1: Anything that's in the game has to be low poly, because games render in real time off the graphics card.
2: All details have to be textured (using bump maps or normal maps, but normal maps are used more because of their control).
3: All texture maps have to be low resolution. Unless you have a super computer, there's no way your graphics card could render in real time a whole bunch of models with 4K texture maps.
4: Texture maps should have their dimensions by powers of twos. These types of resolutions are 256,1024 etc. 5. You have to be able to bake lighting into the model. We'll explain this more later.
How To View Your Model As A Game Model In Maya
Download the file mad_dog_game.mb and open it in Maya.
High Quality Rendering
This powerful feature in Maya is a great tool to creating video game content. You can view textures and reflections, specular diffuser, and color maps in your view port, all in real time.
Setting up Maya for Game Modeling
For game modeling, you'll want to take advantage of the heads up displays. Go to Window>heads up display>poly count. This'll give you real time specifics on your model.
Some people refer to normals as hairs sticking off their models, but normals cause shading of a surface. Since normals control the shading of a surface, you can create a map that tricks the game into believing there's shading when there really isn't geometry. So when it renders in real time it, looks as though the model has a lot of detail because it has a lot of shading.
The image above are pictures of normal maps. They may look like a tasteful collage of pinks and blues, but that is how Maya reads information about a normals map. We'll explain how to create normals maps later in this tutorial series.
Programs That Can Help
Texturing just the color and bump map of a model can be tough in Adobe Photoshop, but texturing normal maps, specular maps, and diffuser maps are impossibly tough. This is where a program outside of Maya can help. The program to help you here is a digital sculpting and texturing program. These programs allow you to paint and sculpt directly on the model, and these programs can automatically generate the maps you'll need. There are two big software applications in sculpting: Z Brush - this is the one I recommend. It has the best features and is capable of extreme detailing. Mud Box - Up until recently is it capable of creating color maps. This software is made by the same company that creates Maya, so therefore there's very little time spent getting the model to and from Mud Box. These softwares are great, but not so good for someone on a budget. So if money's tight, I recommend 3D Coat. 3D Coat is capable of generating normal maps, specular maps, and color maps and can bake occlusion. In this tutorial series we'll be using 3D Coat. But the principals are basically the same for all programs.
Occlusion is basically a shading map. This, when assigned to a Occlusion map using a multiply filter, can give the affect the model has already been lit. Therefore, in the game, you can use less lights, therefore faster real time rendering off your graphics card.