Some might argue (perhaps validly) that art is the single most important part of a video game
, but no matter where you place it's importance it is one of the key elements that go into a sucessfull game.
Early video game art
Of course, in games like Pong, calling the game's images art is a bit of a stretch. Actual art in video games could truly be considered to start with systems that have what is called video RAM or VRAM. In early game systems VRAM was orginized into small rectangular arangements of 'dots' or pixels. These roughly square arangements where often refered to as tiles. An artist working on such a game had to create all of the game's art using these little tiles, which were generally 8 x 8 pixels. Each tile was also limited to only a few colors. Once the tiles where created they could be used in a map to produce the games background.
The players avatar and the enemies in the game were created using objects called sprites. Sprites are similar to tiles, in that they are also small square 'bitmaps' with few colors. The difference is that tiles can only be used aligned in a grid called a screen, while sprites can be positioned anywhere. As an artist you would create the little creature out of pieces, each piece being a sprite. This was a tough job, because the tools used to create these images were primitive at best. A common technique was to 'paint' the art first with some paint program like deluxe paint and then run it through some sort of conversion utility. Debabelizer was often used to reduce the color count, but I think the best results where achieved by artists who understood the limitations of the hardware and worked within them. It's actually seemed like more trouble to create the art, and have it horribly mangled by some utility program, forcing the art to be re-worked.
Modern game systems
Video game systems like the Sony Playstation, hearalded the dawn of the modern video game. These machines of course have graphics processors that enable the systems to display 3D graphic images that would otherwise have been difficult to display, given the slow speed of the main CPU. And the most recent systems have floating point math units for faster and more accurate calculations. These systems also have more VRAM. The original playstation had 2 Meg and the Playstation 2 has 4 Meg. All this extra power means more work for the artist. Both in 3D and in 2D.
At the start of creating art for video games now, is the creation of 3D models, using a type of program called a 3D Modeler. The modeling process involves creating points or vertices in 3-space. These points are linked together to create polygons, usually quads (4 vertices) or tris (3 vertices) the polygons make up the contour of the object being modeled.
Your probably familiar with the flat geometric appearance of early 3D graphics. One of the reasons for this is that the graphics often had only solid colored polygons. In order to compensate for this lack of realism, pictures, also called textures or texture maps, are applied to the polygons to give the illusion of a more detailed surface. The textures can be scanned from a photograph or painted with a paint program such as Adobe Photoshop.
These days we expect quite a performance from the creatures we see inhabiting games these days. So after the artist creates the creature's model, they use a 3D animation systems to move the creatures appendages. Interestingly enough, underneath the polygon and texture 'skin' are 'bones'. Bones in the 3D animator's lexicon refer to special linkages in the model that describe how the models parts are connected to one another, and they also describe where the joints are and to what extent they are allowed to move.
The explosions, particles, sparkles, and glow effects you might see, generally, are not really 3d graphics. Most of these effects are actually are old freinds from the early days, sprites. Of course these are sprites on steroids. They can be as big as 256 x 256 pixels and can contain 1000's of colors as well as varying degrees of transparency or alpha as it is called. Another special effect technique involves the use of paletted textures. These images store the colors the picture uses as a seperate table in VRAM. The picture, itself only stores a link into the color table. The hardware uses the pixel's value to 'look up' the color in the palette.That's why these palettes are often refered to as a CLUT or color look-up table. The primary reason to use this technique is that it conserves precious VRAM. A secondary reason is that it's posible to change the images appearance by just updating the palette. Static picures can appear to move or glow by cleverly manipulating the palette.
Building the game
Once all this work is done, the art is exported or converted to a form that's optimized for the game program to use. The artist then takes a look at how the art looks on the target platform. The phrase target platform refers to the actual game hardware (or at least something close to it). The reason for this check is that off the shelf 3D tools will often let the artist do something the programmer would rather the artist not do. Like use too many polygons. Or create an animation that's too complex for the system to handle. Sometimes the colors on a tv look significantly different then the colors on a pc monitor, and the artist needs to check this too.
Finally the art is finished and given to the programmer for final integration into the game. Of course, the art is never really done, much like everything else in the game and there will be considerable fine tuning involved, going back and forth between the programmer and artist.
A lot of the art that goes into a '3D' game is actually 2D. I mentioned the textures for the polygons, but there are also fonts, icons, title screens, and other interface elements, most of which are 2D, sometimes even if they look 3D. Quite often pickup items will be created with 2D sprites, and many inventory screens are constructed with 2D art.
It's perhaps not suprising that the bulk of the effort in a game, these days, involves creating the art for the game. It's a huge job. It's like creating a movie set
, except of course that the artist can't control the camera
's view so it's in some ways even more difficult. Add to that the creation of the games animations, models and 2D bits and you wonder how a game gets done at all. And of course there's game programming
, sound and music