Theory
Game Art
Game Art Asset Production
To create the game art you need software. If the game is a 2D game, a 2D paint or vector-based software solution may be adequate, such as Flash, Photoshop, or Illustrator. If the game is a 3D game, you will need modeling and animation software.
2D Game Art
A 2D Flash game can be created with Flash alone, since Flash has the ability to create graphics, and the ability to script those graphics (Actionscript). Graphics for a 2D game using a game engine such as the Unity engine can be created in Photoshop, Flash, Illustrator, or any other graphics package that is able to save a JPG, GIF, or PNG format. While the creation of game art for a 2D game is much easier than for a 3d game, the characters must still be animated to give the illusion of life.
3D Game Art
3D Game Art is first usually sketched, then modeled according to the sketch, then the model is "unwrapped" so that it can be properly painted in a paint package like Photoshop. Then, if the game art needs to be able to move around like a character, the model must be rigged with some kind of skeletal bones-type structure. In this rigging process, the vertices of the model mesh are assigned to one of the many supporting bones, so that when the bones move, the mesh moves as well. Finally, the skeletal structure of the character is animated in various cycles to achieve the illusion of movement and life.
Idle, Walk, and Run Cycles
In both 2D and 3D games, the characters must be animated in some basic ways; the most basic animation cycle is the Idle cycle, where the character is just standing in place, apparently not doing a thing. However, if you look closely, the character usually will appear to be breathing, perhaps shifting weight from foot to foot, and perhaps looking around for a friend or an enemy.
The Walk cycle is a cycle where the character takes a few steps - then that cycle is repeated when the game is scripted, so that the short walk cycle loops, over and over, giving the appearence that the character is walking naturally. The Run cycle is exactly like the Walk cycle, except that the character's movements are more pronounced, and cover more ground. There can be other cycles as well, such as a fall or death cycle that can occur when a character is shot or falls down for some other reason. Jump cycles, side-run cycles, backwards run cycles, attack cycles, and others just add to the possibilities for character movement and are created based on the demands of any given game.
Free Modeling and Animation Software
If you have chosen to go the route of a 3d game, you are going to need a Modeling / Animation package. Milkshape is free, and though it may be a little clumsier and less powerful than the heavyweights like 3ds Max and Maya, it can get the job done on a budget. Read more about (or download) Milkshape here. Milkshape works
Also check out this free Milkshape tutorial here.
Inexpensive Modeling and Animation Software
Cinema 4D (C4D) has struggled for years to have the same kind of capabilities as the more advanced and established packages out there. Over the years this solution has improved and now has a respectable reputation. Cinema 4D Core is the base package and goes for about $995 in the US. Cinema 4D is made by a company named Maxon; Click here to go to the Cinema 4D page.
3ds Max and Maya are both solutions owned by Autodesk, both of which have very powerful capabilities and strong followings. Both of these are in the range of $3000, depending on where you live. In fact, until Autodesk bought Maya, 3ds Max and Maya led the market in 3d modeling and animation. They competed neck and neck for first and second place in overall worldwide market-share. 3ds Max was always ahead in the field of Game Development, and Maya was winning out in the field of Movie making. In one fell swoop, Autodesk doubled their market penetration by purchasing Alias, the makers of Maya. If you already own or are considering 3ds Max, you should also consider our book Creating Game Art for 3D Engines which goes step-by-step through the process of creating game pickups and characters with 3ds Max.
Click here to go to our Links page and look under the section for 3ds Max, which discusses how to get a student version of 3ds Max, how to get the full version, and more.
Don't forget to factor in your time and potential frustration
You must also throw time and frustration into this balancing act. That is because when you select a package, you are now constrained to its way of doing things. You may find that Milkshape gets the job done, but you can't always find answers to your questions about how to use it. You may wish for the same huge user base and community that Max and Maya have so you can ask questions and follow the trails that others have left, and so that you will have access to tens of books written on modeling, texturing, animating, etc in those packages.