Since im often asked, by the laymen, how a 3D picture is created i will give a very general overview of some of the processes involved.
First there is to say that there are dozenz of good 3D programms on the market and you will find some links in the friends section of this page, if you happen to catch on the idea of doing some 3D art of your own.
Personally i favour 3D life grafix by Neon-Software, a modeling and rendering tool wich is fairly easy to use and decently priced.
Unfortunately i think any further development on it has been stopped so that im forced to look out for some other tool.
A 3D model consists of polygons.
A polygon is a geometric shape consisting of at least 3 points defined in virtual space, which are positioned on the x (width) y (height) and z (depth) axis of the modeler.

Any 3D object is composed of several polys, complex objects consist even of several hunderdthousands of these basic shapes.

The edgepoints of the polys are connected to each other thus giving the 3D model its shape referred to as wireframe model.

I will demonstrate this on hand of a simple sphere.

In this case, 720 polys define a spherical shape.
In a modeling program the edgepoints of the polys can be altered as to deform the model into the preferred shape and size using diverse modeling tools like bending, resizing extruding and more.
Thus having the shape and size of an object it will now need to have a surface. This is one of the toughest tasks to tackle when doing 3D (apart from modeling lol)
When observing realworld objects you will notice that their surfaces have attributes like:





and many more. These attributes have to be attached to the surface of the 3D model. Usually the 3D artist uses a seamless picture map to be projected onto the surface of the model. Then he adjusts those attributes in a texture editor, which is telling the renderer (renderer = the program making the object visible) how to display the surface of the model.
A complex 3D model is made up of several such basic shapes (meshes) and usually owns more then one texture. With loads of practice and expierience the 3D artist will be able to create anything in his mind and make it appear realistic.
The models can then be used in a scenery editor where they are "virtually photographed" delivering the final image, or even be animated to give a film sequence.

Youll get an idea here, what may be achieved nowadays using a normal PC and affordable software (some freeware even).