Polygon Realm: A Brief History of Graphics, Part Three.

Two dimensions are all very well and good, but even the earliest game developers yearned to extend into the third. The ability to craft a virtual space. The forging of a polygon realm. Of course, with limited hardware it was no mean feat - early 3D games were burdened with heavy compromise.

The very first were limited to wireframe representations - and although simple, games like Atari's Battlezone could paint an immersive scene with just a few vector lines. Similar tech was used to great effect in 1983's Star Wars Arcade: putting the player in the pilot seat of an X-Wing to recreate the attack on the Death Star, complete with trench run.

Even the 8-bit home micros managed to get in on the wireframe action: space trader Elite's visuals might have been spartan, but the game offered a huge swathe of space to explore. The next logical step from wireframe polygons was to fill them with flat shading: a simple effect, but still tricky to achieve on early systems without dropping the frame rate to unacceptable levels.

The very first flat-shaded polygonal game was arcade title I, Robot all the way back in 1983. It was definitely ahead of its time, but a new paradigm is a tough sell, and the game would not prove a financial success. The advanced hardware needed for 3D games and the decline in arcade interest over the next few years rendered them prohibitively expensive - so it wouldn't be until the end of the decade that 3D games would become more prevalent.

As home computers became more powerful, certain genres would embrace flat-shaded polygons: a trademark of early flight simulators, which valued full freedom of movement over arcade action or graphical detail. Some driving games employed this technique, too: Geoff Crammond's Stunt Car Racer in 1989 had you driving at breakneck speed round a fanciful track complete with three dimensions.

Not content with dull flat-shading, some turned to hardware tricks to simulate 3D worlds: and the Super NES' Mode 7 could be considered a rudimentary form of texture mapping. It was only a half-measure, but an ideal way to introduce a 3D feel to classic 2D action: and games like Super Mario Kart maintained a healthy frame rate while still giving the illusion of into-the-screen racing.

The SuperFX coprocessor included in carts like Star Fox enabled polygonal 3D graphics, blended with sprite scaling effects and other 2D elements. Offloading graphics onto another processor would prove a useful technique in the future: but some machines would rely on sheer grunt instead.

IBM-compatible PCs had the benefit of a modular design - along with a price point far aloft from console hardware. This meant that by the early 90s, they could start to push graphical boundaries. However, early PC games could be pretty ugly: 4-colour CGA and 16-colour EGA modes often left games with a distinctive, simple look.

VGA graphics were a step up, offering 256 colours with far more nuance and a break from unnaturally bright shades. Early PC titles would sometimes make use of prerendered backgrounds - games like Alone In The Dark reserved polygons only for the player and enemies, with the remainder of the world painted as a bitmap.

This technique is a useful one for preserving limited graphical power: instead of rendering a full 3D scene, you can instead divert attention to more detailed character models. Some early games were more ambitious, taking a first-person perspective instead of a fixed camera view.

Ultima Underworld: The Stygian Abyss was an impressive game that took RPGs into the third dimension - and in turn would influence the rise of the first person shooter. One technique that made early texture-mapped games viable was raycasting. It's an efficient approach to scene rendering that focusses solely on what the player can see, and when combined with simple level geometry can be made quite performant.

Wolfenstein 3D's levels were built on a simple square grid, all on a single level: this meant that the walls could be fully texture mapped, while the game remained playable even on a modest PC. Wolfenstein is the grandfather of 3D shooters, but in terms of overall impact: Doom was the daddy.

Building on the Wolfenstein engine, Doom extended its featureset to permit levels with more organic design: no more fixed grid maps, the addition of variable lighting, and elements at different elevations. As a result, Doom was more atmospheric, its locations more believable - and paired with high-octane action it proved quite the success.

It inspired a huge number of clones, and paved the way for the FPS genre as we know it today. Many of these early games were reliant on tricks to simulate a 3D world - limited geometry, the use of sprites - or other time-saving hacks. True texture-mapped 3D games required a great deal of processing power, and so it wasn't really until the second half of the 1990s that such games took hold.

Vanguards of hardware, the arcades led the way with titles like Ridge Racer: although dated today, at the time it was universally praised for its sound and graphics. Treading in the arcade's footsteps, the fifth generation of consoles could more confidently tackle full 3D graphics, and so platforms like the PlayStation and Nintendo 64 saw the rise of the polygon within a home setting.

Super Mario 64 transplanted the previously-planar plumber into a colourful 3D world: and would prove to be arguably the first successful 3D platform game. It blended the finest elements and charm of previous Mario titles with new technology - full freedom of movement and a dynamic camera system that permitted exploration without frustration.

The PlayStation had its own 3D platforming heroes, with games like Crash Bandicoot: and despite the low-polygon count afforded by the hardware, its characters are expressive and its artstyle charming. These games were not only technically impressive - they were fun to play: true 3D games were a novelty no more, and instead an integral part of mainstream gaming.

While console hardware arrives in discrete generations, the pace of PC development is continuous: and with the popularity of PC gaming post-Doom, there was no shortage of 3D titles. Magic Carpet was an interesting attempt at transplanting Bullfrog's earlier god-game formula into a third-person perspective.

Hugely impressive from a technical perspective, although its gameplay was slightly lacking and was otherwise overshadowed by more conventional games of the era. Descent was notable for its six degrees of movement, permitting full exploration of its maze-like mines.

A peculiar blend of space shooter and Doom clone, it stands as an important example of early software rendering - full 3D without shortcuts or compromise. Id software were prime innovators within the PC gaming space: and not content with the countless clones their creations spawned, they set the bar even higher with the release of Quake.

Quake was very much a true 3D game: gone were the sprites and lack of vertical aiming of Doom, replaced with polygonal enemies, weapon viewmodels and biaxial aiming. Quake, in all its brown-hued lovecraftian glory, was a prelude to the next wave of 3D graphics development.

One final footnote worth a mention are voxels: volumetric pixels, an alternate approach to polygon construction. Instead of triangular faces, objects are built from 3D pixels: essentially building blocks, in a manner similar to Minecraft. Ideal for carving out terrain from heightmaps, games like Delta Force and Outcast are an interesting example of what would prove to be an evolutionary dead-end.

Although voxels showed some promise, any progress was nipped in the bud by the rise of 3D acceleration. With dedicated hardware games now had the power to construct smooth and detailed worlds without compromise. The magic of hardware acceleration was about to unfold.