATURE • April 20, 2001

by Hayden Duvall

Your hardware is primed and ready to hurl out 16,000 gigatexels per second. Your engine is a thing of almost poetic loveliness and will throw millions of light-mapped, volumetrically fogged polygons around the screen without even breaking a sweat. Your design document makes the unabridged edition of the Encyclopaedia Britannica look like a pamphlet, and you have enough concept art to fill a medium-sized aircraft hangar.

You're looking good. Your project is set to excite and amaze with its technical wizardry. Its groundbreaking gameplay will doubtless spawn a thousand imitations, and you have already begun writing your acceptance speech for next year's Gaming Legends of the Twenty-First Century awards ceremony. But there is one small problem: your graphics are as uninspiring as a bag of wet socks. Unfortunately, the game-buying public demands more and more from their visuals with each passing week, and all but the most devoted of gamers will probably ignore your game if they turn the box over and see the kind of screenshots that would make their Grandma yawn.

It is true that many a dreadful game has scammed its way into the charts by dressing up its tedious and aggravating gameplay with a flurry of screen-bending special effects and delicious visuals. But this kind of fakery is usually short-lived, and once the word gets out, many of these games end up being exposed as the fur-coat-and-no-knickers acts that they actually are.

However, in today's world of octilinear, bump-mapping, ray tracing, realtime refractive-index-calculating hardware, a great game that doesn't deliver a sizable chunk of graphical excellence, is in danger of becoming a great game that nobody's ever heard of. It might not be fair, but just stand behind a bunch of 14-year-olds looking for their next purchase, and see how quickly they lose interest if a game doesn't quite cut it in the looks department.

What can you do? Well, the answer to that question will of course depend to some extent on the hardware and software limitations that you have to work within, as well as the design considerations of your particular type of game. However, there are a few general areas in the visuals department where many games can benefit from a metaphorical strategic splash of mascara, and a well-considered application of eye shadow.

I can sing a rainbow

Unless you have been living in a monastery for the last couple of years, you will no doubt be aware of the rate at which the War of the Polys is escalating. Whether it be consoles or graphics cards, the polygon-crunching muscle of today's hardware seems to increase weekly.

This, of course, is marvelous. We can never have enough triangles surging through our GPU, but what we mustn't overlook in our stampede to build a perfectly accurate model of the Sydney Opera House, are the textures.

Not so long ago, those of us who had the happy task of making textures for scenery and characters in a videogame found that our two biggest enemies were resolution and the palette. Creating a convincing set of stone, wood, plant, and metal textures with only 256 colors to choose from was like asking an orchestra to play Handel's Messiah using just an oboe and a set of maracas.

Today however, resolution is much less of a problem, and color depth is one of our best and most attractive friends. We no longer have an excuse for churning out bland textures. Now that our palette is large, we need to use it.

Of course I am not suggesting that cramming a scene with every color available is automatically a good thing. Rather, tonal variation within a texture, as well as the range covered by the whole of your texture set, should, where appropriate, make full use of the colors available.

Consider the following examples:

Rock textures are some of the hardest to deal with. They are often a good example of the scale dilemma (more on this later), and perhaps also the area where we all have to struggle the hardest not to end up with a brown and gray overload.

The above examples hopefully give some indication of the variety of color information that can be contained within a rock texture, while still retaining a decent level of realism. Obviously in cases like this, the source image from which the texture is derived needs to be reasonably interesting, but it will usually be the hand-coloration that makes the difference.

Color variation within a texture is certainly important, especially when the texture in question is generally going to be viewed from close range, but for textures that will most often be seen at a distance, we can turn to lighting (which I'll discuss later in a separate section) and vertex coloring. When applied with skill and moderation, vertex coloring can liven up the dullest areas, reducing the chances of producing a bland environment.

Vertex coloring basics:

1. The effect achieved through adding color values at vertices will naturally depend on the placement of the vertices, so obviously large-scale diffuse color changes will be all you can manage across large polygons. You may need to add extra vertices if you are looking to achieve a more controlled color-change effect:

2. Normal rules of color combination apply, so remember that the texture on top of which the vertex coloring is applied needs to be taken into account, and a decision made as to which colors will work well together—and equally importantly—those that won't.

3. If you intend to rely heavily on vertex coloring, you'll get the best if your textures are designed specifically for this purpose. Too much color variation within a texture can be a problem, while low color saturation coupled with high contrast generally gives the best results:

4. Some textures will begin to look flat when vertex-colored, and planning to have several variations of a particular object by changing the vertex coloring may not always work. Some things will always require color-specific textures.

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